Post-Molded Part Finishing PLET 370 Mike Alabran Andrew Magenau Bret Neese

Objective Introduce and give a brief overview of the different methods of gate and flash removal. Introduce and give a brief overview of the different methods of gate and flash removal.

Outline Gate Removal Gate Removal –Theory and background –Basic operation with examples –Gating Designs Flash Removal Flash Removal –Theory and background –Basic operation with examples –Design requirements

Introduction to Gate Removal Manual Manual –Hand-held tools Automatic Automatic –3 plate molds –Pneumatic sprue cutters –Floor or robot beam-mounted fixtures –Punch presses –CNC gate cutters –Robots –Lasers

Theory and Background-gate removal Reasons for de-gating Reasons for de-gating –Remove runner from part –Visual aesthetics –Medical applications –Assembly purposes

Theory and Background-gate removal (continued) Advantages-manual de-gating Advantages-manual de-gating –Low equipment cost Disadvantages Disadvantages –Inconsistent cut –Increased operator cost –Cycle time issues

Basic Operation-gate removal Hand-held tools Hand-held tools –Blades

Basic Operation-gate removal (continued) –Side Cutters –Saws –Pneumatic cutters

Basic Operation-gate removal (continued) Pneumatic sprue cutters Pneumatic sprue cutters –Integrated onto robotic EOAT (end of arm tooling) –Additional air circuits and programmed sequence from robot –Work best on cylindrical or rectangular runners –Estimated gate vestige ( inches) –Can be cost effective

Basic Operation-gate removal (continued) Floor or robot beam-mounted fixtures Floor or robot beam-mounted fixtures –Framework mounted to robot beam or floor –Pneumatic sprue cutters or cutting blades mounted to pneumatic cylinder –Prolongs life of robot Doesn’t support weight of cutters Doesn’t support weight of cutters –Change-over tooling –No extra air circuits

Basic Operation-gate removal (continued) Floor-mounted Floor-mounted Robot beam-mounted Robot beam-mounted

Basic Operation-gate removal (continued) Punch Press Degating Punch Press Degating –Used when vestige is critical Between.003 and.01 in Between.003 and.01 in –Operated automatically or manually –Components Pneumatic slide Pneumatic slide Ram cylinders Ram cylinders Slide table with rods and bearings Slide table with rods and bearings

Basic Operation-gate removal (continued) Punch Press Punch Press

Basic Operation-gate removal (continued) CNC degating CNC degating – Ideal for Multiple gate-cutting applications –Robot beam-mounted or floor mounted –Holds up to 20 different programs Robot Beam Mounted Robot Beam Mounted –Equipped with a pneumatic sprue cutter Floor Mounted Floor Mounted –Works in conjunction with a sprue picker

Basic Operation-gate removal (continued) Robot Beam Mounted Robot Beam Mounted Floor Mounted Floor Mounted

Basic Operation-gate removal (continued) Robotic Degating Robotic Degating –5 or 6 axis robot –Gate vestige to.015 in Advantages Advantages –Multiple gate types –High repeatability

Basic Operation-gate removal (continued) Robotic Degater Robotic Degater

Basic Operation-gate removal (continued) Laser Degating Laser Degating –Usually not cost effective –Driven by pneumatic cylinder or electric motor –Gate vestige in

Gating Designs Automatically Degated Automatically Degated –Tunnel Gate, Cashew/Banana Gate, Jump Gate, Pinpoint Gate, Chisel Gate Manually Degating Required Manually Degating Required –Sprue Gate, Edge Gate, Fan Gate, Film Gate, Ring Gate, Diaphragm Gate

Theory and Background – Flash Removal Causes Causes –High injection pressure –Low clamp tonnage –Oversized shot dosage –Excessive melt temperature –Improper Drying –High residence time

Theory and Background – Flash Removal (continued) Locations of flash Locations of flash –Parting line –Part features Holes, small features, or vents Holes, small features, or vents

Background – Flash Removal (continued) Reasons to eliminate flash Reasons to eliminate flash –Visual aesthetics –Functional purposes Medical applications Medical applications Assembly requirements Assembly requirements Tolerance issues Tolerance issues

Basic Operation- Flash Removal – (continued) Methods of flash removal Methods of flash removal –Manual Trimming methods Knives Knives Cutters Cutters Flame Flame

Basic Operation- Flash Removal – (continued) Methods of flash removal Methods of flash removal –Other methods Wire brushes Wire brushes Hot wire deflashing Hot wire deflashing –Electric resistance heated wire Flash removal machines Flash removal machines High pressure water High pressure water Liquid nitrogen Liquid nitrogen

Basic Operation- Flash Removal – (continued) Flash Removal Machine Flash Removal Machine

Basic Operation- Flash Removal – (continued) High Pressure Water High Pressure Water

Basic Operation- Flash Removal – (continued) Liquid Nitrogen Liquid Nitrogen

Design requirements – Flash Removal Strong clamping mechanism Strong clamping mechanism Rigid mold Rigid mold Strong support plate or pillars Strong support plate or pillars

Conclusion Gate removal Gate removal –Application sensitive –Recommendations –Costs Flash Removal Flash Removal –Application sensitive –Recommendations –Costs