Production of high-strength laminated sheets

The present invention generally relates and has · essentially as a new industrial product, a laminated product in sheet, plate or panel or the like of high mechanical strength or toughness composed of films, films or similar thin layers of material thermoplastic polymer and an improved process for manufacturing this product as well as the various applications and uses resulting from their use.

Cross-layered laminated products of uniaxially oriented films of crystalline polymers are known. as having a generally very advantageous combination of different mechanical strength or toughness properties, the most surprising of which has been the resistance to propagation of^:tearing (see US Patent No. 3,322,613) especially when a relatively poor adhesive or sticky bond is made between the layers. · During tearing from an incision or notch, - the layers separate / nt. then by detachment, cleavage or delamination around the notch while they split or spread by propagating in different directions (fork tearing, that is to say branched or branched off), so that the notch effect is thus dampened or softened. Sheets or sheets of this kind are particularly usable for various applications' hard service, that is to say, to heavy loads or. tiring working conditions, such as materials or substitutes for tarpaulins or tarpaulins, sheets or tablecloths for covering or covering, bags that can withstand service, hard or heavy loads or tiring conditions working and films, or thin wrapping or wrapping films' capable of withstanding heavy loads or service.

, hard and tiring.

The most practical or advantageous process for producing a sheet of the aforementioned type is described in the specification of British Patent No. 816,607 and consists of ·

- • strongly orient the molecules of a tubular film in

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in its longitudinal direction, to cut it helically and to unfold or deploy it flat according to a flat film with the orientation directed at a certain angle of bias, that is to say oblique or inclined (for example 45 °) and then to continuously assemble this film by bonding '. adherent of lamination with a flat or planar film produced · 'in a similar way while the respective directions'

.... &gt;

»With · 'orientation are arranged in a crisscross according to a cross configuration or mutually intersecting.

It is known that, for a given thickness, the resistance to the propagation of the tear is markedly increased by the use of three layers with three different directions of orientation, for example obtained by assembling or joining together, by bonding. adherent lamination, a film oriented longitudinally to two films which are oriented. · · In a skew, inclined or oblique direction as

... this has been described above.

. A disadvantage of the process described above (and of the resulting product) is that it is practically impossible to produce a really thin film, so that the economic advantage of the mechanical strength per unit mass.

. or of weight is limited ·· .. It has turned out that the lower techno-economic limit, linked to the execution of the operations or methods of spiral cutting and assembly by adhesive bond of stratification, is , • •&gt; 2 • generally, about 30 g / m. So for a product .. laminated with two layers, the lower limit is approximately. 60 g / m while, for a three-layer laminate product which, as mentioned above, is necessary for proper or correct use of the effects. 'tear stop, is about 90 g / m.

-A second drawback is the practical limitation in. width. caused by the rotation of elements, organs or parts of machine and heavy coils in correlation with.

spiral cutting. As a very general indication, we can say that the width is thus limited to a value. from 1.5 m to 2 m. · ·. . - ·· (· ί -. /¹ j

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A third disadvantage relates to certain energy absorption values ​​for the cross-ply laminates thus produced. Relatively low energy absorption was found in connection with tearing at high speed (Elmendorf tear test) and for tests of mechanical tensile strength or toughness at low and high speed (injury to qhærphoncl.'energy at traction eu rœüfnce âu choo d'Elmo'viàf.) On this subject, it appears that the very adisotropic nature of the layers is disadvantageous. If for example a laminated product with 2 phso ^ oudnscroisés of this type is stretched parallel to the direction of orientation of one from layers, the elastic limit and 3'allongement'reTati'f “at break are then essentially determined by said layer.

Previous work by the inventor, to overcome the aforementioned drawbacks and to create a cheaper manufacturing process for a product with similar or analogous properties, is described in the specification of British Patent No. 1,261,397. In the aforementioned description, a process is revealed which produces a - / intercrossed structure via a die with rotating parts or parts while forming, in the same die, a soft or tender and weaker middle zone by co-extrusion. or simultaneous extrusion. This process consists. by co-extruding or simultaneously extruding several concentric or almost concentric layers of crystalline polymer alternating with layers of softer or softer polymer and dividing said layers inside the die by means of teeth arranged in rows and fixed to the cylindrical walls of the die being directed inwards from the surface, from the concave wall and outwards from there, the wall surface, convex. The parts or elements of the die are rotated in opposite directions and the layers are thus divided · '' following-helices with left pitch near a sheet surface and · helices with right pitch near the other . on the sheet face, it is specified that the combing can be • 7 ·

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performed through the middle of the movie or be limited to. near portions of surfaces. Co-extrusion or 'extrusion',. simultaneous polymers before the combing zone is intended '· to create a soft and weak middle zone.

• 5 · The film, extruded by this method, is essential^γ in non-oriented material. However, the systems.

'of alternating stiff or rigid layers of a' first polymer and of soft or tender layers of a second polymer divided into filaments or the like according to '. linear drawing by the teeth, produce, in each half or half of the leaf, a tendency to split or to flow or to spread in one direction and, like the linear drawings on the two surfaces are cross each other or intersect / and a tendency to separation by detachment, delamination or cleavage is manifested, a tear stop effect is obtained which is analogous to the fork or branching effect in a true, cross-ply laminate.

The aforementioned description also proposes to stretch or biaxially stretch the laminate thus produced in. conditions such that instead of producing biaxially oriented layers, the molecular orientation will generally become uniaxial or monoaxial in each layer, the orientation directions in the different layers · · .. intersecting or crossing each other some with. the others in a secant way. In order to obtain · such a uniaxial orientation, the second material must be very inclined to yield or to deform, for example because it ·· ,.

,. is always melted or semi-melted while the first -

3Ö. material is solid and the filaments of the first material must be kept rectilinear by a biaxial tension constraint. ''

Although the aforementioned method in principle solves the problems of obtaining a thinner thickness and a wider width in cross-ply laminates, °. · Some essential difficulties were noted during recent technical developments. It has been confirmed that the extrusion process is commercially feasible or feasible for the production of a non-oriented film with high resistance to the propagation of the tear but with it. . poor impact resistance or resilience due to lack · '5 or lack of orientation. However, essential drawbacks were noted - in correlation with a biaxial extension · · · As it is also indicated in the thesis. 'above description, we must use a relatively large number of rows of teeth in the extrusion die in order ·· .............

to obtain the fineness of fiber which is necessary for the extension, stretching: or tensioning system.

This however makes it difficult to maintain the die and causes frequent hanging or hanging of polymer pieces between the teeth. In addition, the interaction between the teeth in half or half a part of the die and that occurring in the other half or half part necessitated either the use of excessive amounts of material for coating. soft median or limiting combing to two relatively thin areas of the leaf. Furthermore, it was very difficult to restore and maintain or maintain the biaxial extension conditions necessary to obtain a generally uniaxial molecular orientation as described. .

The present invention is based on the discovery that even a strongly biaxially oriented film, with the same orientation in two directions perpendicular to each other, can exhibit a marked direction of splitting ability, provided that the film either extruded from a mixture and either attenuated or drawn in the molten state · θη correlation with extrusion. Thanks to attenuation - or stretching it in the ford state, a unidirectional fibrous morphology is formed which can be observed in an ordinary microscope. There is also a uniaxial orientation by attenuation, or stretching in the state -&gt; ·· '·' r melted but this orientation is generally very '^. Weak. When the film (which can be composed for example ·

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about. 50% polypropylene and 50% polyethylene) is stretched at an angle to the grain direction, i.e. to the natural direction of the fibers, for example perpendicular to it, so the '' portions of fiber, as seen on a microscopic scale, will deform, will bend or be deflected and • branch but it is still possible to follow the zig-zag path of the grain forming the natural direction of the fibers from one branch point to another and, in '10 following different paths in this way, we will see &lt;that ··. on a macroscopic scale, there is always a grain • unidirectional, that is to say a single natural direction of fibers. This microstructure is very different ..........

of the filament structure described in the memo '• v 15 description of the British patent n ° 1,261,397 cited above.

After a certain elongation, for example after a relative elongation of approximately 40% perpendicular to the grain forming the natural direction of the fibers, the examination of the film in polarized light (or more exactly by -20. Diffraction x-rays) shows that the orientation is equal

·. in all directions. After an additional stretching or stretching operation in the same direction, there is always a pronounced ability to split along^J grain direction to a certain point for example

.. up to approximately 80% of total relative elongation and this

- ·. ability to split is equal in all directions.

- · When stretching by additional extension operation, the main direction of the ability to split coincide with the main direction of orientation. The film may '30. for example, being stretched 100% in this direction and then stretched in the initial direction of the grain, i.e. in the natural direction of origin of the fibers to the point where it has an equal orientation in

·. all directions. At this point there is again one. marked ability to split in the initial direction

--- 'of the grain forming the natural direction of origin of the ...

- · fibers and, by microscopic examination / it will be possible,.

ΊΟ u 15 although difficult, to follow the zigrzag course of the grain or the direction of the fibers and see that, on a macroscopic scale, .. the direction of the grain or of the fibers will coincide ••• always essentially with the direction of the ability to split. Following this discovery, the method according to the present invention is characterized in that it comprises the operations consisting in attenuation .or 1'extension to the fc-ndu state '·' · during the extrusion of each of at least two layers of at least one polymer mixture · -melted to impart to the polymer, a grain or a direction of fibers unidirectional with a marked direction of ability to split when it is solidified; to combine, before or after solidification of said layers, the layers in a common sheet, the^-grain or fiber directions of adjacent layers extending here in a crisscross configuration while forming a generally weak adhesive bond between said layers? to solidify, if it is not already solid, and finally orienting the solid laminate sheet thus obtained biaxially in several operations or stages which are each generally substantially uniaxial at a temperature sufficiently low to maintain a significant ability to split in each layer.

The product, thus produced, is a laminate with high mechanical strength comprising biaxially oriented films which are generally weakly bonded in an adhesive manner, each of which is formed from a mixture which has a

..different fibrous morphology, the fibers forming a distinct unidirectional grain when measured on a · .macroscopic scale but having the portions of fibers strongly: deviated or deflected from this direction as seen on a microscopic scale and having the respective · ·. unidirectional grains, - in at least two of the films,. . intersecting each other.

