High modulus polyethylene fibres

Solution processing also plays a vital role in the manufacture of high value, lyotropic high modulus fibres and also high modulus polyethylene fibres. In all these cases the additional cost and complication of solvent recovery is offset by the high value of the produced product. 

Jang JS, Moon SI, Impact and behavior of carbon fibre/ultra-high modulus polyethylene fibre hybrid composites, Polymer Composites, 16(4), 325-329, 1995. 

Li Y, Xian XJ, Choy Cl, Guo MI, Zhang ZG, Compressive and flexural behavior of ultra-high-modulus polyethylene fibre and carbon fibre hybrid composites, Composites Sci Technol, 59(1), 13-18, 1999. 

The ability to control the interface is central to successful application of adhesion in a composite. By modifying or tailoring the interface, the improved fundamental adhesion might result in the improved practical adhesion for example, various surface treatments of ultra-high modulus polyethylene fibres used as reinforcemenf in polyester and epoxy composites that changed the values of both monofilament pull-out adhesion and interlaminar shear strength. ... 

Fig. 8 shows that long axial splits also occur in the tensile fracture of a high-modulus polyethylene fibre. 

High modulus polyethylene fibres (up to 70 GPa) can be produced by forcing a polymer bar through a spinneret at a temperature just below melting point. Recently, ultraoriented polyethylene tubes have been obtained by the same technique. 

Ladizesky, N.H. and Ward, I.M., Ultra-High-Modulus Polyethylene Fibre Composites I—The Preparation and Properties of Conventional Epoxy Resin Composites. Comp. Sci. and Techn., 1986, 26, 129-164. 

Hine P J, Ward I M, Abo El Maaty M I, Olley R H and Bassett D C (2000) The hot compaction of 2-dimensional woven melt spun high modulus polyethylene fibres, J Mater Sci 35 5091-5099. Jordan N D, Olley R H, Bassett D C, Hine P J and Ward IM (2002) The development of morphology during hot compaction of Tensylon high-modulus polyethylene tapes and woven cloths, Polymer 43 3397-3404. 

Although there are limitations in the maximum working temperature due to the comparatively low melting point, the chemical inertness will be a positive advantage and in many applications the relevant temperature range is close to ambient. A further positive advantage of ultra high modulus polyethylene fibres is the comparative simplicity of the fibre process which leads to a low projected cost of manufacture. 

Finally, it is of interest to compare the theoretical values for a uniaxially oriented sheet (calculated by averaging the stiffness values using the Voigt averaging scheme) with those obtained for a die-drawn rod and a sheet made by hot compaction of high modulus polyethylene fibres (Table 8.4). It can be seen that although, as expected, these materials have not reached full axial orientation so that the experimental values of C33 are much less than the theoretical value, the patterns of anisotropy are very similar, and some of the values for the other elastic constants are surprisingly close. 

The structure of high modulus polyethylene fibres obtained by optimized drawing of linear polyethylene is viewed as crystalline lamellae linked by intercrystalline bridges.Accordingly, the component B is then viewed as crystalline, and its content (1 — >1) corresponds to the volume fraction of the material incorporated in the crystalline bridges. A more complex model consisting of four components has been proposed for these fibres by Grubb. 

The combined effect of high modulus polyethylene fibre which can be considered as the reinforcing fibre and fibrillated polypropylene pulp, which is effective for processing, was reported by Souroshian etal. [107] showing positive interactions between the two with respect to hardened composite properties. 

Hine PJ, Ward IM, El Matty MIA, Olley RH, Bassett DC (2000) The hot compaction of 2-dimensional woven melt spun high modulus polyethylene fibres. J Mater Sci 35 (20) 5091-5099... 

High-performance polymeric fibres have the potential to revolutionize the use of composites and other fibre applications. Although at present only aramid fibres and high-modulus polyethylene fibres have achieved a truly commercial breakthrough, it can be expected that a large number of fibres based on thermotropic LCPs will be available in the near future, such as Twaron (Enka), Technora (Teijin), Ekonol (Sumitomo) and Vectran (Celanese-Kuraray). ... 

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