US2526738A - Woven fabric - Google Patents

Description

Ocf- 24, 1950 Y D. FlNLAYsoN Erm. 2,526,738

wovEN FABRIC Filed Sept. l0, 1946 Y Patented Oct. 24, l 1950 Harry CraWsha-W,Y London, England, yassignors to Celanese Corporation `of America, a corporation of Delaware Applicationseptember 10, 1946, Serial No. 695,870 In Great Britain September 12, 1945 12 claims. (C1. 13a-4205 .This invention relates to woven fabrics and is particularly concerned with fabrics of the class suitable for use as conveyor belts and power transmission belts, which are required to have exceptional strength in a warpwise direction.

In fabrics of this kind, while the main requirement is that the fabric should have a high tensile strength in a warpwise direction, a substantial degree of strength is required also in the weftwise direction, not only to prevent splitting of the fabric along the warp but also in order that, where two ends of the fabric are joined together, the joint itself may have a warpwise strength commensurate with that of the fabric. It has been found however that, apparently by reason ofinterference between the warp yarns. and the substantial `proportion of weft yarns necessary to give the requisite weft strength, the warp strength of the fabric is aptto fall far short of the aggregate strength of all the individual warps therein. This failure to realise in the fabric the maximum strength of theA warps is particularly marked if the warp consists of materials, and especially continuous lament materials, that have been stretched-.while in Va softened condition at some stage in their manufacture so as to increase their tensile strength. .It has now been found that a particular kind of braid, namely one in which the major proportionof the weight of the constituent yarns consists of yarns running substantially parallel to the axis of the braid and not across or helically round it, is apparently less liable than 1an' ordinary heavy yarn to loss of tensile strength because of interference by other yarns. When such braids are used as warps in heavyfabrics',l

the aggregate strength of thewarps is more closely realised as the warp strength ofthey fabric than when other warps of equal tensile strength are used.

The present invention, therefore, includes a woven fabric, suitable for use in conveyor or power transmission belts, having a warp consisting of or comprising braids in each of which the major proportion of the weight of the constituent yarns, for example 80 to 90% or more, consists of yarns running substantially parallel to the axis of the braid. In order that the principal yarns of the braid may lieparallel to the Aaxis thereof, it is necessary that the braidshould'comprise, in additionv to such principal yarns, auxiliary or binder yarns crossing and interlacin'g with the principal yarns and therefore not lying parallel to the braid. The braid may comprise a tubular ,element or sheath, with the binder yarns running helically round it and may contain a core of parallel yarns co-operating with the principal yarns but not interlaced with the binder yarns. Braids of this kind can be made on braiding machines or can be woven in smallware looms by suitable shedding arrangements. Where a braiding machine is employed, binder yarns may be arranged to run helically in both directions round the braid so that the binder yarns cross one another at intervals. Where a loom is employed for weaving the braid the binder yarn, serving as weft in the loom, will run helically round the braid always in the same direction at all parts of the length of the braid.

The braids employed in warps in the fabric of the presentv invention may be woven into the fabric with wefts of similar construction and of the same or lighterweight. Prefer-ably, however, where a braid is used as the weft a fiat braid is employed. When such a iiat braid is employed in the weft it is of less importance that the bulk of the constituentyarns should run parallel to the aXsthereof than in the case of the braid employed as warp. Thus a flattened tube may be employed in which all the yarns run helically round the braid at an angle to the axis thereof, the atness of the braid minimising the interference between it and the braids used in the warp and thus enabling the aggregate strength of the warp braids to be even more closely realised as the warp strength of the fabric. Or again, singles yarns, or composite yarns whose components are doubled or cabled together but not braided, may be employed as the weft.

The fabric according to the invention is of particular advantage in belts in which a fabric foundation, generally in the form of several layers of fabric secured together by means of rubber or other flexible adhesive, is provided with a covering of rubber or like iiexible material to give a smooth surface of the desired texture and consistency. Oneparticularly important application of the invention is for conveyor belts as used underground in coal mines. Belts for thispurpose work under very severe conditions giving rise to frequent breakage, and the realization of the maximum tensile strength of the fabric is of particular value in reducing such breakage and increasing the life of the belt. When intended for use as a belting, thel fabric according to the invention may bemade as described land claimed in U. S. Application S. Number 607,301, filed on July 27,1945, now Patent Number 2,494,646, issued Jan. 1'7, 1950', i. e. with a weft inserted at short intervals in the fabric that the tear-out strength of the joint between two ends of the fabric.

