LCP blistering

LCP blistering

【Date】:2013-12-31 【Hit】:5300
LCP blistering high temperature engineering material in question is the most common phenomenon, generally no more than the following points: 1 , the material is not completely dried . 2 , the material quality of impure material . 3 , the material itself is not enough other reasons HDT , here I LCP blistering common share with friends

1 large shearing
High shearing action between fire retardant and causes adverse glued plastic , or a gap in the plastic inner layer and the surface , plus the moisture will enter the gap after the water , and then through the high temperature will produce blistering .
Nearby points easier blistering 1.1 irrigation , irrigation near the point because Paul withstand greater pressure than other parts , and materials have a greater role in cutting through the filling point, pour point so near easier than other parts of the blister .
Suggestion: try to reduce injection pressure and holding pressure , another moderate increase irrigation spot diameter can be reduced shearing .
1.2 Molding conditions :
The same products, high rate of fire than the low rate of fire easily blistering .
Recommendation: Short shot selection is not lack of material like rate of fire , speed is not too high .

2 product appearance
Shape of the product is also one of the factors causing blistering .
2.1 Thickness
Part of the meat thin flesh easier than some of blistering .

3 Materials cleavage :
Material is also one of the important reasons cracking blistering , cracking because the material will cause poor material properties , and pyrolysis gas is generated , the formation of small bubbles in the plastic products , the expansion of a few high-temperature environments + bubble formation .
Recommendation: Do not feed tube temperature set too high in order to avoid unnecessary material cracking .
The proportion of recycled material used to control the high proportion of recycled also cause cracking .
Choice of appropriate feeding tube , feeding tube is too large , then the production of small finished feeding tube will cause the material and then stay too long , resulting in lysis, the total reservoir feeding tube feeding amount not to exceed the finished product
10 times the weight of the total .

4.LCP hygroscopic materials :
LCP,尼隆series of plastic material if moisture, blistering phenomenon is likely to occur in the face of high temperatures.
Suggestion: try to keep the product dry to avoid moisture .
I have a client who appeared on half a bag of feed produced OK, but the second half of the bag but adverse product bubbles. The same material

The same material as well as the same mold process , looking for most of the day do not know why . After careful inquiry, turned out to be every weekend , and the remaining half bag of material placed for two days, also coincides with the rains , causing the material caused by excessive water absorption .

5.LCP lack of raw grain baking :
Raw grain itself, high humidity , lack of time and baked products will easily blistering Even if raw material bags with aluminum foil bag, must have enough baking.
Recommendation: the raw grain must be dried before baking enough line production .

6 Pine push position
Intent of the position is to prevent loose push gum , if set incorrectly will re- air suction tube , forming the next time it is easy to bring products
Recommendation: Set the value to glue nozzle does not flow as well.

[ Summary ]: plastic foam no more than three important reasons: there is a gap within one product after moisture at high temperature blistering second material is not drying moisture content , or back enough material mixed with gas . or feeding tube temperature is too high, the material fission gases cause blistering . poor Third mold venting , or too high rate of fire , filling time is too short , can not be successfully discharged gas cavity

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