Substrate based on a nonwoven sheet made of chemical textile and its manufacture

Description

The present invention relates to a dimensionally stable nonwoven fabric nonwoven web support and method of manufacturing the same.

It is known to use nonwoven webs of chemical textile, in particular synthetic textile such as polyester, as a support in many applications: waterproofing membrane, floor coverings such as carpets (tufi, needled), slabs (plastics, textiles ), wall coverings, coating media, flock holder, etc.

In general, these articles have in common on the one hand to require both the laying and aging a high dimensional stability and on the other hand to be subjected during manufacture simultaneously to significant mechanical stress and thermal generally higher than those experienced during use; these constraints can lead to the risk of deformation: elongation in the long direction, withdrawal in the cross direction and inverse deformations during the aging of the article laid, because of the phenomenon of "springback" this specifically for the media of low weight such as those weighing 150 g / m or less².

In this way, waterproofing membranes used in the building industry often consist of a bituminous support or reinforcement. These supports were first jute fabrics, cellulosic fibers, and then fiberglass sails. A few years ago, a new generation of sealants appeared, bringing a clear improvement in the field, on the one hand, thanks to the spectacular improvement of elastomer and / or plastomer modified bitumens, on the other hand partly thanks to the joint use of nonwoven webs of polyester textile, mainly polyethylene glycol terephthalate meeting the requirements of increased deformability, to better support the dimensional variations of the supports (roofs, terraces, thermal insulators) and leading to a very sharp increase in punching resistance of the bitumen / reinforcement complexes thus produced.

However, if nonwovens (melted, dry, wet) are most often chemically bonded to each other, which generally leads to interesting industrial results, this bonding operation implements particular compositions of chemicals, it is performed with a process recovery and is ultimately expensive.

Moreover, it does not obtain perfectly satisfactory results from the point of view of subsequent behavior of the plies, in particular dimensional stability either during the bituminization or thereafter at the screeds (membranes) made and placed on the roof. It is thus noted that previously described that this can lead to deformations: withdrawal in the transverse direction and elongation in the long direction of the reinforcement bituminous and after aging on roofing, inverse deformations and risks of corrugations, this more specifically for reinforcement of lower weight or equal to 150 g / m².

However, the current trend is to lighten the components of the bituminous screed this for economic and technical reasons: decreased cost, storage and handling easier. That is why many manufacturers use, for the lightest waterproofing membranes, a reinforcement consisting of a complex comprising at least one polyester nonwoven web associated with a glass web or a woven or glued glass grid. . The association between nonwoven and glass mat is commonly done during the bituminization operation by simultaneous impregnation of the two frames. It is also possible to associate the glass fleece and the nonwoven polyester by needling or gluing.

Documents describing such products are, for example, French patent FR 2 562 471 in which a polyester nonwoven is associated with two outer layers based on glass fiber; US Pat. No. 4,539,254 which discloses a membrane comprising at least three layers bonded together combining non-woven material (s), glass grid and polyester: British Patent 1,517,595 in which a polyester nonwoven is associated with a network of polyester yarns. glass (grid / crossed ifils). In these embodiments, the amount of glass, although limited so as not to increase the mass, remains relatively important, which in economic terms leads to an increase in the cost.

US Pat. No. 3,834,978 discloses a carpet base for tuft or needled carpet formed by an assembly comprising two nonwoven webs of nylon fibers between which is disposed an interlayer constituted either by a woven nylon grid or by monofilaments of Nylon parallel and arranged in the machine direction (longitudinal). This assembly is subject, during its production, non-regular needling and thermolysis on the outer faces and, intermittently, on the inner faces of the nylon sheets, through the interlayer. Thus, the son constituting the aforementioned grid or monofilaments are made of an identical material or having characteristics similar to that forming the nonwoven webs, while having significantly higher titles. As a result, the reinforcement obtained is a reinforcement having a constant reinforcement rate irrespective of the physical conditions, in particular of the temperatures to which the aforementioned assembly is subjected.

From a technical standpoint, these various embodiments make it possible to improve the dimensional stability of the waterproofing membrane once it is laid. To a certain extent, they also make it possible to reduce the deformations of the polyester web during bituminization, by limiting the elongation in the long direction during the passage through the machine and the narrowing in width as well as the subsequent deformations related to the trend. elastic return of the screeds during aging after laying on the roof.

