US2233274A

US2233274A - Method of making elastic fabric

Info

Publication number: US2233274A
Application number: US221811A
Authority: US
Inventors: Merwyn C Teague
Original assignee: United States Rubber Co
Current assignee: Uniroyal Inc
Priority date: 1938-07-28
Filing date: 1938-07-28
Publication date: 1941-02-25
Anticipated expiration: 1958-02-25

Description

Feb. Y25, 1941. M. grrr-:1mm:l l 2233,274

l Y METHCD 0F MAKNG ELASTIC FABRIC Flel July a8, 19:58

INV ENI' OR.

BY g 5 kavy.

ATTORNEYS Patented Feb.. 25, 1941 UNITED STATES PATENT OFFICE METHOD OF MAKING ELASTIC FABRIC New Jersey Application July 28, 1938, Serial No. 221,811

9 Claims.

Elastic fabrics have previously been made by incorporating in the fabric during the weaving or knitting or other manufacturing operation rubber threads which may be bare or covered with textile yarns. Other types of elastic fabrics have been produced from stretchable ltextile fabrics y by calendering sheet rubber onto a surface of the fabric, or by sandwiching sheet rubber beelastic fabric, but with no greater and generally notas great, ultimate elongation in any direction than was originally present in the textile fabric before treatment.

By the present invention, an elastic fabric may be produced having increased capacity to stretch in one or more directions without diminishing the capacity of the fabric to stretch in any other direction. Textile fabrics may be made elastic and have imparted thereto a capacity or an increased capacity to stretch crosswise or lengthwise or in both directions without lesseningthe capacity to stretch in any other direction. Knitted fabrics having a crosswise or widthwise stretch may be made into elastic fabrics having an increased crosswise stretch without diminishing the amount of stretch, if any, in a lengthwise direction, or maybe made into elastic fabrics having a lengthwise stretch or an increased lengthwise stretch without diminishing the amount of stretch or ultimate elongation crosswise of the fabric. Knitted and loosely woven fabrics and net materials composed entirely of textile threads or yarns and which may contain bare or covered rubber threads, may be ltreated according to the present invention. Such fabrics are hereinafter referred to as textile fabrics.

In the drawing:

Fig. 1 illustrates more or less diagrammatical- 55 different treatments;

dition after stretching, making the fabric anly one embodiment of the process ofA the present Fig. 5 is an enlarged plan view of a portion of the uncondensed fabric shown in Fig. 2;

Fig. 6 is an enlarged plan view of a portion of the condensed fabric shown in Fig. 3; and

Fig. 7 is a still further enlarged view of one 5 of the yarns taken on the line 11- of Fig. 6 and showing the fibers in a separated condition.

According .to the present invention, rubber is deposited from a rubber-containing fluid such as a solvent rubber cement or an aqueous disper- 10 sion of rubber, such as latex, onto a fabric which e is condensed in at least one direction. The rubber thus deposited sets the fabric and maintains it normally in the condensed condition. The textile fabric when condensed has had imparted l5 to it a capacity to stretch in the direction of the condensation of the fabric and to an amount substantially equal to the condensation, and in addition retains all the capacity for stretching it had before the treatment. The rubber imparts to the fabric as a whole the capacity of speedy retraction from stretched condition, thereby making it what is commonly termed an elastic fabric. If the material is a woven fabric substantially without a capacity to stretch either in the direction of its width or length, and the fabric is condensed widthwise, or lengthwise, or both, and then treated with a rubber-containing fluid so as lto deposit the rubber on to the fabric and set the same in the condensed condition, the woven fabric will have imparted to it a. capacity to. stretch and to speedily retract from -the stretched condition in the direction or directions and to the extent of the condensation of the fabric. In fabrics having a capacity to stretch before treatment, as is generally the case with knitted fabrics, whatever capacity to stretch in one or more directions that is imparted to the fabric by the condensation process of the present invention is in addition to whatever capacity to stretch the fabric might already have. The rubber deposit may be very light, as produced with a spray. and' in such case the porosity of the vfabric need be scarcely diminished by virtue of the rubber deposit. If desired, however, heavier films of rubber may be deposited on the fabric, to produce a continuous deposit and which may in addition to making the fabric elastic and imparting a capacity to stretch in one or more directions produce desired water-proofing qualities. The rubber may be used with the deposit on one surface as in the manufacture of rubberized fabrics for shoe manufacture or for the manufacture of rubber lined clothing and the like, or the fabrics may be plied up with4 the surfaces on 55 vwith each other in order to produce laminated fabrics both thesurfaces of which are of textile material and which may simulate an inelastic material, and yet be an elastic fabric with the desired capacity to stretch in one or more directions. f