It has been found that the structure thus formed is particularly suitable for almost all applications of high mechanical strength where absorption. ;

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'Σ' of energy is essential, regardless of whether this absorption of energy takes place during a tear propagation, a perforation or a piercing or a di oc. The ability to split layers in correlation with the weak adhesive bond between the layers produces a forking or branching effect similar to that which occurs in cross-ply laminates of a film., Oriented uniaxially but absorption of energy, during a rapid tear (Elmendorf tear test) is essentially greater. In addition, most of the impact resistance or resilience properties and in particular the impact resistance or resilience of Elmendorf are improved as well as usually the energy absorption during rapid perforation (Beach resistance). . These improvements are considered to result partially from the biaxial nature of the orientation in each layer and partially from the distinct fibrous morphology. The bi-axial orientation also has the advantage that the laminate, in accordance with the invention, has properties of shrinkable film or film which cross-ply laminates of uniaxially oriented films do not have.

It has been mentioned above that the process for producing the folded or cross layering of uniaxially oriented films gives, under practical conditions, a fairly high limit for the sheet thickness (about 90 g / m for a three-ply laminate or. layers) and a fairly low limit for the sheet width. In these two respects, the present method is very advantageous due to the fact that the sheet is strongly stretched or stretched in two or in a greater number of directions after the laminating operation. Thus, it is technically and economically possible to obtain a weight or a surface mass of 10 g / m 2 for the films in the laminate, that is to say approximately 30 g / m 3 for a laminate with three plies or layers. . This greatly expands the scope of employment.

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While blends of highly compatible polymers, for example, of different polyamides, will usually not form a grain as described, blends of semi-compatible or incompatible co-extrudable thermoplastic polymers will, however, do, provided that -the polymer content is not too predominant. To be within the safety margin, there should be no more than 85% of any polymer in the mixture. If the polymers are really incompatible, an alloying agent will preferably be added. '. ..

The best properties will be obtained if the grain is formed from crystalline threads glued or bonded together by small amounts of surrounding elastomer. By small amounts is meant amounts of 5% to 20% of the total.

In order to keep the elastomer content low and always obtain a distinct fibrous morphology with the elastomer tending to surround the other material, the elastomer is preferably used as an alloying agent for the two other polymers. Thus, a preferable composition consists of two incompatible crystalline polyolefins, for example isotactic or syndiotactic polypropylene and. in ·· high or low density polyethylene, with the addition of a tacky, sticky, sticky or adhesive polymer which binds adhesively or adheres to both, for example such as' atactic polypropylene, ethylene rubber -propvlene (preferably a sticky or viscous type with a relatively high propylene content) and polyisobutylene · of a mass or molecular weight as commonly used ·· for pressure sensitive adhesives.

Attenuation by stretch-in the molten state^;,through ·:. which the uniaxial grain is formed, can be performed in different ways. It can, for example, be obtained by a gradual reduction in the size or size of the. outlet chamber in the extrusion die or by passage of the molten material between closely spaced or spaced partitions or the like arranged in a row in the die or by extension, drawing.

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or energized in the molten state after leaving the '------------ die or by combinations of such operations.

The direction of the splitting ability and the ability to split in layers are determined by measuring the resistance to tear propagation by the ·, tear strip tearing process in different ·· - directions. The direction of fitness to split is defined. as the direction with the lowest resistance to tear propagation while the ability to split is defined as the ratio between the highest resistance to tear propagation and the lowest resistance to propagation from the tear. The ability to split in layers after biaxial orientation should preferably be greater than 2: 1, however a value of 1.5: 1 can be tolerated.

To allow local delamination by separation. . where detachment during the tearing and thus realize the fork or tearing bifurcation, it is essential

2 (3 to form a generally weak bonding bond during the stratification of the layers. If · the bonding bond formed is a uniform bonding, regular or equal and if the thickness of each layer ..corresponds to.

g / m, a resistance to detachment, between.-about 5 g / cm and 500 g / cm, is generally appropriate.

. . As there is a competition between the breaking forces. . · And the forces of delamination or separation by detachment during the tearing, the upper limit depends on · ·. ' layer thickness and is generally proportional

30. to the latter. .

As will emerge from the description of various modes

... of realization, there are different means to establish • ... and to control or regulate the force or mechanical resistance of the adherent connection, of which the most practical imply, '

- at a certain stage, a co-extrusion of a special layer of element 'adhesive component or component of _zseparation. ·. .

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'With regard to biaxial orientation, - it has proved essential to execute it in several operations, stages or phases which are each generally substantially · uniaxial. It was thus found that the simultaneous extension or stretching '5 in two directions destroyed the grain, of. so that no fork or bifurcation or branching effect was obtained. There is also a tendency to destroy the grain by stretching or stretching when one is near the melting point of the main component elements of the leaf. Recrystallization and other physical phenomena of phase rearrangement are believed to play a role in this regard. In all cases, the best properties have been found by stretching or stretching below the recrystallization temperature which, for example for polypropylene, is around 70 ° C to 80 ° C and even lower temperatures are preferable. . To stretch or stretch at such low temperatures, special methods of stretching or tensioning are required, which will be. “. discussed later in this description.

Preferably, the biaxial orientation, produced by the stretching or the tensioning below the melting point, must, in any direction, have a component at least equal to the orientation produced by the attenuation, by stretching. · Has molten state and is generally ^r: better to make said biaxial orientation a lot

-stronger. The degree of orientation should, in this regard, be measured by X-ray diffraction but, for a rapid and approximate examination of relative values, observations of interference colors between polarold filters or "Nice cross" are also suitable.

..As explained above, it is essential '...' that the adhesive bond between the granular layers is generally weak in order to allow local delamination by separation or separation to take place during propagation. from the tear. However, this does not necessarily mean that the adhesive bond must be weak over the entire surface, but, on the contrary, a great advantage for the resistance to tearing is generally obtained by using the embodiment described in claim 2. Thanks to this- ci, the necessary local delamination, by separation or detachment -is easily started but.

is then stopped or will continue to meet with great resistance. At the same time, the strongly bonded or bonded portions prevent delamination or separation of separation from the laminate in a bonded or welded joint joint under tension or in the vicinity of such a joint, which delamination could otherwise easily occur.

By an appropriate choice of the adhesive bonding configuration, of the various forces or resistances of bonding bond and of the type of rupture in the regions of weak bonding bond or having no bonding bond,

· 15. Whether fragile or more fluid, the tear resistance properties can be tailor-made for different uses.

The method according to claim 2 is particularly usable in correlation with relatively thin layers. It has already been mentioned that there is a competition between breaking and delamination or delamination forces during the propagation of the tear, which means that an easier start to delamination requires.

make the layers thinner. As a practical rule, it will almost always be advisable to apply the method according to claim 2 if the layers are more.

• 2 thin that a thickness corresponding to about 40 g / m to 50 g / m².

The use of combination configurations &lt;3 ¹ a strong bond with a weak bond or a strong bond with the absence of bond '' are in fact well known in correlation with laminates · 'cross-folded films which are oriented uniaxially • or are biaxially oriented in a very unbalanced manner (see the descriptive memories of the American patents Nos. 3,496,056 and 3,342,657, of the British patent n ° 1.3161640 · 'and of the Danish patent n ° 119.733). However, the known laminated sheet layers, when they are tried or tested individually, have extremely low impact resistance or impact strength and puncture resistance (except in the case of special and expensive polymers such as for example nylon 6) while it has been found that the individual layers, in accordance with the present invention, exhibit impact resistance or resilience. markedly and surprisingly high. Consequently, -a weaker adhesion (or no adhesion) in the zones concerned and / or an extension or elongation · 'greater of these zones is permissible or tolerable without any significant loss of impact resistance or of resilience or perforation.

A preferred way to achieve or enhance the effect

1.5 ·· of the generally weak adhesive bond between &lt;adjacent layers is described in claim 3.

• By separation substance, we mean here a substance,. preferably a polymeric material, with either a low

·. . cohesive strength in itself or with poor adhesion to the adjacent polymer layer.

Whether you choose a release material or an adhesive depends on the. matter of knowing. if and to what extent the polymer blends are. compatible uhs with others and the method of union or bonding, for example the temperature used during stratification.

In all cases, by means of the method according to - • claim 3, it is possible to better control or adjust. the magnitude or intensity of the bonding bond strength.

A preferred way of effecting the adhesive bond is described in claim 4, whereby the advantage is obtained that, during a tearing, the free or weakly adhesively bonded parts of the middle layer will elongate. because of the extension or traction forces applied and will absorb a certain energy thereby additionally stopping the notch effect. Although there are several operational or functional advantages in joining the layers inside an extrusion die as will be described later with reference to claim 22, the embodiment according to the claim. 5 * is preferable relative to the properties obtained 5 since it allows the formation of the most pronounced uniaxial grain in each layer.

• An embodiment of the method according to claim 5 is described in claim 6, according to which the previously produced solid film can be placed around one.

mandrel which extends through the center of the extrusion die. The solid film can be advanced along the mandrel and, passing through the exit slot of the extrusion die, it grasps and advances and attenuates, or stretches in `` state '' split the polymer always fluid and driven in rotation which, in this way, is wrapped around the solid film forming an outer film with a grain or a direction of fibers' S · extending helically.

As already mentioned, resistance to ·. propagation of the tear, for a given total thickness, is appreciably better in a three-layer laminate. 'only in a two-layer laminate. It is therefore preferable to extrude two or more films successively through two or more slots¹ . .extrusion mutually ..constrsrotatives or turning in opposite directions, on the same film ..solid, - in.the manner mentioned above.

. . Other advantages of the method according to claim 6 ·. are the possibility of producing a fully uniaxial grain during the oblique individual draw, the possibility of

30 'cool the polymer abruptly on the mandrel thus achieving a finer grain and a less tendency to. aging by recrystallization as well as a higher working or shaping speed and the possibility of allowing the use of more difficult polymers, for example polymers of particularly high mass or molecular weight due to the supporting effect or¹ support and tospert or conveying of the film on the mandrel, which: can be very close, λ / 'of · the-' circular outlet slot.

15.

In the above description, the tubular layer, rotating fluid is pulled inward from the rotating extrusion die to the solid film carrier. This characteristic will generally be advantageous because the elastic tensions, produced by rotation, tend to reduce the diameter of the fluid tubular film, thereby favoring the gripping of the fluid film by the advanced solid film and its bonding thereto.

However, it is also within the scope of claim 6 to arrange the film, an advanced solid in a generally tubular shape with a diameter larger than that of the rotating outlet slot and, by blowing or by other means, extruding the outwardly rotating fluid tubular film onto the solid film.

-15 it should be mentioned that the rotating part or part can be the advanced solid film while the extrusion die is fixed.

It should be noted that by machine direction is meant the direction of advancement or of travel of the prefabricated solid film.

A preferred embodiment of the method according to. . the invention is described in claim 7. The advantage of this embodiment is, firstly, that the various process operations, namely extrusion,

25 'the attenuation or stretching in the dark state at the meeting .. in the grain of adjacent layers according to a criss-cross configuration and the biaxial extension, can be executed in series along a working line or chain. Preferably, the sheet consists of three layers, the grain of the • I, middle, intermediate or central layer extending longitudinally as will be described later in correlation with the description of the drawings.