CH 684 232G A3

However, these solutions are not entirely satisfactory, especially in the case of two separate frames. Indeed, bitumen impregnation is effected by passing the web, or rather the nonwoven polyester + glass veil complex, in an impregnation tank. The quality of the impregnation depends on various factors, in particular the viscosity of the bitumen defined as a function of the temperature and the residence time, and the mechanical systems of detour and wetting in the baths. As the temperature is limited because of the risk of degradation of the polyester, it takes a sufficiently large residence time for the impregnation to be complete, which implies a sufficiently long journey in the tank and therefore the passage of the complex on guides or friction causing friction increasing tensile stress up to 80 daN / m web width.

However, under the combined action of the temperature of the impregnating baths or surfacing, often of the order of 160 to 200 ° C, and the tensile forces of the machine, the glass sheet and the polyester mat can to have differentiated behaviors during the impregnation operation and during the relaxation of the laid screed, which can produce phenomena of surface irregularities: undulations, cracks, etc.

Moreover, the mechanical behavior of the two-armed coping during the traction phenomenon is often very heterogeneous. Indeed, the glass veil, given its low elongation at break (less than 5%), breaks first along preferential break lines. At the point of these rupture lines, the stresses on the polyester reinforcement of greater elongation are localized, but this location leads to a decrease in the overall characteristics of load, elongation and fatigue resistance. This can lead to the risk of cracking on the screed.

Further progress has been made by the Applicant in the French patent 2,546,537 which relates to a sealing membrane reinforcement and a membrane made with this reinforcement having good dimensional characteristics over time and, furthermore, performed under conditions economically interesting. This waterproofing membrane is characterized in that its armature is a nonwoven fabric of thermolated continuous filaments, preferably acid-fast, containing:

70 to 90% polyethylene terephthalate glycol and

30 to 10% of polybutylene glycol terephthalate.

The manufacturing method of this reinforcement is characterized in that it is carried out, by extrusion, a web of continuous filaments constituted by the two polymers, which one eventually needle the obtained web, then thermolysis continuously to a temperature between 220 and 240 ° C causing the melting of the most fuse constituent.

For the realization of the waterproofing membrane, the reinforcement is bituminized at a temperature lower than the temperature of thermolysis of the filaments of the sheet. After bituminization, the whole is eventually subject to the usual treatments such as sanding or slate. Here the use of a sail or a glass grid has been eliminated together with the polyester nonwoven, which is technically and economically interesting.

However, it has been found, in particular for low weights of weight less than or equal to 150 g / m², that there are still some problems of dimensional stability during the manufacture of the membrane from the sheet, more especially during the bituminization because of the high mechanical and thermal stresses, and in the conditions of use on terrace of the membrane carried out or, by the phenomenon of elastic return, occur in time deformations in the opposite direction to those occurring during manufacture.

It is also known to introduce longitudinal reinforcing threads of mineral material in a glass veil, said veil then being associated with a sheet of pre-consolidated synthetic fibers for obtaining a sealing membrane support. Such a complex, the purpose of which is first to present non-fire properties and then good dimensional stability, is the subject of the European patent application 0 242 524. However, if this application deals with the dimensional stability in the conditions of use (up to 80 ° C, and without constraint), it does not say anything about the stability of the current product of the bituminization that is to say subjected at high temperatures and stresses. However, the bituminous behavior largely determines the subsequent behavior in the conditions of use and deformations during this treatment are also detrimental thereafter. Problems similar to those encountered in sealing also occur in the use of floor coverings. In this application, for example, synthetic nonwoven webs are used as primary support (primary file) and / or secondary support (secondary file) of tuft carpets. The manufacture of the carpet comprises known operations, such as: back coating, under layer deposition, dyeing or printing, which subject the product under development simultaneously to high temperatures and significant stresses. This can result in elongation deformations in the long direction, withdrawal in the cross direction of the primary and secondary folders and subsequently a tendency to deformations in reverse once the carpet is laid, which is detrimental, especially in the case of printing with connectable patterns.

Similar risks of deformations in the manufacture and tendency to deformations in reverse to aging can also be encountered for plastic or textile slabs reinforced with a nonwovens ply, whereas these are articles that require excellent dimensional stability.

The present invention proposes to solve the above problems. It relates to a nonwoven web support for flat article, good dimensional stability in all conditions.