Fig. 1 ofthe drawing illustrates diagrammatically, one method of carrying out the inventions. vby condensing the fabric in a lengthwise direction but as will be described later, other methods of condensing fabric in a lengthwise direction,

or methodsof condensing the fabric. in a width- Wise direction, or in both directions, are readily accomplished. Referring more particularly to' Fig. 1 of the drawing, an elastic beltV I0, preferably made of rubber, is passed through a pair of pinch rolls II, under a containerI I2 from which a supply of an adhesive material I3, such as glue, is applied to the belt and evenly spread thereon by a spreading knife I4. The adhesive may be sprayed on the belt, if'desired. The belt passes over a heater or cooler plate I5 to increase the viscosity or tackiness of\ the adhesivev on the surfaceof the belt and make it suiciently tacky to adhere a fabric material thereto. The belt travels through a pair of pinch rolls I6 operating at greater surface speed than the pinch rolls II and the rubber belt is thus stretched between Ithe pinch rolls II and I6. ,As the belt in its stretched condition goes between the pinch rolls I6, or slightly in advance of the pinch rolls I6 if desired, the textile fabricv I1 which is to be treatedl according vto the presentinvention is unrolled from supply roll I8 and is made to adhere to the glue or other adhesive I3 on the surface of the belt, as by the pressure of the pinchV rolls I6. Further increasing of the viscosity of thev adhesive I3 may take place after passageA through the pinch rolls I6 by' means of the heater or cooler I9 situated on the egress side of the pinch rolls. The belt I0 after passage through the pinch rolls I6 is allowed to relax, preferably in stages as by travel through pinch rolls 20, 2I and 22 rotating at diminishing surface speeds from that of the rolls I6, the surface speed of the last pair of rolls 22 being preferably approximately equal to the surface speed of the rolls I I. Between .the pinch rolls 20, 2l and 2,2 may be positioned; additional' heaters or coolers 23 and 24 to further dry or increase the Viscosity of the adhes'ive'l3 on the belt as the belt relaxes to insure adhesion of the fabric I1 to the belt during the contraction of the belt between the rolls I6 and 22. AWhen the belt leaves the pinch vrolls Y22, the fabric I1 which is adhered to thev belt while the belt was in a stretched condition will have been condensed in a lengthwise direction and in' an amount approximately equal to the amount of contraction 'of the belt between the pinch rolls I6 and 22. To the condensed fabric `pletely cure the rubberdeposit.

