US3086274A - Method of making composite products incorporating textile fabrics - Google Patents

Description

Ap 3, 1963 M. ARNETT METHOD OF MAKING COMPOSITE PRODUCTS INCORPORATING TEXTILE FABRICS Filed May 19, 1959 United States Patent 3,086,274 METHOD OF MAKING COMPOSITE PRODUCTS INCORPORATING TEXTILE FABRICS Meyrick Arnett, Leyland, England, assignor to BTR Industries Limited, London, England, a British company Filed May 19, 1959, Ser. No. 814,157 Claims priority, application Great Britain May 19, 1958 7 Claims. (Cl. 28-74) The invention relates to a method of producing woven textile fabrics for incorporation in composite products of the type set forth, to a method of manufacture of such products. The type of composite products with which the invention is concerned comprise woven textile fabrics embedded in, or bonded to, elastomeric materials such as rubber, synthetic rubber, or plasticised polyvinyl chloride or similar plastic material. The products may be utilised in, or as, conveyor belting, hose, and for other purposes where a flexible product combining strength and a wear resisting surface are required.

The invention provides the method of making a composite product of the type set forth which comprises bonding to, or embedding in, an elastomeric material, a fabric having some warp and/ or some weft threads with a greater crimp than other warp and/ or weft threads respectively and which has been produced by Weaving the fabric with some warp threads and/or some weft threads having different shrinkage or stress recovery characteristics from other warp and/ or weft threads respectively, and effecting during or after weaving such differential shrinkage or stress recovery between the warp and/or weft threads whereby some of the threads have greater crimp than others.

The invention further provides the method of making a composite product of the type set forth which comprises weaving a textile fabric with some warp threads and/or some weft threads having different shrinkage or stress recovery characteristics from other warp and/ or weft threads respectively, effecting during or after weaving such differential shrinkage or stress recovery between the warp and/or weft threads whereby some of the threads have greater crimp than others and bonding the resultant fabric to, or embedding it in, an elastomeric material.

Preferably in carrying out either of the above forms of the method, the threads having the lesser crimp are made from continuous filament yarns (e.g. nylon or rayon) and the threads having the greater crimp are made from staple yarn (e.g. cotton or staple nylon).

The invention includes products of the type set forth when made by either form of the method.

More specifically, the fabric used in carrying out the invention has Warp threads with different degrees of crimp or waviness whereby those with lesser crimp are adapted to take a tensile stress applied to the fabric and those with greater crimp are caused, by the weft threads, to provide cover portions (erg. ribs) raised from the general surface of the fabric. The crimp in the warp threads, especially when they are of staple fibre construction provides effective keying means for bonding to the fabric rubber, polyvinyl chloride or other material which is bonded thereto, or in which the fabric is embedded. At the same time this construction of fabric provides protection for the stress taking threads against impact damage and the fabric is also found to have good tear resisting properties.

Preferably the differential recovery or shrinkage which textile threads of different compositions exhibit after being tensioned and stretched in a loom during weaving is employed to provide in the product threads of differential lengths and hence different degrees of crimp.

In the accompanying drawings:

FIG. 1 is an enlarged plan view of the presently preice ferred fabric embodying the invention as it appears under weaving tension;

FIG. 2. is a transverse sectional view through the fabric of FIG. 1 parallel with the weft of the fabric;

FIG. 3 is a sectional view parallel with the warp threads of the fabric shown in FIG. 1;

FIG. 4 is a sectional view taken similar to FIG. 3 but showing the condition of the fabric after the warp threads have been permitted to contract and the fabric has thereafter been embedded in an elastomeric material;

FIG. 5 is a plan view similar to FIG. 1 but showing the invention embodied in a fabric of different weave;

FIG. '6 is a transverse sectional view through the fabric of FIG. 5 parallel with the weft of the fabric;

FIG. 7 is a sectional view of the fabric in FIG. 5 parallel with the warp threads of the fabric; and

FIG. 8 is a sectional view taken similarly to FIG. 7 but showing the condition of the fabric after the warp threads have been permitted to contract and the fabric has thereafter been embedded in an elastomeric material.

As already stated, in one form of the fabric employed in the invention, some of the warp threads are of continuous filaments (e.g. nylon or rayon) and other warp threads are formed of staple yarn (e.g. nylon or cotton), the continuous filament threads having the greater recovery or shrinkage and hence, in the product, constituting the load carrying threads.

It is preferred that the load/ elongation characteristics of the different warp threads or yarns are, in relation to their respective crimp in the fabric, such that when the fabric is subjected to maximum tensile working load (eg, about 30% of the ultimate strength) then the threads or yarns will also be subjected to about their maximum working loads.

Various methods of treatment may be employed to bring about the differential degrees of crimp in the warp or other threads. For example, when the warp threads are of suitably different materials as outlined above, they may all be subjected to the same degree of tension during weaving with the result that those threads with the lesser recovery after release of the tension (e.g. threads of staple yarn) will have greater crimp than those with greater recovery. Differential recovery of threads subjected to the same tension may also be obtained by the use of threads of different twist. Alternatively greater tension may be applied in the loom to those threads which are to have lesser crimp in order to effect greater elongation thereof and greater recovery on release of the tension.