CH 684 232G A3 fions of realization, subsequent treatments, and use, comprising at least one nonwoven web based on chemical textile material, in the form of continuous fibers or filaments, characterized in that said sheet comprises high threads reinforcement module arranged parallel to each other in the direction of its length.

The nonwoven web may be obtained by dry, wet or extrusion of a melt in the form of filaments (spunbonded web). The chemical textile material is generally synthetic. It is preferable to use a continuous filament web of synthetic polymers such as polyamide or polyester which exhibit good stability under the conditions of manufacture and use of the article.

Advantageously, polyester-based filaments are used. Polyester may be polyethylene glycol terephthalate alone or in combination with polybutylene glycol terephthalate; both polymers being spun together as bicomponent: bimetallic, coast-side or coaxial, or spun separately from the same die or different dies. The filaments of the web can be of any section: flat, round or profiled. Preferably, filaments of round section are used. The sheet is preferably consolidated by needling and advantageously heat-sealing.

Preferably the characteristics of the single layer in particular and in particular its cold tensile behavior are already compliant or relatively close to the characteristics required for the support in the context of its use.

The weight of the nonwoven web according to use may vary within wide limits. In general, it is between 20 and 500 g / m²preferably between 50 and 250 g / m², the invention being particularly advantageous for sheets of weight less than or equal to 150 g / m², the most likely to suffer deformations during manufacturing operations of the article.

High modulus yarns are yarns having a modulus of elasticity greater than 20 GPa and preferably greater than 50 GPa (1 GPa = 1Ò⁹ Pa); these values ​​being measured at ambient temperature but not substantially modified when the son are subjected to temperatures of the order of 200 ° C and more. High modulus yarns include yarns based on the following materials: glass, aramids, aromatic polyamides, various high-tenacity polyesters, carbon, metal, etc. Preferably, glass threads, which are very widespread and relatively inexpensive, are used. The high modulus wires constitute a reinforcement in the long direction of the nonwoven web. They can be placed on one side, both sides, or sandwiched in the nonwovens. The combination reinforcing yarn / nonwoven web can be made by bonding with a suitable chemical binder, thermoling and / or needling; these means must allow to obtain excellent cohesion between the son and the nonwoven web.

The amount of reinforcement yarn is a function of the characteristics of the sheet to which they are associated, in particular of its cold-rolling behavior and the temperatures reached during the article-making process as well as the stresses supported during the course of the article. this process. The minimum amount is determined by the necessary strength of the support (nonwoven web plus reinforcing threads) at the tensile stresses experienced at the high temperatures achieved during the article making process. This quantity must be sufficient to prevent wire breakage. It is such that when the reinforced ply is subjected to the stress / elongation test in the long direction, the rupture of the glass strands is recorded for a stress of at least 80 and preferably of at least 100 daN per meter of width. The maximum amount is determined according to the load / elongation curve of the cold-laid nonwovens. It is determined so that the shape of the load / elongation curve of the reinforced ply is as close as possible to that of the unreinforced ply. In particular, the Young's modulus is not substantially modified and the shape of the curve does not show any significant discontinuity when the breakage of the reinforcing threads is recorded.

The amount of reinforcement yarn is expressed by the diameter (title) and density (spacing) parameters. These two parameters are optimized in order to have the most homogeneous behavior possible of the support. Knowing that for a given type of web, the load / elongation curve depends essentially on its weight, in the preferred case of use of glass yarns and for polyester continuous filament nonwoven webs, whose weight is between 50 and 250 g / m² and depending on whether they are chemically bonded, thermally bonded and / or needled, advantageously glass threads with a diameter of the elementary strands of between 5 μ and 13 μ will be used, with a title ranging from 2.8 to 272 tex. and which are regularly spaces from 2 mm to 30 mm. Glass threads whose title is between 22 and 68 tex, spaces of 10 to 30 mm are preferably used; the titles indicated above are those of the standard threads of the trade.

