Ultra-high-molecular-weight polyethylene fibers

G.C. Weedon, C.P. Weber, Jr., and K.C. Harding, Ultra high molecular weight polyethylene fibers, US Patent 6 951685, assigned to Integrated Textile Systems, Inc. (Monroe, NC), October 4, 2005. 

The ultra-high molecular weight polyethylene fiber is a highly crystalline fiber with very high stiffness and strength. All of this results from some innovative processing and control of structure of polyethylene. 

Figure 4.11 Flow diagram of the gel-spinning process of making ultra high molecular weight polyethylene fiber.

Composed of ultra-high-molecular-weight polyethylene fibers. Spectra cable is another option that is available to body-powered prosthesis designers and users. Spectra cable is now widely used at almost all major upper-limb fitting... 

Ultra-high molecular weight polyethylene fibers depend on the particular properties of polyethylene. Polyethylene is a polymer consisting of long chains, as shown in Fig. 10.4. It has the simplest chemical stmcture among polymers. 

Ultra high molecular weight polyethylene fiber Dyneema (Toyobo) SK60 26.4-35.2 880-1232... 

Zeng J, Netravali AN. KrF excimer laser surface modification of ultra-high molecular weight polyethylene fibers for improved adhesion to epoxy resin. In Mittal KL, editor. Polymer surface modification relevance to adhesion, 3. Boca Raton, EL CRC Press 2004. p. 159-82. 

Netravali AN. Surface modification of ultra-high molecular weight polyethylene fibers for improving adhesion to epoxy resins. Int J Plastics Technol 2003 6 6-10. 

Pennings A J and Smook J (1984), Mechanical properties of ultra-high molecular weight polyethylene fiber in relation to structural changes and chain scissoring upon spinning and hot-drawing / Mater Sci, 19,3443-3450. 

Penning J, Pras H, Pennings A. Influence of chemical crosslinking on the creep behavior of ultra-high molecular weight polyethylene fibers. Colloid Polym Sci 1994 272 664-76. 

There are several interesting applications reported in the literature, such as insulated wire and cable, UV cross-linking of drawn fibers, and tapes from ultra-high-molecular-weight polyethylene. Semi-interpenetrating networks (IPNs) from acrylates and polyurethanes are suitable as UV curable adhesives with high elasticity, good impact resistance, and excellent adhesion to a variety of substrates. ... 

Carbon fibers have been incorporated in the high density polyethylene used in total knee replacements (Figure 41.5). The standard ultra high molecular weight polyethylene (UHMWPE) used in these implants... 

FIGURE 41.6 Properties of carbon fiber reinforced ultra high molecular weight polyethylene. (Replotted from Sclippa, E. and Piekarski, K. 1973. /. Biomed. Mater. Res., 7,59-70. With permission.)... 

The focus in this chapter will be on the two main polyolefin polymers, namely polyethylene (PE) and polypropylene (PP). The latter especially has established itself as a very versatile fiber with unique applications in the textile and nonwoven industry. Polyethylene, on the other hand, has not been widely used as a fiber compared to other synthetic polymers such as PET, PP, and nylon, due in part to its low melting point. This chapter will, however, discuss ultra-high molecular weight polyethylene (UHMWPE) fiber that given its success and uniqueness in the synthetic fiber industry. 

Conventionally, ultra-high molecular weight polyethylene is used for such applications with certain metallic alloys as counterparts. In comparison to this conventional polymer, PEEK and composites of PEEK with carbon fibers show the lowest wear rate on the counter metallic materials. 

The ballistic properties of high performance fibers such as ultra high molecular weight polyethylene (UHMWPE) and aramid and their composites are very well known. The ballistic properties of flax, hemp, and jute fabric reinforced PP composites processed by hot compression molding have also been investigated. It has been shown that flax composites exhibited better properties when compared with hemp and jute composites [48]. 

Lennite, Lennite XL, Ultra-high-molecular-weight polyethylene, Westlake Plastics Co. Leucopure EGM, Fluorescent whitener for polymers, Clariant Corp., BU Additives Levapren, EVA resins, Bayer Corp., Fibers, Additives Rubber Div. 

Figure 8.1. Overview of high performance fibers mechanical properties. PET = poly(ethylene terephthal-ate), UHMWPE = ultra high molecular weight polyethylene, PBO = poly(benzoxazole), M5 = PIPD or poly[di-imidazo-pyridinylene-(dihydroxy phenylene)]. The p-aramids included in the area are Kevlar, Twaron, Technora and SVM (Armos, Rusar) fibers. The latter fiber tjipe accounts for the high mod-ulus/high tenacity area of aramids (Adapted from ref. [6]). For chemical structures see Scheme 8.1...

From Figure 8.1 [6] it can be seen that in terms of modulus and tenacity (i.e., the tensile strength divided by the linear density) only the more expensive carbon fibers and some even more expensive, relatively new experimental heat-resistant fibers outperform the p-aramides. It is noteworthy that the oriented fibers of ultra-high molecular weight polyethylene (UHMWPE), e.g., Dyneema , a product of DSM, The Netherlands, display tenacities and moduli in the same range as most p-aramids, however without having their excellent thermal and flame-resistance, as well as insolubility in most organic solvents. 

Due to properties like flexibility, light weight and good mechanical properties aramid fiber, polypropylene and ultra-high molecular weight polyethylene based materials were selected and tested according to the safety shoes standards. The results of these tests were helpful to see if these materials were suitable options for the new insert. The results... 

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