US3615967A

US3615967A - Method of manufacturing a fibrous fabric

Info

Publication number: US3615967A
Application number: US749782A
Authority: US
Inventors: Pius Stebler
Original assignee: Individual
Current assignee: Individual
Priority date: 1968-08-02
Filing date: 1968-08-02
Publication date: 1971-10-26
Anticipated expiration: 1988-10-26

Abstract

A method of manufacturing a fibrous fabric in which fibers are injected into a web of fibrous material in a direction substantially normal to a major surface of the web. The web is then impregnated with a binding agent to bond the fibers of the web and the injected fibers. The injected fibers strengthen the web in the direction normal to the web major surfaces and, in the case where the web is constituted from two or more fibrous layers, interlinks the layers. The fibers can be injected by means of a compressed air blower or by electrostatic action between spaced electrodes.

Description

United States Patent Pius Stebler Grillingerstr, Nunninger, Switzerland 749,782

Aug. 2, 1968 Oct. 26 1971 METHOD OF MANUFACTURING A FIBROUS FABRIC 9 Claims, 2 Drawing Figs.

Inventor Appl. No. Filed Patented References Cited UNITED STATES PATENTS 9/1966 Lemelson 156/72 3,477,889 11/1969 Partensky ABSTRACT: A method of manufacturing a fibrous fabric in which fibers are injected into a web of fibrous material in a direction substantially normal to a major surface of the web. The web is then impregnated with a binding agent to bond the fibers of the web and the injected fibers. The injected fibers strengthen the web in the direction normal to the web major surfaces and, in the case where the web is constituted from two or more fibrous layers, interlinks the layers. The fibers can be injected by means of a compressed air blower or by electrostatic action between spaced electrodes.

PATENTEDBCT 26 [9?! 3 615,967 SHEET 10F 2 Inventor: F/u: 5 72-731. eve,

PATENTEDEIBI 26 1911 4 SHEEI 2 BF 2 Inventor: l'us .STEBLEA, 3 him I p 1 W fr-Mae METHOD OF MANUFACTURING A FIBROUS FABRIC BACKGROUND OF INVENTION Varied methods and apparatus are known for manufacturing fibrous fabrics from stranded fibrous materials such as threads, yarns, twines, cords, ropes, strings, tresses, ribbons, braids, hoses and the like, for meeting industrial demand for shaped bodies formed from such fabrics. Attempts have been made to give such fabrics, and shaped bodies made from them, an adequate breaking strength and resistance to shock not only in the directions lying in the plane of the fabric but also in the directions normal of the fabric.

In one known method, mineral, animal or synthetic fibrous material is fed into a swirl nozzle of a compressed air or gas blower. The fibrous strands assume a helical or spiral formation and the strands in one layer become entangled with those in the next, so that some cohesion between the layers is obtained. The results obtained are, however, not entirely satisfactory because, although the strands are not barbed in any way no reliable interlinking of the layers takes place.

In another known method, superimposed layers of waddinglike and feltlike materials are are impregnated with adhesive. Cohesion between the layers is the result merely of the properties of the adhesive, interaction of the fibers playing no part in interlinking the layers. Despite the use of colloidal, particularly water-soluble, organic, inorganic, hydraulic or bituminous binding agents, the strength of the fabric in the direction normal to the surface of the fabric is still inadequate.

In the manufacture of glass-fiber fabric, a plurality of threads are delivered by a reciprocating device onto a rotary drum which performs several revolutions during each reciprocation of said device. The cylindrical fabric so formed is slit open and stretched, and may be divided into individual pieces of desired dimensions. Cohesion within the fabric in the direction normal to the plane of the fabric is obtained since the superimposed threads are fused or coalesced. However, elasticity and the ability of the fabric to bulge" decrease to such an extent that the fabric can not be used in cases where both properties are required.

Although this process may be applied to the manufacture of fabric from synthetic fibers the continuous individual threads are all aligned, i.e. all extending helically through the cylindrical fabric prior to slitting. Interlinking of the threads is absent, so that the strength of the material depends on the adhesion of one parallel thread with the next, both within each layer and between superimposed layers.

SUMMARY OF INVENTION The disadvantages of the prior art are overcome, in accordance with the invention, by injecting fibers into a fibrous web in a direction substantially normal to a major surface of the web, and impregnating the web with a binding agent. The injected fibers provide strength and breaking resistance in the direction normal of the major surface of the fabric. If the web is composed of a plurality of fibrous layers, the injected fibers link the layers together. The impregnation of the web bonds the strands making up the layers with the injected fibers to produce a fabric which has strength in all dimensions.

