Stelray Plastic Products

Reference Tables

Shrinkage Values | Density Values | Common Abbreviations

SHRINKAGE VALUES FOR MISCELLANEOUS RESINS
MATERIAL	SHRINK in/in
ABS High Impact	0.005 - 0.007
ABS Heat Resistant	0.004 - 0.005
ABS Medium Impact	0.005
ACETAL	0.020 - 0.035
ACRYLIC General Purpose	0.002 - 0.009
ACRYLIC Heat Resistant	0.003 - 0.010
ACRYLIC High Impact	0.004 - 0.008
ETHYLENE VINYL ACETATE	0.010 - 0.030
IONOMER	0.003 - 0.020
NYLON 6/6	0.010 - 0.025
NYLON 6/6	0.007 - 0.015
NYLON 6/10	0.010 - 0.025
NYLON 11	0.010 - 0.025
NYLON 12	0.008 - 0.020
NYLON Glass Filled	0.005 - 0.010
POLYBUTYLENE	0.020 (molded)
POLYBUTYLENE	0.040 (aged)
POLYCARBONATE	0.005 - 0.007
PET (Amorphous, petg, pctg)	0.003 - 0.005
POLYESTER .025 - .050 THICK	0.006 - 0.012
POLYESTER .050 - .100 THICK	0.012 - 0.017
POLYESTER .100 - .180 THICK	0.016 - 0.022
POLYESTER PBT	0.010 - 0.020
POLYESTER PET 30% GF	0.001 - 0.002
POLYESTER PBT 30% GF	0.003 - 0.005
POLYETHERIMIDE	0.005 - 0.007
POLYETHYLENE Low Density	0.015 - 0.035
POLYETHYLENE High Density	0.015 - 0.030
PPO/STYRENE CO (NORYL)	0.005 - 0.007
POLYPROPYLENE	0.010 - 0.030
PPO/STYRENE G.P.	0.002 - 0.008
PPO/STYRENE Heat Resistant	0.002 - 0.008
PPO/STYRENE Impact Mod	0.003 - 0.006
POLYSULPHONE	0.008
POLYURETHANE	0.010 - 0.020
PVC Rigid	0.002 - 0.004
PVC Semi-Rigid	0.005 - 0.025
PVC Flexible	0.015 - 0.030
SAN	0.002 - 0.006

NOTES:

Shrink rates can vary with process conditions,mold design, etc.
Shrink may be less in direction perpendicular to the flow due to differences in orientation(divide by 1.6 for transversedirection; more pronounced with crystalline resins: i.e. PP) Does not apply for glass filled resins.
When possible, prototype the job to better determine shrink for a given mold and product design.
Refer also to manufacturer's guidelines, if available.
Shrink may be affected by additives such as color or filler.