In comparison with the embodiment according to claim 6, the embodiment according to claim 7 'has the functional or operational advantage that all' the layers are extruded from the same die. but this is achieved at the expense or to the detriment of the carrier effect.

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By solidifying each granular layer before it is joined to a common sheet as described in claim 8, simpler or more conventional equipment can be used. A preferred embodiment of this method, according to claim 8, consists of ........

producing the sheet as described in claim. 9 with a special apparatus or machine system! ' · Cheap and simple (at the expense or expense of the benefits of a continuous manufacturing operation

- in aligned series or chain).

- Another preferred embodiment of the method according to claim 8 consists in producing the sheet as described in claim 10. This will give the possibility of producing fairly wide layers. Lateral enlargement. or the licking can be carried out by means of a widening or rowing machine, preferably in an oven with circulating air which is maintained at a temperature slightly above the melting point.

In order to simplify the lamination of separately extruded and solidified films and thus also make possible the lamination of thinner films, at least the first phase of the joining or joining process can be · combined with at least the first phase of the extension operationlateral as indicated in claim 11. /

This essentially helps prevent wrinkles or folds from forming during lamination. If the . desirable temperature for extension or tensioning is less than the temperature necessary to bond the films together, the first part, for example 10% to 20%, of. the extension or elongation operation can take place at a higher temperature without any appreciable damage.

·. · In order to facilitate the connection of assembly in correlation with the method according to claim 5, an adhesive polymer, melting at a lower temperature, can be

35. .co-extruded on at least one surface of at least one layer as indicated in claim 12.

This can be carried out as described in claim 13 with the practical advantage of avoiding controlled, controlled or regulated heating means, so that the apparatus thus becomes particularly cheaper.

. In this regard, it has been found that the simultaneous extension or stretching of two films while they are pressed together, in particular as in the embodiment according to FIG. 19 which will be described below, exhibits a surprisingly high tendency to cold weld the films together, so that only a low degree of tack or tack is required. For example, surface or surface layers of polyethylene with 16% copolymerized vinyl acetate have been found to melt at room temperature in this manner, giving a peel strength of 10 g / cm. The bonding bond strength can subsequently. be increased by passing over or between heated rollers or cylinders.

The adhesive polymer can be co-extruded in strips as indicated in claim 14. It is thus possible to conveniently obtain the configuration according to the combination of strong adhesive bond / weak adhesive bond or strong adhesive bond / without adhesive bond, explained in correlated with claim 2.

Another method, for conveniently obtaining an adhesive bonding configuration of the aforementioned type, consists in co-extruding, on one of the adjacent surfaces of two layers, a ply or a continuous layer of an adhesive polymer and in addition providing 'other of said surfaces. of a separation layer arranged in strips or at discrete points as mentioned in claim 15.':

30_e · Yet another method, to obtain the aforementioned type

- of adherent bond configuration) consists in co-extruding '·' the adhesive polymer as described in claim 16. Thanks to this characteristic, the zones devoid of adherent bond form a dotted configuration.

or-à'points.

A very important embodiment of the process according to the invention is described in claim 17. As mentioned previously, the extension operation. where stretching is carried out preferably at a relatively low temperature, for example at room temperature and the use, as this is .normal, of a widening or rower of licking under these circumstances will almost inevitably give an irregular or uneven effect of forum * ·· * - * - '.ûiatiôn of necks or Zones' narrowed central of stretching with a resistance to the propagation of. tear varying ^ Lateral

It is known to produce a lateral extension or elongation under uniform, regular or equal application of extension or summer forces (French patent No. 1,331,095 and British patent No. 1,078,732). The two patents recommend the use of two conveyor belts or rubber conveyor belts which are expanded

715 laterally at the same time when they are firmly pressed · together against each other, thus gripping and pulling the film. However, for use in the present invention, the simpler method according to claim 18, has been found to be more convenient. It should be noted in this regard. that a strictly regular or uniform distribution or distribution of the extension or stretching forces is not necessary but, on the other hand, a certain irregularity where inequality on a small scale will be advantageous as regards the resistance to the propagation of the tear.'

It has in particular proved to be advantageous for the. -. . resistance to propagation-of the tear to allow the orientation state to vary in accordance with a configuration of striations (see FIGS. 8 and 9), so that, in a group of striations, the biaxial orientation

30. · · Is unbalanced and is the most strongly parallel or.

. _; almost parallel to the striations whereas, in the intermediate ·· striations, it is also unbalanced but is most strongly perpendicular or almost perpendicular to the striations. In order to obtain this configuration, the extension or stretching method according to claim 18 can be advantageously carried out.

• as specified in claim 19.

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- '..... When specially high resistances to the propagation of the tear and to the perforation are desirable and lets cy'me: relatively low elastic limit is permissible, the extension or the stretching is carried out as it is additionally specified in claim 19.

A higher relative elongation at break is thus obtained. In order to allow contraction at the same time as the longitudinal stretching or stretching is carried out in a narrow area, the laminate is preferably provided with fine longitudinal pleats or pleats, in a manner analogous to what is revealed in US Patent No. 3,233,029. In this regard, an appropriate result is usually obtained "when the fine folds formed by the last operation of the method of lateral extension or elongation according to claim 12 are maintained or preserved in the sheet when the latter is introduced into the area extension, or. of longitudinal elongation.

Although it has been stated above that there are advantages to producing a striated pattern of variations in orientation and thickness especially for resistance to tear propagation, this effect should not normally be exaggerated since this would have an unfavorable or detrimental effect on the printability as well as on the resistance to puncture by articles or pointed or tapered objects.

The object of claim 19 is therefore ·· to avoid an exaggerated tendency to the accentuated formation of areas of linear extension or elongation which occurs. would usually occur if the leaf was oriented longitu30 dinal "ament to any significant degree.

· Regarding attenuation, stretching. or at 1¹ molten state, and the joining of layers, another preferred embodiment of the invention is described in the

. claim 22. Here we lose some of the advantages · ·. obtained by the method according to claim 5 since it is impossible here to obtain truly uniaxial directions of. grain but you get the advantages of the operational kind of having to handle or handle. only a common sheet on the outside that the extrusion die. . · · 'It is simple to build the parts or parts of

'.5 the extrusion die to extrude three or more layers, which has several advantages as mentioned above. .

It is preferable, in addition to the features according to claim 22, to co-extrude a polymer to control or regulate the adhesive strength as indicated in claim 23. ......, 'Due to the fibrous morphology, the stretching operation; elongation or extension will normally produce internal voids or hollow spaces, but usually not encroaching

Î5 in the granular layers. This effect is particularly important when stretching or stretching takes place at a relatively low temperature and more or less opacity is thus produced. Effect rating can be used for. - replace the white pigmentation but can also be removed by a subsequent rolling under pressure as specified in claim 24.

• The invention will be better understood and other aims, '• characteristics, details and advantages thereof will appear more clearly on reading the explanatory description which follows, referring to the schematic drawings .. ... .- attached given only to. by way of nonlimiting examples'. illustrating various specific embodiments currently preferred of the invention and in which:

- Figure 1 shows a sectional view through an extrusion die for the manufacture of a sheet material according to the invention;

- Figure 2 is a perspective view with displaced sections illustrating the principle of an extrusion die with two outlet slots conta? .arotatives or rotating in opposite directions, and means for extruding two layers through., each slot; _

- Figure 3 is a similar view showing the

<img file="LU74136A1_D0008.tif" />

principle of an extrusion die with two counter-rotating slots and a fixed slot and with intermediate outlet slots for drafts;

- Figure 4 is a perspective view and partially '.5 in section showing the principle of a rotary extrusion die of annular shape with a mandrel extending through its center;

- Figure 5 is a functional block diagram or flow diagram showing the sequence of successive operations relating to a preferred embodiment of the method according to the invention; '...

- Figure 6 shows a working chain of work in a preferred method of extension or cold drawing;

'.15 - Figure 7 is a detail view of' canals or grooved iœlsîux which achieve lateral extension or elongation in irregular or uneven areas called striations, ·.

- Figure 8 is a schematic sketch, drawn on an enlarged scale, of the configuration of the striations and the orientation in them, of a stretched, stretched or cross-stretched film in accordance with the operating chain, work according to figure 6? ,and

- Figure 9 is an enlarged cross-sectional view of the film according to Figure 8, · as actually revealed by

- microscopy but where, for clarity, the thickness is represented on a scale twice that of the width.

The extrusion die, shown in Figure 1, is an example showing how to carry out the process, in which two dispersions of a polymer in a polymer are extruded in a common collecting chamber through two rows of rotating partitions in opposite directions. The two streams ôufluxde'dspsrsioil at 2 are brought -to .through two channels or inlet conduits in .the lower part of the die respectively to channels or conduits_ ·. _ 'annulars 4 and 5 in the two walls provided in the passageway 6 in which, the two rings or crowns 7 and 8 are moved in opposite directions by means /

drive or control, for example by teeth and toothed wheels (not shown). The two rings or crowns 7 and 8 are provided with rows respectively. ' partitions 9 and 10 through which are formed two 'rows 5 of openings 11 and 12 through which the two dispersions are extruded into the collecting chamber 15 formed by the two parts or parts 13 and 14 and ending with' the slot of exit 16. For the sake of simplification, the partitions 9 and 10 are shown as extending radially but, in reality, they are placed at a certain angle relative to the radial direction to prevent the formation of lines or traces of die in the extruded sheet. By extrusion through the two rotary rings • or rotating crowns. 7 and -8, the two dispersions will each be attenuated, or stretched to ïétoi frdi 'and will thus acquire.

a fibrillar morphology. The two rows of attenuated streams or streams, or stretched in the molten state, will then meet in the collecting chamber 15 and form a laminate having a cross-fibrous morphology. The thickness of this laminate is reduced by. passage through the exit slot 16 and further by a normal stretching operation. down and blowing. After that, the film is stretched, stretched or stretched both in the longitudinal direction and in the transverse direction to one. relatively low temperature. Due to the two different directions of the fibers, the two halves or half-parts of the film will exhibit tendencies to split in different directions during tearing. The materials from which the two halves or half-parts are formed are chosen so that they. adhere poorly to each other.

The material will thus separate by delamination or peeling in a small area around the incision or the notch from which the tear occurs and this will dampen or soften the notch effect.

The 'sector, shown in Figure 2, consists of _The '' four main parts or parts, namely a fixed part or input part 17.for distribution or distribution i^r circular of polymers as explained below, a fixed part or bearing part 10 9üi supports '5' 5, 20, 20

25.