The fibrous web or its constituent layers may be made up from strands in the form of threads, yarns, twines, cords, ropes, strings, tresses, ribbons, braids, hoses and the like. The strands making up the web or the layers may be woven, knitted or randomly tangled or otherwise.

The invention is not limited to the treatment of substantially flat layers or webs. Fleeces on cottonwool-type bodies, whose dimensions may be varied at will, may also constitute the web subjected to the invention. The strands making up the fibrous web or the layers can be formed from any substance which is capable of being stranded, as may be the injected fibers, and particularly from animal, vegetable and mineral fibrous materials. Mineral fibers are natural fibers or inorganic synthetic fibers of mineral raw materials, such as glass, slag, stone, quartz, asbestos, or cermet fibers, and mixtures or compounds thereof. Examples of vegetable fibers are: cotton, kapok, flax, hemp, jute, Ramie or Chinese nettle, sisal, sisal fibers, ixtle, sanfevieria, Manila hemp (zebuor abaca-hemp), piasava, bauginia (apta), esparto, (alfa) and coconut fiber (coir). Examples of animal fibrous materials are: wool (merino-, colonialand crossbred-wools; crossbred-, cheviot-, cashmere-wools), mohair, natural silk, alpaca (llama) and camelhair. Examples of chemical or synthetic fibers are the manmade threads such those of the polyvinyl-, polyamide-, polyacryland polyester-groups, and the so-called manmade spun fibers (staple fibers) again of the polyvinyl-, polyamide-, polyacryland polyester-groups. With regard to the polyvinyls, examples are PeCe, PeCeU, Rhovyl. Examples of the polyamides are Perlon and Nylon (Trademarks). Examples of the polyacryls are Dralon, Redon and Dolan (Trademarks). An example of the polyesters is Diolen, and of the polyester manmade spun fibers an example is Terylene (Trademarks).

Suitable binding or strengthening agents have been mentioned above in the previous section. Any substance is suitable which can be used to strengthen stranded material and, in particular, adhesives, i.e. substances which, in a thin liquid or pasty layer between the strands or injected fibers, cement these by means of a setting process. This process may involve evaporation of a solvent, in interlacing polymerization though chemical bonds or even in solidification of a smelt. Suitable substances are glue, paste, pap, binders, adhesive dispersions, mastics, adhesive solutions, adhesive cement, solvent adhesives, reaction adhesives, heat-sealing adhesives, dry adhesives, coldsetting adhesives, hot-setting adhesives, contact adhesives and wet adhesives.

The invention also provides apparatus for manufacturing a fibrous fabric comprising means for supporting a fibrous web, means for injecting fibers into the web in a direction substantially normal to a major surface of the web, and means for impregnating the web with a binding agent.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. l is a diagrammatic representation of a machine in which the fibrous web is tubular in form and the fibers are injected into the web from within the tube.

Fig. 2 is a diagrammatic representation of a machine in which electrostatic action is used to inject the fibers.

DESCRIPTION OF PREFERRED EMBODIMENTS Embodiment of Figure l: The machine includes an arrangement for forming a hose from intersecting continuous strands, splitting the hose, unwrapping it and winding it upon a takeup roller. The wall of the hose may be formed from several concentric layers which may be interlinked and the wall strengthened by fibers injected into the wall, which is subsequently impregnated with binding agent.

In greater detail, the machine has a frame comprising a baseplate l and a vertical wall 2. Compressed air blowers 5 and 6 are mounted on wall 2 by brackets 3 and 4, respectively. The blower 5 introduces a fibre-carrying airstream into the interior of the hose [8 which is in the process of being formed. An outlet 7 from a container 10 containing a supply ll of fibers opens into the blower housing and is provided with a metering device in the form of brush roller 9 driven by shaft 8. The blower 5, which has impeller 12, has a discharge duct terminating a diverging surface 14 surroundingaconical head 15 of hose mandrel 16. Surface 14 and head I5 define together an annular, radially outwardly directed nozzle 17 such that the fiber-laden airstream emerges radially outwards from duct 13. In order to increase the forces urging the fibers carried by the airstream against the web constituted by hose 18, the second blower 6 is provided with an outlet duct 33 terminating in a nozzle 32 within duct 13.

The arrangement for forming a tubular web in the form of a hose, comprises a plurality of spools 19 on each of which is coiled a continuous strand of fibrous material. The strands may be formed from organic or inorganic fibrous substances, suitable substances having already been listed, or from synthetic substances such as Polystyrol, Polyvinyl alcohol, Polyvinyl chloride, Polyvinyl acetate, Polyvinyl nitrile, Polyethylene terephtalate, Polyhexamethylenediaminadipate. Poly-E-aminocaprolactum, Polyurethane and so on. Also may be used are materials without a fibrous structure, which arise by way of example annealing pastes, which contain carbon, silicon and so forth, or consist of suitable modifications of these elements.