In another alternative, the result is obtained by heat or moisture treatment during or after weaving in order to obtain a differential shrinkage of the threads. For instance in the case of fabric having warp threads composed of fibres of coarse staple cotton and continuous filament nylon respectively, the woven cloth may be subjected to steaming to causethe nylon portion of the cloth to shrink.

, This operation may be followed by length-wise and crosswise stress to control the degree of shrinkage and the threads subjected to cooling by air or water. Another method of obtaining differential crimp is to insert a high twist into a thin yarn, ultimately to have the lesser crimp, set the twist by treatment with a water saturated size, weave the fabric and then wash out the size. This will cause the yarn of lesser twist to have greater crimp and rise to the surface.

When the treatment of the threads is carried out after weaving either as an auxiliary to the treatment during weaving or as the main treatment, it may form part of a press vulcanising or like operation primarily connected with the application of the elastomeric material and consist of an addition thereto or a modification thereof. It may employ heat, pressure or moisture or combinations thereof.

As a further alternative, the differentiation in recovery or shrinkage may be obtained wholly or mainly by the use of threads of the same construction but of different diameters. For example the threads with lesser recovery characteristics (i.e. those which are to have the greater crimp) may have a diameter up to about four times that of the threads of greater recovery characteristics.

It is not essential that the two kinds of threads are equal in number.

The following is an example of a woven fabric according to the invention and suitable for use in a conveyor belt:

MATERIAL Warp (Stress) Type Nylon type 600. Denier 840. Filament Continuous.

Warp (Cover) Type American cotton. Staple 1" ave. Preparation Carded.

Weft

Type Staple nylon (Indus. 4.0 g./d.). Staple 2 /2" ave. Preparation Cotton system.

CONSTRUCTION Standard Wt./sq. yd. (02s.) 18.70. Ends/inch (cover) 20. Ends/inch (stress) 20. Picks/inch 14. Warp yarn constr. (cover) 3/ 7s. Warp yarn constr. (stress) 3/ 840D. Weft yarn constr 4/ 7s. Cover warp singles t.p.i 7.28 (2). Cover warp ply t.p.i 5.5 (8). Stress warp singles t.p.i 0.75 (2). Stress warp ply t.p.i 1.5 (S). Weft singles t.p.i 7.28 (2). Weft ply t.p.i 4.5 (S). Warp tensile 750 lbs. Percent elong. at break 27%. Weft tensile 350 lbs. Percent elong. at break 19%. Crimp cover warp 16%. Crimp stress warp 14%. Crimp weft 4%.

Warp arrangement: One cover end, one stress end working 2 as l.

Weave: Plain order.

FIGS. 1-4 illustrate a fabric having the above enumerated characteristics. As indicated in FIGS. 1 and 2, the warp threads 19 and 11 are under equal tension during the weaving operation with the warp threads 10 formed of continuous filament nylon yarn and the warp threads 11 formed of staple cotton yarn. The warp threads 10 and 11 are woven in pairs with the continuous filament warp threads having a lesser twist and a lesser cross sectional area than the warp threads 11. This difference in size and construction of the warp threads results in a small difierence in the crimp or undulations thereof about the weft threads 12 even under the weaving tension, see FIG. 3. However, the difference in crimp or undulations is accentuated, as indicated in FIG. 4, when the weaving tension is released and the fabric is condensed in the direction of its length. {This figure also shows the manner in which the threads 12 interlock with elastomeric material M when the fabric is covered by or embedded in such material.

Modifications may be made in the above example. For instance the cover ends may be worked separately from the stress ends.

This embodiment is illustrated in FIGS. 5-8. As shown in FIGS. 5 and 6, the continuous filament warp threads 13 and the staple yarn threads 14, which may be similar in construction, respectively, to the threads 10 and 11 of the embodiment illustrated in FIGS. l4, alternate across the weft of the fabric but do not pass in pairs above and beneath the weft threads 15. Instead, the adjacent warp threads pass on opposite sides of each weft thread 15. The crimp or undulations of the warp threads 13 and 14 under the weaving tension is indicated in FlG. 7 while the increased crimp and the resulting accentuation of the extent of the projection of the bends of the warp threads 14- beyond the faces of the fabric, as the result of contraction of the warp threads 13 when the weaving tension is released, is indicated in FIG. 8. This latter figure also illustrates the locking of the threads 14- with elastomeric material M when the fabric is covered by or embedded in such material.

It will be evident that similar results are achieved by weaves other than the two specifically illustrated and that accentuation of the crimp of certain of the threads of the fabric relative to the other threads thereof can be effected by one or more of the expedients mentioned heretofore as Well as by the specifically discussed and illustrated difference in the warp tension during and after weaving.

When the fabric is to be incorporated in a belt, it is important that the material employed for the threads should be able to withstand the temperatures and other conditions used in the coating or impregnation of the fabric.

The fabric of the present invention may be used as the fabric in the construction described and illustrated in British specification No. 811,108.

