NL9002686A - YARN INCLUDING POLYAL OVEN FIBERS AND A PROCESS FOR THE MANUFACTURE OF THE YARN. - Google Patents

Description

YARN INCLUDING POLYAL OVEN FIBERS AND A METHOD FOR MANUFACTURING THE YARN

The invention relates to a yarn comprising a core portion extending in the longitudinal direction of the yarn and a jacket portion surrounding the core portion, the core portion comprising fibers of high strength and the jacket portion comprising natural fibers.

Such a yarn is known from U.S. Patent No. 4,922,701. In the yarn of the above patent, the core consists entirely of high strength fibers. The disadvantage of the known yarn is therefore the high price of the yarn, so that the yarn is only applicable to a limited extent.

Surprisingly, a yarn is obtained, the strength of which remains at a sufficiently high level, if the core part as strong fibers comprises polyolefin fibers with a modulus of at least 40 GPa and a tensile strength of at least 1.5 GPa, while the content of polyolefin fibers in the core part is only 1-50% by weight amounts.

In general, a cheaper yarn is also obtained.

Furthermore, the yarn exhibits many improved properties such as higher resistance to abrasion, higher flexibility and improved fatigue resistance.

When used in clothing, the yarn provides excellent wearing comfort.

Examples of natural fibers are cotton, jute, wool and linen.

In a yarn according to the invention in which the above-mentioned advantages are even more clearly expressed, the core part comprises 3-30% by weight of the polyolefin fibers, while preferably the core part comprises 5-15% by weight of the polyolefin fibers.

A yarn according to the invention in which a very good connection exists between the core part and the jacket part is obtained if the core part comprises the natural fibers of the jacket part.

Preferably relatively thin polyolefin fibers are used in the yarn according to the invention with a titre of at most 5 denier, more preferably with a titre of at most 2 denier.

Very suitable polyolefin fibers for the purpose of the invention have been obtained if the polyolefin fibers have been produced by the gel spinning process described for example in GB-A-2,042,414 and GB-A-2,051,667. This process essentially consists of manufacturing a solution of the polyolefin which preferably has a weight average molecular weight of at least 600,000 g / mol, forming the solution into filaments at a temperature above the dissolution temperature, cooling the filaments below the dissolution temperature so that gelation occurs and drawing the gelled filaments while removing the solvent. The filaments are then reduced to fibers by one of the known methods, for example by cutting or chopping the filament. The length of the fibers is preferably between 1-50 mm, more preferably between 2-25 mm and even more preferably between 3-10 mm.

Preferably, the polyolefin of the polyolefin fiber is linear polyethylene. Linear polyethylene is here understood to mean polyethylene with less than 1 side chain per 100C atoms, preferably with less than 1 side chain per 300C atoms and which may additionally contain up to 5 mol% of one or more copolymerizable other olefins such as propylene, butene, pentene, 4 -methylpentene, octene.

Other polyolefins are also suitable, such as propylene homopolymers and copolymers.

Furthermore, the polyolefins used may contain small amounts of one or more other polymers, especially olefin L-polymers.

The yarn can be made by any of the known methods.

Preferably, the method of manufacturing the yarn consists of at least one roving comprising the polyolefin fibers and at least one roving comprising the natural fibers simultaneously but separately by passing a roving stretcher, after leaving the stretcher the roving comprising the natural fibers to winding the roving comprising the polyolefin fibers and simultaneously rotating the resulting yarn about its axis. One of the advantages of such a method is that the core portion and the sheath portion in the yarn exhibit an even further improved cohesion. An example of such a method is given in U.S. Patent No. 4,922,701.

Very good results are obtained if the yarn has been treated with a flame retardant. A method of treating a yarn comprising natural fibers and polyolefin fibers with fire retardants is described in European patent application No. 377,243.

Also included in the invention are textile structures, such as fabrics and knits, which comprise the yarn of the invention.

Claims (11)

Yarn comprising a core portion extending in the longitudinal direction of the yarn and a core portion surrounding the core portion, the core portion comprising fibers having a high strength and the jacket portion comprising natural fibers, characterized in that the core portion comprises as strong fibers polyolefin fibers with a modulus of at least 40 GPa and a tensile strength of at least 1.5 GPa, the polyolefin fiber content in the core portion being 1-50 weight percent. Yarn according to claim 1, characterized in that the content of polyolefin fibers in the core part is 3-30% by weight. Yarn according to claim 1, characterized in that the content of polyolefin fibers in the core part is 5-15% by weight. Yarn according to any one of claims 1 to 3, characterized in that the core part comprises the natural fibers of the jacket part. Yarn according to any one of claims 1 to 4, characterized in that the polyolefin fibers have a titre of at most 5 denier. Yarn according to any one of claims 1 to 4, characterized in that the polyolefin fibers have a titre of at most 2 denier. Yarn according to any one of claims 1-6, characterized in that the polyolefin fibers are produced by means of the gel spinning process. A yarn according to any one of claims 1 to 7, characterized in that the polyolefin of the polyolefin fibers is linear polyethylene. A method of manufacturing a yarn according to any one of claims 1 to 8, characterized in that the method comprises at least one roving comprising the polyolefin fibers and at least one roving comprising the natural fibers simultaneously but separated by a roving stretching device after exiting the stretching device, the roving comprising the natural fibers to wrap the roving comprising the polyolefin fibers and simultaneously rotating the resulting yarn about its axis. A yarn according to any one of claims 1-9, characterized in that the yarn is treated with a flame retardant. A textile structure comprising the yarn according to any one of claims 1 to 10 or as described in the text of this application. EXTRACT A yarn with good properties and a favorable cost price comprises a longitudinal portion of the yarn-extending core portion and a sheath portion surrounding the core portion, the core portion comprising 1-50 weight percent polyolefin fibers having a strength of at least 1.5 GPa and a modulus of at least 40 GPa and at least the jacket portion comprising natural fibers.