Strands wound from the spools are taken via deflector rollers 21 which are supported within a stator 22 secured to the wall 2.. The tangents of rollers 21 lying nearest to the axis of the machine, and extending parallel thereto, lie on an imaginary cylinder. A further series of spools 23 are supported in yokes 24 which form extension pieces of a rotor 25. Rotor 25 is rotatably supported on the stator 22 through the intermediary of bearings 26. The rotor is driven by a pinion 28 meshing with a ring gear 27 carried by the rotor. The pinion is driven by a gear wheel 29 from a motor 30.

Strands 20 from the first set of spools and strands 31 from the second set of spools intersect and form a tubular web in the form of hose 18. The angle at which the strands intersect is determined by the rate at which the strands are fed, and at which the hose advances. At slow speeds the angle is nearly 90.

The airstream emerging from nozzle 32 accelerates the fiber laden airstream considerably so that the individual fibers are injected forcibly into the hose wall. Depending upon the mesh size, a proportion of the fibers are decelerated and frictionally caught in the meshes. if a plurality of layers are formed concentrically about hose 18, the injected fibers will serve to link these and give support and strength to the composite web.

Alternatively, these may be initially formed, a multilayer hose, or a tangled layer, fleece or the like consisting of several layers, and fibers then injected as disclosed hereinbefore. The mandrel 16 supports and guides the hose 18. The hose 18 is impregnated with a strengthening or binding agent which is sprayed onto the hose in the vicinity of the mandrel through nozzles 34 directed radially inwardly towards the hose. The mandrel can have cooling ducts or a cooled jacket, so that the strengthening agent hardens rapidly and acts before the hose reaches a cutting knife 35, which cuts the hose open along one line extending axially along the hose wall. The material of the hose wall is spread apart and rolled up onto the takeup roller 36. A housing 37, surrounding the machine has an opening for the hose 18 and the mandrel l6 and ensures that the strengthening agent does not escape.

Embodiment of Figure 2: in the machine of Figure 2 a web 38 of one or more layers of intersecting strands is fed via guide rollers 40 to a duct 41. The upper run 42 of an endless belt 43 passes through the duct. The belt carries fibers fed to it from a container 44 via a metering device consisting of counterrotating brush rollers 45, 46. The speed of the rollers 45, 46 is adjustable, whereby the rate of flow of the fiber material can be varied. The fibers fall through a sieve 47 onto a pair of out-ofphase grilles 48, 49, the eccentric drive of grill 49 being shown at 50. The grille 48 has a similar drive but out of phase by 90 from the drive 50. The grills prevent agglomerations of fibers occuring so that the upper run 42 of the endless belt is evenly coated.

The duct 41 is defined between

parts

51 and 53 which constitute two

electrodes

52 and 53, the electrode 53 also forming a guide for the upper run 42 of the endless conveyor belt 43. The electrode 53 is earthed at 54, whilst the electrode 52 is under the potential of a high-tension direct-current source 55. Between the

electrodes

52, 53 there thus prevails a high-tension field, under the influence of which the fibers having earth potential are accelerated towards the high-tension electrode 52. The fibers are thereby shot into the web 38. Fibers shot through the web 38 become charged and are repelled by electrodes 52, and are again again shot into the web. The various layers of the web are interlinked by the fibers which penetrate through it normal to the plane of the web. Subsequent to the

electrode arrangement

52, 53, a strengthening agent is fed via nozzles provided in series or via a fishtail nozzle 56, to finish the operation and provide a web having strength in the direction normal of its plane.

lt lies within the scope of the invention that what has been represented as a single procedure can analogously be repeated. Furthermore, the web may be formed from elongate strands intersecting in one layer only. If tangled layers, fleeces or similar fiber accumulations are used, then these can be provided in any desired thickness and be subjected to the method in accordance with the invention, whereby the increase in the strength in the normal direction can be achieved, which in doing can be brought to any desired further values by application of strengthening agents. Furthermore, the fibers need not be straight. The threads serving as the fibers may be in the form of crinkled crepe threads with sharp reversals of direction, giving a barb formation, whereby upon the introduction the fibers transiently deform through stretching, whilst after the introduction the fibers again assume their crinkled form. These procedures can be fostered through aftertreatments, for instance through treatment of the web in a warm, moist atmosphere. For the same purpose, the web can be passed through furnaces or for instance by subjected to an infrared radiation, so that through such measures the crinkling is strengthened or upon a transiently affected stretching the return pass again enters into the original shape. These further and additional measures being known per se, require no diagrammatic representation, but it lies in the essence of the invention that the described and further measures can be realized within the spirit and scope of the present invention as a need for them occurs.

