Yesterday, we introduced the plastic mold in the plastic molding characteristics of the analysis of liquidity shrinkage, shrinkage, specific volume and compression of these characteristics. Today, Dongguan Plastic mold factory editor to continue to introduce the plastic mold in the plastic molding characteristics of the next part of the analysis.
First, crystallinity, compatibility, heat sensitivity, curing and melt fracture
Crystallization refers to the polymer molecules can do the rules of space to produce the ability to produce crystals. The crystallinity of the polymer is related to the size of their crystallinity. Volatile content refers to the volatiles in plastic, including water, chlorine, air, formaldehyde and other low molecular weight content. Thermosensitive refers to poor thermal stability of plastics.
Second, the melting marks, internal stress, after-product processing
Reduce the melting marks, the use of better mobility of plastic, or increase the number of gates, shorten the process to a faster time filling; appropriate to improve the material temperature or mold temperature; to enhance the mold exhaust measures; Fold marks generated in the plastic parts of the secondary parts; try not to release agent and so on. An important factor in the generation of internal stress is the shear stress at the time of injection and feeding. Reduce the stress measures: injection pressure should not be too high, the use of higher material temperature and mold temperature, packing time to moderate, can take step-down pressure method, after forming the product heat treatment. The post-treatment (heat treatment) of the product has an annealing treatment and a tempering treatment.
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