Effect Of Plastic Wood Raw Material On Properties Of Plastic Wood

Molecular Weight Distribution: From the point of view of moulding processing, the wide molecular weight distribution is narrower than the distribution, better fluidity, easy to control, and the wide molecular weight distribution can reduce die pressure, reduce the tendency of parison melt rupture, improve processing performance, and increase extrusion speed under the same conditions of plastic wood. However, the wide molecular weight distribution also indicates that there are relatively low and high molecular weight parts. When the proportion of relatively low molecular weight parts is too high, the mechanical properties and thermal stability of products decrease. The grading effect of wood-plastic flooring and flowing process makes the low molecular weight parts of polymer concentrate more on the extruded parison surface, even from the surface, the parison surface can be seen clearly. Up there are some small white particles sprinkled on it. The inner wall of blow-moulded products is rough. The falling white particles are easy to block the air valve and cause the failure of the air passage system. When the proportion of high relative molecular weight is too high, plasticizing is difficult, particulates on the surface of parison appear incompletely plasticized, and the appearance quality decreases. At present, resin with bimodal distribution tends to replace single peak distribution. Under the same conditions, resin with bimodal distribution has excellent processability and melt strength, and its environmental stress cracking resistance is also significantly improved. Melt flow rate: The melt flow rate reflects the relative molecular weight to a certain extent. The smaller the melt flow rate is, the larger the relative molecular weight is. The bigger the relative molecular weight, the better the melt strength of the billet. It can change the weight sag of the billet. It is advantageous to improve the tensile strength, impact strength and hot deformation temperature of the product. However, the bigger the relative molecular weight, the higher the viscosity, the worse the fluidity, and the difficulty of processing. At the same time, the billet has a high "shrinkage" property, and the billet will have a larger shrinkage before joining. Under the same conditions, the unstable flow of billet intensifies, even the melt breaks down. Therefore, considering the processing capacity and technological feasibility of the equipment, almost all 200 L plastic drum manufacturers choose HMWHDPE resin. The melt flow rate can meet the product quality requirements, generally about 2.0 (g/10min, 21.6kg).