US2996872A - Composite yarns or cord and fabrics made therefrom - Google Patents

Description

1961 2. K. PORCZYNSKl 2,996,872

COMPOSITE YARNS OR CORD AND FABRICS MADE THEREF'ROM Filed June 14, 1957 2,996,872 COMPOSITE YARNS R CORD AND FABRICS MADE THEREFROM Zbigniew K. Porczynski, Shelf, near Halifax, England,

assignor to Scandura Incorporated, a corporation of Maine Filed June 14, 1957, Ser. No. 665,834 Claims. (Cl. 57140) This invention relates to composite yarns or cords and fabrics made therefrom, and is particularly concerned with an improved method of making composite yarns or cords having improved properties.

There are at present two well-known methods for the production of composite yarns from two types of textile fibre.

The combination of two fibres, such as nylon and cotton, both in staple form, by blending the fibres on a carding machine and processing the resulting slivers by normal spinning and drafting technique is known; such yarns have many valuable properties but, in respect of tensile'strength, the blended yarns have been observed to be lower, and often considerably lower, than might be expected from the strengths of the component fibres.

In another known method, a continuous filament yarn, such as nylon or high strength viscose, may be combined, at the condenser end of the carding machine, with a staple fibre sliver made by the machine. The resulting reinforced sliver is converted into a yarn in the usual way by twisting in a spinning machine. In such yarns, known as core yarns, both the continuous filament and the staple fibre component, are twisted in the same di reotion in the spinning operation. These yarns, in general, have a tensile strength about equal to that of the stronger component, usually the continuous filament, the other component contributing little to the strength of the combination.

The present invention has for its object to provide an improved method of combining continuous filament yarns and staple fibre yarns in such a way as to give improved properties not heretofore obtainable in composite yarns.

According to the present invention, a method of manufacturing composite yarn or cord including continuous filament yarn and staple fibre yarn, comprises doubling continuous filament yarn with staple fibre yarn or low twist roving, the direction of twist in the doubling operation being in a reverse direction to the twist of the staple fibre yarn or roving, whereby an intermediate stage yarn is produced in which the fibres of the staple fibre yarn or roving are untwisted and disposed in substantially helical arrangement around the continuous filament yarn, and cabling two or more of the intermediate stage yarns with a relatively low twist in the reverse di rection to the twist inserted in the doubling operation, thereby producing a composite yarn or cord in which the staple fibre is in a relatively loose form but effectively reinforced and bound by the continuous filament component.

The amount of twist given at the doubling operation may be in excess of, equal to or less than the amount of twist given initially to the staple fibre yarn or low twist roving so that the twist given finally at the cabling operation causes the staple fibre yarn to become in relatively loose form. In particular, the amount of twist given at the doubling operation may be between 50% and 100% of the amount of twist given initially to the staple fibre yarn or low twist roving.

Composite yarns or cords made according to the in vention have the outstanding advantage that the strengths of both components in the finished yarn or cord are fully utilised. The tensile strength of the composite yarn or team Patented Aug. 22, 1961 cord is usually about equal to the sum of the strengths of the components and in some cases the strength of the composite yarn or cord is, for example, 5% to 10% greater than the sum of the strengths of the components. This is a very surprising and valuable result which hitherto has not been obtainable in any type of composite yarn.

The composite yarn or cord produced according to the invention has a somewhat corkscrew appearance and also possesses other substantial advantages. For example, another advantage of great value for many purposes lies in the incorporation, in a composite yarn of high strength, of substantial proportion of staple fibre. In certain important industrial applications, staple fibre yarns, such as cotton, are used in conjunction with rubber for example; in tyres and in solid woven or laminated machine or conveyor belting, or with plastics or synthetic rubber, for example, in resin-bonded fabrics, and in machine or conveyor belting. In these applications it is usually easy to get good adhesion of the rubber or plastic to the cotton, but the final product suffers from the disadvantage that cotton as the reinforcing textile has a moderate tensile strength only.