'25.

two rotating parts or rotating parts 19 and 20 which. form an outlet orifice 21. The pepper shakers A and B are brought to the entry element 17-where they are distributed according to concentric circular currents and flows. Polymer A is extruded through annular conduits 22 and 23 for which one or two extruder machines can be used. The polymer B is extruded through the annular conduit 24. For regular or uniform distribution, the conduits 22, 23 and 24 are provided with baffles or distribution deflectors or other distribution means (not shown).

For the sake of clarity, the bearings or bearing surfaces and the seal gaskets or hermetic junctions between the bearing part 1S, the rotating part and the rotating part 20, are not shown and the drive controls for elements 19 and 20 are also not.

From the three annular conduits 22, 23 and '24, the polymer streams pass through the bearing or support part 18 through three circular rows of channels or conduits 25, 26 and 27 each communicating with an annular chamber 23 , 29 ·., And 30.

The two rotating parts 19 and 20 are preferably rotated at almost equal speeds but in different directions as indicated by the arrows 31 and 32. Each rotary part itself constitutes a co-extrusion die for two layers-one of which is made up of polymer A and the other of polymer B For the sake of clarity, reference figures for Explanation of flow is indicated only on the part but the flow through part 19 is similar. From the chamber 29, the polymer A passes in the rotating part through channels 33 while the polymer B. passes from the chamber 30 into the rotating part through channels 34. Inside the rotating part is

Ζ * Ί ·

<img file="LU74136A1_D0009.tif" />

• «• 7 · i · *

<img file="LU74136A1_D0010.tif" />

find two annular conduits 35 and 36 in communication respectively with the channels 33 and 34 and separated from one another by a thin circular wall 37.

. 'After having passed or crossed the edge or the edge of the wall 37, the polymers A and B meet to merge or merge together in an annular collecting chamber 38 which ends in the outlet orifice 21.

By the passage through the collecting chamber 38 and into the outlet orifice 21, the thickness of the fluid sheet 10 is greatly reduced, so that the material is thus attenuated, thinned or reduced by drawing in the molten state.

The partition walls, respectively between the adjacent channels 33 and 34, must have a hydrodynamic profile or contour as shown. For the sake of clarity, they extend radially in the drawing but in reality they must form a certain angle with this direction to reduce the tendency to form lines or traces of the die.

The polymer, A is a mixture of two incompatible, or semi-compatible polymers, while the polymer B '·' ^;· ·: Ίΐκ&gt; · ί is intended to give the sheet an appropriate tendency to delamination or delamination. It can therefore consist, for example, of an elastomeric substance which is poorly adhesive for the two layers of polymer A • 25 and can be extruded into strips. However, if channels 22 and 23 are supplied with two mixtures of different polymers which are mutually incompatible, the polymer B /

may be an adhesive or sticky substance having a · · • relatively strong adhesive bond with the two mixtures:

of polymers and must in this case be extruded into strips or otherwise interrupted.

... The device, shown in Figure 3, consists • of essentially main parts or parts, similar. 39, 40, 41 and 42 but there is a slot respectively

.. · exit 53 and 54 in each of the rotating parts 41 and 42 and there. further has a fixed outlet slot 43 which is formed by the bearing or support part 40. ' From i

;· :

ί!

!

&gt;

;

kSk. '·· .V *' · ·,

<img file="LU74136A1_D0011.tif" />

three groups of annular conduits 44, 45 and 45, the streams or streams of polymers C and D pass through the bearing or support part 40 respectively through channels 47 and 48 and penetrate into the^- three annular chambers 49 and 50, the last of which continues in the fixed outlet slot 43.

Each of the chambers 49 is composed of a fixed part or part 40 and of a rotating part or part 41 or 42. Through · channels 51 provided in the elements 41 and 42, each of the chambers 49 communicates with a corresponding chamber among the two annular chambers 52 provided in the rotary parts and each chamber 52 ends respectively with an outlet slot 53 and 54.

x Arrows 55 and 56 indicate the direction of rotation.

Having left the die, the three tubular films are fused together when the two films, formed by the stream of polymer C, are subjected to a torsion due to the rotations of the elements 41 and 42.

From the outside and from the inside of the room 40, air is led through the channels 55 ending in orifices 56. For the sake of clarity, the channels 55, '•' extending from the outside of part 40, are not shown. Through other channels 57 provided in parts 41 and 42, the air is led through outlet slits.

and 59 provided respectively between the fixed part 40, and the rotating parts 41 and 42. The channels 57 in the part 42 are not represented by. for the sake of clarity. The

.. annular air pockets, thus created between adjacent layers, prevent the respectively exterior and interior rotating polymer films from creasing against the intermediate or middle layer immediately outside the outlet slot.

Preferably, the extruded film is blown and both internal and external cooling air is applied.

The arrangement, shown in Figure 2, is usually 35 simpler to operate than that shown ί

in Figure 3 although the latter offers some special possibilities. One of these is to use the polymer • / s. '• / ..'. I! ·· »»!¹”'·’·’’··

<img file="LU74136A1_D0012.tif" />

dilated or expanded for the middle or intermediate layer · and another consists in making a longitudinal grain in this layer, so that there will be 3 grains in the sheet 'The presence of hats takes place in two directions correlated 5 with the tendency preferable to delamination or separation. by detachment will significantly increase the resistance to the propagation of the tear. In addition to or apart from attenuation, OR stretching in the ohid state, the operation is more clearly finished before lamination, which is advantageous as mentioned previously.

In FIG. 4, the reference 60 designates a rotary extrusion die of annular shape. Through a fixed part of the extrusion die (not shown) which is in connection with a sealed connection with the rotating part 60, a mixture of polymers is introduced into a circular groove 61 and leads to the slot of outlet 62 through channels 63 which are separated by thin partitions in the form of plates 64. For the sake of clarity, the partitions 64 are shown as extending radially but they actually form a certain angle with the radial plane to avoid lines or traces of die in the resulting sheet. The reference numeral 65-designates a • mandrel which is fixed by means not shown and the reference 66 designates a prefabricated and longitudinally attenuated flat sheet, by etir ^ p: then melted and folded in a tubular shape around the mandrel 65. For the sake of clarity, a space is shown between the mandrel 65 ′ and the folded sheet 66 but the sheet is. obviously finds' ·

·. · In close · contact with -the mandrel.,.. · Sheet 66 is drawn '30. through the extrusion die; sure . the mandrel 'as indicated' by arrow 67. When the film of. polymer 70-still fluid leaves the rotating outlet slot 62, it is caught or grasped by the folded sheet • 66 because of the elastic retention in the mixture of. attenuated polymers,_ωddrée in the molten state and is thus wound: around-said folded sheet and advanced together with it, so that one obtains a direction '

27.

<img file="LU74136A1_D0013.tif" />

ability to split helically extending, indicated by arrows 68.

The direction of ability to split in the prefabricated or previously formed folded sheet 66 is indicated by the arrows 69.

The adhesive bonding force can be controlled or adjusted for example by co-extruding an adhesive layer with the film 66. With a sufficiently high temperature of the mandrel 65, the laminating of the sheet can be carried out thereon. However, often the film 70 is preferably · - cooled heusquemenb on I^e mandrel, in which case the temperature of the mandrel must be sufficient for the welding of the two films 66 and 70 together. The lamination can therefore be completed by hot and cold welding after the films have left the mandrel 65.

By the words machine direction, which have been used previously in the description in relation to claim 5, is meant the direction of advancement or progression. from sheet 66..

The functional block diagram of FIG. 5, forming the flowchart of sequential unfolding of the operations, schematically indicates the various operations, phases or steps of a preferred method in which the use of rotating or rotary die parts is avoided. The block or block I symbolizes the extrusion and attenuation, (by stretching in the molten state) '* longitudinal of a tubular film K and the co-rextrusion of adhesive layers. The block or block II symbolizes the extrusion and the attenuation, (by stretching-in the molten state) longitudinal of a film L and the co-extrusion of adhesive layers. The block or block III symbolizes the extrusion and the attenuation, -. '. (By stretching in the molten state)' - longitudinal of a tubular film M and the co-extrusion of adhesive layers.

- The rectangle IV symbolizes the helical cutting of the solidified tubular film - and 'soh', 'unfolding /' deployment or development in a flat film K '. Rectangle V symbolizes solidification.

. y The rectangle VI symbolized by the helical cutting of the

28.

.solidified tubular film - and its unfolding, deployment or development into a flat film H '. Rectangle VII symbolizes the stratification into a sheet with the oblique grain (the direction of ability to split) of the films K 'and M' extending in a criss-cross configuration. Rectangle VIII symbolizes lateral extension or elongation • 'cold in' several phases or multiple operations by fluted rollers or cylinders. The rectangle IX symbolizes the cold longitudinal extension or elongation until the state of equilibrium θ-fc the operation of allowing transverse contraction. .. ..

The last two operations can be carried out by the extension or stretching method, cold when indicated by the operating chain according to FIG. 6, on which section Q is the extension or elongation line. cross section and section R is the longitudinal extension or stretch line. The roller system in section Q consists of driven or driven nip rollers 71 / driven fluted rollers or cylinders 72, idler guide or idler rollers 73 and banana rollers 74. ·

The banana rollers 74 serve, after each operation, to remove, by stretching, the folds produced by the extension or • the lateral elongation. Passing on the idler roller 75, the film 79 enters the section “R which constitutes the stretching line ·· or. Of longitudinal extension where it is .. · drawn through a water bath 76 serving to remove heat. . extension or elongation and to maintain a suitable extension temperature, for example at a value of 20 ° C to 40 ° C to reach a coil 77.. -^:

The arrow 78 indicates the direction of travel in: 'the machine.

In FIG. 7, a pair of grooved rollers 72 is shown in detail with the film 79 pressed and stretched or elongated between the teeth 80 of the rollers or cylinders 72.

…. In FIG. 8, the relative lengths of the arrows' in the striations I and II of the film 79 indicate the relative amounts of orientation carried out by the extension method

<img file="LU74136A1_D0014.tif" />

biaxial illustrated in Figures 6 and 7.

In FIG. 8 as well as in FIG. 9, the reference numbers I and II indicate the striations which have 'generally one. variable width and an irregular or uneven nature. It should also be noted that the outer layers 81 and 82 of the film 79 are not always symmetrical with respect to the middle or thin intermediate layer 83. · This asymmetry is also used to produce a fork or tear fork.

