SPC WPC PVC materials

Processing Temperature, specific gravity and shrinkage rate of Common Plastic materials

Material shrinkage is a reduction in the volume of a material occurs when plasticizing plate cooling after moulding, it is a reduction of the dimensions of cooling plasticizing part, compared with its mould dimensions.

Material shrinkage is the contraction of a plasticizing plate as it cools after mould. It always occurs after ejection, as the part continues to cool. After that, the plate may continue to shrink very slightly for several hours or even days until the temperature and moisture content stabilize.

All polymers have different shrinkage rates depending on many factors. These include material category, moulding condition, mould structures, plate shape, plate interior structure, complexity, inserts etc.

Our chart below shows typical shrinkage ratios for the list of common materials:

Abbreviation	Full title	Specific gravity	Shrinkage rate	Temperature of processing	Temperature of mould
LDPE	Low density polyethylene	0.92	3	220~260	20~40
HDPE	High density polyethylene	0.96	3	190~280	30~70
PP	Polypropylene	0.91	2	210~280	20~50
PVC	Polyvinyl chloride	1.38~1.41	1.5	170~190	20~40
ABS	Polyacrylonitrile Polybutadiene Polystyrene	1.05	0.6	210~260	50~80
AS	Polyacrylonitrile Polystyrene	1.07	0.6	220~270	40~80
BS	Polybutadiene Polystyrene	1.01	0.5	190~230	30~50
GPPS	General purpose Polystyrene	1.16	0.3~0.6	200~250	40~60
HIPS	High impact Polystyrene	1.08	0.5	210~270	20~50
EVA	ethylene-vinyl acetate copolymer	0.95	2	140~200	20~40
PMMA	polymethyl methacrylate	1.18	0.6	220~240	60~80
PA6	Polyamide 6	1.13	0.7-1	250~270	40~60
PA66	Polyamide 66	1.13	1.3	280~300	40~60
PA66+30%GF	Polyamide 66 +30% glass fibre	1.39	0.3	240~270	80~90
POM	polyformaldehyde	1.42	2.1	205~225	80~100
PC	Polycarbonate	1.2	0.5	271~293	71~93
PET	Polyethylene glycol terephthalate	1.33	0.4	277~293	15~30
PET+30%GF	Polyethylene glycol terephthalate +30% glass fibre	1.67	0.2	265~305	95~150
PETG	Polyethylene terephthalate glycol	1.27	0.2~0.5	250~270	15~40
PCTG	Poly Cyclohexylene Terephthalate Glycol	1.23	0.2~0.5	275~295	15~40
PBT	polybutylene terephthalate	1.4	1.5~2.2	225~245	40~80
PBT+30%GF	polybutylene terephthalate +30% glass fibre	1.61	0.4~0.9	225~250	40~100
PCT+30%GF	Polycarbonateterephthalate +30% glass fibre	1.45	0.1~0.4	295~370	105~135
CA	cellulose acetate fibre	1.26	0.5	160~230	40~60
CAP	cellulose propionate	1.2	0.5	215~240	40~75
CAB	cellulose butyrate	1.19	0.5	230~250	40~85
Heat-resisting PP	Heat-resisting polypropylene	1.12	0.9~1.1	180~220	60~80
Fire retardant PP	Fire retardant polypropylene	0.95	1.4	180~220	30~50
PPS+40%GF	Polyphenylene sulfide +40% glass fibre	1.67	0.25	300~340	120~150
PPO	polyphenylene ether	1.07	0.5~0.8	270~310	70~93
PSU	Polysulfone plastics	1.24	0.5	330~360	120~160
PES	Polyethersulfone resin	1.37	0.68	340~380	120~160
LCP	Liquid Crystal Polymer	1.7	0.02	385~400	35~200
SBS	Styrene-butadiene-styrene block copolymer	0.96~1.1	1.5	145~160	25~30
SEBS	Styrene Ethylene Butylene Styrene	0.87~0.91	1.6	180~220	35~65
TPU	Thermoplastic polyurethanes	1.24	1.2	190~220	24~49
TPV	Thermoplastic Vulcanizate	0.97	1.5~2.5	180~190	10~80
TPEE	Thermoplastic elastomers	1.2	1.4	220~250	45

This information should only be used as a quick reference.
Users should always refer to the processing data sheets provided by the material supplier. Differential shrinkages are not considered. Your use of this data is entirely at your own risk and BOYU accepts no liability of any kind.