Purge Guidelines
Purge and shutdown compounds are generally used to reduce changeover time and start up yield loss for injection molding and extrusion lines. These products help speed the turnaround, reduce start-up scrap, increase productivity and free up capacity when there is a color or material change on your lines.
Product |
Purge Recommendations |
| ABS | HDPE, PS (see note #2) |
| ABS/PVC Alloys | Cast Acrylic, PS, HDPE (see note #4) |
| Acetal Copolymer | HDPE, PP, PS (see note #1) |
| Acrylic | Clean Acrylic Regrind |
| ASA Blends | HDPE, PP (see note #3) |
| Flame Retardant Compounds | Immediate purging with natural non-FR resin mixed with 1% sodium stearate |
| Fluoropolymers | Cast Acrylic followed by PE (see note #4) |
| Isoplast | GPPS, HIPS, SAN, ABS |
| LCP | PP (see note #1) |
| Nylon PBT | HDPE, PP (see notes #1 and #3) |
| PBT | PS, HDPE |
| PC / PBT Alloys | HDPE, PS (see note #2) |
| PC / ABS | Natural ABS, SAN, PS, Cast Acrylic (see note #4) |
| PEI | HDPE, Glass reinforced PC |
| PET | Cast Acrylic, ASA, HDPE (see note #4) |
| Polycarbonate | Cast Acrylic, ASA, HDPE (see note #4) |
| Polylefins | HDPE (see note #3) |
| Polystyrene | Cast Acrylic (see note #4) |
| Polysulfone | Reground Polycarbonate, extrusion grade PP |
| Polysulfone / ABS | Reground Polycarbonate, extrusion grade PP |
| PPO / PPE | Cast Acrylic, PS (see note #4) |
| PPS | Acrylic, LDPE |
| PPS | HDPE |
| PVC - Flexible | HDPE (see note #2) |
| PVC - Rigid | General Purpose, non-FR ABS, Acrylic, PS (see note #2) |
| Thermoplastic Polyester Alloys | HDPE |
| TPE | HDPE, PP (see note #) |
| TPU | General Purpose, non-FR ABS |
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Resin Resource recommends and sells Phoenix Plastics Co., Inc. Cel-Span Purge and Shutdown Compounds. |
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Notes
Note 1: Run barrel dry and leave the screw forward if resuming with the same material after shutdown.
Note 2: CAUTION! Do not combine acetal and PVC in the barrel for any reason!
Note 3: Tide laundry detergent can be used in a 50/50 blend with PP or PE for abrasion in barrel and on screw. Polypropylene can also be used with 1-2% water to create steam and foaming action to clean barrel and screw.
Note 4: Remove nozzle when purging with cast acrylic.