Vsecured by the adhesive I3 to the belt surface is applieda rubber-containing fluid, for.V example latex 25, as froma spray device 26 or if desired normally i the condensed condition. In ordinary practice'wheije a vulcanizable latex compo. sition is used, this drying may partially or com- In order to remove the thus treated fabric from. the belt to which it is` secured by the adhesive I3,"the'be1't` and adhered fabric isi passed by means of pinch rolls 28 through a'steam chest 29 which softensV the adhesive and permits the fabric and belt to be easily separated by means of. pull rolls 30. In 5 some cases the heat of the drier 21 sufficiently softens the adhesive while drying the rubber' deposit to eliminate the necessity for further softening of the. adhesive as by thelsteam chest^ 29.' The fabric/as it is separated from the bea 10 I0 is drawn by the pull-rolls 30 through a washer 3I to wash off the adhesive remaining on the fabric surface and is then passed through a drier 32 which if desired may vulcanize to any degree or complete the vulcanization of the rubber 15 `series of pinch rolls of gradually diminished surface speeds, if desired. The adhesive may be a water soluble material such as the glue described above or incase itis desirable to eliminate all water-soluble substances from the elastic fabric, 3o shellac or copal or cellulose compounds or other gums or resins which are soluble in rubber nonsolvents instead of a water-soluble adhesive may be used, whereupon the belt, after deposition of the-rubber on the fabric, may be passed through 35 such a rubber non-solvent to remove the adhesive: The rubber may be deposited from the rubber-containing fluid,vif a latex composition, by a chemical coagulation of the rubber particles as by treatment with a latex coagulant, which V40 may be admixed with the adhesive, to at least aid in setting the fabric in the condensed-condition. The rubber-containing fluid may contain the rubber in vulcanized condition in which vcase l no further vulcanization is necessary. .Prefer- 45 ably, the rubber-containing fluid takes the' form of a vulcanizable latex composition, and where the fabric is to vbe utilized without doubling or plying, substantially complete vulcanization is made to take place by the time the elasticV fabric l"50 leaves the drier 32. 'Where two fabrics treated f according to the invention are doubled orvpliedv with their rubbersides in contact'or an untreated fabric is so doubled or plied to the rubber side of 'a treated fabric'to. .form a laminated 55 fabric, \at least complete vulcanization ofthe 1,

deposit is preferably prevented until after the plying operation. The rubber-containing fluid may be. so modified a's to adjust the feel, modulus of stretch and other properties of the finished 60 condensed fabric as described. Instead of single or plied fabrics, as above describedthe rubberside of a single texture fabric, or of a plied fabric e having a rubber exposed `surface may be flocked.

'Ihe apparatus in Fig. 1 condenses continuous 65 lengths of a textile fabric irronly a. lengthwise direction and hence imparts a capacity to stretch or gives the fabric an increased ultimate elongation only in a lengthwise direction. In 'order to produce, a contraction in the width of the fabric 70 to -be treated, `pieces of the fabric may be cut in lengths equal tothe width of the -belt "I0 and' the4 cut lengths` placed crosswise on lthe belt beforethe pinch rolls I6.

If it is desired to impart a stretch or to add 75' 0 of rubber, fabric or metal or the like, and apply-A additional stretch lto continuous lengths of a fabric in a crosswise direction, then a -rubber belt similar 'to the rubber belt lli may be used as in the apparatus of Figure 1 but the stretch of the belt should be crosswise instead of lengthwise. This is readily accomplished by means of a conventional tentering device in which the opposite rows of pins lor clamps holding the edges of the elastic belt are caused to diverge during the forward movement of amx'ed belt and thereby stretch the belt in a crosswise directionand maintain this relation until thel fabric has been adhered to the belt, following which the opposite rows of pins or clamps are then ycaused 'to gradually converge to a parallel relation during the continuous forward motion of affixed belt to ,release the crosswise tension on belt vand thereby' condense the fabric in the crosswise direction. It is to be understood that the adhesive may be applied to. the belt either before or after stretch- .ing crosswise by means of tentering device fand .that the subsequent steps of treating condensed fabric would then follow in the manner previously outlined after crosswise tension has been released as described in reference to Fig. 1.

If desired, belt I0 of Fig. 1 may be stretched by a tenter frame in a crosswise direction after it has been stretched in a lengthwise direction as fby the pull rolls Il and I6, and in such a case on retraction of the belt in both crosswise and lengthwise directions after the fabric has been sufficiently adhered to the stretched belt, acondensation of the fabric will occur both crosswise and lengthwise.

The removable adhesive may be applied to the belt in any desired pattern as by means of spaced or engraved rollers or a grooved or notched bar or knife instead of -by a spreading or spraying operation and the fabric made to adhere to the belt only at those parts where the adhesive has been applied in the -desired design. In this way the fabric will be condensed only in those areas which were adhered to the belt and the nished elastic fabric vwill have a design by virtue of those portions of the fabric which were not adhered to the belt presenting a more or less crinkled or -puckered appearance.