The invention is also of particular advantage where the yarns employed in the fabric, Vand particularly in the Warp braids, are of high tensile strength and are made by stretching filamentsof.

cellulose acetate or other organic derivative of cellulose in the presence of Wet steam or other softening agent adapted to facilitate stretching. Where the filaments that are stretched are of cellulose acetate or other cellulose ester, they are preferably saponied after being stretched. Warps which are of high tensile strength because they or their constituent yarns have been stretched in this way are particularly liable to diminution of their tensile strength because of interference by the weft with which they have been Woven, and the present invention is of particular advantage since it reduces this tendency. The invention may, however, be applied also to fabrics containing other kinds of yarns, egg. to fabrics in which the warp or weft or both are of linen or cotton, or artificial staple libres made by cutting continuous laments into suitable lengths.

The fabrics according to the present invention may be classified generally as heavy fabrics that cover a substantial range of weights. Thus for example, they may be woven from braids of a Weight of say 45,000 denier each, spaced at say. ends per inch giving a fabric of the order of 4 lbs. per square yard in weight, or from braids of about 9000 denier or less at a spacing of 18 ends per inch, giving a fabric of about 1.5 lbs. per square yard or less. Where flat braids are used in the weft they may be of similar weight or rather lighter Weight than the Warp braids though much more widely spaced, e. g. at from 2 to 5 picks per inch.

The following are given as examples of fabrics in accordance with the invention.

Eixample 1 l The fabric is made with a Warp of braids each consisting of continuous filament yarns made by stretching continuous laments of cellulose acetate in the presence of wet steam to ten times their original length and then saponifying the stretched yarn. Each braid comprises eight longitudinal sheath yarns and three core yarns all of 1100 denier, the sheath yarns being braided with four binder threads each of 275 denier. Of the binder threads two run in one direction and two in the other direction round the braid, the total number of laps per inch of binder threads round the braid being about seven. These braids are woven at 18 ends per inch With'a. at braid made by helically braiding together 48 yarns, each of 275 denier, 24 of -the yarns running in one direction and 24 in the other round the braid and giving a braid of about 51g of an inch wide. The weft braid is inserted at a density of 3 picks per inch. The resulting fabric is about 2.2 lbs. per square yard in weight.

Emample 2 inch with a weft braid as described in Example l woven at 3 picks per inch, the resulting fabric bee ing about 3.6 lbs. per square yard in Weight.

Example 3 A braid is formed by weaving 22 heavy warp yarns, made of continuous filaments like those of Examples 1 and 2, and each of 2750 denier, with a single weft of 275 denier, the mode of weaving being Ysuch that I of the warp yarns are not interlaced with the weft but form a core surrounded by a tube formed by the interlacing of the remaining 15 yarns with the weft. This braid is woven as the warp at nine ends per inch with a flat braid as described in Examples 1 and 2, woven at 21/2 picks per inch. The resulting fabric is of the order of 5 lbs. per square yard in Weight.

Emample 4 The warp braids of Example 2 are woven at 12 ends per inch with a continuous filament doubled yarn of 4500 denier employed as the weft and woven at 4 picks per inch.

Example 5 The fabric is of the kind described in U. S. Application S. Number 607,301 led July 27, 1945, and contains a heavy weft occurring at intervals along the fabric. A braid similar to that of Example 1, but having six sheath yarns and two core yarns each formed by doubling together three 550 denier yarns, is employed in the warp at a spacing of about 14 ends per inch. In the weft, a 3300 denier continuous filament yarn is employed at an average spacing of 15 picks per inch, 5 picks in separate sheds alternating'with 5 picks all in the same shed so as to give a heavy weft occurring at about every z/3".

The fabrics described in the preceding eX- amples, and the braids employed in the construction thereof, are shown in the accompanying drawings in which:

Figure 1 is an enlarged diagrammatic view of a warp braid in which a plurality of binder yarns are employed.

Figure`2 is a similar view of a Woven warp braid in which a single binder yarn is employed.

Figure 3 is a similar view of a flat braid suitable for use in the weft of the fabric.

Figure 4 is a diagrammatic view of a fabric of the kind described in Examples l and 2, and

Figures 5, 6 and 7 are similar views of the fabrics described in Examples 3 to 5, respectively.

