Method and machine for producing a web of textile fibres held together by a binder

Aug. 17, 1965 μ. casse 3,201,499

METHOD AND MACHINE FOR PRODUCING A WEB OF TEXTILE FIBRES HELD TOGETHER BY A BINDER

Filed Oct. 17, 1961 3 Sheets-Sheet 1

<img file="US3201499A_D0001.tif" />

Aug. 17, 1965 m. CAssif 3,201,499

METHOD AND MACHINE FOR PRODUCING A WEB OF TEXTILE FIBRES HELD TOGETHER BY A BINDER

Sheets-Sheet 2

Filed Oct. 17, 1961

<img file="US3201499A_D0002.tif" />

<img file="US3201499A_D0003.tif" />

Aug. 17, 1965 μ. cass^ 3,201,499

METHOD AND MACHINE FOR PRODUCING A WEB OF TEXTILE FIBRES HELD TOGETHER BY A BINDER

Filed Oct. 17, 1961 3 Sheets-Sheet 3

<img file="US3201499A_D0004.tif" />

3,291,499

Patented Aug. 17, 1965

United States Patent Office

3,201,499

METHOD AND MACHINE FOR PRODUCING A WEB OF TEXTILE FIBRES HEW TOGETHER BY A BINDER

Marcel Casse, 69 Rue Feray, 'Corbeil-Essonnes, France Filed Oct. 17,1961, Ser. No. 145,607

Claims priority, application France, Dec. 7, 1960, 846,240, Patent 1,282,103

Claims. (CI. 264—121)

The present invention relates to the production of sheets or webs of textile fibres held together by a binder.

Various methods and apparatus are already known for producing such webs of natural or synthetic textile fibres, which latter are of the same or mixed type.

The known apparatus comprise a plurality of separate machines disposed in series relation to one another. In a first machine, (machine producing a layer of fibres) the fibres are open and dispersed in a current of air and drawn onto the perforated wall of a rotary drum or on a woven metal sheet.

In a second machine they are agglomerated by a binder. The latter is usually in solution in a liquid. This solution is generally distributed over the web disposed in the flat position, by pulverization spraying or dipping. The web is thereafter drained or dried, if need be by application of pressure or suction so as to remove the excess solution. The liquid binder instead of being spread in a uniform manner over the web can also be deposited or injected into the web at separate points, in lines or in any other manner, which leaves portions of the web devoid of binder and renders the web more supple and more permeable to air.

Sometimes, a binder in powder form, which is a thermoplastic product, is mixed with the fibre at the moment of formation of the web.

The two types of binder, namely the solution and the powder, are sometimes combined.

In a third machine, the web supported in the flat condition by a belt or sheet material which is usually metallic, passes into an oven where it is dried and where the binder is, if required, melted if it is a thermoplastic powder or polymerized if it is a synthetic resin.

In these known apparatus, the machines disposed in series relation to one another are interconnected by suitable devices, such as belts or other conveyors.

The assembly is costly and space-consuming, and serious difficulties are encountered as concerns advancing the web and synchronization between the various machines.

The object of the present invention is to provide an improved method of producing a web of textile fibres held together by a binder which avoids the aforementioned disadvantages. This method comprises slowly and continuously rotating a single perforated cylindrical wall of large diameter and continuously forming on said wall the web of fibres, agglomerating the latter by means of the binder and drying the web on said wall and finally removing, this dried web from said wall.

This method avoids all the problems of advancing or feeding the web and synchronization.

Another object of the invention is to provide a machine for carrying, out said method. This machine comprises in combination: a perforated cylindrical wall, means for driving the wall in rotation about its geometric axis which is stationary, and various fixed stations arranged about said axis in such manner as to be traversed successively in a fluid-tight manner and continuously by the various portions of said wall in the course of its rotation, said stations comprising at least one station for depositing fibres in the form of a web on said wall, a station for depositing a binder on said web, a station for heating the web which has received the binder and a station for separating the dried web from said wall.

Further features and advantages of the invention will be apparent from the ensuing description, with reference to the accompanying drawings to which the invention is in no way limited.

In the drawings:

FIG. 1 is a longitudinal vertical sectional view, with parts cut away, of a machine according to the invention, this view being taken along line 1—1 of FIG. 2;

FIG. 2 is a sectional view taken along line 2—2 of FIG. 1;

FIG. 3 is a plan view of the machine;

FIG. 4 is a partial view of a modification of the web forming station which produces a sandwich type web;

FIG. 5 is a partial sectional view of another modification of said web forming station, and

FIG. 6 is a plan view, partly in section, of the station shown in FIG. 5.