On the other hand, when synthetic continuous filament textiles, such as nylon or high tenacity rayon, are used in conjunction with rubber, synthetic rubber, or plastics in the same applications, considerable difliculty is found in getting satisfactory adhesion of the rubber or plastic to the smooth surface of the continuous filament yarns. Special extra treatments or processes are usually necessary, in the case of tyre cord for example, and even then there is some doubt as to whether such good adhesion is obtained as with cotton.

With the composite yarn or cord made according to the invention, good strength characteristics are combined with a surface suited to give excellent adhesion to plastics or rubber, by reason of the relatively untwisted staple fibres present.

This yam construction, moreover, again because of the relatively untwisted state of the staple fibre component, allows excellent impregnation with synthetic resin when such is desirable, as for example, in the impregnation of fabric with thermosetting resins for the manufacture of rigid laminated products.

Another feature of the improved composite yarn or cord is its relatively high bulk factor. This is of value, especially in the manufacture of heavy fabrics, as it provides fullness and thickness when required without undue weight or cost.

Another advantage realised in certain cases by the improved composite yarn or cord is that of cost. In the case, for example, of nylon and cotton yarn combinations, such as described in the examples below, the cotton component may be of the type known as a waste yarn, one of the cheapest cotton yarns obtainable.

A nylon and cotton combination also shows a very good relationship between dry and wet strengths. The slight loss of strength of the nylon is counter-balanced by the substantial increase in strength of the cotton yarn.

The invention includes composite yarns or cords produced by the method above described and also includes fabrics made from said composite yarns or cords.

The invention may be carried into efiect in various ways and in order to illustrate a composite yarn formed in accordance with the invention reference is made to the accompanying drawing in which:

FIG. 1 shows a continuous filament having a staple yarn associated therewith forming an intermediate stage y FIG. 2 shows diagrammatically three intermediate stage yarns illustrated in FIG. 1 cabled together,

FIG. 3 shows a continuous filament having two staple fibre yarns associated therewith forming an intermediate stage yarn, and

FIG. 4 shows diagrammatically three intermediate stage yarns illustrated in FIG. 3, cabled together.

It will be appreciated that in FIGS. 2 and 4 the yarns are shown cabled together very loosely for the purpose of illustration.

Example 1 As shown in FIGS. 1 and 2 of the drawings, one filament of 840 denier nylon yarn A is doubled with a single 2s cotton yarn at turns per inch 8 forming an intermediate stage yarn shown in FIG. 1. The twist 8 imparted at the doubling operation is opposite in sense to that imparted initially to the cotton yarn B. Thus the cotton yarn B is substantially untwisted and disposed in a helical path around the nylon filament A. Three intermediate stage yarns are then cabled together at 2.5 turns per inch Z as shown in FIG. 2.

FIGS. 3 and 4 show two 4s preparation cotton yarns C and D doubled at 5 turns per inch 8 with 840 denier continuous nylon yarn E forming the intermediate stage yarn of FIG. 3. Three such yarns are then cabled together at 2.5 turns per inch 2 as shown in FIG. 4.

This composite yarn has the following tensile properties:

At standard atmosphere, 65% RH. and 70 F. the above composite yarn possesses a breaking strength of 61.5 lbs., a knot strength of 48.0 lbs. and a breaking extension of 17.5%. This is opposed to the breaking strength of the nylon filament of 40.5 lbs. and a breaking strength of 6 ends of preparation cotton of 13 lbs., the sum of which is 53.5 lbs. The breaking strength of the composite yarn is thus 8 lbs. greater than the sum of the breaking strengths of the component yarns.

Under wet conditions, i.e. total immersion in water for one hour, the breaking strength of the composite yarn is 63 lbs. as opposed to a breaking strength of the nylon filament of 37.4 lbs. and a breaking strength of the cotton yarns of 16.5 lbs. Thus the increased breaking strength amounts to 9.1 lbs.

The knot strength of the composite yarn under wet conditions is 46 lbs. and the breaking extension is 20%.

The above figures indicate that the actual strength of the composite yarn is -17% greater than the theoretical strengths of its components in both dry and wet conditions.

