Polyethylene fiber reinforcements

Reinforced thermoplastics pipe can currently be made using E-glass fiber or carbon, aramid or polyethylene fiber reinforcement. The development of these new materials for high performance applications is still relatively recent compared with thermosetting resins and there are no long term case histories of product performance available yet. The pipes are made by... 

Ishida H and Bussi B (1991) Surface induced crystallization in ultrahigh-modulus polyethylene fiber-reinforced polyethylene composites. Macromolecules 24 3569-3577. 

Lacroix F V, Loos J and Schulte K (1999) Morphological investigations of polyethylene fiber reinforced polyethylene. Polymer 40 843-847. 

Kazanci, M. Cohn, D. Marom, G. Ben-Bassat, H. Surface Oxidation of Polyethylene Fiber Reinforced Polyolefin Biomedical Composites and its Effect on Cell Attachment. J. Mater. Sci. Mater. Med. 2002,13 (5), 465 68. 

S. Soroushian, A.Tili, A. Alhozaimyand A. Khan, Development and characterization of hybrid polyethylene fiber reinforced cement composites , ACi Mater. J. 90,1993, 182-190. 

HDPE, high density polyethylene PP, polypropylene EVA, ethylene—vinyl alcohol SMC, sheet-molding compound ERP, fiber-reinforced plastic LDPE, low density polyethylene PE, polyethylene BMC, bulk mol ding compound TPE, thermoplastic elastomer. 

Advanced composites and fiber-reinforced materials are used in sailcloth, speedboat, and other types of boat components, and leisure and commercial fishing gear. A ram id and polyethylene fibers are currentiy used in conveyer belts to collect valuable offshore minerals such as cobalt, uranium, and manganese. Constmction of oil-adsorbing fences made of high performance fabrics is being evaluated in Japan as well as the constmction of other pollution control textile materials for maritime use. For most marine uses, the textile materials must be resistant to biodeterioration and to a variety of aqueous pollutants and environmental conditions. 

The actual experimental moduli of the polymer materials are usually about only % of their theoretical values [1], while the calculated theoretical moduli of many polymer materials are comparable to that of metal or fiber reinforced composites, for instance, the crystalline polyethylene (PE) and polyvinyl alcohol have their calculated Young s moduli in the range of 200-300 GPa, surpassing the normal steel modulus of 200 GPa. This has been attributed to the limitations of the folded-chain structures, the disordered alignment of molecular chains, and other defects existing in crystalline polymers under normal processing conditions. 

The lower thermal stability of natural fibers, up to 230°C, the thermal stability is only small, which limits the number of thermoplastics to be considered as matrix materials for natural fiber composites. Only those thermoplastics whose processing temperature does not exceed 230°C are usable for natural fiber reinforced composites. These are, most of all, polyolefines, such as polyethylene and polypropylene. Technical thermoplastics, such as poyamides, polyesters, and polycarbonates, require... 

Short fiber reinforcement of TPEs has recently opened up a new era in the field of polymer technology. Vajrasthira et al. [22] studied the fiber-matrix interactions in short aramid fiber-reinforced thermoplastic polyurethane (TPU) composites. Campbell and Goettler [23] reported the reinforcement of TPE matrix by Santoweb fibers, whereas Akhtar et al. [24] reported the reinforcement of a TPE matrix by short silk fiber. The reinforcement of thermoplastic co-polyester and TPU by short aramid fiber was reported by Watson and Prances [25]. Roy and coworkers [26-28] studied the rheological, hysteresis, mechanical, and dynamic mechanical behavior of short carbon fiber-filled styrene-isoprene-styrene (SIS) block copolymers and TPEs derived from NR and high-density polyethylene (HOPE) blends. 

Lauke B. and Schultrich B. (1986a). Calculation of fracture work of short glass fiber reinforced polyethylene for static and dynamic loading rates. Composites Sci. Technol. 26, 1-16. 

Finally the use of carbon-fiber-reinforced carbon materials for implantation purposes in human medicine should be mentioned. One of the most impressive applications is that for hip joints. In Figure 7 a state-of-the-art hip joint made from a cobalt alloy with a polyethylene socket is compared with a design concept employing a carbon-fiber-reinforced carbon stem in a polygranular carbon socket. Such a stem design offers the possibility to approach closely the femur structure by appropriate combination of 1D-, 2D,... 

One can classify fibers in a variety of ways. For example, one may divide the whole field of fibers into apparel and nonapparel fibers, i.e. based upon the final use of fibrous material. The apparel fibers include synthetic fibers such as nylon, polyester, spandex, and natural fibers such as cotton, jute, sisal, ramie, silk, etc. Nonapparel fibers include aramid, polyethylene, steel, copper, carbon, glass, silicon carbide, and alumina. These nonapparel fibers are used for making cords and ropes, geotextiles, and structural applications such as fiber reinforcements... 

Another effect of the high degree of chain alignment in these fibers is manifested when they are put in a polymeric matrix to form a fiber reinforced composite. High modulus polyethylene fibers such as Spectra or Dyneema are hard... 

Friedrich, K. Microstructure and Fracture of Fiber Reinforced Thermoplastic Polyethylene Terephthalate, Center for Composite Materials, University of Delaware, U.S.A., Report No. CCM-80-17, 1980... 

U.S. Pat. No. 6,743,507 [40] discloses cellulose-fiber-reinforced composites comprising a matrix polymers such as polyethylene, polypropylene, copolymers, terpoly-mers and mixture thereof in an amount ranging from about 25 to 99% by weight, and cellulose pulp having an a-cellulose purity of greater than about 80, 90, or 98% by weight. 

U.S. Pat. No. 5,288,772 [75] discloses a cellulose-fiber-reinforced thermoplastic composition for compression molding, where thermoplastic material is polypropylene, or a mixture of polypropylene, polystyrene, and polyethylene (40-90% of plastic by weight), and the cellulosic material (10-60% by weight) was milled scrap newspaper with an initial moisture content of at least 30% by weight. The patentees suggest that lignin present in the cellulosic scrap provides a coherent mass of thermoplastic and cellulosic material. 

U.S. Pat. No. 7,022,751 [111] describes a fiber-reinforced composite plastic material comprising thermoplastic polymers such as HDPE, LDPE, polypropylene, PVC, and polystyrene a high melting point waste polymer fiber material such as polyethylene terephthalate and nylon, an inorganic filler, such as glass and other material, and an organic filler such as wood or particles of a thermoset plastic, such as rubber and polyurethane foam. 

F. Yehia, S. Law, M.T. Kortschot. Water absorption in wood fiber reinforced polyethylene. In Progress in Wo odflbre-Plastic Composites, Conference Proceedings, Canadian Natural Composites Council, University of Toronto, Toronto, Canada, 2002. 

If the materials are anisotropic, they will present different properties in the different directions. Examples of these polymeric materials are polymer fibers, such as polyethylene terephthalate, PET, nylon fibers, injection-molded polymers, fiber-reinforced composites with a polymeric matrix, and crystalline polymers where the crystalline phase is not randomly oriented. A typical method for measuring the modulus in tension is the stress-strain test, in which the modulus corresponds to the initial slope of the stress-strain curve. Figure 21.4 shows typical stress-strain curves for different types of polymeric materials. 

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