In Figure l the principal sheath yarns are indicated at 8 and the coreyarns at 9. The binder yarns I0 and II pass helicallyround the braid in one direction and the binder yarns I2 and I3 in the other direction, the yarns I0-I3 being interlaced with the sheath yarns 8 so as to. form a tube enclosing the core yarns 9, and crossing each other.

The braid shown in Figure 2 also comprises sheath yarns 8 and core yarns 9, but in this case there is only a single binder yarn I5 running helically round the braid and interlaced with the sheath yarns 8 to form a, woven tube enclosing the core yarns 9.

The braid shown in Figure 3 is a flat tubular braid, containing no core yarns, in which the yarns I 6 al1 pass helically round the braid, equal numbers in both directions, and are interlaced with each other..

- Figure 4 showsl a plain woven fabric inwhich, as described in Examples 1 and 2, the warps I'I are in the form of braids of the kind shown in l?.

'Figure l, while the vvefts I8 kind shown in Figure 3.

ments are braids of the In Figure 5, asimilar weft yarn I8 is employed, but, as .described in Example 3, the warps I9 are braids of the kind described with reference to Figure 2.

. -InvFigures 6 and '7 the warps are againv in the formA of braids of the kind shown in Figure l, while the wefts, as described in Examples 4 and 5, are simply doubled yarns of continuous fila- The wefts in Figure 6 are'wovenwith the warp at uniform intervals in a plain weave, as described in Example l but in Figure 7, while vmost of the wefts 2D are single picks of yarn,

certain wefts 2I, occurring at regular intervals along the length of .the fabric, consist of several picks ofthe same yarn, as described in Example 5.

Having described our invention, what we desire to. secure by Letters Patent is:

1. .'Abelting fabric of woven construction and having a Warp comprising braids consisting of a tubular sheath of textile yarns and a core of parallel textile yarns enclosed therein, the major proportion by Weight of said sheath consisting of textile yarns running substantially parallel to the axis of said sheath and theminor proportion consisting of textile binder yarn running helically around said sheath and crossing and interlacing with the yarns of said major proportion but not with the yarns of said core.

2. A belting fabric of 'Woven construction and having` a warp comprising braids each consisting of a Woven tubular sheath of textile yarns and a core of parallel textile yarns enclosed therein, the major proportion by Weight of said sheath consisting of textile yarns ruiming substantially parallel to the axis thereof and the minor proportion consisting of a single textile binder yarn runningv helically rOundsaid sheath and interlacing with the yarns` of said major proportion kbut not with the yarns of said core.

3. A belting fabric of woven construction and having a warp comprising braids each consisting of a tubular sheath of textile yarns and a core of parallel textile yarns enclosed therein, the major proportion by weight of said sheath consisting of textile yarns running substantially parallel to the axis of said sheath and the minor proportion consisting of a plurality of textile binder yarns running helically in both directions round said sheath so as to cross one another at intervals, and crossing and interlacing with the yarns of said major proportion but not with the yarns of said core.

4. A belting fabric of woven construction, comprising a flat textile braid as a weft and having a warp comprising braids consisting of a tubular sheath of textile yarns and a core of parallel textile yarns enclosed therein, the major proportion by Weight of said sheath consisting of textile yarns running substantially parallel to the axis of said sheath and the minor proportion consisting of textile binder yarn running helically around said sheath and crossing and interlacing with the yarns of said major proportion but not with the yarns of said core.

5. A belting fabric of woven construction and having a warp comprising braids of textile material in each of which the major proportion by Weight of the constituent yarns consist of yarns running substantially parallel to the axis of the braid and the minor proportion comprises binder yarn running helically around said sheath and crossing and interlacing With yarns of said major proportion, said Warp being woven with textile .wefts 'at intervals .amongst which, distributedy along the' length of the fabric, a weft is inserted ofV several times the .weight of the Wefts elsewhere in the fabric.

6. A belting fabric of woven construction and having a warp comprising braids consisting of a tubular sheath of textile yarns and a core of rparallel textile yarns enclosed therein, the major proportion by weight of said sheath consisting of textile yarns running substantially parallel to the axis of said sheath and the minor proportion consisting of textile binder yarns-running helically around said sheath and crossing and inter- -lacing, withthe yarns of said major proportion but not with the yarns of said core, said warp being Woven with textile Wefts at intervals amongst which, distributed along the length of the fabric, a weft is inserted of several times the weight of the wefts elsewhere in the fabric.