In practice, for polyester sheets of preferential weight 50 to 250 g / m² and whatever the final destination of the support (waterproofing, carpet, slabs, etc.) the use of a few grams / m² glass thread is sufficient; 2 to 3 g / m² of glass threads are sufficient for sheets of 50 to 150 g / m²intended for the manufacture of waterproofing membranes, the passage in the bituminizer machine is in this case without any problem. Indeed, the breaking load of the glass strands over 1 m machine width can be calculated as follows. For 2,244 g / m² of glass threads, ie 66 threads of 34 tex spaced 15 mm apart, the breaking load per meter of width of sheet of glass threads alone will be:

CH 684 232G A3 χ 66 × 33.5 = 75174 g = 75.174 kg of the yarn in tex number of yarns / m tenacity of the yarn in g / tex is substantially 73.67 daN

In the case of an assembly of threads on a continuous polyester filament web of 110 g / m² followed by a thermolysis, the rupture of the glass yarns on the load / elongation curve of a specimen of 5 cm wide (3 considered threads) and 20 cm between the jaws of the dynamometer (according to the AFNOR Standard

G07 001) is recorded at 18 daN, which corresponds to 18 x 20 = 360 daN for 1m wide. This considerable apparent increase in the initial breaking load of the glass strands is explained by the excellent son / nonwoven cohesion resulting from the multiple bonding zones of the strands in the textile structure by means of the melted binder fibers and generating a behavior. at the perfectly homogeneous break of the whole.

As will be seen in more detail in the examples, examination of the cold load / elongation curve of said nonwoven web armed with glass threads in metered quantity shows:

a cold Young modulus identical in the long direction with respect to the same non-armed nonwoven web.

- About half load, break glass son without causing too much curve break. On the other hand, the examination of charge / extension curve at 180 ° C. shows a notable improvement of the hot Young's modulus. This module is multiplied by at least 2 and preferably by 2.5 to 3.

It can clearly be seen from these tests that the stabilization can be perfect during a bituminous operation, the machine tensions not exceeding 100 daN / m in width and that, on the other hand, the dimensional stability of the product under the conditions will be significantly improved by reducing the memory effect. These results are obtained with very little glass and for a minimum cost of the order of 0.08 F / m². This material cost is compared with a cost of 0.80 F / m² approximately for a glass veil of 50 g / m² used frequently in bi-polyester polyester-glass-veil copings or even with the realization of complex non-woven-glass grid 1x1x34 tex (1 thread / cm in warp and weft), structure considered as minimally practical, the cost of which in all cases, is greater than 1 F / m².

The present application also relates to a method of manufacturing the above support, characterized in that during the manufacture of a nonwoven web of chemical textile material or after its manufacture is provided, by appropriate means, reinforcement son that there is continuously parallel to each other at a predetermined distance against at least one of the faces of the nonwoven web or between two layers and that is made the connection between said son and said web.

For the production of the molten web is practiced the extrusion of the polymer and the manufacture of the web using preferably the means described in French patents 1,582,147 and 2,299,438 of the applicant. The establishment of reinforcement son can be done continuously or discontinuously. In both cases, the son are fed from beams or coils disposed in the vicinity of the sheet and distributed so that they run parallel to each other at a constant predetermined space in the longitudinal direction. Preferably the establishment of the reinforcement son is carried out continuously with the manufacture of the sheet, immediately after it or during it, tors of the lay.

The connection of the son with the sheet is performed either by application of a chemical binder, or preferably by needling and / or thermoling.

In the case of chemical bonding, it is possible to use either son coated with a chemical glue, or for the chemically bonded layers to introduce the threads into the twisted web of the chemical bonding thereof.

In the case of thermoling, it is possible to use either son coated with heat-sealing material or covered with a heat-sealing yarn, or for thermally-bonded sheets, to introduce the yarns into the sheet during its manufacture and to bond the sheet and yarns during the thermolysis of the sheet. . For example, in the case of thermoling, without prior needling and son applied to the surface, the first solution is used: fusible threads.

In the case of needling, special needles are preferably used, the reinforcing threads being embedded in the surface or in the mass of the entangled textile filaments. For example, in the case of needling and assembly of the son on one side, special needles of round section with two opposite edges are used with beards positioned directed in the longitudinal direction, so as not to touch the reinforcing son : such as needles FOSTERS NEEDLES type Pinch Blades.

