Thermoplastic Elastomer Molding Guidelines
Suggested Remedies Perform in numerical order by column |
Problem | ||||||||||||
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Flash | Jetting | Knit Lines | Non-uniform Color | Over Mold Breaks Thru | Shorts | Surface Sinks | Surface Splay | Parts Sticking in Cavity | Poor Adhesion | Warp | |||
Add Mechanical Interlocks | ![]() |
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Add Surface Texture | ![]() |
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Add Pneumatic Air Poppets | ![]() |
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Check for Material Contamination | ![]() |
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Check Mold Shut-Off | ![]() |
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Check Vent Depth | ![]() |
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Clean Mold Surface | ![]() |
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Decrease Back Pressure | |||||||||||||
Decrease Injection Pressure | ![]() |
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Decrease Injection Speed | ![]() |
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Decrease Hold Pressure | ![]() |
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Decrease Material Temperature | ![]() |
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Decrease Mold Temperature (Cavity) | |||||||||||||
Decrease Shot Size | |||||||||||||
Dry Material | |||||||||||||
Gate in Thickness Cross Section | |||||||||||||
Imcompatible Materials | |||||||||||||
Increase Amount of Gates | |||||||||||||
Increase Back Pressure | |||||||||||||
Increase Hold Pressure | |||||||||||||
Increase Injection Pressure | |||||||||||||
Increase Injection Speed | |||||||||||||
Increase Material Temperature | |||||||||||||
Increase Mold Temperature | |||||||||||||
Increase Shot Size | |||||||||||||
Increase Substrate Support | |||||||||||||
Move Gate Location | |||||||||||||
Redesign Ejection Mechanism |
This information is intended to be used only as a guideline for designers and processors of modified thermoplastics for injection molding. Because injection mold design and processing is complex, a set solution will not solve all problems. Observation on a “trial and error” basis may be required to achieve desired results.