US3010180A

US3010180A - Method for manufacturing non-woven pile fabrics

Info

Publication number: US3010180A
Authority: US
Inventors: Hoffman Maufred Turner
Original assignee: Individual
Current assignee: Individual
Priority date: 1959-04-08
Filing date: 1959-04-08
Publication date: 1961-11-28
Anticipated expiration: 1978-11-28
Also published as: GB950068A

Description

Nov. 28, 1961 M. HOFFMAN METHOD FOR MANUFACTURING NON-WOVEN PILE FABRICS 2 Sheets-Sheet 1 Filed April 8, 1959 Novjzs, 1961 M, H FFMAN 3,010,180

METHOD FOR MANUFACTURING NON-WOVEN FILE FABRICS Filed April 8. 1959 2 Sheet5-Sheet 2 IN V TOR.

BY M00 0M MM WWW atent Patented Nov. 28, 1981 3,010,180 METHOD FOR MACTURING NQN-WOVEN PEE FABRICS Manfred Turner Hofiman, 187 High St, Newburyport, Mass. Filed Apr. 8, 1959, Ser. No. 805,077 6 Claims. (Cl. 28-722) This invention has reference to manufacturing nonwoven pile fabrics.

The present patent application is a continuation-in-part of my copending patent application Ser. No. 711,262, filed January 27, 1958 for elastic non-woven fabric and method of producing the same, now United States Patent 2,951,278.

It is a general object if this invention to improve the manufacture of pile fabrics and to reduce the cost involved therein.

Another object of this invention is to provide a novel and improved method for manufacturing fabrics suitable for wearing apparel.

Another object of this invention is to provide a novel and improved method for manufacturing fabrics comprising the step of instantly holding fibers by means of elastic forces in a position into which they have been brought by the action of a needle loom.

Another object of this invention is to provide a method for manufacturing fabrics adapted to take on some instances the place of conventional tufted fabrics which are more expensive to produce.

Another object of the invention is to provide open or porous needled non-woven fabrics suitable for use in wearing apparel not requiring any woven or similar backmg.

Further objects and advantages of the invention will become apparent as the followng description proceeds, and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to, and forming part of, this specification.

According to this invention an elongated substantially iso-elastic sheet is moved horizontally in a direction longitudinally thereof, a layer of relatively loose fibers is deposited on a horizontal side of said sheet, said sheet and said layer are horizontally jointly passed through a needle loom, constituent fibers of said layer are punched by said needle loom through said sheet to form an integral fabric including portions of fibers projecting through said sheet, and said portions are instantly clamped in position by the substantially iso-elastic forces inherent in said sheet acting at right angles to said portions.

For a better understanding of the invention reference may be had to the accompanying drawings wherein FIG. 1 is a diagrammatic side elevation of machinery used in the process of this invention arranged to show successive steps involved in the process;

FIG. 2 is a top plan View of a material which may be used in the process;

FIG. 2a is a section along 2a2a of FIG. 2;

FIG. 3 is a section on a large scale of a non-woven fabric;

FIG. 4 is an isometric view on a large scale of a small element of a non-woven fabric of the kind shown in FIG. 3; and

FIGS. 5a and 5b are cross-sections along the lines 5a5a and 5b-5b of FIGS. 5b and 5a, respectively.

Referring now to the drawings, and more particularly to FIG. 1 thereof, numeral 1 has been applied to indicate a supply roll of an iso-elastic, sheet material, i.e. a sheet material having substantially the same elastic prop erties in all directions which are situated in the plane of the sheet. The elongated sheet 2 is being unwound from supply roll 1 and may be fed into a perforating punch 3 wherein sheet 2 is perforated by removal of small circular, or confetti-shaped, increments therefrom. FIGS. 2, 2a, 3 and 4 show sheet 2 upon having been perforated by the action of punch 3, reference character 2a having been applied to indicate individual perforations. Numeral 4 in FIG. 1 designates a supply roll of non-elastic open fabric or netting 5 which is being continuously superimposed upon the vulcanized iso-elastic sheet 2 and moved at the same rate and in the same direction as sheet 2. There is a loose physical engagement between open fabric 5 and sheet 2. The supply roll 6 comprises a sheet, mat or fleece of relatively loose fibers which are deposited upon the open fabric 5 and upon iso-elastic sheet 2. A garnetting machine, or other relatively loose fiber depositing means, may take the place of supply roll 6. The sandwich comprised of

layers

2, 5 and 7 is then fed to a needle loom of conventional design, generally indicated by reference character 8. Needle loom 8 comprises a horizontal surface horizontally supporting sheet 2, open fabric 5 and the sheet, mat or fleece taken from roll 6. Needle loom 8 punches constituent fibers of layer 7 through the open fabric 5 and through the sheet 2 to form an integral fabric including portions of fibers projecting through iso-elastic sheet 2. Theme portions have been indicated in FIGS. 3 and 4 by reference character 7a. Portions 7a are instantly clamped in position by the iso-elastic forces inherent in sheet 2, acting at right angles to said portions 7a. Vectors V shown in FIGS. 3 and 4 represent the elastic clamping or pinching forces by which the portions 7a of fibrous layer or mat 7 are held in place.