For economic reasons, the present invention is particularly usable in conjunction with mixtures which mainly contain crystalline polyolefins. The best for most common applications are blends of polypropylene and polyethylene of

15 ·, high or low density. The question of which mixing ratio should be applied and whether a high or low density polyethylene should be used depends on the desired stiffness or stiffness,^:mechanical resistance '' at low temperature and in general properties; mechanical strength which are particularly desired. In order to obtain sufficient cohesion resistance in each. ·. layer, the polypropylene must either be a semi-compatible copolymer with polyethylene, for example polypropylene with a content of 2% to 5% of ethylene or else an appropriate alloying agent must be used. In this regard, it is sufficient to maintain high contents in modification

j. atactic in ixiotäc'tiqüe or syndiotactic polypropylene. · During the manufacture of this polymer instead of eliminating this impurity as is normally done. It's a . Special aim of the invention is that propylene with a high content of atactic material can be made widely usable.

• Other combining agents have been mentioned previously in the description. ₍ · Are also economically advantageous mixtures of propylene and an elastomer such as for example rubber based on ethylene-propylene, the copolymer of ethylene and vinyl acetate, polyisobutylene or a thermoplastic rubber based butadiene / styrene.

<img file="LU74136A1_D0015.tif" />

30 '' · When a particularly high resistance at low temperature and / or great flexibility or suppleness are. mixtures of low density polyethylene and a semi-compatible rubber are preferred. It will be understood that the mixture does not need to be formed by mechanical mixing or kneading but can be formed already in the operation or the polymerization process. Thus, polypro-. .. ·· pylon with an extremely high content of atactic component can be used, .without, .no other addition in mixing and known polymerization operating procedures, which aim to produce mixtures of polypropylene, polyethylene and .polymers blocks, en masse or sequenced between them can also be adopted.

- Considering .polymers outside of the groups15. of polyolefins, the following combinations can, for example, be used for special purposes:

a) Polyester / polyamide or polyurethane? b) polyester.

- · or polyamide / polycarbonate; c) vinylidene copolymers in different combinations.

In addition to the layers having the special morphology as described, there may also be layers with special properties. Thus, it is almost always advantageous to co-extrude surface or thin surface layers of a suitable adhesive component in order to allow bonding ·

- or sealing of the laminate without destroying the orientation.

As another example, it will also often be necessary or advantageous, especially for the packaging of foodstuffs or food, to add one or more special layers to improve barrier / barrier, protective or screen properties.

'The laminate with high mechanical strength according to' the invention is considered to be advantageous for use in the following fields:

1) Packaging of products or foodstuffs or food: bags for hard service or very tired for. food in general, consisting of 100% of '. 'plastic or combined. ^ with paper. Packaging for frozen food.

<img file="LU74136A1_D0016.tif" />

• 2) Packaging for non-food products: bags for · fertilizers, bags for cement, bags for precious or expensive chemicals, such as granules of

.. plastics, bags for coarse chemicals 5 (for example rock salt, piece: -: of rock) and for other sharp, sharp or tapered articles, sheet envelopes; or ~ 'steel sheets, packaging of carpets, packaging or envelopes. - bales or bales, for example of cotton or wool, - envelopes for old furniture or bulky objects or packages of lumber, · of construction or in logs,. .bags for groceries, individual packaging of machine parts, weapons, etc., sterilization bags for heavy or pointed, acute or tapered objects, various: for example for textiles, for clothing or clothing, for paper 15 for drugs, for soaps, for toilet, sanitary or sanitary articles, for tobacco.

3) Film relating to containers: shrinkable envelope and expandable envelope for pallets or the like, garbage bags, waste or refuse, in particular to bind compactor bags, packages or parcels of industrial shipment.

4) Uses other than packaging, wrapping or wrapping: fumigation film, earth cover for erosion control, coating or filling in ponds or water basins, χ-water tanks and construction of canals, underlying layers for roads or carriageways, windshields, films for greenhouses, protective films. plantations or plants: (for agriculture and horticulture), cover on deposits or heaps of agricultural and horticultural products, salt, etc., protection of ·.

weatherproof animals (habitsrua? sniaax) raincoats or rain coats, tents, inflatable architectural structures, water-inflated structures, lighter than air nitrogen streetcars, ribbed constructions '35. (architectural, containers or inexpensive knowledge);

.cushions or mattresses as filling elements in cargo ships or for the transport of goods,

<img file="LU74136A1_D0017.tif" />

<img file="LU74136A1_D0018.tif" />

.. coatings or linings 'for cars or railroad cars, covers or coatings for trucks or utility vehicles, weather protection' on buildings under construction, barrier or tarpaulin. 5 waterproof protection over water,. ; 'cement constructions to delay drying,' insulation.

of roofing under shingles, armpits, hangers or tavaillons, insulation of · refrigerating rooms or cold rooms, films-membranes in the construction of houses, roof tile or $ 5 ceiling., various papers for buildings or constructions (in stratification with paper) , construction of cheap swimming pools or swimming pools, industrial ribbons.

It will be understood that the new processes and apparatuses

15. extrusion described above, which make use of rotating parts or parts of the die, will also have certain. . useful applications outside the field defined by claim • Thus, they can be used to extrude and laminate grain-free films as described, which are still advantageously applicable for certain uses. In addition, the general extrusion system, shown in Figure -4 and claimed in claim 6, may for example be used to wind by '.rotation a film oriented by fusion (with or without grain as described) around of a cold stretched or stretched film. ' .

Example 1. · · '• •' A three-layer tubular film is extruded with the following composition: · ............

Middle, middle or middle layer (70% of the total.

• 30 or all):,

85% isotactic polypropylene of the gas phase type • Novolene with a high content of atactic substances

- 15% of ethylene copolymer and. vinyl acetate (16% vinyl acetate).

The. two surface layers (one representing 10% of the

<img file="LU74136A1_D0019.tif" />

• η?

total and the other 20% of the total):

Copolymer of ethylene and vinyl acetate (.16%. Of vinyl acetate) to serve as adhesive layers. Propylene has a melt index of 0.3 to 0.6 5 '' in accordance with condition L specified in the American standard. ne ASTM D 12 38 (from the United States as a material sweater) while the ethylene and vinyl acetate copolymer has a melt index of 2.5 in accordance with the same standard American ASTM but under condition 12. The tubular film is extruded from a 1 mm wide slit at a temperature of 150 ° C. to 230 ° C. and stretched to 0.130 mm in the molten state. The swelling or blowing ratio is kept at a very low value, namely 1.2: 1. It is then cut helically into a flat film at a grain angle or fiber direction of 45 °. Two such helically cut films, with their grain perpendicular to each other and the thinner surface layers facing each other, are brought together at 20 ° C. through 7 groups of fluted rollers or cylinders '20 (see figures 6 and 7). The width of each groove or groove is 1 mm and the 'width of each edge or rib' is 0.5 mm. The mutual meshing of the edges or ribs with each other (level difference between the vertices) is 2 mm. Between each pass through a group of fluted rollers, the folds, formed in the laminate, are removed by stretching. .

Due to the mechanical work between the grooved rollers and due to the polymer layers which act as adhesive or tacky means, the two films are thus cold welded together with a relatively low adhesive bonding strength (measured peel strength as being equal to 1.0 g / cm) and are at the same time stretched transversely. After the seven passages at 20 ° C, the film is passed once through a similar group of rolls 35 - grooved having the same dimensions and meshing with each other. but heated to 120 ° C, so that strong bonding bond lines are formed.

<img file="LU74136A1_D0020.tif" />

. &lt;/ &lt;'v. ? ..

'' Finally, the laminate is oriented longitudinally • in three operations, phases or stages · with a stretching interval ·^rabout îcm entre'mÿens de reteües et imjers &amp; taction fe way to render ”...

¹ ,, minimum transverse contraction). The last extension or elongation is adjusted so that the total lateral cold extension or elongation ratio and the total longitudinal cold extension or elongation ratio are equal, so that the product of these ci, i.e. the ratio of surface area to stretching or extension elongation is 2.4: 1 ,. -......----- - --The test results were comparable to those of a quality low density polyethylene film suitable for heavy duty or fatigue work bags having a 85% greater surface mass and a melt index • 15 of 0.3 in accordance with the same condition E of the standard or.

.American ASTM technical specification. The thickness corresponded to a surface mass of 100 g / m 'for the laminate and to 185 g / m' for the polyethylene film. The

- resilience or impact resistance, measured by the fall of a falling ball (with a diameter of 61 mm and a weight of

320 g) for the 100 g / m laminate film was 5.5 m while for the 180 g / m polyethylene film it was 2.0 m.

Tear resistance on test piece. tabs:.

Tearing at a speed of 100 mm / min, total sample width: 5 cm, length of notch or incision; Cm:

For the laminated film, de'100 g / m.² : 5.9 kg in the direction of travel in the machine, and 6.8 kg in the transverse direction. '

For the polyethylene film from 180 g / m: 1.3 kg. Resistances the tear by test of Elmendorf · '·. (shock tear):

The test is a modification or variant of standards aimed at a more symmetrical tear. Results:

.· ·· 2 2

For the 100 g / m laminate film: 441 kg-cm / cm in -. longitudinal direction and 344 kg-cm / cm in direction

I transverse. :,.

* 2 2 For the 180 g / m 'polypropylene film: 167 kg-crr / crn ~' in the longitudinal direction and 172 kg-cm / cm in the transverse direction.

. A piece of leaf is delaminated or peeled off by peeling or detaching the layers to separate them and the structure ...

is examined under a microscope. The main layers have a pronounced fibrous morphology with grain directions. or zigzag fibers.

Example 2 - '' '

...- · '' The procedure of Example 1 is repeated with the following modifications:

The three-layer co-extruded film had the following composition:

Middle, middle or middle layer (70% of the total):

85% isotactic polypropylene (of the same type as in Example 1),

15% ethylene-propylene rubber (with; approximately the same melt index as propylene).

“. X ·. The two surface or surface layers (each representing 15% of the total):

Copolymer of ethylene and vinyl acetate (of the same type as in Example 1).

The film was more strongly attenuated. stretched in the molten 25 ′ state after leaving the die, that is to say by stretching it from 1 mm thick to 0.055 mm thick. (corresponding to 60 g / m). ...

'·. Examinations in polarized light showed that the orientation a'I'àat foidu. , thus produced, corresponded to a dtagpmaicu

I cold uniaxial drawing of approximately 35%.

. . After spiral cutting, we got a laminate '.' . -three folds or layers. The third layer, which was placed · in the middle, had a direction of longitudinal grain obtained by longitudinal cutting of the same film.

35 'The layering and stretching took place on the machine system of Exerrple 1 but all operations were performed at 20 ° C. And the apparatus was adjusted so as to produce a surface area ratio thus total stretching or · a • 36 extension of 2.5: 1-by which the thickness of the final laminate '' became equal to a value corresponding to a surface mass of 72 g / m.