What is claimed is:

l. A method of manufacturing a fibrous fabric, wherein fibers are injected into a fibrous web in a direction substantially normal to the major surface of the web, and the web is impregnated with a binding agent.

2. A method according 'to claim 1, comprising:

forming a tubular wall from intersecting strands of fiber,

injecting fibers into the tubular wall in a direction substantially normal to the wall,

impregnating the wall with a binding agent,

slitting the wall along an axially extending line, and unfolding the tubular wall to form a fabric lying substantially in one plane.

3. Apparatus for manufacturing a fibrous fabric comprising: means for supporting a fibrous web, means for injecting fibers into the web in a direction substantially normal to a major surface of the web, and means for impregnating the web with a binding agent.

4. Apparatus as claimed in claim 3, further comprising means for providing a fiber-carrying gas stream, and nozzle means adapted to direct said fiber-carrying gas stream towards the web.

5. Apparatus as claimed in claim 3, wherein said means for injecting the fibers into the web comprise spaced high-tension and earth-potential electrodes, said electrodes defining together a passage for the web; and a means for feeding fibers into said passage between the web and one of said electrodes.

6. Apparatus as claimed in claim 5, comprising means for feeding the web through said passage, and binding agent discharge nozzle means located after the passage.

7. Apparatus as claimed in claim 5, comprising an endless belt for feeding the fibers into said passage, and means for metering fibers from a storage container onto said belt.

8. Apparatus for manufacturing a fibrous fabric, comprismg:

first feeding means for feeding a plurality of continuous fibrous strands parallel to, and spaced about, an axis so as to define a tubular structure formed by a plurality of axially extending strands,

second feeding means rotatably supported downstream of said first feeding means for feeding fibrous strands around lar structure subsequent to the injection of fibers into the wall thereof.

9. Apparatus as claimed in claim 8, wherein said takeup means includes means for axially slitting the wall of said wound tubular structure, means for unrolling the slit wound tubular structure to form a flat web and a takeup roller for continuously taking up said flat web.

# i i t

Claims

2. A method according to claim 1, comprising: forming a tubular wall from intersecting strands of fiber, injecting fibers into the tubular wall in a direction substantially normal to the wall, impregnating the wall with a binding agent, slitting the wall along an axially extending line, anD unfolding the tubular wall to form a fabric lying substantially in one plane.
3. Apparatus for manufacturing a fibrous fabric comprising: means for supporting a fibrous web, means for injecting fibers into the web in a direction substantially normal to a major surface of the web, and means for impregnating the web with a binding agent.
4. Apparatus as claimed in claim 3, further comprising means for providing a fiber-carrying gas stream, and nozzle means adapted to direct said fiber-carrying gas stream towards the web.
5. Apparatus as claimed in claim 3, wherein said means for injecting the fibers into the web comprise spaced high-tension and earth-potential electrodes, said electrodes defining together a passage for the web; and a means for feeding fibers into said passage between the web and one of said electrodes.
6. Apparatus as claimed in claim 5, comprising means for feeding the web through said passage, and binding agent discharge nozzle means located after the passage.
7. Apparatus as claimed in claim 5, comprising an endless belt for feeding the fibers into said passage, and means for metering fibers from a storage container onto said belt.
8. Apparatus for manufacturing a fibrous fabric, comprising: first feeding means for feeding a plurality of continuous fibrous strands parallel to, and spaced about, an axis so as to define a tubular structure formed by a plurality of axially extending strands, second feeding means rotatably supported downstream of said first feeding means for feeding fibrous strands around said tubular structure, and means for rotating said second feeding means around said tubular structure to form a wound tubular structure, takeup means downstream of said second feeding means for pulling said wound tubular structure past said second feeding means, a nozzle for feeding a fiber-carrying gas stream into said wound tubular structure, deflection means for deflecting the fiber-carrying gas stream radially outwards, and impregnation means for impregnating said wound tubular structure subsequent to the injection of fibers into the wall thereof.
9. Apparatus as claimed in claim 8, wherein said takeup means includes means for axially slitting the wall of said wound tubular structure, means for unrolling the slit wound tubular structure to form a flat web and a takeup roller for continuously taking up said flat web.