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Ultra High Molecular Weight Polyethylene Highway Guardrail

Jul 01, 2019

In the existing plastics, ultra-high molecular weight polyethylene (hereinafter referred to as UHMWPE) has the highest impact strength and impact energy absorption capacity. UHMWPE raw material is a white powdery material with a density of only 0.93-0.94g/cm2 and more than 5 million. The relatively high molecular weight and the densely entangled structure of the strands of the molecular chains give it outstanding properties. Compared with many thermoplastic polymer materials, the ultrahigh molecular weight polyethylene products have a very low friction coefficient and good Anti-abrasive wear resistance, corrosion resistance, low temperature resistance, impact resistance, stress crack resistance, hygienic non-toxic and many other advantages, non-notched impact specimens even using existing impact test test means, even at liquid nitrogen temperature (- Excellent impact strength and certain ductility can also be maintained at 196 ° C), while ordinary carbon steel exhibits low temperature brittleness. Although UHMWPE products have such excellent comprehensive performance, their processing is very difficult, mainly in: 1, very high melt viscosity, very poor fluidity; 2, UHMWPE friction coefficient is small, high viscoelastic melt is common The single-screw extruder is difficult to continuously convey and process; 3. The critical shear rate is low during melt extrusion, and melt fracture is likely to occur. It is difficult to achieve high efficiency and low cost processing. In order to improve the processing difficulties and production efficiency of UHMWPE, Tsinghua University and the Institute of Chemistry of the Chinese Academy of Sciences have also made significant improvements in the blending modification formula of UHMWPE materials. The blending of liquid crystal polymer and UHMWPE has been modified to improve the individual use. The disadvantage of poor flowability of UHMWPE melt; however, the cost of liquid crystal polymer materials is too high and economically stressful. The road guardrail products manufactured based on existing materials and technologies have shortcomings such as low safety, inconvenient installation and high production cost, and UHMWPE has not been reported for the manufacture of highway guardrail structural materials. Through in-depth research and experiment by Nantong Yamba Company, it is found that the scientific principle of UHMWPE fiber manufacturing can be used for reference, and UHMWPE-based formula material has appropriate high tensile strength (4/5 of existing Q235 carbon steel) and With high elongation at break (more than 2 times of existing Q235 carbon steel), good impact energy absorption performance, economical highway guardrail materials and product production process, corrugated beam plate, round tube, square tube, wire rod UHMWPE highway guardrail material in the shape of a shape or a bar.