TROUBLESHOOTING

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Incompatible Color Or Additive Carriers
We recommend using only polyolefin carriers, such as polypropylene or polyethylene, for colorants and additives. Never use polyvinyl chloride-based additives because they can react with TPVs at typical processing temperatures and cause a safety hazard. To rule out an incompatible color or additive carrier as a cause, run natural virgin material under the same conditions. If the problem disappears, it is likely associated with an additive.

Prior Runs Have Contaminated The Plastification System
We recommend always physically cleaning the entire injection molding system, including the hopper, barrel, screw, shut off valve, nozzle and mold, prior to beginning a run with our TPV materials. Foreign materials in these areas may not blend properly with our materials and cause streaking or chunks in the part. The system can be purged using polyethylene or polypropylene. Never use polyvinyl chloride or its derivatives to purge the system.

Insufficient Blending Of Color Concentrate
Blending of our TPV materials and the color concentrate happens when both materials reach the melt phase. Check our Injection Molding Guide to ensure that melt temperature is within the recommended processing range. If melt temperature is correct, then focus should be placed on increasing the shear, heating and mixing of material in the barrel.

• First try increasing the back pressure


• Next try reducing the rear zone temperature


• If these suggestions do not work, it may be necessary to replace the screw or nozzle with one that has a mixing design

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