The non-elastic open fabric 5 may be omitted, if desired, i.e. its provision is optional. 'If the open fabric 5 is needle loomed or punched to the sheet 2 the stretchability of the latter is limited, as required for a number of apparel applications. During the manufacturing proc ess of the laminated fabric to which reference numeral 9 has been applied in FIG. 1 the open fabric 5 is held in loose physical engagement with the iso-elastic sheet 2. The open fabric 5 is secured to sheet 2 merely by the punching action of the needle loom 8, thus dispensing with any additional means such as, for instance, adhesives, for attaching the open fabric 5 to sheet 2.

The perforations 2a which are punched by punch 3 into sheet 2 before the mat or fleece 7 is superimposed upon the former are of a nature different from that of the perforations which are punched into rubber sheet 2 by the action of any of the barbs 8a of needle loom 8. The punch 3 removes small discs from sheet 2, thus making the sheet 2 pervious to the passage of air. The

V barbs 8a of the needle loom 8 do not remove any matter from the sheet 2 at the points thereof where they penetrate through the sheet 2. They form but small slits 2b in sheet 2 tending to close instantly as the barbs are being pulled out of, or withdrawn from, slits 2b, and then firmly pinch or clamp in position the portions of the constituent fibers of layer 7 which are punched through sheet 2. The firm clamping action of the lateral Walls of slits 2b is due to the high degree of iso-elasticity inherent in thin sheet, or membrane 2. Sheet 2 may either be a vulcanized rubber sheet or may be a fleece of polyposed fibers having spot deposits of an elastic binder such as, for instance, vulcanized rubber, at the crossing points of the constituent fibers thereof whereby said fleece is caused to be substantially iso-elastic. If sheet 2 is an iso-elastic fleece of polyposed fibers the punching process by means of punch 3 may be dispensed with since a fleece of this kind is generally inherently porous, i.e. it is more or less an open fabric having interstices between the constituent fibers thereof. Isoelastic sheets of polyposed fibers are generally much less stretchable than sheets of solid vulcanized rubber. Therefore, if sheet 2 is an iso-elastic fleece of polyposed fibers, superposition of open fabric 5 upon it may generally be dispensed with. Since an iso-elastic fleece of polyposed fibers is generally a more or less open fabric the barbs of needle loom 8 can push the fibers of top layer 7 through the open spaces or interstices in an iso-elastic fleece of polyposed fibers if such a fleece is used as foundation layer 2. The constituent fibers of layer '7, if pushed through a more or less open iso-elastic flee e of polyposed fibers, are clamped in position by the isoelastic forces inherent in 'the latter substantially in the same fashion as if they were pushed through the slits 2b in an iso-elastic sheet of solid vulcanized rubber. If sheet 2 is a solid rubber sheet it must be sufficiently vulcanized to render it iso-elastic at the time it is passed through needle loom 8 and punched therein. If desired a rubber sheet 2 may not be entirely vulcanized at the time it is passed through the needle loom 8, and the integral pile fabric 9 may be subjected to additional heat treatment and vulcanization after having passed through the needle loom 8. This causes the portions of fibers projecting transversely across sheet 2 to more firmly adhere to sheet 2 than effected by the elastic clamping action of sheet 2. As a general rule the elastic clamping action of sheet 2 is suflicient to maintain the fibers in position, and post-needle-looming vulcanization is not required. On the other hand, pre-needle-looming vulcanization is vitally important since the clamping action of layer 2 depends upon its elasticity, and the latter depends upon vulcanization.

If desired, the integral fabric 9 may be turned over, covered by another layer of relatively loose fibers which layer may then be secured to the fabric 9 by passing the latter for a second time through a needle loom.

Referring now to FIGS. 5a and Sb reference character 2 has been applied to indicate an elongated iso-elastic sheet which may take the place of the iso-elastic sheet 2 shown in FIGS. 2-4. Iso-elastic sheet 2' is a non-woven substantially open fleece made up of random oriented fibers and including elastic tie means 1 between the constituent fibers thereof substantially localized at the cross over points of said constituent fibers. Tie means 2? may be formed by droplets of vulcanized latex, or any other elastic means substantially restricted to cross-over points of fibers imparting similar iso-elastic properties to the fleece as droplets of vulcanized latex. Fleece 2 is being moved and passed through a needle loom after a layer of relatively loose fibers has been deposited thereon. When fleece 2 is passed through the needle loom the constituent fibers 7 of said layer are punched through fleece 2' and form with fleece 2' an integral fabric including portions 7a of fibers projecting substantially at right angles through fleece 2'. These portions 7a are instantly clamped in position by the iso-elastic forces in fleece 2' acting at right angles to portions 7a..

