Fibrillated yarn

Modylen 2-5112 - carpet stitching yarns, fibrillated yarns, fiber for woven bags, monofilaments for ropes and bristles concrete reinforcement... 

UK), in which the basic technique is to emboss a pattern of parallel indentations onto the hot melt immediately after extrusion. This results in a series of continuous and uniform fibrils connected by relatively fine membranes extending across the film s width. The film is next divided into tapes of the required denier, and processed through drawing and winding operations. It is then twisted to produce a continuously fibrillated yarn (300-600 denier), with high tenacity (6.5-8.0 cN/ denier) and regular round cross section. 

Film can be heated and/or stretched and cut eventually giving filament-like materials. Unfibrillated slit-film materials are used in weaving sacks and other packaging. Randomly fibrillated slit-film material is used to make twines and ropes, while controlled fibrillated material is used to make yarns for use in carpet backings and furnishing fabrics. 

Table 3.1 presents the worldwide production of polyolefin fibers in 1996 2002, according to Fiber Organon [1]. In 2002, the total production of polyolefin fibers grew to 5.913 million tons (MT). The annual rate of growth was 2% as compared to 8% for polyester, 6.4% for PAN, and 4.4%i for polyamides. The production of polypropylene fibers, excluding fibrillated fibers, reached 3.99 MT in 2002 and 4.20 MT in 2003. About 70% of its production was in filament yarn and 30%i in staple. As Table 3.1 also shows the portion of polypropylene filaments increased from 40.4%i in 1996 to 45.5%i in 2002, while fibers from fibrillating film decreased from 35.2 to 32.5%i. The portion of ST remained steady at 22.1%. 

Polypropylene fibers are produced by a larger variety of processes than other melt-spun fabrics. At one end of the range, the long air-quench process produces high-quality multifilament yarns, and, at the other end, fibrillating slit film produces coarser fibers. The success of the lower-cost polypropylene slit-film fiber is due to the lower price of the polypropylene resin and the unique adaptability of polypropylene to the less expensive slit-fibn fibrillation process. The water-quench process for monofilament has long been an established technique... 

After the yarn is drawn, it is fibrillated. A large number of devices have been invented for fibrillating tapes in-line to give them a more fiber-like character. In various processes, the tapes are rolled, twisted, brushed, pulled, treated with air jets, subjected to ultrasonics, or contacted with rotating rolls that have cutting or punching devices on their periphery. The most prevalent method is that which uses rotating rolls. This method is simple, easy to... 

The shear stresses associated with surface rubbing cause severe abrasion of the surface of aramid fibres. In yarns that have been carelessly handled, fibrillation is clearly apparent. In laboratory tests with rubbing on a pin, the surface becomes worn away until break occurs. 

Abraded yarn 9- brMod n. A filament yam in which filaments have been cut or broken to create hairiness (fibrillation) to simulate the surface character of spun yarns. Abraded yarns are usually plied or twisted with other yarns before use. Kadolph SJ and Langford AL (2001) Textiles. Pearson Education, New York. 

Fibrillated-film yarn See slit-film yarn. 

Slit-film also finds its way into many other applications. These include twine, woven fabrics for feed and fertilizer sacks, sand bags and bulk container bags, tarpaulins, mats, screens for erosion prevention, and geotextiles to stabilize soil beds. Fibrillated slit-film is used as a face yarn in outdoor carpets and mats. 

New forms of polypropylene (PP) fibrous material have emerged to supplement the established forms of staple fiber and continuous filaments [1]. These are of two distinct types. The first is stretched tape used extensively for woven sack fabrics. The second type relate to spht fiber tape yarns produced by splitting or fibrillation of highly oriented stretched tapes. 

One of four basic yarn types, shown in Figure 2.2, is normally employed in the production of woven fabrics monofilaments, multifilaments, staple spun yams and fibrillated tape yams (a helpful summary of trade names is given by Purchas and Sutherland, 2002). 

Staple spun yarns Fibrillated tape yarns... 

Fibrillated tape yarns are produced from narrow width polypropylene films that are converted into relatively coarse filaments using special cutters and pins. These yarns find only limited use in filtration, mainly as coarse, open weave structures to provide support or drainage fabrics behind finer grade filter cloths. 

The tape yarn and film method (initially called the split-film method or fibrillation of plastic films) consists of extruding or casting thin films or tapes of thermoplastic crystalline POs, followed by their stretching to obtain a substantially parallel orientation of the fiber-forming crystallites embedded in an amorphous matrix. Because the interchain bonds are missing, lateral cohesion is low and the films or tapes can be spliced very easily into a network of interconnected fibers (fibrillation). 

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