US2029172A - Material for leather substitute and other purposes - Google Patents

Description

A. J. HANLEY Jan. 28, 1936.

MATERIAL FOR LEATHER SUBSTITUTE AND OTHER PURPOSES Filed April 19, 1955 m fi m A m w A Patented Jan. 28, 1936 PATENT OFFICE MATERIAL FOR LEATHER SUBSTITUTE AND OTHER PURPOSES Albert J. Hanley, Cranston, B. 1., assignor to Respro Inc., Cranston, B. I., a corporation of Rhode Island Application April 19, 1933, Serial No. 666,843

This invention relates to the manufacture of materials for use as leather substitutes and the like.

Special objects of the invention are to eiiect improvements in the product and in the mode of production, particularly to provide a material which will be strong, non-ravelling, pliable, plastic, soft, resilient, porous and cushiony, suited for use as a leather substitute, adapted to take further finishing coatings or treatmentand to produce such a product by practical, economical methods.

These and other desirable objects are attained by the novel combinations of features hereinafter described and claimed.

The drawing accompanying and forming part of the specification illustrates in a somewhat exaggerated way certain practical features of the invention, but it is to be imderstood that the structure may be varied as regards this disclosure all within the true intent and broad scope of the claims.

Fig. 1 is a fragmentary view illustrating on an exaggerated scale the form of the base structure with attached loops.

Fig. 2 is a sectional view illustrating the impregnating of the base and fibrous layers, the smoothing and compacting and the application of the surface coatings.

30 Special features of the invention arethe use of a centrally located woven fabric, acting as a base holding interwoven projecting loops of threads or fibrous material and all saturated by an adhesive substance binding the assembly together in a 35 composited sheet.

A base suitable for the purpose is a woven fabric such as indicated at 3, in Fig. 1, of cotton or other textile material and in the weaving of which, additional woof or more usually, warp 40 threads 4 are interwoven in a manner to produce the loops 5," of threads standing away or projecting out from the relatively tightly woven central base after the manner of Turkish toweling.

The projecting thread loops may stand away from one or both sides of the base and, if desired, may be inserted in large numbers of fine or heavy threads, according to the smoothness or coarseness desired in the product. Also, if desired, these loop threads may be spun loosely with little twist to produce the eifect of a loose projecting fibrous surface or layer with ends of the same anchored in a relatively tightly woven base.

The fabric prepared as described, may be firmly wound on suitable cores in rolls of 300 yards or other practical lengths and these rolls may be mounted in a machine similar to a doubling machine, that is, a machine equipped with two steel pressure rolls approximately twelve inches in diameter, driven so that their surface speeds are approximately the same, the separation of the 5 rolls being subject to regulation.

The base fabric suitably tensioned by brake mechanism acting on the core of the fabric roll is passed or pulled between the pressure rolls and before reaching the bite of these rolls, it is wetted on one or both sides by the saturating adhesive material. These rolls then act to press the adhesive as indicated at 6, into the fibrous surface layers and into the central woven base and to push back the surplus adhesive. In such wet- 5 ting and pressing, the fibers of the loops are flatended or spread and the loops themselves flattened down and spread longitudinally and trans- .versely of the sheet as indicated at I, in Fig. 2.

In this flattening down and spreading operation, the loops are more or less overlapped and in effect, interlocked, providing generally continuous fibrous surfaces made up of the flattened and matted loo'p strands.

The impregnated or saturated fabric is dried by evaporating the solvent used in the saturating adhesive, usually and preferably by passing it through a drying chamber suitable for the removal of the particular solvent. This drying chamber may be equipped to save the solvent for 80 re-use.

While drying, the fabric may be maintained under continuous tension, or it may be subjected to tension after drying.

Smoothing or compacting pressure may be ap- 5 plied after drying or when the fabric is practically dry, to bend any upstanding loops or fibers back into the body of the sheet and/or to smooth the surfaces as in Fig. 2. Such pressure may be effected by passing the product between rollers 40 and the pressure of these rollers may be regulated to only bring the fibrous surfaces into an orderly smooth condition, avoiding excessive pressure such as would over-consolidate the sheet into a dense condition, such as would destroy the myriads of air pockets or voids 8, within the body and surface layers of the structure.