7. A belting fabric of woven construction and having a warp comprising braids made of yarns of continuous filaments of cellulose acetate or other organic ester of cellulose that have been stretched in the presence of a softening 'agent adapted to facilitate stretching and that have been saponiiied after stretching so as to increase their tensile strength, each of said braids consisting of a woven tubular sheath and a core of parallel yarns enclosed therein, the major proportion by weight of said sheath consisting of yarns running substantially parallel with the axis thereof and the minor proportion consisting of a single binder yarn running helically round said sheath and interlacing With the yarns ofl said major proportion. but not With'the yarns of said core.

8. A belting fabric of. woven construction and having a Warp comprising braids made of yarns of continuous filaments of cellulose acetate or other organic ester of cellulose that have been stretched in the presence of a softening agent adapted to facilitate stretching and that have been saponied after stretching so as to increase their tensile strength, each of said braids consisting of a tubular sheath and a core of parallel yarns intervals and interlacing with the yarns of said major proportion but not with the yarns of said core. f

9. A belting fabric of woven construction having a weight of from 1.5 to 4 lb./sq. yd., said fabric comprising a flat textile braid as weft and having a warp comprising braids mad-e of yarns of continuous filaments of cellulose acetate or other organic ester of cellulose that have been stretched in the presence of a softening agent adapted to facilitate stretching and that have been saponied after stretching so as to increase their tensile strength, each of said braids consisting of a Woven tubular sheath and a core of parallel yarns enclosed therein, the major proportion by Weight of said sheath consisting of yarns running substantially parallel With the axis thereof and the minor proportion consisting of a single binder yarn running helically round said sheath and interlacing with the yarns of said major proportion but not with the yarns of said core.

10. A belting fabric of woven construction having a weight of 4from 1.5 to 4 lb./sq. yd., said fabric comprising a flat textile braid as weft and having a warp comprising braids made of yarns of continuous lament's of cellulose acetate or other organic ester of cellulose that have been stretched in the presence of a softening agent 'adapted to facilitate stretching and that have been saponied after stretching so as to increase their tensile strength, each of said braids consisting of a tubular sheath and a core of parallel yarns enclosed therein, the major proportion by weight of said sheath consisting of yarns running substantially parallel to the axis thereof and the minor proportion consisting of a plurality of binder yarns running helically in both directions round said sheath so as to cross one another at intervals and interlacing with the yarns of said major proportion but not with the yarns of said core.

11. A belting fabric of woven construction having a Weight of from 1.5 to 4 lb./sq. yd. and having a warp comprising braids made of yarns of continuous filaments of cellulose acetate or other organic ester of cellulose that have been stretched in the preence of a softening agent adapted to facilitate stretching and that have been saponifled after stretching so as to increase their tensile strength, each of said braids consisting of a woven tubular sheath and a core of parallel yarns enclosed therein, the major proportion by weight of said sheath consisting of yarns running substantially parallel with the axis thereof and the minor proportion consisting of a single binder yarn running helically round said sheath and interlacing with the yarns of said major proportion but not with the yarns of said core, said warp being woven with textile wefts at intervals amongst which, along the length of the fabric, a weft is inserted of several times the weight of the wefts elsewhere in the fabric.

12. A belting fabric of Woven construction having a weight of from 1.5 to 4 lb./sq. yd. and having a warp comprising braids made of yarns'of continuous filaments of cellulose acetate or other organic ester of cellulose that have been stretched in the presence of a softening agent adapted `to facilitate stretching and that have been saponified after stretching so as to increase their tensile strength, each of said braids consisting. of a tubular sheath and a core of parallel yarns enclosed therein, the major proportion by weight of said sheath consisting of yarns running substantially parallel to the axis thereof and the minor proportion consisting of a plurality of binder yarns running helically in both directions round said sheath so as to cross one another at intervals and interlacing with the yarns of said major proportion but not with the yarns of said core, said warp being woven with textile wefts at intervals amongst which, along the length of the fabric, a weft is inserted of several times the weight of the wefts elsewhere in the fabric.

DONALD FINLAYSON.Vv HARRY CRAWSHAW.

REFERENCES CITED The following references are of record the file of this patent:

UNITED STATES PATENTS Number Name Date 40,379 Darker, Jr Oct. 20, 1863 905,946 Stevenson Dec. 8, 1908 1,640,946 Lloyd Aug. 30, 1927` 2,096,592 Petersen Oct. 19, 1937 2,217,826 Van Laer Oct. 15, 1940 FOREIGN PATENTS Number Country Date 48,527 Austria Feb. 1, 1911 333,279 Great Britain Aug. 8, 1930

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