ISo-elastic fibrous sheets may be made of any kind of fibers, natural or synthetic, as long as the fibers are in cardable form. Cardable fibers may be formed in a card into thin webs in which the fibers are preponderantly oriented in a direction longitudinally thereof. Several such Webs are superimposed in angular relation. In a fleece formed by appropriate angular superposition of webs with preponderantly oriented fibers the fibers extend substantially in random directions. One refers to such a fleece as a fleece wherein the fibers are polyposed. A fleece comprising polyposed fibers may be impregnated as, for instance, by spraying with an aqueous dispersion or emulsion of a rubber. When the dispersion or emulsion of rubber is dried and vulcanized the rubber deposits primarily at the crossing points, or cross-over points, of the constituent polyposed fibers, and then imparts substantial iso-elasticity to the fleece. The resulting isoelastic fleece retains substantially all the interstices originally formed between the constituent fibers thereof. In

other words, such a fleece combines a high degree of porosity with iso-elasticity. Therefore, as mentioned above, it does not need to be passed through a punch to make it pervious, as in the case of a rubber film. The aqueous dispersion or emulsion of a rubber, i.e. a rubberlike elastomer, may not only be applied by spraying, but also in any other fashion well known in the art of making non-woven rubberized fleece materials. The iso-elastic fibrous fleece may then be further processed in the same way as above described in connection with the iso-elastic layer 2.

if desired the fleece may be further impregnated with a suitable plastic in liquid form before being passed through the needle loom. The impregnation may be carried out to such an extent as to close substantially all the interstices formed between the constituent fibers of the fleece, thus converting the porous structure into a film-like structure. The conditions under which this impregnation is carried out vitally aifect the properties of the fleece. By using a suitable vulcanizable impregnant the iso-elasticity of the fleece may be increased. A fibrous fleece which is so impregnated requires at least two vulcanizing steps before being passed through a needle loom, i.e. pre-vulcanization intended to elastically connect the cross-over points of the fibers, and another vulcanization to vulcanize the film-forming interstice closing liquid binder with which the fleece may subsequently be impregnated. Generally sequential vulcanizing steps call for increasing vulcanizing temperatures, as is well known in the art.

The aqueous dispersion or emulsion used for forming the fleece structure--whose elasticity is caused by spotbinding of fibers at cross-over points and which is characterized 'by its large interstices between fibersrnay include about 25% by weight natural rubber. Other ingredients may be added to that dispersion or emulsion as, for instance, wetting agents, or antioxidants.

The final product formed by placing a sheet of relatively loose fibers on an iso-elastic fleece and punching the fibers through the fleece by means of a needle loom may have a thickness from about & to A. Such a product has an aggregate thickness and an aggregate pliability adapting the same for application in wearing apparel.

It will be understood that substantial iso-elasticity is a characteristic feature of the foundation or ground structure of fabrics manufactured according to this invention. While the foundation or ground structure must be isoelastic at the time it is passed through the needle loom, the final composite product must not be iso-elastic. The orientation of the fibers on the foundation or the ground structure may limit the stretchability of the final product in one direction and if an open woven fabric forms parts of the composite fabric structure or laminate, the stretchability thereof may be virtually eliminated.

It will be apparent from the foregoing that the product illustrated in FIG. 4, on the one hand, and the product illustrated in FIGS. 5a, 5b, on the other hand, are different. Also the steps for obtaining these products differ from each other. According to FIG. 4 the base layer into which loose fibers are needled is an elastomeric sheet or film, e.g. a sheet or film of vulcanized rubber. According to FIGS. 5a, 5b the base layer into which loose fibers are needled is composed of random oriented fibers defining openings therebetween and including elastic spotbonds substantially limited to cross-over points of the constituent fibers of the base layer.

It will be understood that an entirely different product results depending upon Whether the foundation sheet is a solid sheet of vulcanized rubber, or a more or less open iso-elastic fleece of polyposed fibers. Generally speaking, the physical characteristics of a non-woven laminate are much more like those of a woven material if the base sheet is a more or less open iso-elastic fleece of polyposed fibers. This will readily be appreciated when considering that such a fleece is of a predominantly fibrous nature, its rubber content being generally limited to a number of spaced discrete points.

Cutting by means of the barbs of a punch loom of small slits into a base sheet of solid vulcanized rubber involves some problems which can be avoided if the base sheet is formed of a porous rubberized fleece of polyposed fibers. It will be apparent that the clamping action of a small slit upon fibers inserted into the slit tends to be larger at right angles to the slit than in a direction longitudinally of the slit. This yields a directional clamping action notwithstanding the fact that the rubber sheet is entirely homogeneous and iso-elastic.

