US2291258A - Resilient stretchable fabric and process of making it - Google Patents

Description

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RESILIENT STRETCHABLE FABRIC AND PROCESS" OF MAKING IT Original Filed April 26, 1933 INVENTOR. W1. 4 MM M; 4 4c: flow ,5.

ATToRNEYs.

Patented July 28, 1942 RESILIENT STRETCHABLE FABRIC AND PROCESS OF MAKING IT William Wallace Rowe, Cincinnati, Ohio, assignor to Cincinnati Industries, Inc., a corporation of Ohio Original application April 26, 1933, Serial No. 668,105. Divided and this application April 12, 1937, Serial No. 136,379

Claims. (01. 154-33135) comprising part of an article of manufacture,

namely, a stretchable fabric in which not only is resistance interposed to the removal of stretch, but also a resilient means opposes the removal of stretch and tends to restore the fabric to its original unstretched condition.

I have shown in my co-pending application Serial No. 668,106, filed April 26, 1933, now matured into Patent No. 2,069,778, dated February 9, 1937, that the interposition of a coating substance between non-conjointly creped layers of fabric is capable of very greatly resisting stresses tending to remove the stretch; and where a universally stretchable web is employed remarkable serviceability is secured in the resultant product. My present invention has to do with the use of coating substances, which, while distortable, are resilient and are not subject to a preponderan't degree of permanent distortion under stress. I

The primary objects of my invention will follow from what has been said. More specific objects relate to the production of novel fabrics in which stretching strains are resiliently resisted and to novel procedures in the manufacture of these.

The objects referred to and others which will be set forth hereinafter or will be apparent to one skilled in the art upon reading these specifications, I accomplish in those certain constructions and arrangements of parts and in those procedures of which I shall now set forth exemplary embodiments, reference being had to the accompanying drawing.

In the drawing:

Figure 1 shows in section a sheet of creped paper having a coating of rubbery material which is substantially continuous with respect to the paper surface and extends fully within the crinkles thereof.

Fig. 2 shows in section a creped web having essentially a superficial coating of rubbery material, which does not extend down into the crinkles at all points.

Fig. 3 shows somewhat diagrammatically one which may be the second creping cylinder of a double creping mechanism.

Fig. 5 is a somewhat diagrammatic view of a machine for creping a fabric by means of a resilient coating, or for coating a fabric with a resilient substance prior to creping it.

Fig. 6 shows a combined fabric of creped layers joined by means of rubber derived from latex.

Fig. 7 shows in section two plies creped by means of a thermoplastic adhesive and joined together by means of a rubbery substance.

Primarily in the practice of my invention, I employ rubbery materials in connection with creped webs, usually of paper. My invention is not limited to any particular resilient coating or combining substance, but since rubber is the primary resilient gum commercially obtainable, I shall describe my invention in connection with the use of it, it being understood likewise that the rubber may be used with such other diluents or binder substances as may be desired. More particularly in some phases of my invention, I employ dispersions of rubber, whether naturally or artificially produced, and especially rubber latices, which may be used with or without vulcanizing or modifying agents as desired.

I am aware that attempts have been made in the past to combine rubber and creped paper, but such attempts have usually resulted in the removal of a great part of the stretchability in the paper and have been primarily for the purpose of securing a rubber coated product or the temporary or permanent adhesion of the coated material to other substances. No such result as I secure, has hitherto been obtained. It is one of my objects to produce the combination of a highly and universally stretchable creped fabric and a body of stretchable resilient material which must be likewise stretched when stretch is removed from the web, and novel types of coaction between the resilient material and the crinkles of the creped web. Another feature of my invention is the provision of novel ways of associating resilient and elastic materials with webs prior to, concurrently with, or after the creping of the web, so that the association of the materials does not ipso facto result in the removal of stretch from the web.

I have shown in Figure 1, a section through a creped web of paper or the like indicated at l and having a coating 2 of rubbery material. It will be noted that this coating extends well down into the crinkles of the creped web and is substantially continuous with respect to the surface thereof. A product of this general nature may be made by spraying, for example, a coating of rubbery material upon a pre-creped web, but may also be made by coating the web prior to or coricurrently with the creping operation as will hereinafter be set forth, and then carrying on the creping operation prior to the setting of the coating. In this way, continuity of the coating is secured with respect to the surface of the web. The amount of the coating may be varied to control to what extent, if incompletely, the coating fills the valleys of the crepes, or whether or not there shall be an excess of the coating material forming a more or less smooth external coating. All of these factorswill determine the resistance to the removal of stretch per unit weight of the coating materialemployed.

I have shown in Figure 2 another creped web of material 3, having what is essentially a superficial coating of rubbery materials 6, the primary characteristic of which is surface continuity rather than a penetration into the valleys of the crinkles. The rubbery body thus has to be more directly stretched rather than distorted when the creped web is stretched.