To produce another type of leather substitute, the smoothing pressure may be increased to the magnitude of calendaring pressure to effect consolidation into a dense, firm and compact sheet. Material of this character is usefulas a leather substitute for innersoles "or non-slip'o'utersoling.

The quantity of absorbed adhesive 'may be in creased. if desired, by repeating one or more times the steps described of wetting, impressing, dry-' ing, tensioning and smoothing.

To produce the material in a chamois-like form, the pressure step described as the smoothing operation following the drying may be omitted.

The present preferred saturating adhesive is a rubber compound containing vulcanizing materials and dissolved in naphtha. The adhesive may be dissolved or dispersed in any suitable medium other than naphtha and the compounding of the rubber may be according to known practice in the art, of any desired color, mineral or organic, firm or soft, tacky or dry, heavy or lightly loaded and may contain loading of fibers of textile or wood origin, or both. It is also within the contemplation of the invention that liquid, such as a water solution of vulcanized compounded latex may be used as the adhesive. Blowing agents such as sodium bicarbonate together with stearic acid may be incorporated in compounding the rubber, the purpose of same being to evolve gases during the later curing step and thereby to create additional minute voids or spaces within the rubber film itself, after the formation of such film during saturation and the pressure rolls force the saturating adhesive may be entirely through the central fabric or to a lesser extent. When it is desired that penetration shall not extend beyond the central fabric and be not thoroughly and equally throughout the under fibrous layer, the adhesive solution may be applied in a more viscous solution to Only the top side of the fabric and the adhesive applying pressure roll be caused to move a trifle slower than the fabric pulling roll of the doubler machine. When both sides are to receive mainmum amounts of adhesive, it is often desirable to wet down both sides of the fabric with the adhesive solution before passing through the pressure rolls.

While pressure rolls have been referred to as a preferred form of pressure applying surfaces, it is contemplated that other types of pressure surfaces may be employed, such for example, as plates set at a converging angle and forming an orifice through which the adhesive wetted fabric may be pulled. I

The next step, when the material is to be used as undressed leather, or is to receive a dressing that does not require vulcanization, is to vulcanize the saturating adhesive, unless the adhesive be an already vulcanized latex. If a vulcanizable rubber-compound coating is to be later used as a dressing, it is preferable to reserve vulcanization until after such coating has been applied.

Vapor cures to effect vulcanization and obviating any need for vulcanizing materials in compounding the rubber adhesive may be employed as within the scope of the invention.

After vulcanization is effected, as by one of the modes described, the product is useful in place of and as a substitute for some undressed leathers.

When the material is to be used as a substitute for dressed leather, coatings such as indicated at 9, Fig. 2, are applied, similar to those used in dressing leather, or in accordance with methods employed in coating ordinary so-called artificial leather. For example, this may be effected by applying a number of successive coats of rubber,

pyroxylin, or oil, any, or all, of which may be modified in compounding and applying, according to accepted practice in the art. 'The finished coated product may be embossed or printed upon, or otherwise treated.

It is recognized that the prior art, in the patent to Roland B. Respess 1,441,376, discloses the use of napped flannel in making leather substitutes. The present invention involves as one of the novel features, the production of the loose fibrous surfaces, otherwise than by napping a woven base fabric and avoids the disruption and consequent weakening resulting from the napping of the base fabric.

As the central fabric is not weakened by napping, it has the original strength and uniformity, properties not present where vigorous and repeated napping has attacked a fabric to produce loose fibrous surfaces.

This uniformly strong base makes it possible to run long pieces in production without the dificulties, waste and ineconomies of frequent breaks on the machine and as this uniformity of strength is retained in the finished product, inspection is easier, more accurate and reliable and less wasteful. The user furthermore, has a uniform product that can be put on a standard basis for the entire yardage, without having to make allowances for a percentage of weaknesses.