In the embodiment shown in FIGS. 1-3, fixed on a stand 1 (FIG. 2), is a column 2, carrying at its upper part a fixed case 3. Journalled in the latter on two bearings 4 is a horizontal shaft 5 having an axis X—X. This shaft is rotated in the direction of arrow f¹ (FIGS. 1 and 2) by an electric motor 6 through belt means 7, a speed variator 8, a transmission having a sprocket 9, a chain 10 and a sprocket 11 and through a gear train having a worm 12 rigid with the sprocket 11 and a worm wheel 13 keyed on the shaft 5.

The shaft 5 extends out of the case 3 and carries keyed thereon a circular large diameter disc 14 (FIG. 2). Fixed to the periphery of this disc is a ring 15 on which is fixed a cylindrical wall 16 constituted by a perforated sheet. A second ring 17 is fixed at the other end of the cylindrical wall 16 and renders the latter rigid.

The rotary drum T constituted by the disc 14, the perforation wall 16 and the rings 15 and 17, is located within a large housing or casing C whose main function will be explained hereinafter and which consists of (FIGS. 1 and 2) base 18, disposed within the stand 1 and having front and rear traverse walls 19 and 20 respectively in which are provided apertures 21 and 22 concentric with the axis X—X and having a diameter slightly greater than the cylindrical wall 16, side walls 23 and 24 and a partial top wall 25. Fluid tightness between the drum T and the walls 19 and. 20 is obtained by means of two elastically yieldable sealing rings 26 and 27 of rubber or like material.

The drum T having a perforated cylindrical surface 16 furthermore rests by its ring 17 on two rollers 28 which are freely rotative on their spindles 29 carried by the casing C, for example directly by the rear wall 20.

The rotary drum T is closed at the end thereof remote from the disc 14 by a fixed disc 30 located with slight clearance in the ring 17 and fixed to the sealing ring 27.

The drum T which rotates in the direction of arrow f¹ with the shaft 5 with which it is rigid, co-operates with five fixed stations which are arranged about the axis X—X and are continuously traversed by the wall 16 in the course of rotation of the drum.

The stations are:

A station I for depositing a web n¹ (FIG. 1) of fibres on the cylindrical wall 16.

A station II for providing this web with a liquid containing a binder so as to obtain an agglomerated web n².

A station III for drying the web and, if required, melting or polymerizing the binder so as to provide an agglomerated web n³.

A station IV for removing the completed web N from the drum T.

A station V for cleaning and preparing the perforated wall 16 of the drum T.

3,201,499

The station I comprises two associated casings A¹ and A² located respectively outside and inside the drum T. At the upper part of the casing A¹ arrives a current of air denoted by the arrows /². This current of air is tranquillized and downwardly directed by a grid 31.

The outer casing A¹ is open at its base and a seal is provided between the wall 16 and this casing by a roll 32 which is capable of rolling and freely moving vertically in a slideway or guide 33. A rubber strip 34 fixed to the wall 35 of the guide lightly bears against the roll 32.

The casing A² disposed within the perforated wall 16 has an upper opening corresponding to the lower opening of the outer casing A¹. Sealing strips 36 of synthetic rubber or like material are fixed along the edges of this upper opening.

The inner casing A² is fixed to the fixed disc 39 and it comprises a rear opening 37 which puts it in communication with the inlet of a fan 39 by way of a duct 38, this fan being driven by a motor 49 (FIG. 3). The air discharged by the fan 39 is directed by a duct 41 to the upper part of the casing A¹ above the grid 31.

The station I is completed by means for feeding and dispersing fibres in the casing A¹ below the grid 31. These means comprise:

A lower feed device G (FIG. 1) formed of an endless belt 42 on which the fibres are deposited at F¹ either manually or by means of a known device (not shown) such as a loading or combined loading and weighing device, two feed rolls 43 which feed the fibres toward a picker 44 (cylinder provided with spikes or pins) and a duct 45 for raising the fibres F² dispersed by the picker.

An upper receiving device H, for receiving the fibres F² and for dispersing the latter at F³ in the current of air f² emanating from the grid 31, comprises a rotary perforated cylinder 48 which is located within a lateral housing 46 formed in the wall 47 of the casing A¹ and which receives the fibres, two feed rolls 48α against which the perforated cylinder 48 lightly rubs, a picker 49, and a rotary brush 50 carrying longitudinal bars 51.

The various rolls and cylinders, the pickers and the brush are driven in rotation in the directions indicated by the arrows in FIG. 1 through conventional transmission means (not shown) by electric motors 52 and 53 respectively.

