US2235682A

US2235682A - Method of making elastic ply fabric

Info

Publication number: US2235682A
Application number: US125367A
Authority: US
Inventors: Jr Thomas G Hawley
Original assignee: United States Rubber Co
Current assignee: Uniroyal Inc
Priority date: 1937-02-12
Filing date: 1937-02-12
Publication date: 1941-03-18
Anticipated expiration: 1958-03-18

Description

March 18, '1941- T. G. HAWLEY, .11R

METHOD OF MAKING ELASTIC ILY FABRIC Filed Feb. l2,l 1937 v ATTORNEYS.

INVENTOR. gwe Je atented Mar. 18, 1941 UNITED `STATES PATENT FFICE METHOD OF MAKING ELASTIC PLY FABRIC tion of New Jersey Application February l2, 1937, Serial No. 125,367

4 Claims.

This invention relates to the method of making an elastic ply fabric consisting of two textile fabrics having a binding sheet of rubber con-A fined therebetween to hold the fabric sheets 5 yieldingly in a condensed condition, and to the fabric resulting from the method.

It has been proposed` heretofore to provide an elastic sheet consisting of a stretchable textile fabric such as knitted goods having a rubber backing applied thereto in an unstretched condition to cause the fabric to contract again after it has 4been stretched. It has also been proposed heretofore to providean elastic ply fabric of limited stretch and consisting of two textile fabrics united by a rubber sheet or binder which secures the two fabrics together with the textile faces out.

In these prior constructions the rubber backing was so applied to the fabric that it would serve to return the stretched fabric to what might be regarded as the relaxed or ordinary condition of the fabric before the rubber backing was applied thereto, but these rubber backings would not serve'to contract the fabric to a substantial degree past such ordinary relaxed condition to place the fabric in what might be called a super-relaxed condition.

The present invention contemplates the method whereby an elastic ply sheet may be formed by first uniting by a rubber binder two textile sheets which may constitute woven, knitted or other textile fabrics, and then condensing these united textile sheets so as to place the threads thereof extending in the direction of stretch in what is herein called a super-relaxed condition to permit the fabric a substantial range of stretch. The united sheets may then be heated or otherwise treated to set or vulcanize the rub- -ber binder so as to form an elastic sheet between the two fabric sheets, which elastic sheet normally holds the fabric sheets yieldingly in the condensed or super-relaxed condition. The present invention not only provides a simple and practical method of forming an elastic sheet having a textile fabric at each outer face and a rubber binding sheet therebetween, but alsovserves to provide an elastic sheet having a long range of stretch.

As a result of the present invention the textile fabrics having the rubber binder sandwiched therebetween are held by the binder contracted to such an `extent that they are much shorter in length than these same fabrics were before they were condensed. That is, these fabrics are not only held in a relaxed condition by the rubber binder but they are held in a condensed or super-relaxed condition so that the fabric may stretch a substantial degree before it reaches what may be regarded as its relaxed condition before it was condensed and may then stretch 6 considerably further. In order that the fabric may have imparted thereto the maximum range of stretch or elongation it is necessary that the threads ofthe fabric extending in the direction of stretch be normally held in a thoroughly rel laxed or unextended condition. This, as above stated, is secured by condensing the fabric to place it in a super-relaxed condition and by providing it with a rubber backing adapted normally to retain the fabric in this super-relaxed 15 condition.

The various features of the invention will be more fully understood from the following description when read in connection with the accompanying drawing, illustrating one good prac.- 20 tical form of mechanism for carrying out the present method, and also illustrating a fabric constructed by the method.

In the drawing: l

Fig. 1v is a side elevation of mechanism shown 25 more or less diagrammatically for carrying out the present method; and

Fig. 2 isa perspective view of an elastic ply fabric constructed in accordance with the present invention. 30

In carrying out the' invention, two strips of textile fabric of any desired width are provided. These strips of fabric may be woven, knitted or otherwise constructed but the fabric, if woven,

preferably has a relatively loose or open con- 35.

struction so that it can be condensed to a substantial degree, in the manner hereinafter pointed out.

In the construction shown in Fig. l, one length A of textile fabric is supplied by the upper roll III 40 4supplied between them or upon the adjacent faces thereof so as to secure these fabrics to- 50 gether and form an elastic or rubber sheet therebetween. In the construction illustrated, the adhesive binder is applied to the adjacent faces of the fabrics I2 and I3 by the spraying nozzles I4. It will be apparent, however, that other 55 means for applying the binder material to the adjacent faces of these fabrics may be employed.