Other methods of condensing the fabric may be utilized, as for example, using a non-elastic belt ing the removable adhesive to the belt, and then passing.A the fabric and.. belt betweenv a pair of squeeze rolls or under a single roll located between two adjacent rolls in which the roll next to the fabric to be condensed runs at a faster or friction speed as compared tothe speed of the belt or rolls whereby if the adhesive is still somewhat plastic yet very sticky, and if the friction of the greater speed roll has a gripping surface, the fabric will be condensed and adhered to the belt as a result of the friction speed. The fabric will be held in -the condensed condition as illustrated in Fig. 1 until the rubber'has been deposited from the rubber-containing uid onto the fabric. The fabric is then set by the rubber deposit and the treated fabric removed from the belt.

Other methods than by the utilization of glue or other temporary adhesive may 4be utilized to maintain the fa-bric in a condensed condition until after deposition of the rubber from the rubber-containing fluid to set the fabric in the condensed condition. For example, the fabric .may be treated with the rubber-containing fluid and before depositing the rubber from the same to set the fabric, the thus treated fabric may be sandwiched tightly between two stretched belts, the tensions on which belts are released before or while setting or depositing the rubber, as by a drying operation or by coagulation. In this case, the friction between the rubber belts and the fabric causes the fabric to condense.

It is desired to point out that while the apparatus illustrated in Fig. 1 of the drawing is constructed to apply the rubber-containing fluid to the fabric after the fabric has been condensed, it is also contemplated that the rubber-containing fluid may -be appliedy to the fabric before the latter isvcondensed and then coagulated or vulcanized after the fabric is condensed to yieldingly hold the fabric in the condensed-or contracted condition. The use of rubber-containing fluid, first as an adhesive "to secure the fabric to the stretched portions ofthe belts. and later as a permanent elastic binder is thesubject matter of an application Serial No..69,302, filed March 17, 1936, by Merwyn C. Teague and Thomas G. Hawley, Jr.

Figs. 3 and 4 illustrate the condensation of the textile fabric of Fig. 2 in a lengthwise direction, and in a widthwise direction, respectively. In Fig. 2 is shown. a ribbed-knit textile fabric, the horizontal lines a of which representing the knitted courses of yarn in the under surface of the fabric widthwise of the material, and the vertical columns b representing the .wales'on an outer surface of thel fabric, lengthwise of the material.. Such a knitted textile fabric as shown in Fig. 2 has a considerable capacity to stretch crosswise, that is in the direction of the courses but very little capacity'to stretch lengthwise in the direction of the wales.

When the fabric of Fig. 2 has been treated by the apparatus of Fig. 1, that is condensed in a lengthwise direction and the fa'bric set in-the condensed condition and made elastic by mean's ofthe rubber deposit, it will have the appearance of the fabric of Fig. 3. The capacity of the fabric to stretch in a widthwise direction, that is in the direction of greater stretch in the direction o'f the courses, is substantially unchanged, but theV fabric has had imparted to it a considerable capacity to stretch in a lengthwise direction, that is in the direction of the wales where previously it had a small or'no capacity for a stretching. 'I'he condensing of the fabric lengthwise has produced from `a textile fabric having a capacity to stretch substantially `only in a widthwise direction, an elastic fabric with a capacity to stretch in a lengthwise direction as well as a widthwise direction, and substantially without diminishing the amount of stretch widthwise of the fabric.

When the fabric of Fig. 2 has been treated according to the present invention and condensed in a widthwise direction as described above, it will have the appearance of the fabric of Fig. 4; The fabric remains substantially incapable of stretching Iengthwise in the direction of the wales but the condensation of the fabric widthwise has substantially increased the amount` of stretch possible in the direction of the courses by the amount of condensation of the fabric. Thus from a textile fabric having a capacity to stretch in substantially only one direction has been produced an elastic fabric capable of stretching in the same direction but to an appreciably greater amount than before treatment.

