Plastic products aging become fragile Various reason

Automobil plastic net news: it’s not hard to find, plastic containers, plastic cups, plastic buckets, etc. We are living in the most commonly used to plastic products in the long run will appear the phenomenon of aging brittle, so this is the reason?Actually this with mold, equipment, raw materials, process, design of these five aspects are closely linked.A, mold (1) the gate is too small, should consider to adjust the gate size or adding auxiliary gate.(2) the shunt way too small or misallocation, should try to arrange reasonable balance or increase the size of distributary channel.(3) the mold structure bad cause abnormal injection cycle.Second, the equipment (1) barrel inside corner or obstacles, easy to promote the degradation of melting.(2) the plasticizing capacity of the machine is too small, plastic inside the barrel plasticizing inadequate;Machine plasticizing capacity is too big, plastic is heated and the shearing action in the barrel time is too long, plastic easy to aging, make the products become fragile.(3) ejection device tilt or imbalance, dry area small or improper distribution.Three, raw materials (1) in terms of raw materials mixed with other impurities or with improper or excessive solvent or other additives.(2) some plastics such as ABS, etc., will under the condition of be affected with damp be affected with damp heat and water vapor catalytic cracking reaction, result in large strain of parts.(3) plastic regeneration frequency or reworked material content is too high, or within the barrel heating time is too long, cause embrittlement of fabrication.(4) the quality of the plastic itself, such as molecular weight distribution, contains the uneven structure such as molecular chain rigidity is too large in the number of components;Or the other plastic doping pollution, bad additives pollution, dust pollution of impurities is also the cause of brittle.Four, process (1) barrel, nozzle temperature is too low, to raise it.If the material easy degradation, should raise the temperature of barrel, nozzle.(2) reduce the screw plastic back pressure and rotational speed, make the material a little loose, and reducing the plastic degradation caused by shear overheating.(3) the mold temperature is too high, demoulding difficulty;Mold temperature is too low, premature plastic cooling, fusion welded seam bad, easy to crack, especially when high melting point, such as polycarbonate plastic.(4) the mold core to a proper draft.Core difficult demoulding, to improve the mold temperature, shorten the cooling time.Cavity is difficult to take off, want to lower the temperature in the cavity, extend the cooling time.(5) as far as possible with a metal insert, such as polystyrene plastic of this kind of specific volume of brittleness of cold heat is big, can’t join the insert molding.Five, the products design (1) products with prone to stress cracking of sharp corners, gaps, or thickness vary widely.(2) the product design is too thin or hollow out too much.Conclusion: plastic products provided a lot of convenience to our life, while it also has many flaws, but we believe that the future plastic industry can develop more perfect and more convenient products.Editor: Zhao Pei male