This binder may be applied to the fabrics I2 and I3 in the form of a liquid, plastic or paste containing rubber. It is found in practice, however, that aqueous dispersions of rubber such as natural latex, preferably containing vulcanizing agents and otherwise suitably compounded by methods well known in the art, are well adapted for this purpose.

Should it be desired to coagulate or partially coagulate the latex when sprayed upon the fabric, this may be done by applying a coagulating acid upon areas of each fabric before such areas arrive at the nozzles I4. 'Ihis coagulation may ybe desirable to avoid excessive penetration of the latex into or through the fabric to the opposite face thereof and to decrease the water absorbing properties of the rubber film. After the latex or other binding material containing rubber has been applied to the fabrics I2 or I3, it may be desirable to dry this binding material to some extent and this may be done by subjecting the sheets I2 and I3 to the action of heated coils I5 or the like, .or a fan may be used for this purpose.

The drying at this time however should not be suiiicient to render these rubber covered faces of the fabric non-tacky before they are brought together, and if it should be found thatthe rubber faces to be united are too dry for satisfactory adhesion a thin lm of fresh latex may' be sprayed over such faces. It is important that `these rubber surfaces be in the proper condition as they reach the uniting rolls to be described, so that they will adhere together to `form an integral union without causingthe latex to penetrate through to the outer face of the fabric. It is also important that the latex treated fabrics be in a moist condition when they are subjected to the condensing operation for these fabrics will not condense properly unless damp.

The fabrics I2 and I3 after they have the rubber binder .applied to their adjacent faces may be led between the slightly spaced rolls I6, which serve to bring these fabrics close together before they are subjected to the condensing action that forms an important stepin carrying out the present method. The word condensing is herein used to designate the treatment of the fabrics I2 and I3 so as to place the threads thereof extending in the direction of stretch in a thoroughly relaxed condition, or what may be better defined as a super-relaxed condition. It will be apparent that if the elastic ply fabric of the present invention is to have a relatively long stretch, then the textile threads extending longitudinally of the fabrics I2 and I3 will need to be in a super-relaxed condition when the elastic ply fabric is in its normal contracted condition. As the two fabrics I2 and I3 are forced together ythe rubber coating or layer deposited upon each and I3 comprises the elastic belts I3 and I9.

These belts may constitute endless sheets of rubber each having a width equal to or greater than the width of the fabric to b e condensed, or these elastic belts may be formed of woven elastic webbing. When the belts I8 and I9 are used to condense woven fabrics I2 and I3 it is important that constant width belts be Used; that is belts that will not contract width-wise as they stretch longitudinally, and expand transversely as they contract lengthwise, for it is found that if it is attempted to condense woven fabrics between belts that expand transversely as they contract longitudinally the woven fabrics will tend to tear under the transverse stretching action or the fabric will not be condensed satisfactorily.

The condensing belts I8 and I9 in the construction shown pass around the positively driven rolls 20 and 2I and about the

idler rolls

22 and 23, and the positively drivenrolls 20 and 2I are preferably provided with the pinch rolls 24. The rolls 2| are operated at a slower peripherial speed than the rolls 20 to thereby tension the portion of each belt I8 and I9 passing about the

idler rolls

22 and 23, and to relieve the tension upon the portion of each belt extending from the roll 20 to the roll 2| and forming the belt runs 25 and 26.

'I'he means illustrated for holding the runs 25 and 26 in firm, gripping engagement with the elastic fabrics comprises the

caterpillar belts

21 and 23 having the transversely extending slats or bars 29. These belts pass around and are operated by the rolls 30 Aand 3| to travel at the same surface speed as the rolls 20, and shouldbe maintained in a tightly stretched condition, 'Ihe arrangement is such that the caterpillar belts will exert a firm, gripping pressure upon the belt runs 25 and 26 lying therebetween. The pressure is greatest adjacent the rolls 30 but decreases in the direction of travel to permit the stretched belts to contract gradually therebetween so as to condense the fabrics I2 and I3.

As the ply fabric lies between the caterpillar belts 21 and 29 it should be subjected to the heating action of the heaters 32 in order to set and/or partially vulcanize the rubber sheet I1 suiliciently to cause it to retain the fabrics I2 and I3 in the condensed condition before these fabrics arev released from the pressure of the condensing belts. Final vulcanization of the rubber sheet I1 may be secured by passing the ply fabric between the heaters 33, but if it is desired to avoid subjecting the belts I8 and I9 to the action of these heaters 33 they may be placed beyond the range of these belts, whereupon this finished ply fabric may be wound upon the roll 34 in an untensioned condition, ready for the market or any desiredl subsequent treatment.