In the case of the introduction of reinforcing son in a layering phase according to a traveling method, it is desirable to incorporate the son between two lapper devices. In this case, it will be possible to use standard needles (for example: 40 RB Singer needles) to achieve a first needling cohesion of the web. Indeed, it is found that the reinforcement son are more easily made consistent throughout by this method, while supporting an aggressiveness of the needles given the protection by the filaments of the sheet located on either side of these son. This needling will advantageously be followed by a line thermolysis. During these successive operations, care will have been taken to give sufficient tension to the entire web of chemical filaments and reinforcing threads so that the latter are perfectly tensioned during all phases of the process.

CH 684 232G A3 consolidation in order to obtain a maximum modulus of elasticity in the long direction of the reinforced ply constituting the article support according to the invention.

For the production of the dry ply, the methods customary to this technique are employed. The incorporation of the reinforcement son, their connection with the web and the eventual consolidation thereof are carried out in the same way as for the tablecloths obtained by molten route.

For the production of the tablecloth by wet methods used in this technique are used. The combination of reinforcement son is made after manufacture of the web and their connection with it is effected by chemical or thermal bonding on said web or between two lighter layers. The nonwoven web support for flat articles, according to the invention has many advantages in all cases of use: sealing membrane reinforcement, primary or secondary carrier of tuft mats, reinforcing slabs of flooring, etc.

- On a general level:

- Elimination of the deformations of the tablecloth under mechanical stress at high temperature during the treatments included in the article manufacturing process.

- Removal of the deformations inverse to aging on the article posed, against the previous deformations.

- economy of material and low cost price.

- In the case of waterproofing membrane, compared to the use of two frames: glass mat and nonwoven impregnated simultaneously and bonded together during the impregnation:

- Substantial savings on raw materials.

- elimination of a double reinforcement stock at the manufacturer of bituminous screeds.

- ease of impregnation giving the possibility of substantial increase in the production rates of screed.

- Elimination of screed appearance problems due to the use of very different module frames: folds, cracks, ripples, etc.

- much more satisfactory mechanical behavior at break: better continuity of the load / elongation curve of the screed leading to better resistance to fatigue (cracking).

- greater flexibility of the screed facilitating the installation of screeds in cold weather.

- In the case of waterproofing membrane, compared to the nonwoven-glass-grid complexes or the non-woven-glass-veil complexes (associated before impregnation):

- easier limitation of the total quantity of glass to the m².

- economy on raw materials.

- easy impregnation.

- mechanical behavior at break more homogeneous because limitation of the amount of glass.

- greater flexibility of the screed.

elimination of the risks of modification of appearance and / or dimensional presentation due to the different physical behavior of the two sheets during impregnation and subsequent use.

But the invention will be better understood using the examples and figures below given for illustrative and non-limiting.

Fig. 1 represents the comparative diagrams charge / cold elongation of a nonwoven nonwoven web and a support: nonwoven web plus associated reinforcing son, according to the invention, respectively in the long direction and the cross direction.

Fig. 2 represents the comparative load / elongation diagrams of the same plies as in FIG. 1, at a temperature of 180 ° C.

Fig. 3 schematically shows a first form of implementation of the method according to the invention.

Fig. 4 schematically represents a second form of implementation of the method according to the invention.

Fig. 5 schematically shows a device for measuring the characteristics of a sealing membrane made from the support according to the invention.

Fig. 6 schematically illustrates a method of manufacturing a waterproofing membrane from the support according to the invention.

According to the process schematized in FIG. 3, the support is made in a single step, the reinforcing son being associated and bonded to the nonwoven web during the making thereof. The sheet is made by molten route, according to the method described in French Patent 1,582,147, by extrusion of a molten polymer in the form of filaments 1, pneumatic stretching of these filaments and deposition on a receiving deck 2 using a traveling-type topping device, not shown, as described in French Patent 2 299 438. The reinforcing son 3 are associated with the forming web, from the entrance of the receiving deck. They are fed from coils 4, mounted on a reeling creel

CH 684 232G A3

5, pass on a system 6 for powering up then each through a guide eyelet 7. The eyelets 7, aligned and spaced judiciously spaced, at the entrance of the receiving deck 2 are intended to provide guiding son 3 parallel to each other and with the desired spacing on the receiving deck 2. The nonwoven web 8 is formed on the receiving deck 2 by integrating on its underside the reinforcement son 3. At the exit of the receiving apron 2, the ply and the reinforcing son pass continuously in the needling 9 where they are subjected to a needling operation providing a web / reinforcing son bonding part. The connection is completed by thermobonding by passage in the shell 10. The support 11 according to the invention thus produced is wound on a receiving means 12.