I claim:

1. The method of making a fabric reinforced elastomeric material adapted for use in articles subject to tension comprising providing a fabric including interwoven threads extending generally in directions lengthwise and crosswise of the fabric, respectively, with alternate threads in the lengthwise direction of the fabric contractible by different amounts and with any single thread of said alternate threads formed of a single textile substance, subjecting all of the threads in the lengthwise direction to uniform tension during weaving, subjecting the fabric to a thread-contracting condition after weaving whereby those of said alternate threads which contract the lesser amount acquire greater crimp than those of greater contractibility thereby forming spaced projections on either face of the fabric while the said alternate threads which contract the greater amount comprise tensionresistant elements in the fabric, and applying elastorneric material to the fabric with the said material penetrating between the spaces provided by the said projections.

2. The method of making a fabric for use in reinforced elastomeric articles subject to tension comprising interweaving threads extending generally lengthwise and crosswise, respectively, of the completed fabric with alternate ones of the threads extending in the lengthwise direction contractible a greater amount than the threads with which they alternate and with any single thread of said alternate threads formed of a single textile substance, subjecting all of the threads in the lengthwise direction to uniform tension during weaving, and subjecting the fabric to a thread-contracting condition after weaving whereby those of said alternate threads which contract the lesser amount acquire greater crimp than those of greater contractibility thereby forming spaced projections on either face of the fabric facilitating adhesion thereto of an elastomeric material while the said alternate threads which contract the greater amount comprise tension-resistant elements in the fabric.

3. The method according to claim 2 in which the threads having the lesser crimp are made from continuous filament yarn and the threads having the greater crimp are made from staple yarn.

.4. The method according to claim 2 in which the threads having the lesser crimp are made from continuous filament nylon yarn.

5. The method according to claim 2 in which the threads having the greater crimp are made from staple cotton.

6. The method according to claim 2 in which the said thread contracting condition comprises release of said tension.

7. The method of making a fabric reinforced elastomeric material comprising interweaving threads extending generally lengthwise and crosswise, respectively, of the completed fabric with alternate ones of the threads extending in the lengthwise direction formed of continuous filaments consisting of a single textile substance which elongates when subjected to tension and with the others of said alternate threads formed of staple fibers and with all of the threads in the lengthwise direction subjected to equal tension during weaving, removing the tension after weaving thereby causing said continuous filament threads to contract a greater amount than said staple fiber threads so that the latter form spaced projections on either face of the fabric, and applying elastomeric material to the fabric with the said material penetrating between the spaces provided by the said projections thereby securing the elastomeric material to the fabric while the said continuous filament threads constitute tension-resisting elements in the material.

References Cited in the file of this patent UNITED STATES PATENTS 1,875,517 Steere Sept. 6, 1932 2,067,816 Barnick Jan. 12, 1937 2,391,950 Croft et a1. Jan. 1, 1946 2,401,829 Kahil a- June 11, 1946 2,450,948 Foster Oct. 12, 1948 2,515,778 Knowland July 18, 1950 2,574,029 Foster Nov. 6, 1951 2,627,644 Foster Feb. 10, 1953 2,701,406 Bloch Feb. 8, 1955 2,703,774 Morrison Mar. 8, 1955 2,713,193 Robbins et a1. July 19, 1955 2,720,226 Helwith Oct. 11, 1955 2,793,151 Arnett May 21, 1957

Claims (1)

1. THE METHOD OF MAKING A FABRIC REINFORCED ELASTOMERIC MATERIAL ADAPTED FOR USE IN ARTICLES SUBJECT TO TENSION COMPRISING PROVIDING A FABRIC INCLUDING INTERWOVEN THREADS EXTENDING GENERALLY IN DIRECTIONS LENGTHWISE AND CROSSWISE OF THE FABRIC, RESPECTIVELY, WITH ALTERNATE THREADS IN THE LENGTHWISE DIRECTION OF THE FABRIC CONTRACTIBLE BY DIFFERENT AMOUNTS AND WITH ANY SINGLE THREAD OF SAID ALTERNATE THREADS FORMED OF A SINGLE TEXTILE SUBSTANCE, SUBJECTING ALL OF THE THREADS IN THE LENGTHWISE DIRECTION TO UNIFORM TENSION DURING WEAVING, SUBJECTING THE FABRIC TO A THREAD:CONTRACTING CONDITION AFTER WEAVING WHEREBY THOSE OF SAID ALTERNATE THREADS WHICH CONTRACT THE LESSER AMOUNT ACQUIRE GREATER CRIMP THAN THOSE OF GREATER CONTRACTIBILITY THEREBY FORMING SPACED PROJECTIONS ON EITHER FACE OF THE FABRIC WHILE THE SAID ALTERNATE THREADS WHICH CONTRACT THE GREATER AMOUNT COMPRISES TENSIONRESISTANT ELEMENTS IN THE FABRIC, AND APPLYING ELASTOMERIC MATERIAL TO THE FARIC WITH THE SAID MATERIAL PENETRATING BETWEEN THE SPACES PROVIDED BY THE SAID PROJECTIONS.

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