' It should be noted that the rolls 20 are spaced some distance apart, the effect of this being that if any contraction in the belts I3 and I9 occurs, between these rolls 20 and the rolls 30, this contraction will not affect the fabrics I2 and I3 since these belts do not grip the fabrics I2 and I3 until they are subjected to the confining pressure of the slats 29 of the caterpillar belts 21 and 28. Since however the rolls 20 and caterpillar belts 21 and 28 travel at the same surface speed no appreciable contraction in the portions of the belts just mentioned should occur. Inorder to facilitate the contraction of the belt runs 25 and 25 relative to the caterpillar belts 21 and 29 it may be advisable to apply powdered talc or the like to the faces of the belts I8 and I9 which contact with the slats 29.

It will be seen from the foregoing that through the present method the textile fabrics I2 and I3, are united by a rubber binder and then condensed to form a multiple elastic fabric having a single rubber sheet I1 formed between the textile fabrics and molded to the inner faces of said aaaacea fabrics. t will also be seen that this is readily accomplished in a continuous operation.

The fabrics I2 and I3 are shown in Figure 2 as knitted fabrics united by and normally held in a condensed or super-relaxed con-dition by the rubber sheet Il. The ply fabric thus produced may have a substantial degree of stretch, for example or more.

Practically any textile fabric that has a sufficiently open or loose construction to permit the same to be condensed, by placing the longitudinally extending threads in a super-relaxed condition, may be formed into an elastic ply fabric in accordance with the present invention, but as above pointed out when a woven fabric is condensed it should not be subjected to Aa transversely expanding action that tends to tear the fabric, or cause the belt to creep relative to the fabric.

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

l. The method of making an elastic ply fabric comprising applying aqueous dispersion of rubber to the surfaces of two textile fabric sheets, adhering said sheets together with the adhesive binder formed from said aqueous dispersion of rubber, engaging the outer surfaces of the textile sheets with stretched elastic surfaces and pressing said textile sheets together between, said elastic surfaces, releasing at least some of the tension on said elastic surfaces while in engagement with the outer surfaces of the textile sheets and thereby condensing the textile sheets by the contraction of said elastic surfaces, and heating and drying said adhesive binder while said textile sheets are retained in engagement with said contracted elastic surfaces and held thereby in the condensed condition to some extent and until said binder is imparted sufficient strength to retain said textile sheets in the condensed condition.

2. The method of making an elastic ply fabric comprising applying aqueous dispersion of rubber to the surfaces of two textile fabric sheets, partially drying said aqueous dispersion of rubbei', adhering said sheets together with the adhesive binder formed from said aqueous dispersion of rubber, engaging the outer surfaces of the textile sheets with stretched elastic surfaces and pressing said textile sheets together between said elastic surfaces, releasing at least some of the tension on said elastic surfaces while in engagement with the outer surfaces of the textile sheets and thereby condensing the textile sheets by the contraction of said elastic surfaces, and heating and drying said adhesive binder While said textile sheets are retained in engagement with said contractedl elastic surfaces and held thereby in the condensed condition to some extent and until said binder is imparted sufcient strength to retain said textile sheets in the condensed condition.

3. The method of making an elastic ply fabric comprising introducing between two textile fabric sheets natural rubber latex containing vulcanizing ingredients, engaging the outer surfaces of the textile sheets with stretched elastic surfaces and pressing the textile sheets together, releasing at least some of .the tension on said elastic surfaces While in engagement with the outer surfaces vof the textile sheets and thereby condensing the textile sheets by the contraction of said elastic surfaces, heating and drying said latex to form an adhesive binder while said textile sheets are retained in engagement with said-contracted elastic surfaces and held thereby in the condensed condition to some extent and until said binder is imparted sufficient strength to retain said textile sheets in the condensed condition, removing said elastic surfaces from engagement with said textile fabric sheets, and Vulcanizing said binder to produce an elastic sheet of rubber which is bonded to the textile fabric sheets.

4. The method of making an elastic ply fabric comprising the steps of treating two textile fabric sheets With a coagulant, spraying one side of each of said sheets with natural rubber latex containing vulcanizing ingredients, partially dry- 4ing said rubber latex, placing the sprayed surfaces of the textile sheets together, engaging the outer surfaces of the textile sheets with and pressing said sheets together between stretched elastic surfaces, releasing at least some of the tension on the stretched elastic surfaces while in engagement with the outer surfaces of the textile sheets and thereby condensing the textile sheets by the contraction of the elastic surfaces, heating and drying said latex to form an adhesive binder while said textile sheets are retained in engagement with said contracted elastic surfaces and held thereby in the condensed condition until said binder is imparted sufficient strength to retain said textile sheets in the condensed condition.

THOMAS G. HAWLEY, JR.