The process schematically fig. 4 is similar to that shown schematically fig. 3, it differs only in the supply of the reinforcing son 3 on the receiving deck 2. Here the son are arranged between two layers of the sheet and are fed on the receiving deck between two laparing devices located respectively at A and B by means of individual guide tubes 13. As in FIG. 3, at the outlet of each tube 13 is arranged an eyelet 7, the set of eyelets ensuring the parallel positioning of the son to the desired spacing.

EXAMPLE 1

A nonwoven web of filaments of 100 g / m is produced² 2 m wide, from extruded yarns of polyethylene terephthalate glycol and polybutylene glycol terephthalate, in the proportion of 87% / 13% respectively, filaments of title Ί dtex.

Continuously, from the schematized means fig. 4 is incorporated therein at the time of the lapping, every 1.5 cm, a Silionne glass wire type EC 9 34 T 6 Z 28 (diameter of the strands 9 microns, 34 tex, sizing type 6, torsion 28 t / m Z) of the VETROTEX Company.

These yarns have a breaking strength of 33.5 g / tex and an elongation at break of about 5.5%. They are fed from reels of 2.7 kg mounted on a creel as shown in FIG. 4.

The complex polyester tablecloth + glass thread is needle punched with 40 RB Singer needles (40 gauge, Regular barbes) 50 perforations / cm², 12 mm penetration.

At the outlet of the needling machine, the sheet is calendered at 235 ° C., under a pressing force of 25 daN / cm on a calender provided with non-stick coating cylinders. Conditions: calender speed 13 m / min, passage in S, total contact time of the sheet with the two cylinders: 15 seconds, then passage on cooling cylinders and winding.

This gives an armed sheet weighing 107 g / m². The dynamometric characteristics of this reinforcement, compared with those of a reinforcement without glass threads are indicated in the following Tables 1 and 2. Table 1 relates to cold measured characteristics (20^DC), Table 2 the characteristics measured at 180 ° C. The characteristics are measured on a specimen measuring 5 cm wide (3 threads considered) and 20 cm long; cold according to standard NF G 07 001 and hot according to the same dimensional and tensile speed criteria but the traction system and the specimen fixed in the jaws are in a thermal chamber regulated at a temperature of 180 ° C. The charge / elongation curves are reproduced in FIGS. 1 (cold) and 2 (at 180 ° C), L: long direction, T: cross direction, C1: with son, C2: without son.

Referring to Table 1 and FIG. 1, it can be seen that the load and elongation at break of this long-length armature are very little modified by the addition of glass. We also note that the lengthwise elongations under 3 daN and 5 daN remain unchanged and that the elongation under 10 daN is also virtually unchanged. This is a reflection of the non-modification of Young's modulus. It is well located in the break in the long direction the breakage of the glass strands at 18 daN, which constitutes a significant increase in the breaking load, since taken out of the sheet, the three son considered together have a theoretical breaking load of 3.35 daN. This breakage does not cause any disturbance in the nonwoven whose breaking curve continues without any noticeable change.

Referring to Table 2 and FIG. 2, the torque curve at 180 ° C shows a significant improvement in the modulus at the origin of the reinforced ply. The elongations under 3 daN, 5 daN and even 10 daN are significantly reduced. Knowing that the stresses to which the support (the reinforcement) is subjected during bituminization are at most 80 to 100 daN per linear meter, ie 4 daN at 5 daN for 5 cm of width, it results in a very slight deformation of the support to bituminization (or other heat treatment according to its final destination) therefore improved dimensional stability both during bituminization or other heat treatment and subsequently, once the support in place. The rupture of the glass strands is recorded at 5 daN, a sufficiently high value to deduce from this that the reinforced ply will withstand without risk of breakage of the glass strands, the stresses undergone during bituminization (or other heat treatment).

The frame has also been hot-tested and energized in bitumen.

The bitumen test is carried out using the apparatus shown in FIG. 5. It consists mainly of a tray 20 for receiving the bitumen 50, provided with heating and temperature control means 21, a removable basket 22 of calibrated dimensions for introduction and maintenance specimen 23 in the tray, different guides or references 24-25 to define the path of the specimen and a reading scale millimeter 26.