This product may conveniently be made by coating with rubber latex or other rubber suspension, a support to which the rubber substance will not strongly adhere when set. Metal and glass form supports of this character as well as certain impervious web materials such as Cellophane, glassine and parchment papers, cellulose acetate films and the like. The coating of rubber suspension may be allowed partially to set on the support and the creped web brought into contact with it. After the coating has completely set, the web and coating may be removed from the support.

It is characteristic of the products of Figs. 1 and 2 that there isin association with a creped sheet of paper, a rubber coating so disposed that it must be stretched when the paper is stretched. Not all coatings of rubbery substances have this property, and indeed so far as I am aware, a product of this character is novel with me. To illustrate the distinction let it be supposed that two sheets of plain paper are cemented together by means of rubber derived from latex in a uniform film. Afterwards the duplex sheet so produced is creped. In this operation the two layers of paper and the layer of rubber are conjointly creped, as will be clear, and when the combined product is stretched the crinkles come out of the rubber in the same way as they come out of the paper, and do not involve any substantial elongation of the rubber layer. phenomena may be observed in single layers of paper coated with rubber, as will be clear. The phase of my invention to which this application primarily relates contemplates the union of a creped sheet, having substantial stretchability, with a layer of resilient substance which must be elongated rather than distorted when the combined product is stretched. In its ordinary forms the product of my invention will be characterized either by a substantially continuous layer of unstretched rubber in union with creped paper having resilient stretchability, or such a disposition of the rubbery substance, that it ties across peaks of the crinkles in the creped paper so that Similarly the same it must be elongated when the paper is stretched.

My invention, however, includes certain novel.

these product difierentiations referred to are not a necessary limitation. It is to be pointed out also that when two layers of previously creped paper are cemented together by means of rubber or other resilient gum, such a combination tends to produce a disposition of the resilient gum to give the quality hereinabove referred to.

It is possible in the practice of my invention, to coat a web of paper with rubbery material and then crepe the web either before or after the coating has set. Ifthe creping is carried on after the coating has set, the effect is one of creping the web and the rubber together, and if the rubber has lost its adhesive character by vulcanization or otherwise, it offers relatively less resistance to the removal of the stretch of the paper. However, if the rubber is unvulcanized or incompletely vulcanized, as the crinkles are forced against each other by the creping doctor, the coatings will adhere to each other, at least at interspaced points, tying across the crests of the crinkles. This result is illustrated in Fig. 3, where a creped web 5 has a coating 8 of rubbery material which is substantially continuous as respects the papersurface, but ties across the crinkles as at 1. It will beunderstood that Fig. 3 is a diagrammatic representation. The effect is produced by the crowding of the crinkles together by the creping doctor or knife during the crinkling operation, and while the coating substance is adhesive to itself at least, and the product may vary from one in which there are sporadic rubbery bridges across the peaks of the crinkles to one in which theultimate result is very much like that shown in Fig. 1.

It is a characteristic of my invention that the rubbery material is imposed upon the web under circumstances not involving a removal of the stretch of the web during the imposition step. My result may be obtained either by applying the rubbery material to the web prior to the creping step, whether or not the rubbery mate- 'rial is in the form of a dispersion, or by applying dispersed and therefore initially substantially liquid rubbery materials to a precreped web.

In Fig. 5, I have shown a creping cylinder at 9 to which a web I0 is led. The web may be coated by means of a roll I l, turning in a pan I2 of latex or the like and may be pressed against the surface of the cylinder 9 by means of a back up roll 13. The web is removed from the creping cylinder 9 and creped by means of the doctor l4. Under these circumstances the latex may be employed, as an adhesive to bind the paper to the creping cylinder 9 and to assist in the creping operation. 1

Instead or in addition, however, latex may be flowed or sprayed against the side of the web away from the cylinder as by the pipe 15 ahead of the back-up roll l3 and a result secured. although this method is productive in general of a light coating of rubber and comparatively less resistance to the removal of stretch.

With respect to a universally stretchable web. I prefer a creped product characterized by crossing sets of diagonally disposed creping crinkles, as set forth in the United States Patents to William C. Kemp, No. 2,008,181, dated July 16, 1935, and No. 2,071,347, dated February 23, 1937. The process of Kemp contemplates in general two creping operations upon the web. In the preferred mechanism and process the paper is led to a first creping cylinder and removed therefrom by a knife which is diagonal to the direction of movement of the paper. It is preferably a knife of the band type, helically disposed about the periphery of the cylinder. After this first creping, the product is led to a second cylinder, to which it is caused to adhere, and from which it is removed by a second helical band knife again diagonally disposed to the path of movement of the paper, but in the opposite direction, so as to produce in the paper crossing sets of diagonal crinkles. An operation involving a second creping of already creped paper complicates the problem of creping by means of the adhesive action of rubber. For the first creping operation the steps and mechanism illustrated in Fig. are satisfactory. For the second operation, the problem of adhesion is rendered more difiicult, both because of the crinkled surface of the paper and because the crinkling stiflens the paper and makes it difiicult to crepe in the opposite direction. The paper having first been creped by means of rubber retains a rubber coating, but

