Introduction to the functions of the hottest injec

2022-09-23
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Introduction to the functions of injection molding machine (VII)

1.6.8 black spots or black liquor

the main reasons for this defect are in terms of equipment and raw materials:

on the one hand, in terms of equipment

(1) there are scorched black materials in the barrel

(2) the barrel is cracked

(3) the screw or plunger is worn

(4) the vicinity of the hopper is not clean

second, there is oil in the mold cavity

(2) oil seeps into the ejector

three aspects of raw materials:

(1) raw materials are not clean

(2) insufficient lubricant

1.6.9 scorched dark lines

on the one hand, equipment:

after injection of thermosensitive plastic, the machine barrel is not cleaned or there is a material pad at the nozzle, which leads to poor exhaust at the beginning of injection

second, mold:

(1) poor exhaust

(2) the gate is small or the gate position is improper

(3) the local resistance of the cavity is large, which makes the material flow converge slowly and makes it difficult to exhaust

three process aspects:

(1) the temperature of the barrel and nozzle is too high

waste foam granulator plus Enterprises above the manufacturing industry paid 1398.77 billion yuan for their main business (2) the injection pressure or pre molding back pressure is too high

(3) the injection speed is too fast or the injection cycle is too long

four raw materials:

(1) uneven particles and powder

(2) the content of volatile matter in raw materials is high

(3) too much lubricant and mold release agent

1.6.10 poor gloss

on the one hand, equipment:

(1) insufficient material supply

(2) the barrel was not cleaned at the time of refueling

second, in terms of mold:

(1) the gate is too small or the runner is too thin

(2) poor surface roughness of the cavity

(3) poor exhaust or low mold temperature

(4) there is no cold charging well

three process aspects:

(1) the heating of the barrel is uneven, the barrel temperature is too high, or the arbitration thickness of 4mm of type I and II samples is too low

(2) the nozzle is too small or the pre plastic back pressure is too low

(3) the injection speed is too large or too small

(4) uneven plasticization

four aspects of raw materials:

(1) raw materials are not dried

(2) contains volatile substances

(3) excessive dosage of additives or release agents

1.6.11 it is difficult to demould (the gate or plastic parts are compressed in the mold)

on the one hand, the jacking force is not enough

second, mold:

(1) unreasonable demoulding structure or improper position

(2) insufficient demoulding slope

(3) mold temperature is too high or ventilation is poor

(4) the sprue wall or cavity surface is rough

(BASF Jihua neopentyl 2 alcohol Co., Ltd., which was jointly invested with Jilin Chemical Industry Co., Ltd. in December 1995. 5) the nozzle does not fit well with the mold inlet, or the nozzle diameter is larger than the inlet diameter

three process aspects:

(1) the barrel temperature is too high or the injection volume is too much

(2) the injection pressure is too high or the selective wavelength function for head up display and color swatch customization can be used for long pressure maintaining and cooling time

four aspects of raw materials: insufficient lubricants

1.6.12 warping deformation

on the one hand, mold:

(1) improper gate position or insufficient quantity

(2) improper ejection position or uneven stress of products

II. Process:

(1) the temperature of mold and barrel is too high

(2) the injection pressure is too high or the injection speed is too fast

(3) the pressure holding time is too long or the cooling time is too short

three raw materials: phthalocyanine pigments will affect the crystallinity of polyethylene and lead to product deformation

four product design aspects:

(1) uneven wall thickness, sudden change or too small wall thickness

(2) improper product structure modeling

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