The resistance to detachment of the adhesive bond 5 · · between the layers was measured to be 10 g / cm.

Microscope examinations showed a similar structure

<td colspan="2">to that obtained in 1 '</td><td colspan="2">example 1. The test results</td>

<td>following were '•• ",. ..</td><td>obtained</td><td>Present film</td><td>Comparison with</td>

<td></td><td></td><td>3-layer</td><td>poly film</td>

<td></td><td></td><td>72 g / m²</td><td>bass ethylene density 184 g / m²</td>

<td colspan="2">resilience</td><td colspan="2">1000 gm</td><td>530 gm</td>

<td>Resistance to tear propagation</td><td>DM⁺⁾</td><td> 848</td><td>gm</td><td>307 gm</td>

<td>(slow tearing)</td><td>DT⁺⁺⁾</td><td> 1120</td><td>gm.</td><td>620 gm</td>

<td>Breaking load</td><td>DM</td><td> 11,1</td><td> ·· /</td><td>• 10.6 kg</td>

<td>(sample of</td><td></td><td></td><td></td><td></td>

<td>.25.4 mm wide)</td><td>DT</td><td> 8,3</td><td>leg</td><td>10.7 kg</td>

<td>• Elongation at break</td><td>LM</td><td> 286 ·%</td><td> ; . 7'</td><td> 467·%'..</td>

<td></td><td>'DT-' -</td><td rowspan="2"> 347 %</td><td></td><td> 620· .;</td>

<td>Withdrawal .._ ......</td><td></td><td></td><td> .</td>

<td>1 min at 130 ° C.</td><td>• EM</td><td> ;28 %</td><td></td><td> • ··-</td>

<td></td><td>DT</td><td> 14 %</td><td> 1 /</td><td> -</td>

<td>1 min at 155 ° C</td><td>DM </td><td> 58 %</td><td></td><td></td>

<td></td><td>DT</td><td> '41 %</td><td></td><td> -</td>

<td>+) Direction, from</td><td>scrolling</td><td>in</td><td>machine</td><td></td>

<td colspan="2">4- +) Cross direction</td><td></td><td></td><td></td>

Example 3. .

. A series of polyolefin-based sheets was produced

-by the extrusion die shown in Figure 2. The diameter of the outlet slot 21 of the die was Γ3Ο mm and the width of the latter was de.l mm. The greatest width of the collecting chamber 38 was

- 5 4 mm, which. meant that the amount of attenuation cud'ÉÔ ^ p • in the molten state, during passage through. ·^r '' 'the collecting chamber towards the outlet slot,' · was smaller than the preferred value. The extrusion temperature was about 240 ° C. '10 · After the longitudinal cutting of the tubular film, the stretching or extension was first performed laterally: in a number of operations between 4 and S operations and, then, longitudinally in a number of operations included- between-2 and 4 operations in the same machine system as that used in examples 1 and 2.

The composition, the width of the flat or flattened tube (measurement of the swelling or blowing ratio), the stretching temperature, the stretching ratio and the results are shown in the table below. The symbol Nov designates

20. '' Novolene, a gaseous phase polymerized polypropylene with a relatively high content of atactic modification, the symbol P2 denotes low density polyethylene, the symbol CEPd denotes ethylene propylene rubber

-, and. the. symbols “SA 872, 7823 and 8623 denote different types of polypropylene with low levels of polymerized ethylene.

The fact that even the best samples in this example are generally lower than those in the examples. 1 and 2, is explained by an attenuation, ^ ·· stretching 'in the molten state' · total uniaxial. - 'lower. A certain baxtialè attenuation by stretching in the molten state is inevitable in this embodiment since the currents are first gathered inside the die according to a cross-configuration and then , attenuated later or more by stretching in the 'melted' state 'during passage through the outlet and immediately thereafter. Furthermore, this process is particularly simple to carry out.

; /· ' - . ' '

LLXFJ JA

<img file="LU74136A1_D0021.tif" />

· Λ "Λ '

<td>at</td><td> +)·</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td> $</td><td>d</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>Q) *.</td><td> (0</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>υ v</td><td>h!</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td> •</td><td></td><td></td><td></td><td></td>

<td>CJ</td><td>E</td><td>"· -X</td><td>co</td><td>in</td><td>CO</td><td>CO</td><td></td><td>Does the</td><td>CN</td><td></td><td>m</td><td>Γ-</td><td>CO</td><td>i-I</td><td> 0“)</td>

<td>0 ο</td><td> 0</td><td>b</td><td> 0</td><td>ro</td><td>o</td><td>O</td><td></td><td>r-</td><td>* S?</td><td>Ο</td><td>ο</td><td>o</td><td>o</td><td>Γ '</td><td>o</td>

<td>P 0</td><td>P</td><td></td><td>s</td><td>X</td><td>s</td><td></td><td></td><td>X</td><td>x</td><td>X</td><td>X</td><td>X</td><td>X</td><td>X</td><td> *.</td>

<td>mq • H 0</td><td>Ό</td><td>S</td><td>(NOT</td><td>Γ0</td><td>CN</td><td>CM</td><td></td><td>CN</td><td>m</td><td>P '</td><td>ΓΜ</td><td>P¹</td><td>CM</td><td>CM</td><td>CM</td>

<td>m</td><td>P</td><td>s- /</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>Ό b</td><td>ro</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>f4 ro</td><td>• -O</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>he</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>d</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>w ·</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>U)</td><td></td><td></td><td>H</td><td>m</td><td>H</td><td>M *</td><td></td><td> 00</td><td> 01</td><td>in</td><td>Ο</td><td>tp</td><td>in</td><td>P&gt;</td><td>o</td>

<td>+ J &lt;0</td><td>AT</td><td></td><td>X</td><td>X</td><td>S</td><td>X</td><td></td><td>•not,</td><td>X</td><td>X</td><td>X</td><td>X</td><td>X</td><td>X</td><td>X</td>

<td>S Ü</td><td>Q</td><td></td><td>tl</td><td>tP</td><td>CM</td><td>H</td><td></td><td>cm</td><td>tp</td><td>CM</td><td>ro</td><td>CM</td><td>co</td><td>ro</td><td>m</td>

<td>g 3 P tn</td><td></td><td></td><td>O</td><td>ORP</td><td>tp</td><td></td><td></td><td>VO</td><td>P¹</td><td>in</td><td>kl '</td><td>in</td><td>in</td><td>cm '</td><td>o</td>

<td>Tl fj.</td><td></td><td></td><td>X</td><td>x</td><td></td><td>X</td><td></td><td>s</td><td>X</td><td>X</td><td>X</td><td>X</td><td>X</td><td>X</td><td>X</td>

<td>,vs; m</td><td>Ö</td><td></td><td>CM</td><td>CN</td><td>CO</td><td>tp</td><td></td><td>tn</td><td> P</td><td>P "</td><td>vo</td><td>ro</td><td></td><td>in</td><td>vo</td>

<td>υ h</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td> -</td><td></td>

<td>ί · ι 0 d -S</td><td>E</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>0 d 0) +&gt;</td><td>U</td><td></td><td>O</td><td>o.</td><td>o</td><td>O-</td><td></td><td>O ·</td><td>O,</td><td>ο</td><td>Ο</td><td>O</td><td>o</td><td>o</td><td>m</td>

<td>P</td><td rowspan="2">S</td><td></td><td>m</td><td rowspan="2"> 00...· -</td><td>ro</td><td>ro</td><td></td><td>• CO</td><td>ro '</td><td>CO</td><td>CO</td><td>ro</td><td>CO</td><td>co</td><td>P '</td>

<td rowspan="2">0 d, _r 3</td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"> •</td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2"></td>

<td></td><td></td>

<td>d 0) 0</td><td></td><td></td><td></td><td>\ 6 WE</td><td></td><td>XO CN</td><td></td><td></td><td>xo © S ·</td><td>X</td><td>s &amp;</td><td></td><td>χ, ο WE</td><td>X</td><td>xo bone</td>

<td>P * rl</td><td></td><td></td><td>o</td><td>O</td><td>O</td><td> 0</td><td> -</td><td>o</td><td> .0</td><td>ο</td><td>ο</td><td>O '</td><td>o</td><td>o</td><td>not</td>

<td>d +&gt;</td><td></td><td></td><td>o</td><td>o</td><td>If)</td><td>υ</td><td></td><td>o</td><td>o</td><td> ο</td><td>m</td><td>O</td><td>in</td><td>o</td><td>m</td>

<td>• | J ro</td><td></td><td></td><td>H</td><td>RL-</td><td></td><td>Τ'-J</td><td></td><td>H</td><td>ip</td><td>"Η</td><td></td><td>ORP</td><td></td><td>tH</td><td></td>

<td rowspan="2">(0 iJ dd • 0 d</td><td>© X &amp; \</td><td></td><td>TJ</td><td></td><td>^rH</td><td>b</td><td></td><td>d</td><td>•at</td><td>Ό</td><td> ' ^rat</td><td>ORP</td><td>^Γ0</td><td> 3</td><td> Tf</td>

<td>d</td><td></td><td>• Services</td><td>• Services</td><td></td><td>d ·</td><td></td><td>• r (</td><td>'rl'</td><td>• Η</td><td>Ή</td><td>• Services</td><td>d</td><td>d</td><td>• Services</td>

<td>Ph · Η</td><td> 3</td><td></td><td> 0</td><td> . 0</td><td>(V</td><td>II</td><td></td><td> 0</td><td> 0 .</td><td>Ο</td><td> 0</td><td> 0</td><td> 0</td><td> 0</td><td> 0</td>

<td>E d</td><td></td><td></td><td>P</td><td>P</td><td>al</td><td>rd</td><td></td><td>P</td><td>P</td><td>Ρ</td><td>P</td><td>P</td><td>rd</td><td>rd</td><td>P</td>

<td>ü o E * i. ·</td><td></td><td></td><td>m</td><td>ΨΤ</td><td>• Ü</td><td>O</td><td></td><td>VH</td><td>Ή</td><td>Μ-Ι</td><td>Ή</td><td>vp</td><td> 0</td><td>U</td><td></td>

<td>-P · QX '</td><td></td><td> •</td><td> ,0</td><td> •0</td><td> /0</td><td> *0</td><td></td><td> . *0</td><td>r0</td><td> »0</td><td> »0</td><td> /0</td><td> '0</td><td> *0</td><td> r0</td>