CH 684 232G A3

The bitumen used is an impregnation bitumen from SHELL (ref 100-130 PX), penetration 10C / 130 (penetration in 1 / 10th of a mm at 25 ° C measured according to standard NF T 66004).

The 10 χ 120 cm test pieces are cut in the long direction of the sheet. Three specimens taken across the width are used, one at the center and one at each edge 10 cm from the selvedge. The test is run according to the following mode:

The apparatus is heated to 185 ° C., and the temperature is allowed to stabilize.

- A clamp is attached to each end of the test piece 23, one of them 27 constituting a fixed point.

- The specimen is introduced into the hot bitumen using the basket 22 which then rests on the bottom. The basket is fixed with a bar 28; the level of bitumen and the dimensions of the basket being determined to have a length immersed in the bitumen of 500 mm.

- The load 29 is fixed, ie 4 daN then 7 daN for a layer of 107 g / m².

- We wait 30 s and we find the elongation using the millimeter scale.

The elongation is expressed as a percentage of the immersed length,

- After removing the load and the basket, remove the test tube and wring it out using a suitable device.

The test piece is suspended vertically and, after complete cooling, the shrinkage is measured in width and expressed as a percentage of the width.

The values ​​are shown in Table 3 below.

Another test, more accurate, is carried out in a thermal enclosure at 200 ° C, on test tubes 20 cm wide and 30 cm long (length of the test specimen taken in the direction of the length of the sheet) between clamps. The test piece is suspended by the upper clamp in the thermal enclosure at 200 ° C with a load of 8 daN hooked to the lower clamp. The dimensional variation of the test piece is measured after cooling at ambient temperature in the long direction and the cross direction and these variations are expressed in%. The values ​​are shown in Table 4 below.

In these two tests, there is a markedly improved behavior in the hot and tension deformation of the nonwoven reinforced with respect to unreinforced nonwoven (see the different levels of deformation in Tables 3 and 4).

The nonwoven base can be used as a waterproofing membrane reinforcement.

At the bituminous screed manufacturer, the reinforcement is bituminised using the system shown fig. 6. The armature 11 is unwound from a feed roller 30, then passes to an assembly station 31 and a battery 32. The assembly station allows to connect the beginning of a new roll at the end the length of reinforcement during treatment and the accumulator can absorb discontinuities in the supply. The reinforcement then passes through a first bituminization station 33, a second bituminization station 34, a slate station 35, a plastic film application station 36, a cooling zone 37, a second accumulator 38 and is received on a receiving device 39 provided with a cutting means 40 of the armature when the winding on reception has reached the desired size.

Bituminization is carried out in two phases:

a first full bath impregnation phase at 180 ° C. (station 33) followed by a spin between two metal rollers 41-42 with an oxidized bitumen of the 100/40 type, penetration 40 / 10th of a mm (according to the NF standard) T 66 004) ball-ring softening point 100 ° C (according to standard NF T 66 008).

a second so-called surfacing phase (station 34) by coating on both sides with SBS-type elastomeric bitumen (styrene butadiene styrene) at 175 ° C., followed by a calibration between rolls 43-44 with a pre-set spacing according to the thickness desired, screed slate on one side and polypropylene film on the other side and drum cooling in zone 37.

This same frame of 107 g / m² unarmed could not have undergone the bituminous treatment without a very strong deformation in the machine in the long and cross direction with an extremely undulating appearance rendering the screed completely unusable.

In this case, the behavior during the bituminization is excellent and the appearance of the perfectly flat screed. The subsequent performance of the dimensional stability test at 80 ° C, recommended by the UEATC (European Union for Technical Approval in Construction) complies with the requirements of dimensional variations or variations less than 5 0/00 in the both directions.

Obviously, the invention is not limited to the example described, but encompasses all the embodiments falling within the scope of the general definition.

