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. | Tech Tip May 1997 |
General Purging Guidlines:
Last month we talked about how to purge. The following is a suggested list of what to purqe with when going from one material. Please note that you may want to look at what you are going to see if the purging material is compatible. Nothing is worst than to have purged the one material out, only to have the purging material cause you contamination for the next four hours.
|
Material to be purged |
Preferred compounds |
Comments |
|
ABS |
Crystal Polystyrene, ABS, Acrylic, HDPE |
|
|
Acrylic |
Cast Acrylic, Crystal PS |
|
|
Acetal |
HIPS, Crystal PS, Cast Acrylic |
No PVC, Santoprene, Alcryn contact |
|
Nylon |
HDPE, Cast Acrylic Crystal PS |
|
|
Polycarbonate |
HH Crystal, Acrylic |
|
|
PET/PBT |
Crystal PS, HDPE, Cast Acrylic |
|
|
PE HDPE |
Acrylic Regrind |
|
|
PP HDPE |
Acrylic Regrind |
|
|
PVC |
GP ABS, Acrylic Regrind |
No Acetal,PE, or PP |
|
SAN |
SAN, ABS, or next resin |
|
|
PS |
Crystal PS |
|
|
TPU |
Crystal PS, SAN, Acrylic |
|
|
ASA |
Crystal PS, HDPE, ABS |
|
|
ABS/PC |
Crystal PS |
|
|
ACS/Nylon |
Crystal PS |
|
|
PPS |
HDPE |
|
|
EVA |
LDPE |
|
|
K-Resin |
Crystal PS |
|
|
Alcryn |
LDPE, PVC purge compound |
Thanks for the time.
Steven L Silvey
Sr. Technical Service
General Polymers