A meaning: after the melt into the mold cavity does
not fill completely, causing plastic parts shortage of material.
Second, Causes and Remedy:
①, improper selection of equipment: When sorting
equipment, melt glue machine must be greater than the amount of molten plastic
products, plastic parts by weight of the machine can only account for 85% of
the total amount of melt.
②, feed shortage: the charging port if there is
"bridging" phenomenon, may be appropriate to increase the screw
injection stroke, increasing the feed rate.
③, raw illiquid: improved die casting system stagnation
defect, a reasonable set of pouring glue position, expanding gates, runners and
injection spout sizes and use larger nozzle, an appropriate increase in raw
material temperature.
④, gating system design is unreasonable: gating system
design, pay attention to the gate balance, the weight of the plastic parts of
each cavity is proportional to the gate, the cavities are filled
simultaneously, gate locations to be selected in the original wall parts,
sub-runner balance design layout can also be used.
⑤, mold exhaust bad: check cold material cavity, or
location is correct, for deep cavity mold, should be added to the exhaust vent
in the trenches and less injection site, the clamping surfaces can be opened
Deep 0.02 -0.04mm, 5-11mm in width exhaust ducts, vents should be provided in
the final filling of the mold cavity. Also in the process of operation, by
increasing the die temperature, reducing the injection speed, gating system to
reduce resistance, and to reduce the clamping force.
⑥, mold temperature is too low: the mold must be
preheated to the required temperature before starting the process, if the mold
temperature does not rise up, check the mold design is not only reasonable
waterway.
⑦, the injection pressure is insufficient: the length
of the injection pressure is close to a positive relationship with the die,
injection pressure is too small, short filling length, filling the cavity
dissatisfaction, which can slow down the plunger forward speed through proper
injection ting long time to improve injection pressure.
more information www.plastic-injectionmoulding.com www.injectionmoldchina.com
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