First of all, look at the appearance. The surface of the inner and outer walls of the high-quality PE pipe is smooth, flat, free of bubbles, depressions, impurities and other defects; the surface of the inner and outer walls of the inferior pipe is not smooth, not bright, has pitting, and has many granular impurities. The inner and outer surfaces are markedly concave. High-quality PE pipe products are shiny and flat, and are not easy to break after repeated folding; inferior products are dark in color, easy to break when folded, and are relatively fragile. The flanging of high-quality PE pipe products is smooth and flat, and after the joint pressure, the flanging can be longer; the surface of inferior products has a large number of pores after flanging. Short hem after seam pressure. The high-quality PE pipe has a slight plastic fragrance after processing or heating and melting, and the product after cooling has no peculiar smell; the inferior product has a strong pungent odor. The high-quality PE pipe burns and melts stably, the flame base is light blue, and there is no peculiar smell. Inferior products have unstable combustion, irregular melting droplets, and a small amount of black smoke and peculiar smell. Oxidation induction time is the time when the sample begins to undergo autocatalytic oxidation reaction under high temperature oxygen conditions, and it is an index to evaluate the thermal degradation ability of materials during molding, storage, welding and use. The longer the oxidation induction time, the better the aging resistance of the product and the better the performance.
