SFDC183507-01 EXPHC68500 TRANS 172885-04 EXPA82065 TRANS 9034 GEON A88065 TRANS 9034

SF306188-01 EXP4110 UV-TRANS SF301062-01 EXPA6DE4 TRANS 9040 SF291267-02 EXPA6DU65 TRANS 9000

EDGE-GLO TRANS PINK DARK TRANS BLUE TRANS PURPLE 260C

TRANS AMBER PC NO UV TRANS RED PC NO UV 16872-02 EXPL0189 TRANS

TECHNIQUE TRANS BLUE 291C TECHNIQUE TRANS BLUE 291C TRANS PURPLE EVA

TRANS RED 185U TRANS PURPLE 252U TRANS FL RED

TRANS LAVENDAR 2% TRANS PURPLE TRANS PURPLE

Design Guide 33 Mold damages Loss of clamp force Barrel malfunction Melt temperature too Transfer position too low Excessive pack pressure Excessive back pressure Repair mold damage Clean parting line Reduce pinch-off land Increase clamp force Dry material Reduce melt temperature Reduce mold Reduce hold pressure Increase transfer Flash • Excess material commonly found at parting lines or mold features Root cause: Too much plastic or mold damage. 34 Gravi-Tech Design of gate too small or in wrong location Machine not providing Heater overriding Viscosity too low Injection velocity too high Melt temperature Remove sharp corners Change gate type Move gate to a position where the melt stream will impinge upon a mold feature Dry material Reduce injection velocity Increase melt Jetting Root cause: Injection speed is too high for the viscosity of the material Design Guide 35 Finish too rough Screw configuration Overworking material Non-compatible additive Melt temperature too Remove sharp corners Use smaller screw/barrel Check melt uniformity Check L/D ratio Check additive compatibility Reduce screw speed Reduce residence time Plate-Out • Build-up or deposit on mold surface Root cause: One component of the material is not totally compatible. 36 Gravi-Tech Shut-off partially turned Screw problems Barrel heater problems Material too dry Under-packing Not enough pack pressure Transfer position too high Make sure gate is not blocked Insure runner shut-off is not turned Check venting Change gating location Add flow leader Insure cushion position Make sure screw is trans- ferring at a correct Change screw/barrel Make sure material was dried at proper settings Increase melt Increase mold Decrease transfer Short Shot • Not enough material is being injected into the mold to fill out all of the cavities Root cause: Not enough plastic is getting into the cavity. Design Guide 41 Hot spots Improper cooling Impaired venting Melt temperature Reduce transfer position Check gate for blockages Check runner shutoffs Add a flow leader Ensure cushion is maintained Make sure screw is trans- ferring at correct Dry material Increase/decrease melt temperature Increase mold Reduce injection speed Voids • Usually occurs in a thick section where the melt remains hotter than the rest of the part.

TRANS RED CD4989 TRANS. TRANS.

TRANS RED P199C SAN V2 TRANS RHOD. TRANS TURQUOISE P319C SAN