Example 2 In this example continuous filament nylon is doubled with cotton waste yarn. Four ends of 210 denier nylon are twisted with a single 4s cotton waste yarn, with a doubling twist of 6 turns per inch, the direction of donbling being reversed to that of cotton yarn. During this operation, the cotton fibres are untwisted and disposed in a helical path around the nylon filaments. Three ends of the yarn formed as above are then cabled with 2 turns per inch in reversed direction. This cabling operation with a small reverse twist results in a very strong composite yarn or cord incorporating all the cotton fibres in a relatively loose form, but well held by the nylon filaments.

Example 3 In this example, 7 ends of 210 denier filament nylon are doubled with 2 ends of 4s cotton condenser yarn, with 5.5 doubling twist, the direction of doubling being reversed to that of the twist in the cotton. Three ends of the above yarn are then cabled with 2.5 turns per inch in a reverse direction to the doubling twist to produce a composite yarn or cord.

The strength of the above yarn or cord ranges from 75-80 lb. at break, while the strength of the nylon component only is 60 lb. and of cotton waste yarn 12 lb. when broken separately. Thus, it may be seen that the final strength of the composite yarn or cord prepared according to this invention is more than the sum of the strengths of the components.

The bulk factor of a composite yarn according to any one of the above examples is very great, but can be altered by changes in the balance of twist between the doubling and cabling operation.

Also, the amount of twist given at the doubling operation may be greater than that given initially to the staple fibre yarn so that the twist given at the cabling operation may result in the fibre yarn being completely untwisted.

It has been found that when composite yarns or cords according to this invention are coated with polyvinyl chloride (plus plasticiser) and cured, such coated yarns or cords retain all the original properties and in some cases the strength is found to be increased.

T he improved composite yarn or cord is specially suited to the weaving of belting impregnated in a loom with plasticised polyvinyl chloride paste, according to British Patent No. 706,403, March 31, 1954.

Fabrics woven from the improved composite yarn of cord after coating or impregnating with ungelled polyvinyl chloride or other plastic solutions possess excellent strength and flexibility, and have good abrasion resistance, due to the fact that loose cotton fibres form a substantially solid felted and cemented flexible structure.

It will be appreciated that an important feature of the present invention lies in the relatively loose form of the staple fibres, which facilitates adhesion and impregnation, improves the strength and assists in the production of impregnated or coated type products of unique strength, at a considerably lower price than has previously been possible.

It will be understood that the invention is not limited to the particular embodiments hereinbefore described. For example, while a combination of nylon and cotton in particular provides a product in which high tensile rength and good properties in respect of adhesion and impregnation are combined, the invention includes the combination, as above described, of any continuous filament yarn with any stable fibre component. The continuous filament yarn may be, for example, nylon or any other polyamide yarn, or terylene, or any other polyester yarn, or polyacrylonitrile, polyurethane, or vinyl polymer or copolymer yarn, cellulose acetate or triacetate, viscose or saponified acetate yarn, polyethylene yarn or glass filament yarn or polytetrafiuoroethylenc filaments. The staple fibre component may be any of the above materials in staple form or any of the natural staple fibre yarns, such as cotton, wool, flax, hemp, sisal, coir or asbestos, or combinations thereof.

I claim:

1. A method of manufacturing composite yarn includ ing continuous filament yarn and staple fibre yarn comprising doubling the continuous filament yarn with the staple fibre yarn, the direction of twist in the doubling operation being in a reverse direction to the twist of the staple fibre yarn whereby an intermediate stage yarn is produced in which the fibers of the stable fibre yarn are untwisted and disposed in substantially helical arrangement around the continuous filament yarn and cabling at least two of the intermediate stage yarns with a relatively low twist in the reverse direction to the twist imparted in the doubling operation thereby producing a composite yarn in which the staple fibre yarn is in relatively loose form but effectively reinforced and bound by the continuous filament yarn.