this rubber coating will be relatively non-adhesive to the second creping cylinder, both because it has dried, and because its surface is likely to be rough. It is again possible to recoat paper with rubber, but in order to form a good bond with the cylinder the paper must be led against the cylinder before the coating is dry. It is then necessary to dry the paper on the cylinder prior to its removal therefrom by means of the knife, if the proper cohesion in the coating is to be developed. This requires an inordinate length of time, since the paper is already sealed by one coating of rubber, and there is relatively little opportunity for the water to dry out of the coating interposed between an impervious layer' of paper and an impervious cylinder. Moreover, to

get good adhesion to the cylinder, such a coating of rubber would have to be fairly thick, i. e., preferably thick enough to fill up the rugosities of the already creped paper. This may entail the use of an uneconomical quantity of the rubbery substance, and increases the difiiculty of creping because thickened areas of the rubber must be factorily without the use of a large excess of' rubber.

The coating 'may be applied to the second cylinder by spraying, or the like, but I prefer to use such an apparatus as that shown diagrammatically in Fig. 4, where 8 indicates the second creping cylinder, and 9 the diagonal knife by which the paper is removed therefrom. 2| is a pan of latex in which a roll 22 turns and transfers a portion of the latex to coating roll 23. Arrows on the several rolls indicate their direction of movement, and it will be noticed that, optionally but preferably, the coating roll 23 turns oppositely to the cylinder 8-, wiping therefrom a film of latex which may be accurately controlled as to thickness. The cylinder 8 may be heated if desired, or blasts of drying air applied against the film formed thereon todry it prior to the application of the creped web 24 thereto. The

web will ordinarily be pressed into contact with from latex will enter the web, there is an advantage in removing the web from the under side of the cylinder where it can, if desired, be supported by a conveyor, or the like, while it is limp.

In all of the fabrics hitherto described, additional resistance may be secured by joining plies together. Where unvulcanized rubber coats both fabrics such juncture may readily be obtained merely by pressing the plies together. Fabrics having an external coating of rubbery materials, are particularly useful under many circumstances because of their impervious character and their so called non-skid surfaces. shown in section webs of universally stretchable, non-conJointly creped paper 26 and 21, Joined by means of a layer 28 of resilient substance.

I have also found that webs creped by means of a thermoplastic adhesive substance asset forth in my Reissue Patent No. 17,633 may be ccmented by a latex or solutions or dispersions of rubber. I have shown in Figure 7 layers of creped paper l6 and I1 bearing relatively thin layers of asphalt or the like l8 and I9, cemented together by a layer 20 of rubbery material.

The resilient character of the coating substance coacts particularly well with a universally stretchable character in the web or webs employed, since the removal of stretch in one direction also has a result upon the stretchability in other directions. In this way unusually tough and resistant fabrics may be made. The resilient layer may be reinforced, if desired, by means which will resist but not destroy the universally stretchable character of the coating substance. Thus relatively short and heterogeneously arranged fibers may be embedded in the rubber,

which is either a cementing agent between plies,

or an external coating-thereon. In the case of an external coating, fibers such as cotton or the like, caught in the resilient matrix, but projecting therefrom, will provide a desirable and attractive surface texture.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

l. A process of creping paper which comprises producing upon paper a coating of rubbery substance and producing upon a creping support a coating of rubbery substance, said coatings having the property of adhering to other coatings of substantially the same. characteristics, afterwards bringing said paper with its coated surface into contact with the coated surface of said support-and removing said paper and the coating substance from said support by means of a doctor, whereby to crepe the same.

2. A process of creping paper, which comprises coating paper with rubber latex and allowing said latex to set, coating a creping support with rubber latex and allowing said latex to set, afterwards bringing the coated surfaces of said paper and said support together and creping said paper by removal from said support.

3. A process of creping paper, which comprises producing a preliminary creping in said paper by means of the adhesive action of a rub- -bery substance whereby to produce a creped paper coated with rubbery substance, then coating a creping support with rubbery substance, leading said paper to said support so as to cause the coated surfaces of said support and said paper to adhere, and afterward again creping said paper by removing it from said support by means of a doctor.

4. A process of creping paper which'comprises In Figure 6 I have coating initially creped paper with a rubbery substance, coating 2. c'reping support with rubbery substance, allowing both coatings to set, then leading said paper onto said support so as to cause said coatings to adhere together and recreping said paper by removing said paper from said support by a doctor.

5. A processot creping paper which comprises leading paper onto a creping support with the interposition oi! an adhesive coating of rubbery substance therebetween, removing said paper from said support so as to form a plurality of diagonally disposed creping crinkles therein, coating a second support with rubbery substance, allowing said rubbery substance to set, leading said paper onto said second support so as to cause the coated surfaces of both to adhere, and then removing said paper irom said second support so as to form therein diagonally disposed crinkles crossing the first mentioned set of creping crini0 kles.

' WILLIAM WALLACE ROWE.

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