CH 684 232G A3

Table 1

<td></td><td>Test with glass thread</td><td>Wireless glass witness</td>

<td>Weight per area (g / m²)</td><td>107</td><td>106</td>

<td>Break load SL * (daN)</td><td>32.0</td><td>30.6</td>

<td>Burst load ST * (daN)</td><td>31.2</td><td>27.7</td>

<td>Isotropy: SL / ST</td><td>1.02</td><td>1.1</td>

<td>Lengthening SL (%)</td><td>23.3</td><td>26.4</td>

<td>Lengthening ST (%)</td><td>24.4</td><td>24.0</td>

<td>Lengthening / 3 daN - SL (%)</td><td>0.3</td><td>0.3</td>

<td>Lengthening / 5 daN - SL (%)</td><td>0.5</td><td>0.5</td>

<td>Lengthening / 10 daN - SL (%)</td><td>1.1</td><td>1.2</td>

<td>Lengthening / 3 daN - ST (%)</td><td>0.3</td><td>0.3</td>

<td>Lengthening / 5 daN - ST (%)</td><td>0.5</td><td>0.6</td>

<td>Lengthening / 10 daN - ST (%)</td><td>1.2</td><td>1.4</td>

<td>Energy rupture - SL - (j)</td><td>11.2</td><td>12.0</td>

<td>Energy rupture - ST - (j)</td><td>11.2</td><td>10.0</td>

<td>Glass wire breaking load (daN)</td><td>18.0</td><td>-</td>

<td>Elongation rupture son glass (%)</td><td>2.2</td><td>-</td>

<td>* SL = long direction, ST = cross direction</td><td></td><td></td>

<td colspan="3">Table 2</td>

<td></td><td>Test with glass thread</td><td>Wireless glass witness</td>

<td>Weight per area (g / m²)</td><td>107</td><td>106</td>

<td>Breaking load (daN) - SL -</td><td>21.0</td><td>16.7</td>

<td>Breaking load (daN) - ST -</td><td>16.7</td><td>19.6</td>

<td>isotropy SL / ST</td><td>1.25</td><td>0.85</td>

<td>Lengthening (%) - SL -</td><td>27.0</td><td>23.6</td>

<td>Lengthening (%) - ST -</td><td>21.3</td><td>23.3</td>

<td>Lengthening / 3 daN (%) - SL -</td><td>0.9</td><td>2.1</td>

<td>Lengthening / 5 daN (%) - SL -</td><td>1.9</td><td>3.9</td>

<td>Lengthening / 10 daN (%) - SL -</td><td>6.4</td><td>9.6</td>

<td>Elongation / 3 daN (%) - ST -</td><td>1.6</td><td>1.6</td>

<td>Elongation / 5 daN (%) - ST -</td><td>3.3</td><td>3.3</td>

<td>Elongation / 10 daN (%) - ST -</td><td>8.9</td><td>8.9</td>

<td>Energy rupture (j) - SL -</td><td>6.3</td><td>4.7</td>

<td>Energy rupture (j) - ST -</td><td>4.3</td><td>5.5</td>

<td>Glass wire breaking load (daN)</td><td>5.2</td><td>-</td>

<td>Elongation rupture son glass (%)</td><td>2.0</td><td>-</td>

CH 684 232G A3

Table 3

<td></td><td>Test with glass thread</td><td>Witness without glass thread</td>

<td>Weight per area (g / m²)</td><td>107</td><td>106</td>

<td>Armature thickness (mm)</td><td>0.45</td><td>0.48</td>

<td>Bitumen test with 4 daN load</td><td></td><td></td>

<td>- lengthening SL (%)</td><td>0.7</td><td>1.9</td>

<td>- ST withdrawal (%)</td><td>0</td><td>0.5</td>

<td>Bitumen test with 7 daN load</td><td></td><td></td>

<td>- lengthening SL (%)</td><td>1.3</td><td>3.7</td>

<td>- ST withdrawal (%)</td><td>0</td><td>1</td>

Width of test pieces: 10 cm

<td colspan="3">Table 4</td>

<td></td><td>Test with glass thread</td><td>Witness without glass thread</td>

<td>Weight per area (g / m²)</td><td>107</td><td>106</td>

<td>Armature thickness (mm)</td><td>0.45</td><td>0.48</td>

<td>Thermal shrinkage 200 ° C - 10 'SL (%)</td><td>0.7</td><td>0.9</td>

<td>Thermal shrinkage 200 ° C - 10 '- ST (%)</td><td>0.1</td><td>0.1</td>

<td>Creep (200 ° C - 15 ') under 8 daN</td><td></td><td></td>

<td>- lengthening SL (%)</td><td>0.4</td><td>2.4</td>

<td>- ST withdrawal (%)</td><td>0.5</td><td>1.7</td>

Width of test pieces: 20 cm

SL = long direction

ST = meaning across