CS255850B1 - Core yarn for secondary base fabrics - Google Patents

Abstract

The core yarn is produced by friction spinning and its core consists of at least two polyolefin-based tapes with a thickness of 0.030 to 0.058 mm and a width of 0.8 to 1.5 mm with a total strength in the range of 20 to 35 N. The core tapes may also contain 0 to 6% of CaCO^ or TiO2 filler.

Description

The yarns for secondary backing fabrics are solved in many different ways. However, the most economical yarn is a core yarn produced by a frustrating spinning process, which uses a polypropylene strip that is integral and has a rectangular cross-section as the core. Staple polypropylene fibers are used as sheaths.

A disadvantage of this yarn is that the production of the tapes for this purpose requires special technology, since the conventional tapes undergo a significant decrease in tensile strength after passing through the friction spinning device, so that the resulting yarn cannot be used as a weft secondary fabric for these reasons. Tapes produced by this special technology are imported from KS without exception.

GDR pat. No. 138,682 discloses an economical method of fibrillating a polymeric film tape, which is then used inter alia for floor coverings. Other secondary backing fabric of U.S. Pat. No. 4,145,467 has one of the warp and weft members consisting of a 0.5 to 4 mils polyolefin tape and other warp and weft members include a fibrillated polyolefin band and have fibrils having a fineness of from 3 to 235 denier and a mean fineness of from 12 to 235 150 denier. French Patent No. 2,348,990 discloses a carpet backing fabric, woven from warp and weft tape yarns, which is spun by needling after weaving.

These flooring fabrics have a common disadvantage, which is the unattractive appearance of the back of the carpet, resulting in poorer merchandise. The cause is a cross-section of the weft and warp members, which is rectangular and the resulting fabric lacks the appearance of natural materials.

Partly this problem is solved by other carpet backing, which according to Japanese pat. No. 8,023,937 by combing leno fabrics woven from split weft yarns and smooth yarns of thermoplastic resin in the warp. The split yarn consists of at least two main fibers and coiled fibers coated with combed pile. Preferably, a polypropylene fiber is used. Although the backing has improved adhesion to the latex binder and less tendency to rot and bacterial attack, the combed pile used for coating also has a rectangular cross section. In addition, high dust levels occur during combing. Another similar solution is disclosed in U.S. Pat. No. 4,433,536, which discloses a twine. A longitudinally oriented oriented synthetic tape that is zero twist and slit-fibrillated to exhibit substantially a sieve structure in which fine fibrol strains are connected by finer fibril branches, a synthetic bonding element in the form of a thin ribbon that is spirally wound around at least one synthetic tape to which it adheres. However, this formation is unsuitable for the production of a secondary backing fabric.

In order to reduce the strain on the tapes during wrapping, a core yarn for secondary backing fabrics has been proposed, the core of which according to the invention consists of a polypropylene strip mechanically treated by fibrillation, which is wrapped with a sheath of textile fibers. This core yarn is reminiscent of jute. The secondary backing fabric produced from this yarn has an attractive natural material appearance and is more resilient than the secondary backing fabric of polymeric tapes, but the disadvantage remains the reduced relative strength of the starting fibrillated polypropylene strip forming the core of the yarn.

This disadvantage is overcome by the core yarn for secondary backing fabrics, the core of which according to the invention consists of at least two polyolefin-based tapes having a thickness of 0.030 mm to 0.058 mm and a width of 0.8 to 1.5 mm with an overall strength in the range of 20 to 35 N. the cores may further comprise from 0% to 6% calcium carbonate or titanium dioxide filler according to the invention.

Example

The polyolefin-based polymer or copolymer strip contains 0% to 6% filler, e.g. micronized CaCO 3 or TiCl 3. Its dimensions are: 1 mm wide, 0.042 mm thick. The strip is made in the form of a double strand with two ends and passed as doubled to a friction spinning device and wrapped with POP fibers. The strength of the yarn thus produced, having a fineness of about 200 tex, is 100% to 90% of the original strength of the two starting tapes.

The smaller width of the tapes and said thickness of the tapes result in less loading and stress on the core wrapping and the core yarn production. The technical consequence is furthermore that thin, about 1 mm wide strips are produced by known technology in the form of two-end windings and that the resulting tensile strength of these strips complies with the required strength of the core yarn, i.

Since it is technically possible to produce fine strips with a fineness of 200 to 450 dtex as well as three-end windings, a triple strip can be used as the yarn core.

The fineness of the wrapped yarn is 180 to 220 tex.

Claims (2)

1. A core yarn for secondary backing fabrics produced by frictional spinning, the core of which is wrapped with a textile fiber sheath, characterized in that the core consists of at least two polyolefin-based tapes having a thickness of 0,030 mm to 0,058 mm and a width of 0,8 mm to 1 5 mm with a total strength in the range of 20 to 35 N. 2. A core yarn for secondary backing fabrics according to claim 1, wherein the core strips comprise 0% to 6% calcium carbonate or titanium dioxide filler.