<td>0 b</td><td></td><td></td><td></td><td>SP bone</td><td>\ O</td><td></td><td>XP ox</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>d Q)</td><td> 0</td><td></td><td>SO</td><td>S. n ft</td><td>O- ip</td><td>p7</td><td>o tp</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td> 0 £</td><td>d</td><td></td><td>O</td><td>H</td><td>fk</td><td>H</td><td></td><td>bone</td><td></td><td>xo BONE</td><td>so • os</td><td>XO οχ</td><td>BONE</td><td>xo © s</td><td>xo · - ex</td>

<td>• rl U</td><td> 0</td><td></td><td>H</td><td>θ I</td><td> 10 1</td><td>o</td><td>I</td><td> . 0</td><td>O</td><td>Ο</td><td>o</td><td>o</td><td> 0</td><td>o</td><td>' vs</td>

<td>• P. d</td><td>Ή</td><td></td><td></td><td></td><td>o</td><td></td><td></td><td>K.</td><td>ORP</td><td>tp</td><td>i-I</td><td>tp</td><td>H</td><td>H</td><td>tp</td>

<td>• H 0</td><td>Ti</td><td></td><td>I</td><td>El</td><td> 0</td><td></td><td>K</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>WU</td><td> '0</td><td></td><td rowspan="2">M</td><td>Ο Ck</td><td rowspan="2">o &amp; LT) * -</td><td>o</td><td rowspan="2">Λ</td><td>i:</td><td> 1</td><td> 1</td><td> 1</td><td> 1</td><td> 1 .</td><td> 1</td><td>. I</td>

<td> 0</td><td>E</td><td></td><td>me</td><td>m</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>&amp; ta</td><td></td><td></td><td rowspan="2">Ck -</td><td> \</td><td> \</td><td> \</td><td></td><td> &amp; '</td><td>IK</td><td>pi</td><td>Could</td><td>(k</td><td>pi</td><td>ck</td><td>P.</td>

<td>E: H -</td><td></td><td></td><td>- o</td><td>o</td><td>· O '</td><td></td><td> 0</td><td> «</td><td> •0</td><td>El</td><td> 0</td><td>El</td><td>w</td><td>El</td>

<td>0 U · '</td><td></td><td></td><td></td><td>in</td><td>m</td><td>Ln</td><td></td><td>O </td><td>υ</td><td>ο</td><td>O</td><td>at</td><td>u</td><td>Ü</td><td>O</td>

<td> 0</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>ck</td><td></td><td></td><td></td><td></td><td></td>

<td>rd</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td> 0</td><td></td><td></td><td></td><td></td><td></td>

<td> 0</td><td></td><td></td><td></td><td></td><td> -</td><td></td><td></td><td></td><td></td><td>BONE ο</td><td></td><td></td><td></td><td></td><td></td>

<td>U</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>ιΡ</td><td> : 0</td><td></td><td></td><td></td><td></td>

<td rowspan="2"> (0</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>Ck.</td><td>X</td><td rowspan="2">ck</td><td></td><td></td><td></td><td></td>

<td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>W</td><td>Η</td><td> ;</td><td></td><td></td><td></td>

<td>H</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>o</td><td>ck</td><td> &lt;&amp;</td><td></td><td></td><td></td><td></td>

<td> 0</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>o</td><td></td><td></td><td></td><td></td>

<td>0 Ö</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>X</td><td></td><td>ro</td><td></td><td></td><td></td><td></td>

<td>TJ fi</td><td></td><td></td><td>Yes</td><td></td><td></td><td></td><td></td><td></td><td>O</td><td>Q</td><td></td><td> «</td><td></td><td></td><td></td>

<td> 0</td><td></td><td></td><td>£ X</td><td></td><td></td><td></td><td></td><td></td><td>CN</td><td>CN</td><td></td><td></td><td></td><td></td><td></td>

<td>d -d</td><td></td><td></td><td>Or</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>CM</td><td> 1</td><td> 1</td><td> 1</td><td> 1</td>

<td> 0 «</td><td></td><td></td><td></td><td> 1</td><td> !</td><td> 1</td><td></td><td> 1 .</td><td></td><td> . _χ</td><td>r *</td><td></td><td></td><td></td><td></td>

<td>• rl · 0</td><td> ··</td><td></td><td> &lt;3</td><td></td><td></td><td></td><td></td><td></td><td>ro</td><td>ro</td><td rowspan="2">co</td><td>x;</td><td>X</td><td>X</td><td>X</td>

<td>p ·</td><td></td><td></td><td>ω</td><td>X</td><td>s</td><td>X</td><td></td><td> □ ,</td><td>CN.</td><td>CN</td><td></td><td></td><td></td><td></td>

<td>• H ·</td><td></td><td></td><td rowspan="2"></td><td></td><td></td><td></td><td></td><td></td><td> 00</td><td>co</td><td> ..4 !&lt;&lt;</td><td> 1</td><td> 1</td><td> 1</td><td> 1</td>

<td>U)</td><td></td><td></td><td> 1</td><td>I</td><td>I</td><td></td><td>I '</td><td>· t '</td><td>Γτ</td><td rowspan="2">w</td><td></td><td></td><td></td><td></td>

<td>Ω</td><td></td><td></td><td>O</td><td></td><td></td><td></td><td></td><td></td><td> ,</td><td></td><td></td><td></td><td></td><td></td>

<td>Q). '</td><td></td><td></td><td>o</td><td></td><td></td><td></td><td></td><td></td><td>n BONE</td><td>sp bone</td><td></td><td></td><td></td><td></td><td></td>

<td>Ei</td><td></td><td></td><td>Ή</td><td></td><td></td><td></td><td></td><td></td><td>ο,</td><td>ο</td><td>o</td><td></td><td></td><td></td><td></td>

<td> 0</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td rowspan="2">• CO '·</td><td>Γ-</td><td> • &gt;</td><td></td><td>_t</td><td></td><td></td>

<td>there</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td></td><td></td><td></td><td>CO</td><td>NOT*</td><td>m</td><td>vo</td><td></td><td>r ·</td><td>co</td><td>in</td><td>o</td><td>tp</td><td>CN</td><td>CO</td><td>P '</td>

<td></td><td></td><td></td><td>rM</td><td>ι-Ί</td><td>r ~ i</td><td>ORP I</td><td></td><td>TJ</td><td>ιΗ</td><td>ORP</td><td>CN</td><td>CM</td><td>CM</td><td>CN</td><td>CN</td>

ί

<td></td><td>laughed</td><td>• ri</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td></td><td>P</td><td>VS</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>VS)</td><td>Λ</td><td>(Ü</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>d</td><td>'d</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>vs:</td><td></td><td>E b</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>fo</td><td>u</td><td> 0</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td rowspan="2">at</td><td></td><td rowspan="2">CM</td>

<td>4J</td><td> 0</td><td>• laughed laughed</td><td></td><td>CO</td><td>W</td><td>r ~ i</td><td>M</td><td>r- ·</td><td>ι-H</td><td>Γ-</td><td></td><td></td><td></td>

<td>W</td><td>rRI</td><td>ό</td><td>o</td><td>o</td><td>not· ·</td><td>not-</td><td>not-</td><td>o</td><td>t&gt;</td><td>o</td><td></td><td></td><td>ro</td><td></td><td> &lt;1</td>

<td>• ri</td><td rowspan="2">υ</td><td>'D * -'</td><td>s</td><td>S</td><td>s</td><td>s</td><td>s</td><td>S</td><td>s</td><td>s</td><td></td><td></td><td>s</td><td></td><td>s</td>

<td>W</td><td>ri</td><td>s?</td><td>CM</td><td>or</td><td>CM</td><td>or</td><td> &lt;&lt;</td><td>m</td><td>if"</td><td></td><td></td><td>ro</td><td></td><td>tn</td>

<td> '(!)</td><td>ri</td><td>ri</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>fi</td><td>K)</td><td>'d</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td> -</td><td></td><td></td><td></td><td></td>

<td>ri</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>ri</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>ω</td><td>tn</td><td></td><td></td><td></td><td></td><td>m</td><td>o</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>h</td><td>Q)</td><td></td><td>m</td><td>ω</td><td>"Φ</td><td>not</td><td>or</td><td>CO</td><td>• tn</td><td>m</td><td></td><td></td><td>'D'</td><td></td><td>m</td>

<td>ri</td><td>ri</td><td>th</td><td> %</td><td>S</td><td>S</td><td>s</td><td>K</td><td>S</td><td>s</td><td> *.</td><td></td><td></td><td>S</td><td></td><td>... s</td>

<td>d</td><td>-ri</td><td>at</td><td>fo</td><td>CO</td><td>tn</td><td>o</td><td>o</td><td>'φ ·</td><td>co</td><td>to</td><td></td><td></td><td>or</td><td></td><td> •4’</td>

<td> 0</td><td> (!)</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>S</td><td>ri</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>ri</td><td>IU</td><td></td><td></td><td></td><td></td><td>co</td><td>m</td><td></td><td></td><td>_r</td><td></td><td></td><td></td><td></td><td></td>

<td>• H</td><td>VS</td><td></td><td>o</td><td>tO</td><td>O</td><td>VD</td><td>-if· '</td><td>s ··</td><td>tn</td><td>at·</td><td></td><td></td><td>co</td><td></td><td>in</td>

<td>rf</td><td> (0</td><td></td><td></td><td></td><td></td><td></td><td>S.</td><td></td><td>s</td><td> ·.</td><td></td><td></td><td>s</td><td></td><td>S</td>

<td>U</td><td>Services</td><td>at</td><td>in</td><td>'tn</td><td>at</td><td> 0</td><td>o</td><td>Ν '</td><td> •3*</td><td>m</td><td></td><td></td><td>if·</td><td></td><td></td>

<td>ri U</td><td>G) • g</td><td>s</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>o</td><td> ?</td><td>u</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>tn</td><td> +&gt;</td><td></td><td>LO</td><td>tn</td><td>m</td><td>o.</td><td>o</td><td>O</td><td>o</td><td>o</td><td></td><td></td><td>O</td><td></td><td>o</td>

<td>ri</td><td></td><td rowspan="2">s</td><td>-J *</td><td></td><td rowspan="2">"Φ</td><td>ro</td><td>ro.</td><td>m</td><td>CO</td><td>CO</td><td></td><td></td><td>ro</td><td></td><td>ro</td>

<td>(Ü</td><td>ri</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>or</td><td>'d</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>ü</td><td>we</td><td></td><td>SP bone</td><td>&gt; S ° '</td><td>n uS</td><td>n bone</td><td>n bone</td><td>n CS</td><td>SO bone</td><td>n bone</td><td></td><td></td><td>n bone</td><td></td><td>n bone</td>

<td>ri</td><td>• H</td><td></td><td>o</td><td>o</td><td>o</td><td>o</td><td>o</td><td>o</td><td>o</td><td>Q</td><td></td><td></td><td>o</td><td></td><td>o</td>