The textile fabric base with the loops projecting from the central structure may be woven on standard machinery, such as now employed in the production of Turkish toweling or the like,

and the other operations may be carried out largely on standard machines. The process is an economical one and the product is superior for many purposes for which leather substitutes are employed. The woven fabric base unweakened by napping, clipping or the like, and impregnated with the binder, forms a strong tear-resisting and non-ravelling base carrying a layer or layers of massed rubber-reinforced threads that by their looped and arch-like structure'provide porous, cushiony, absorbent, abrasive, resilient and soft characteristics, enabling use of the material as a substitute for suede and chamois leathers. The surfaces are rough enough to have marked cleaning properties for glass or finishes, such as lacquer on automobile bodies and soft enough to prevent scratching. The material is porous and absorbent enough to have sponging properties for drying like chamois and breathing properties like suede and chamois. When the surface or sur- 1 faces are heavily saturated with rubber compound and heavy pressure is employed, the product is characterized by great strength and marked wear-resistance to friction and the ground gripping properties derived from the mass of consolidated loops embedded in the rubber, making it valuable as a non-slip outersoling or as a nonslip layer for rugs and carpets used on polished floors.

e preferred methods have been herein described, it will be appreciated that modifications and changes may be made all within the true spirit and broad scope of the invention.

t is claimed is:

l. The herein disclosed process of making a leather substitute or the like, which comprises applying a rubber compound to a textile fabric base having attached loops of thread projecting therefrom in an uncut state, drying and effecting vulcanization of the rubber compound and at one stage in the process pressing the uncut loops of thread into fiattenedcondition in the applied compound, substantially parallel to the general plane of the fabric to provide asmooth fibrous surface.

2. The herein disclosed process of making a leather substitute or the like, which comprises applying a rubber compound to a textile fabric base having attached loops of thread projecting therefrom in an uncut state, drying and effecting vulcanization of the rubber compound and at one stage in the process pressing the uncut loops of thread into flattened condition in the applied compound, substantially parallel to the general plane of the fabric to provide a smooth fibrous surface and coating over said flattened loops with a surface dressing to hold the loops forming such smooth fibrous surface in that condition.

3. The herein disclosed process of making a. leather substitute or the like, which comprises producing a textile fabric base with interwoven outstanding loops of thread projecting away from the central body of the fabric, saturating said outstanding lcop surface layer with a vulcanizable rubber compound solution under pressure, drying and pressing sufficiently to flatten the loops down into matted relation in the rubber compound to provide a smooth fibrous surface with numerous cells or voids in the mass of the base and vulcanizing.

4. The herein disclosed process of making a leather substitute or the like, which comprises producing a textile fabric base with interwoven upstanding loops of threads projecting away from the central fabric as a looped fibrous surface layer, saturating with an aqueous solution of vulcanized, compounded latex under pressure, drying, pressing gently to smooth the surface and flatten down the loops into the compounded latex to provide a smooth fibrous surface without consolidating the surface layer or eliminating voids between the arched loops.

5. The herein disclosed process of making a leather substitute or the like, which comprises providing a textile fabric base with interwoven upstandng loops of threads projecting away from the central fabric as a looped fibrous surface, saturating the same with a vuleanizable rubber compound solution under pressure, drying, pressing the loops into the rubber compound to provide a smooth fibrous surface and to consolidate the sheet into a dense condition and vulcanizing.

6. The herein disclosed process of making a leather substitute or the like, which comprises providing a textile fabric base with interwoven upstanding loops of thread projecting away from the central fabric as a looped fibrous surface, saturating the same with an aqueous solution of vulcanized, compounded latex under pressure,

drying, pressing the loops into the compounded latex to provide a smooth fibrous surface and with sufficient pressure to consolidate the sheet into a dense condition and vulcanizing.

7. A sheet material suitable for the purposes of leather substitutes and the like, comprising a woven fabric base with interwoven upstanding looped threads pressed back uncut into the body of the fabric and bound together by a saturating vulcanized rubber compound, holding the mass of looped threads in a spongy, springy, porous, airy condition, said loops lying embedded fiat in the rubber compound and forming a smooth fibrous surface.

8. A sheet material suitable for the purposes 2.

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