2. A method of manufacturing composite yarn including continuous filament yarn and staple fibre yarn comprising doubling the continuous filament yarn with the staple fibre yarn, the direction of twist in the doubling operation being in a reverse direction to the twist of the staple fibre yarn, the amount of twist given at the doubling operation being between 50% and of the amount of twist given initially to the staple fibre yarn whereby an intermediate stage yarn is produced in which the fibres of the staple fibre yarn are disposed in substantially helical arrangement around the continuous filament yarn and cabling at least two of the intermediate stage yarns with a relatively low twist in the reverse direction to the twist imparted in the doubling operation thereby producing a composite yarn in which the staple fibre yarn is in relatively loose form but effectively reinforced and bound by the continuous filament yarn.

3. A method of manufacturing composite yarn including continuous filament yarn and staple fibre yarn comprising doubling the continuous filament yarn with the staple fibre yarn, the direction of twist in the doubling operation being in a reverse direction to the twist of the staple fibre yarn, the amount of twist given at the doubling operation being in excess of the amount of twist given initially to the staple fibre yarn whereby an intermediate stage yarn is produced in which the fibers of the staple fibre yarn are untwisted and disposed in substantially helical arrangement around the continuous filament yarn and cabling at least two of the intermediate stage yarns with a relatively low twist in a reverse direction to the twist imparted in the doubling operation thereby producing a composite yarn in which the staple fibre yarn is substantially untwisted.

4. A method of manufacturing composite yarn including continuous filament yarn and staple fibre yarn comprising doubling the continuous filament yarn with the staple fibre yarn, the direction of twist in the doubling operation being in a reverse direction to the twist of the staple fibre yarn whereby an intermediate stage yarn is produced in 'which the fibers of the staple fibre yarn are untwisted and disposed in substantially helical arrangement around the continuous filament yarn and cabling at least two of the intermediate stage yarns with a cabling twist between 40% and 60% of the amount of the doubling twist, the sense of the twist imparted at cabling being the same as that imparted initially to the staple fibre yarn thereby producing a composite yarn in which the staple fibre yarn is in relatively loose form and the amount of twist present in the composite yarn is more than half the value of the initial twist given to the staple fibre yarn.

5. Cabled composite yarn comprising at least two doubled yarns cabled together with a relatively low twist in the reverse direction to the twist of the doubled yarn, said doubled yarns each comprising a continuous filament yarn and a staple fiber yarn in which the fibres of the staple fibre yarn are untwisted and disposed in substantially helical arrangement around the continuous filament yarn, the staple fibre yarns in said cabled composite yarn being in relatively loose form but efiectively reinforced and bound by the continuous filament yarns, each continuous filament yarn in said cabled yarn being a member selected from the group consisting of polyamide yarn, polyester yarn, polyacrylonitrile yarn, polyurethane yarn, vinyl polymer yarn, vinyl copolymer yarn, cellulose acetate yarn, cellulose triacetate yarn, viscose yarn, saponified acetate yarn, polyethylene yarn, glass filament yarn and polytetra-fiuoroethylene yarn.

6. Cabled composite yarn as defined in claim 5 in which the staple fibre yarn is a member selected from the group consisting of polyamide yarn, polyester yarn, polyacrylonitrile yarn, polyurethane yarn, vinyl polymer yarn, vinyl copolymer yarn, cellulose acetate yarn, cellulose triacetate yarn, viscose yarn, saponified acetate yarn, polyethylene yarn, glass filament yarn, polytetrafluorothylene yarn, cotton yarn, wool yarn, flax yarn, hemp yarn, sisal yarn, coir yarn and asbestos yarn.

7. Cabled composite yarn comprising three doubled yarns cabled together at a twist of 2.5 turns per inch in one direction, said doubled yarns each consisting of one nylon filament and at least one cotton yarn doubled together at a twist of two turns per inch in the opposite direction.

8. Woven fabric consisting of cabled composite yam as defined in claim 5.

9. Woven fabric consisting of cabled composite yarn as defined in claim 6.

10. Woven fabric consisting of cabled composite yarn as defined in claim 7.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Kunstseiden: German application 1,040,951, printed October 9, 1958 (kl. 76031), 2 pages spec., 1 sheet dwg.

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