<td>ri</td><td>not a word</td><td></td><td>o</td><td>LO</td><td>o</td><td>o</td><td>Ό</td><td>o</td><td>o</td><td>O</td><td></td><td></td><td>o</td><td></td><td>o</td>

<td>• ri</td><td>ri</td><td></td><td>r4</td><td></td><td>rl</td><td>K</td><td>rj</td><td>tM</td><td>r-4</td><td>Services</td><td></td><td></td><td>rj</td><td></td><td>r-l</td>

<td>ftf ·</td><td>not a word</td><td rowspan="2"></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>b</td><td> ri</td><td>'d</td><td>'d</td><td>• s</td><td>'d</td><td>'d</td><td rowspan="2">'V • H</td><td>'d</td><td>'d</td><td colspan="2"></td><td>'D'</td><td></td><td>^rd</td>

<td>Ό</td><td> 0</td><td></td><td>• H</td><td>ri</td><td>ri</td><td>• H</td><td>• ri</td><td>• ri</td><td>• H</td><td></td><td></td><td>• H</td><td></td><td>• Services</td>

<td>ch</td><td>• H</td><td>ri</td><td> 0</td><td>ri</td><td>ro</td><td> 0</td><td> 0</td><td> 0</td><td> 0</td><td> 0</td><td></td><td></td><td> 0</td><td></td><td> _0</td>

<td rowspan="2"> §</td><td>P</td><td>ri</td><td>laughed.</td><td>rC</td><td>rRI</td><td>ri</td><td>ri</td><td>P</td><td>ri</td><td>ri</td><td></td><td></td><td>ri</td><td></td><td>ri</td>

<td rowspan="2">o</td><td rowspan="2"></td><td rowspan="2">you</td><td rowspan="2">ü</td><td rowspan="2">υ</td><td rowspan="2">MJ.</td><td rowspan="2">MM</td><td rowspan="2">MJ</td><td rowspan="2">MJ</td><td rowspan="2">MJ</td><td rowspan="2"></td><td rowspan="2"></td><td rowspan="2">MJ</td><td rowspan="2"></td><td rowspan="2">-MJ</td>

<td rowspan="2">Ei</td>

<td>-P Q&gt;</td><td></td><td>rRI</td><td>rRI</td><td>'Γ0</td><td>r (Ü</td><td></td><td>&lt;ri</td><td>&lt;κί</td><td>laughs)</td><td></td><td></td><td>'Itf</td><td></td><td>rRI</td>

<td>o</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>'ΰ-</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td rowspan="2">&gt; °° CM tn</td><td></td><td>sp bone</td><td></td><td></td><td>n bone</td><td></td>

<td>r!</td><td></td><td></td><td>'sp</td><td>n bone</td><td>n</td><td>SO</td><td></td><td> 8</td><td>T</td><td> 10</td><td></td><td>w</td><td> 10</td><td rowspan="2">n es</td>

<td> 0</td><td>ri</td><td>ri</td><td>o</td><td>o</td><td>o</td><td>o</td><td>o</td><td>your</td><td>fri</td><td>fri</td><td></td><td></td><td>Fri</td><td></td>

<td>• H</td><td>rC</td><td>• laughed</td><td>r-1</td><td>t-1</td><td>ORP</td><td>rM.</td><td>tH</td><td>O 1</td><td>O: i</td><td>O</td><td>I</td><td></td><td>O</td><td>I</td><td>o </td>

<td>-ri</td><td>ri</td><td>ri</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>rt</td>

<td>• ri</td><td>ri</td><td>• H</td><td> 1</td><td> 1</td><td>i</td><td> 1</td><td> 1</td><td>oa</td><td>oa</td><td></td><td>at</td><td></td><td></td><td>at</td><td></td>

<td>w</td><td> 0</td><td>'d</td><td></td><td></td><td></td><td></td><td></td><td>year a</td><td>tn- a</td><td>O</td><td>at</td><td></td><td> 0</td><td>P-</td><td> 1</td>

<td> 0</td><td>υ</td><td>'ω.</td><td>ü</td><td>at</td><td>at</td><td>at .</td><td>at</td><td> \ '</td><td> \ -</td><td>LO</td><td></td><td></td><td>tn</td><td>^s</td><td></td>

<td> &amp;</td><td></td><td>Ë</td><td>at</td><td>at</td><td>at</td><td>at ·</td><td>at</td><td>O</td><td>o</td><td> \</td><td></td><td></td><td> \</td><td></td><td> 0,</td>

<td>Ë</td><td>ri</td><td></td><td>υ</td><td>u</td><td>υ ·</td><td>ü</td><td>ü</td><td>tn</td><td>tn</td><td>o.</td><td></td><td></td><td>O.</td><td></td><td rowspan="2">Fri U</td>

<td> 0</td><td>• H</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>tn</td><td>• r</td><td></td><td>tn</td><td></td>

<td>· υ</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td> «</td><td></td><td></td><td></td><td></td><td></td><td> -,</td><td></td>

<td>o</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td>'at</td><td> •</td><td></td><td></td><td></td><td></td>

<td>rf</td><td></td><td></td><td></td><td></td><td></td><td>at</td><td></td><td></td><td></td><td>w</td><td></td><td></td><td></td><td></td><td></td>

<td> 0</td><td></td><td></td><td></td><td></td><td></td><td>at</td><td></td><td></td><td></td><td rowspan="2"></td><td></td><td> -</td><td></td><td></td><td></td>

<td>b</td><td></td><td></td><td></td><td></td><td></td><td rowspan="2">u</td><td></td><td></td><td></td><td> »</td><td></td><td></td><td></td><td> -</td>

<td> 0</td><td></td><td></td><td>M</td><td></td><td></td><td></td><td></td><td></td><td>O</td><td></td><td></td><td></td><td></td><td> ——..</td>

<td>υ</td><td></td><td></td><td>at</td><td></td><td></td><td>OS -</td><td>at</td><td></td><td></td><td>cM</td><td></td><td></td><td></td><td></td><td></td>

<td></td><td></td><td></td><td rowspan="2">n bone</td><td></td><td></td><td>tn</td><td>Θ</td><td></td><td></td><td>s</td><td></td><td></td><td></td><td></td><td></td>

<td>(Ü</td><td></td><td></td><td></td><td></td><td>S</td><td rowspan="2">u</td><td></td><td></td><td>at</td><td></td><td></td><td>at</td><td></td><td> &gt;</td>

<td>H</td><td></td><td></td><td>o</td><td></td><td></td><td>w</td><td></td><td></td><td rowspan="2">at</td><td></td><td></td><td>at</td><td></td><td> 0</td>

<td></td><td>you</td><td></td><td rowspan="2">fo</td><td></td><td></td><td rowspan="2">at</td><td></td><td></td><td></td><td></td><td></td><td rowspan="2">n CS</td><td></td><td>at</td>

<td>Q)</td><td>ri</td><td></td><td></td><td></td><td>o</td><td></td><td></td><td></td><td></td><td></td><td></td><td rowspan="2"></td>

<td>'d</td><td>ri</td><td></td><td>S</td><td></td><td></td><td></td><td>rRI</td><td>or</td><td>or</td><td>o</td><td></td><td></td><td>O</td><td></td>

<td></td><td>ri</td><td></td><td>CM</td><td></td><td></td><td>o</td><td></td><td>rs</td><td>r ·</td><td>tH</td><td></td><td></td><td>ro</td><td></td><td>o</td>

<td>ri</td><td>-ri</td><td></td><td>f</td><td> 1</td><td> 1</td><td>ORP</td><td></td><td>ω ·</td><td rowspan="2">co-</td><td>s</td><td></td><td></td><td></td><td></td><td>ro</td>

<td>υ</td><td>X</td><td></td><td>ω</td><td></td><td></td><td> %</td><td>fo</td><td></td><td>or</td><td></td><td></td><td>K</td><td></td><td></td>

<td>• H</td><td>ri</td><td></td><td></td><td>X</td><td>s</td><td>ro</td><td>or</td><td></td><td></td><td>t-</td><td></td><td></td><td> &gt;</td><td></td><td></td>

<td> .+)</td><td></td><td></td><td></td><td></td><td></td><td>or</td><td>you</td><td>CQ</td><td>w</td><td>co</td><td></td><td></td><td> 0</td><td></td><td>at·</td>

<td>• H</td><td></td><td></td><td rowspan="2">w</td><td>I</td><td> 1</td><td>feen</td><td>CO</td><td rowspan="2">i</td><td></td><td>"I.</td><td></td><td></td><td>at</td><td></td><td>not.</td>

<td>tn</td><td></td><td></td><td></td><td></td><td rowspan="2">ω</td><td></td><td>b '</td><td rowspan="2">w</td><td></td><td></td><td rowspan="2">x</td><td></td><td rowspan="2"></td>

<td> .0</td><td></td><td></td><td>n bone</td><td></td><td></td><td>SO 's</td><td>OJ</td><td>o</td><td></td><td></td><td></td>

<td>G "</td><td></td><td></td><td>o</td><td></td><td></td><td>BONE</td><td>o</td><td>Where i</td><td>o</td><td>X</td><td></td><td></td><td>o</td><td></td><td>o</td>

<td>Ë</td><td></td><td></td><td>VS-</td><td></td><td></td><td>m</td><td> 01</td><td>H j</td><td>rRI</td><td>o</td><td></td><td></td><td> !&gt;</td><td></td><td>r-</td>

<td>U</td><td></td><td></td><td></td><td></td><td></td><td rowspan="2">ω</td><td></td><td></td><td></td><td>co</td><td></td><td></td><td></td><td></td><td></td>

<td>o</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td>

<td></td><td></td><td></td><td>tn</td><td>to</td><td></td><td>cj</td><td>σι</td><td>o</td><td>TH</td><td>or</td><td></td><td>co</td><td>if"</td><td></td><td> m</td>

<td></td><td></td><td>X '</td><td>or</td><td>or</td><td>or</td><td>or</td><td>or</td><td>not</td><td>not</td><td>CO</td><td> •</td><td>ro</td><td>ro '</td><td></td><td>co</td>

<img file="LU74136A1_D0022.tif" />

<img file="LU74136A1_D0023.tif" />

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<img file="LU74136A1_D0024.tif" />

<img file="LU74136A1_D0025.tif" />

<img file="LU74136A1_D0026.tif" />

<img file="LU74136A1_D0027.tif" />

<img file="LU74136A1_D0028.tif" />

Of course, the invention is in no way limited to the embodiments described and shown which have only been given by way of example. In particular, it includes all the means constituting technical equivalents of the means described as well as their combinations, if these are carried out according to the spirit and implemented in the context of the claims which follow.