Monofilaments and Multifilaments

The yams in these cloths are composed of soUd polymeric material (polypropylene, polyester, pofyamide, etc.). Cloths of diflerent patterns are produced on the loom by varying the manner in 4iidi the warp and weft yams are woven together. The warp yam is stretched in the machine or longitudinal directian and the weft yam lies at right angles to the warp. Yams are usually cylindrical, although other shapes are available. 

The surface of the fiibric can be modified by finishing this involves heat treatment and calendering in order to flatten the sur ce, reduce pore size, but preserve the constmction by way of reducing any tendency to shrink or stretch in service. 

The effect of changes in weave pattern on flow throu the fabric will be discussed in the section dealing with mathematical modelling of flow flirou monofilaments. 

All interesting variant is where the diameter of the warp yam is different fiom the weft, in the production of Dutch weaves of strong constmction. A Dutch weave produces two openings or pores in the bric, one on the sur ce between parallel yams and a second, triangular pore in the plane of the cloth. These cloths produce excellent performances in the separation of solid, crystalline materials, but are less successfiil in filtering slimy colloids i diidi can lodge in the triangular pores. 

New fiibrics are contimia% being developed by manu cturers aiming to inqtrove particle retention, cake release and filtrate drainage. 

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ISO 1346 2004 Fibre ropes - Polypropylene split film, monofilament and multifilament (PP2) and polypropylene high tenacity multifilament (PP3) - 3-, 4- and 8-strand ropes ISO 1873-1 1995 Plastics - Polypropylene (PP) moulding and extrusion materials - Part 1 Designation system and basis for specifications ISO 1873-2 1997 Plastics - Polypropylene (PP) moulding and extrusion materials - Part 2 Preparation of test specimens and determination of properties ISO 3213 1996 Polypropylene (PP) pipes - Effect of time and temperature on expected strength... 

Early in the manufacture of PP, a concept was developed for dry spinning directly from the solution obtained in the polymerization operation. Had it been feasible, it would have been the realization of a chemical engineer s dream the gaseous olefin fed into one end of the equipment, and the packaged fiber, ready for shipment to a textile mill, coming out the other end. But it did not turn out that way, and today melt spinning is the accepted technique for the production of staple fibers, monofilament, and multifilament yams. To this usual method have been added the fibrillation and the slit film procedures for producing yams. 

The three major constituents of any continuous fiber ceramic matrix composite are the reinforcing fibers, the matrix and a fiber-matrix interphase, usually included as a coating on the fibers. HiPerCompTM composites can be processed with various monofilament and multifilament fibers, such as the SCS family of monofilament SiC from Specialty Materials, Inc. CG-Nicalon and Hi-Nicalon Type S from Nippon Carbon Company Tyranno ZE , Tyranno ZMl and Tyranno S A from Ube Industries and Sylramic fiber from COl Ceramics. However, the composites described in this paper all utilize Hi-Nicalon SiC fiber from Nippon Carbon Company. A companion paper, in this book, by Jim DiCarlo [11] from NASA gives the properties of slurry cast composites reinforced with Sylramic and Sylramic-iBN fibers. 

Additionally, it imparts higher warp tensile properties to the fabric for greater resistance to stretch from the mass of heavy cakes. In the case of the multifilament and staple-fibre yam combination, the inclusion of a staple-fibre weft yam provides the scope for improved resistance to mechanical damage whilst maintaining high particle collection efficiency and acceptable throughput rate. Similarly, the inclusion of a multifilament weft yam in a monofilament and multifilament fabric will lead to an improvement in filtration efficiency, especially if it is suitably texturised. 

A series of tubular fabric samples, typical for use in endovascular prostheses, were woven from polyester monofilament and multifilament yams on a special narrow ribbon shutde loom. They were 8 mm in diameter and 6 cm in length, and bad the structural specifications listed in Table 1. 

The forms in which the reinforcement is used in CMCs include whiskers (with length to diameter ratio as high as 500), particulates, and both monofilament and multifilament continuous fibres. 

Trimbos J B, van Rijssel E J C and Klopper P J (1986), Performance of sliding knots in monofilament and multifilament suture materials , Obstet Gynecol, 68,425. 

Monofilament and multifilament woven fabrics are generally made from PET, the use of monofilament giving the better permeabihty, whereas multifilament is used for higher strength reinforcement. SHt film, flat-tape fabrics are usually PP materials, which are quite strong but they form a fabric that has relatively poor permeability. Alternatively, fabrics made with fibriUated-tape yarns have better permeability and more uniform interstice openings than flat-tape products. 

Wire, cable, film, and fiber. Aurum can be extruded into wire, cable, film, and fiber (Fig. 10.6). The extruded wire and cable are for electrical insulation with outstanding thermal, mechanical, chemical, and electrical properties. Aurum film is available in 1- to 22-mil-thick rolls from Westlake Plastics. The applications include wire, cable, and optic fiber insulation industrial belts heat and radiation panels and other electric and thermal insulation devices. Aurum monofilament and multifilament can be woven and braided into a variety of high-performance industrial and aircraft products including paper-making belts and jet-engine insulation. 

As demonstrated in this chapter, a variety of bioabsorbable polymers, both natural and synthetic, have been investigated as surgical materials and devices. Sutures have the largest market share among the synthetic bioabsorbable polymer used in medicine. Since different types of monofilament and multifilament sutures with... 

Monofilament sutures have no interstices in which to lodge bacteria, but they are more difficult to handle and require more throws to each knot for security than braided sutures. Multifilament sutures are generally easier to handle, with greater knot security, but do allow capillarity and interstitial bacteria colonization which can increase the risk of wound infection, particularly with nonabsorbable sutures. Both monofilament and multifilament sutures can be absorbable or nonabsorbable. 

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