While the invention has been described according to preferred embodiments and the manner of carrying out the process, it will be understood that changes and modifications may be made therein without departing from the spirit of the invention, and it is intended in the appended claims to cover such possible changes and modifications.

What is claimed as new and desired to be secured by Letters Patent is:

1. A method of manufacturing non-woven fabrics suitable for wearing apparel comprising the steps of forming an elongated fleece of polyposed fibers by superimposing carded webs in angular relation; of impregnating said fleece with an aqueous dispersion of a rubber; of drying and vulcanizing said fleece to deposit said rubber primarily at the crossing points of the constituent fibers of said fleece and to impart substantial iso-elasticity to said fleece; of moving said fleece horizontally in a direction longitudinally thereof and of depositing a layer of relatively loose fiber-s on a horizontal surface of said fleece while so moving; of horizontally jointly passing said fleece and said layer through a needle loom and of punching constituent fibers of said layer through said fleece to form an integral fabric including portions of fibers projecting through said fleece; and of instantly clamping said portions in position by the substantially iso-elastic forces inherent in said fleece acting at right angles to said portions.

2. A method of manufacturing non-woven fabrics suitable for wearing apparel comprising the steps of moving an elongated substantially iso-elastic fleece including cardable polyposed spot-bonded fibers horizontally in a direction longitudinally of said fleece; of depositing a layer of relatively loose fibers on a horizontal surface of said fleece while so moving; of horizontally jointly passing said fleece and said layer through a needle loom and of punching constituent fibers of said layer through said fleece to form an integral fabric including portions of fibers projecting through said fleece; and of instantly clamping said portions in position by the substantially iso-elastic forces inherent in said fleece acting at right angles to said portions.

3. A method of manufacturing non-woven fabrics suitable for weaving apparel comprising the steps of moving an elongated substantially iso-elastic non-woven rubberized fleece having interstices between the constituent fibers thereof horizontally in a direction longitudinally of said fleece, of depositing a layer of relatively loose fibers on a horizontal surface of said fleece, of horizontally jointly passing said fleece and said layer through a needle loom and of punching the constituent fibers of said layer through said interstices of said fleece to form an integral fabric including portions of fibers of said layer projecting through said fleece; and of instantly clamping said portions of fibers in position by the substantially iso-elastic forces inherent in said fleece acting at right angles to said portions of fibers.

4. A method of manufacturing non-woven fabrics suitable for wearing apparel comprising the steps of moving an elongated substantially open fleece of polyposed fibers having local deposits of an elastic binder at the crossing points of the constituent fibers thereof in a direction longitudinally of said fleece; of depositing a layer of loose fibers on a surface of said fleece; of jointly passing said fleece and said layer through a needle loom and of punching constituent fibers of said layer through said fleece to form an integral fabric including portions of fi'bers projecting through said fleece; and of instantly clamping said portions in position by the substantially iso-e-lastic forces inherent in said fleece acting at right angles to said portions of fibers.

5. The method of manufacturing non-woven fabrics suitable for wearing apparel comprising the steps of moving a substantially iso-elastic non-Woven substantially open fleece made up of random oriented fibers and including elastic tie means between the constituent fibers thereof substantially localized at cross-over points of said constituent fibers, of depositing a layer of relatively loose fibers on said fleece, of passing said fleece through a needle loom and punching the constituent fibers of said layer through said fleece to form an integral fabric including portions of fibers of said layer projecting through said fleece, and of instantly clamping said portions of said fibers of said layer in position by the substantially isoelastic forces inherent in said fleece acting at right angles to said portions of said fibers of said layer.

6. The method of manufacturing non-woven fabrics suitable for wearing apparel comprising the steps of depositing a first layer of substantially random oriented fibers defining openings therebetween and including elastic spot-bonds substantially limited to cross-over points of said fibers upon a support, of superimposing a second layer of fibers composed of relatively loose fibers upon said first layer, and of needling constituent fibers of said second layer through said openings in said first layer thereby elastically clamping in position constituent fibers of said second layer projecting transversely across said first layer.

References Cited in the file of this patent UNITED STATES PATENTS 430,230 Gruff June 17, 1890 2,132,530 Greiser Oct. 11, 1938 2,429,486 Reinhardt Oct. 21, 1947 2,593,373 Weber Apr. 15, 1952 2,636,460 Seiderman Apr. 28, 1953 2,774,127 Secrist Dec. 18, 1956 2,881,505 Hoffman Apr. 14,, 1959 2,893,105 Lauterbach July 7, 1959 2,970,365 Morgenstern Feb. 7, 1961