Plasco Inc. www.plasco-corp.com (831) 464-1111 -- Clear Plastic, Processing Archive

POLYCARBONATE RESIN MOLDING TROUBLE SHOOTING GUIDE

BLACK SPECKS Purge with ground acrylic or polycarbonate regrind. purge occasionally during startup from 520F until desired melt temp. reached.

BRITTLENESS lower material temp. by lowering cylinders lowering screw speed, or lowering back psi. check for contamination. dry material.

BURN MARKS decrease injection speed. decrease booster time. decrease injection psi. improve mold cavity venting. alter gate size/location.

DELAMINATION raise mold and/or material temp. dry mat'l. eliminate contamination. inc. inject. speed

JETTING decrease inject. speed. increase resin temp increase gate size and/or gate land length

STICKING IN CAVITY decrease inj. psi. decrease inj. hold. de-crease booster time. adjust feed/cushion. increase mold close time. decrease cylinder and nozzle temps. check mold for draft.

STICKING ON decrease inj. psi., inj. hold, booster time adjust feed/cushion. decrease cylinder temp or nozzle temp or core temp. check mold for undercuts or draft.

VOIDS / SINKS increase inj. psi., inj. hold time, use max inj. speed (sinks). raise mold temp (voids) lower mold temp (sinks). decrease cushion relocate gates near thick sections. coreout

WARPAGE &
DISTORTION equalize temp of both mold halves. observe mold ejection uniformity. check handling of parts. increase die-close time. jig parts.

WELD LINES increase inj. psi., inj. hold time. raise mold and/or mat'l temp. vent cavity in the weld area. change gate location.

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BLACK SPECKS		Purge with ground acrylic or polycarbonate regrind. purge occasionally during startup from 520F until desired melt temp. reached.
BRITTLENESS		lower material temp. by lowering cylinders lowering screw speed, or lowering back psi. check for contamination. dry material.
BURN MARKS		decrease injection speed. decrease booster time. decrease injection psi. improve mold cavity venting. alter gate size/location.
DELAMINATION		raise mold and/or material temp. dry mat'l. eliminate contamination. inc. inject. speed
JETTING		decrease inject. speed. increase resin temp increase gate size and/or gate land length
STICKING IN CAVITY		decrease inj. psi. decrease inj. hold. de-crease booster time. adjust feed/cushion. increase mold close time. decrease cylinder and nozzle temps. check mold for draft.
STICKING ON		decrease inj. psi., inj. hold, booster time adjust feed/cushion. decrease cylinder temp or nozzle temp or core temp. check mold for undercuts or draft.
VOIDS / SINKS		increase inj. psi., inj. hold time, use max inj. speed (sinks). raise mold temp (voids) lower mold temp (sinks). decrease cushion relocate gates near thick sections. coreout
WARPAGE & DISTORTION		equalize temp of both mold halves. observe mold ejection uniformity. check handling of parts. increase die-close time. jig parts.
WELD LINES		increase inj. psi., inj. hold time. raise mold and/or mat'l temp. vent cavity in the weld area. change gate location.