The station II for spraying an agglomerating liquid on the layer of fibres deposited on the drum is located immediately after the station I relative to the direction of rotation of the drum T. It comprises two associated casings, namely a casing B¹ outside the wall 16 and a casing B² within this wall.

The outer casing B¹ is carried by the wall 25 and fluid tightness between the casing B¹ and the cylindrical wall 16 is obtained by means of a rubber strip 34 which bears against the roll 32 and by means of a plate 54 the height of which is adjustable.

The inner casing B² is carried by the disc 39 and fluidtightness is obtained therebetween and the wall 16 by means of two rubber strips 55 and 56.

The outer casing B¹ contains a spraying jet 57 whose lower wall is perforated with small-diameter orifices 58. This jet 57 is nearer to the wall 35 of the casing B¹ than to the wall 59.

The inner casing B² is connected to a duct 60 which puts the inside of this casing in communication with the inlet of a fan 61 which is capable of maintaining a high degree of vacuum or negative pressure in this casing, is driven by the motor 62 and discharges into the atmosphere at 63.

The lower wall 64 of the casing B² is inclined and leads to a hydraulic seal 65 (FIG. 2) whose overflow liquid flows by way of a pipe 66 into a tank 67 covered by a wire netting 68. A pump 69 draws the water or the appropriate solution from this tank 67 and pumps it into the jet 57 by way of a pipe 79 provided with a regulating cock 71.

The heating station III is disposed in and around the large casing C. An opening 72 (FIG. 1) formed in the disc 39 puts the interior of the perforated cylindrical wall 16 in communication with the inlet of a fan 74 (FIG. 3) by way of a duct 73 (FIG. 2). This fan, which is driven by a motor 75, discharges the air drawn in through the opening 72 into an air heater 76. In the presently described embodiment, this air heater comprises a vertical case 77 at the lower part of which is located a combustion chamber 78 into which extends a burner 79. The gases of the combustion rise vertically in the tubes of a nest of tubes 89 and are evacuated by way of a chimney 81. The air discharged by the fan 74 passes around the tubes 89 and is returned to the casing C by way of a duct 82.

The hot gases arrive in the part or casing C¹ formed in the housing C about the drum T, pass through the web n³ and the perforated wall 16 and issue from the interior C² of the drum by way of the opening 72.

The station IV adapted to separate the formed web N from the wall 16, comprises (FIG. 1) a strip or doctor 83 which rubs against the outer face of the wall 16 and two rolls 84 and 85, the roll 85 being as close as possible to this perforated wall 16.

These rolls 84 and 85 are operatively interconnected as concerns rotational movement, owing to provision of a pair of gears 86 (FIG. 3), and are driven by a pair of bevel gears 87 which are driven by the shaft of the worm 12 by way of a shaft 88. The gear ratio of the bevel gears 87 is so arranged that the peripheral speed of the rolls 84 and 85 is identical to that of the perforated wall 16.

At the station V for cleaning and preparing the perforated cylindrical wall 16, a case E² inside the wall 16 contains one or more perforated tubes 89 which are parallel to the axis of the cylindrical wall 16 and are capable of being connected to a source of compressed air or steam (not shown). Disposed outside the wall 16 in alignment with the case E² and with a perforated tube 89, is a rotary brush 90 surrounded by a hood E¹ which is connected by way of a pipe 91 to a fan (not shown). A strip of felt 92 impregnated with an oily substance or with a product providing an insulating film, for example a varnish having a silicone base, rubs against the outer face of the wall 16 before the latter passes under the casing A¹.

The machine operates in the following manner:

At the station I, on the portion ab (renewed in a continuous and uninterrupted manner) of the wall 16 there is formed the fibre web n¹, the fibres, divided and dispersed at F³ by the picker 49 and the brush 50 in the casing A¹, being carried by the current of air issuing from the grid 31 and distributed uniformly over said portion ab. This portion ab constitutes in fact a perforated bottom for the casing A¹.

The air is received in the associated inner casing A²and discharged toward the grid 31; this air therefore travels in a closed path across which extends the perforated wall 16.

The web n¹ thus formed reaches in a continuous manner the station II where the jet 57, supplied by the pump 69 with hot or cold liquid containing a binder in solution or emulsion, atomizes this liquid and distributes it in the form of a spray over the entire portion cd of the portion n² of the fibre web. The high degree of suction maintained within the associated inner casing B² by the fan 61 achieves a perfect penetration of the binder in the web n² and a drainage of excess liquid.

Experience has shown that the abundant spraying of the portion n² of the fibre web combined with an energetic suction highly compresses or achieves a packing of the fibres of the web and interconnects the fibers.