The appearance of the fabrics of Figs. 3 and 4 differ vastly from each other and from the fabric courses a are still visible below the outer surface of the fabric but the loops are closer together and the wales b havebecome somewhat zig-gag in appearance due to the lengthwise condensation of the fabric. In Fig. 4, the loops of the knitted course bellowA the surface of the fabric have become completely hidden behind the wales b` while the wales remain substantiallystraight. Other types of knitted constructions will have other changes in appearance depending on whether-the condensation of the` fabric is in a. erosswise or lengthwise direction or both. The invention is applicable to woven and bias and net fabrics and on the constructions of the fabrics and the' direction or directions of condensation will depend the changes in appearance. The constructions of the uncondensed fabric vshown in Fig. 2 and of the condensed fabric shown in Fig. 3 are shown in detail respectively in Figs. 5 and 6. It will-be noted that whenV the fabric is\ condensed in the direction of the wales (as indicated by the arrows b) from the uncondensed condition shown in Fig. 5 to the condensed condition shown in Fig. 6, the courses a are moved closer together and the heads c of the loops in the same course are moved along the necks d of the cooperatingloops of such course'and are spaced therefrom as indicated at e. The length of the loops extending between the courses are also shortened to such an extent-that the fibers of the yarns are caused to buckle to such an extent that they separate` from one uniform modulus of elasticity in all directions,-

and such rubber being applied in a uid or pasty condition to the fabric an excellent bond is obtained. It is preferred to obtain the rubber lamina from rubberlatex to obtain greater elasticity, better aging properties, and greater strength for a given amount of rubber. An elastic fabric thus constructed is provided with a uniform modulus of elasticity and is advantageous over a fabric having a grained rubberbacking. such as is producedby calendering and whose modulus of elasticity is different in the direction of the grain from that in the transverse direction.

As various' other modifications will occur to those skilled in the art, it is not intended to limit the invention other than as lset forth in the appended claims.

'lhis application is a continuation in part of application Serial No. 758,009, filed December 18, 1934.

Having thus described my invention, what I claim and desire to' protect by Letters Patent is:

1. The process of making an elastic fabric cmprising the steps of adhering a textile fabric to a supporting surface with a removable adhesive, applying forces to thetextile fabric in a direction substantially parallel to the surface of the textile fabric, said forces being resisted by the adherence of the textile fabric to the supporting surface so as to crowd the threads of the textile fabric extending transversely to the forces4 closer together and to relax the threads extending in the direction of said forces, holding the textile fabric A$3,233,274; of Fig. 2 before treatment. In Fig. vIt the knitted in the `condensed,condition on the surface by the adhesive', applying a rubber-containingfluid to the surface of the textile fabric opposite tothe side on which is the removable adhesive, treating the rubber-containing fluid' to deposit the rubber therefrom and to convert it into an elastic medium which adheres to and is capable of yieldingly retaining the textile fabric in its condensed condition, and removing the textile fabric with the rubber adhered thereto from the supporting surface. i

' 2. The process of making an elastic fabric com prising the steps of adhering a textile fabric to a supporting surface with a removable adhesive, applying forces to the textile fabric in a direction substantially parallel lto the surface of the textile fabric, said forces being resisted by the adherence of the textile fabric to the supporting surface so as to crowd the threads of the textile fabric extending transversely to the forces closer together and to relax the threads .extending in the direc- `tion of said forces, holding the textile fabric in the condensed condition onthe surface by the adhesive, spraying rubber latexupon the textile fabric, treating the latex to deposit therubber therefrom j. and to convert it into an elastic medium which adheres to and is capable of yieldingly retaining the textile fabric in its condensed condition, andy removing the textile fabric with the rubber adhered thereto from the supporting surface.

' 3. The process of making an el-astic woven fabric comprising the `steps of adhering with a removable adhesive a woven textilefabric to an elastic surface which is stretched in' a longitudinal and transverse direction, releasingsuificient tension on'said surface to cause it to contract in both directions and condense thefabric both longitudinally and transversely by crowding the warps and wefts of the fabric more closely tog'ether to thereby render both the warp and weft threads relaxed in the direction of their length, applying a. rubber containing fluid to the surface of the textile fabric opposite to the side on which is the removable adhesive,. treating the rubbercontaining iiuid to deposit the rubber therefrom .and to cause it to assume properties that will yieldingly hold the fabric in the condensed lcondiric from the elastic surface.