If it is desired to obtain a web of high density, the layer n¹ of fibers has a thickness of several centimeters. It is said that certain fibers “swell.” The compressing

8,201,499 of this thick layer by the rolls would create sliding, wrinkles, and irregularities in the thickness. On the other hand, the abundant spraying at n² of this thick layer subjected to a high suction brings about a very large decrease in the thickness of the fibers and the thickness of the layer could be reduced from, for example, ten centimetres to one centimetre.

The part of the perforated wall 16 carrying the portion of the web impregnated at n² thereafter passes by the Station III in which the air (or other hot gases) passes in the direction from C¹ to C².

This hot air, after having passed through the web at n³, is drawn in by the fan 74 which blows it into the generator 76 generating hot air or other gas and returns it to the outer casing C¹.

At the exit end of the station III the web n³ is separated at IV from the wall 16 by the strip 83 and is gripped between the two rolls 84 and 85. The separated web N can thereafter pass between other rolls (not shown) which could be, if required, cooled; these other rolls grip it and impart thereto a uniform thickness. The web is thereafter either rolled up, cut to the required length, or fed to other devices effecting further operations.

The last station V permits cleaning the perforated wall 16, this cleaning being carried out, for example, by jets of compressed air or steam issuing from the perforated tubes 89. To the same end, the (or several) rotary brushes 90 act on the outer face of the wall 16.

The felt strip 92 (or a brush) deposits on the perforated wall 16 a film of oil, grease, wax or suitable varnish adapted to prevent the binder used for agglomerating the fibers of the web from causing the latter to adhere to the wall 16.

It will be observed that the air drawn into the lower casing B² can be recycled if required in the upper casing B¹ so as to return to the web the fibers or products, such as binding powders, granulated cork or active charcoal which could be incorporated in the web.

Infrared radiators could be disposed in the casing C¹so as to direct a heating flux toward the web n³.

At the station IV the web N could be separated from the wall 16 by.means other than the strip 83, for example by jets of air or other compressed gas.

It might be required that the web be composed of two or several superimposed layers, for example so as to constitute a sandwich type web in which the middle layer of fibers which are cheap or of a mixture of . fibres and various added products (such as granulated cork, wood cuttings, active charcoal) is placed between two layers of fibres of superior quality having for example greater strength or a better appearance than the fibres of the middle layer. In this case the single outer casing A¹ of the example described hereinbefore is. replaced by as many elementary casings as there are layers of fibres to be superimposed, these elementary casings being disposed one after the other along the perforated wall 16 and constituted, for example, by a simple subdivision of the casing A¹. Each elementary casing receives, dis. persed in a current of air, the desired fibres which are, if required, mixed with one or more added products. It will be understood that there is provided for each elementary casing a fibre inlet means and compressed air inlet means.

Thus FIG. 4 shows a modification in which the casing A¹ is subdivided by a partition wall 93 into two elementary casings 94, 95 each of which receives fibres and the air which entrains these fibers through a duct 96 or 97, the fibres being distributed in the lower part of the corresponding duct, for example by a picker 98, whereas the primary air under pressure is injected through a nozzle 99 so as to entrain the fibres in a stream of air formed of this primary air and secondary air entering at 100.

FIGS. 5 and 6 show a modification of the device adapted. to form a composite web-comprising two outer layers p and q of fibres and therebetween a layer r constituted by a granulated or powdered product, such as cork or active charcoal.

A tank or hopper 101 contains at 102 the powdered or granulated product which falls into the apertures 103 of a disc 134 rotating between two side members 105 and 106. The upper member 105 has an opening 107 in alignment with the base of the hopper 101. The lower member 106 has an opening 108 which is diametrally opposed to the opening 107 of the hopper member. The disc 104 is driven at adjustable speed by a motor 109 through a speed variator 110. Under the opening 108 of the lower member 106 there is located a hopper 111 communicating with the inlet of a fan 112 driven by a motor 113. The assembly just described constitutes a dosing or metering device.

The air arriving in the hopper 111 can be taken from the discharge pipe of the fan 39 (FIG. 3).

The discharge side of the fan 112 is equally divided into two nozzles 114, 115 which communicate with a chamber 116 through the side walls of the latter, this chamber being arranged under a hood 117 disposed in the casing A¹. This hood 117 has an ogival vertical sectional shape (FIG. 5) and no bottom. The outlets of the two nozzles 114 and 115 are offset in plane and in elevation in the chamber 116.

Although specific embodiments of the invention have been described, many modifications and changes may be made therein without departing from the scope of the invention as defined in the appended claims.