4. The" process of making an elastic knitted.N

fabric comprising the steps of adhering a knitted textile fabric to a supporting surface with a removable adhesive, applying forces to the textile fabric in a direction substantially parallel to the surface of the textile fabric and in the direction of the wales, said forces being resisted by the adherence of the textile fabric to the supporting surface so as to force the rows of courses closer together and to relax the threads extending in the direction'of said forces, holding the textile fabric in the condensed condition on the surface by the adhesive, applying a rubber containing fluid to the Vsurface of the textile fabric opposite a textile fabric to a supporting surface with a ref 'surface of the textile fabric and in the direction of the courses, said forces being resisted by the adherence ofthe textile fabric to the supporting surface so as to force the wales closer together and to relax the threads extending in the direction of said forces, holding the textile fabric in the condensed condition on the surface by the adhesive, applying a rubber-containing fluid to the'surface of the textile fabric opposite to the side on which is the removable adhesive, treating the rubber-containing fluid to ydeposit the rubber therefrom and to convert it into an elastic medium which adheres to and is capable of yieldingly retaining the textile fabric in its condensed condition, and removing the textile fabric with the rubber adhered thereto from the supporting surface.

6. The process of making an elastic fabric which consists in adhering with .a removable adhesive a fabric formed of interconnected threads to a surface which has been stretched under tension in at least one direction, releasing the tension upon said surface so that it will contract and condense the fabric adhered thereto' by crowding the rows of threads extending transversely of the contraction of said surface more closely together to thereby render relaxed the threads connecting said rows, applying a rubber-containing fluid to the surface of the condensed textile fabric opposite to the side on which is the removable 45 said surface so that it will contract and condense the fabric adhered thereto by crowding the threads of the fabric extending transversely to the lines of contraction closer together and relaxing the threads extending in the direction of 50 the lines of contraction, applying rubber latex composition to the surface of the fabric opposite to the side on which is the removable adhesive, treating the rubber latex composition to deposit the rubber therefrom and to convert it into an elasticv medium which adheres to and is capable of yieldingly retaining the textile fabric in its condensed. condition, and removing the textile fabric with the rubber adhered thereto from the elastic surface.

8. The process of making a patterned elastic fabric comprising the steps of adhering with a removable adhesive a textile fabric to selected areas of a supporting surface and not adhering said fabric to certain other areas of said surface, condensing the fabric in one direction on said surface in the areas to which said fabric is adhered by applying forces to the textile fabric in a direction substantially parallel to the surface of the textile fabric, said forces being resisted by the adherence of the textile fabric to the supporting surface so as to crowd the threads of the textile fabric extending transversely to the forces closer together and to relax the threads extending in the direction of the forces in the adhered areas and to pucker the unadhered areas of said fabric, applying a rubber containing fluid to the surface of the textile fabric opposite to the side on which is the removable adhesive, treating the rubber-containing fluid to deposit the rubber therefrom and to convert it into an elastic medium which :adheres to and is capable of yieldingly retaining said condensed portions of said fabric in their condensed condition, and removing said fabric with the rubber adhered thereto from said surface.

9. Ihe process of making a patterned elastic fabricl comprising the steps of adhering selected areas of a textile fabric to a stretched elastic surface with a removable adhesive and not adhering other areas to the elastic surf-ace, releasing the tension on the elastic surface topermit it to contract and to condense the textile fabric only in the adhered areas by crowding in such areas the textile threads extending transversely to the direction of contraction closer together and relaxing in such areas the threads extending in the direction of contraction, holding the adhered areas of the fabric in the condensed condition on the elastic surface by the removable adhesive, applying a rubber-containing fluid tothe surface of the textile fabric opposite to the surface on which is the removable adhesive, treating the rubber-containing uid to deposit the rubber therefrom and to convertit into an elastic medium which adheres to and is capable of yieldingly retainingVA the textile fabric in its condensed condition, and'removing the textile fabric with the rubber adhered thereto from the supporting surface.

MERWYN C. TEAGUE. l