Shrinkage

The shrinkage of plastics designates the volume contraction of polymers during the cooling step of the processing of polymers. This contraction is partly due to the difference of density of polymers from the melt state and the cooled, rigid state. Shrinkage is a rate, so it is expressed in percent. Semi-crystalline polymers (e.g: PBT or PP) always show a higher shrinkage than amorphous polymers (e.g: PS or PC) because when cooled down semi-crystalline polymers will see part of their macromolecular chains re-arranged to form crystallite, that is a well-organized structure, leading to less space needed for the same amount of atoms. This volume contraction of polymers often leads to wrapped parts and dimension differences between manufactured parts and the mold (the die if we consider extrusion as the processing technique). The shrinkage rate is strongly depending on the polymer itself but also on the processing conditions applied and part design. A standard method to measure “mold shrinkage”, ie contraction compared to the injection molding tool, is the ASTM D955. Other international standard methods related to plastic shrinkage are: ISO 294-4 (for thermoplastics) and ISO 2577 (for thermosets).

Name of the polymer	Explicit name of the polymer	Min Value(%)	Max Value(%)
ABS	Acrylonitrile-Butadiene Styrene	0.700	1.600
ABS FR	Acrylonitrile-Butadiene Styrene flame retardant	0.300	0.800
ABS High Heat	Acrylonitrile-Butadiene Styrene High Heat	0.400	0.900
ABS High Impact	Acrylonitrile-Butadiene Styrene High Impact	0.400	0.900
ABS/PC	Acrylonitrile-Butadiene Styrene/Polycarbonate	0.500	0.700
ABS/PC 20% GF	Acrylonitrile-Butadiene Styrene/Polycarbonate 20% glass fiber	0.200	0.300
ABS/PC FR	Acrylonitrile-Butadiene Styrene/Polycarbonate flame retardant	0.300	0.600
Amorphous TPI Blend, Ultra-high heat, Chemical Resistant (High Flow)	Amorphous TPI Blend, Ultra-high heat, Chemical Resistant (High Flow)	0.800	1.000
Amorphous TPI Blend, Ultra-high heat, Chemical Resistant (Standard Flow)	Amorphous TPI Blend, Ultra-high heat, Chemical Resistant (Standard Flow)	0.800	1.000
Amorphous TPI, High Heat, High Flow, Transparent, Lead-Free Solderable (High Flow)	Amorphous TPI, High Heat, High Flow, Transparent, Lead-Free Solderable (High Flow)	1.000	1.200
Amorphous TPI, High Heat, High Flow, Transparent, Lead-Free Solderable (Standard Flow)	Amorphous TPI, High Heat, High Flow, Transparent, Lead-Free Solderable (Standard Flow)	1.000	1.200
Amorphous TPI, Moderate Heat, Transparent	Amorphous TPI, Moderate Heat, Transparent	0.500	0.700
Amorphous TPI, Moderate Heat, Transparent (Food Contact Approved)	Amorphous TPI, Moderate Heat, Transparent (Food Contact Approved)	0.500	0.700
Amorphous TPI, Moderate Heat, Transparent (Mold Release grade)	Amorphous TPI, Moderate Heat, Transparent (Mold Release grade)	0.500	0.700
Amorphous TPI, Moderate Heat, Transparent (Powder form)	Amorphous TPI, Moderate Heat, Transparent (Powder form)	0.500	0.700
ASA	Acrylonitrile Styrene Acrylate	0.400	0.700
ASA/PC	Acrylonitrile Styrene Acrylate/Polycarbonate	0.300	0.700
ASA/PC FR	Acrylonitrile Styrene Acrylate/Polycarbonate flame retardant	0.400	0.800
ASA/PVC	Acrylonitrile Styrene Acrylate/Polyvinyl Chloride	0.300	0.700
CA - Cellulose Acetate	Cellulose Acetate	0.300	1.000
CAB - Cellulose Acetate Butyrate	Cellulose Acetate Butyrate	0.200	0.900
Celllulose Diacetate- Pearlescent Films	Celllulose Diacetate- Pearlescent Films	1.000	1.500
Celllulose Diacetate-Matt Film	Celllulose Diacetate-Matt Film	1.000	1.500
CP - Cellulose Proprionate	Cellulose Proprionate	0.100	0.900
CPVC - Chlorinated Polyvinyl Chloride	CPVC - Chlorinated Polyvinyl Chloride	0.300	0.700
ETFE	Ethylene Tetrafluoroethylene	3.000	4.000
EVA	Ethylene Vinyl Acetate	0.400	3.500
FEP	Fluorinated Ethylene Propylene	3.000	6.000
HDPE - High Density Polyethylene	HDPE - High Density Polyethylene	1.500	4.000
HIPS - High Impact Polystyrene	HIPS - High Impact Polystyrene	0.200	0.800
HIPS FR V0	High Impact Polystyrene flame retardant V0	0.300	0.600
LCP	Liquid Crystal Polymer	0.100	0.600
LCP CF	Liquid Crystal Polymer carbon fiber	0.100	0.500
LCP GF	Liquid Crystal Polymer glass fiber	0.100	0.400
LCP MINERAL	Liquid Crystal Polymer mineral	0.100	0.500
LDPE - Low Density Polyethylene	LDPE - Low Density Polyethylene	2.000	4.000
LLDPE - Linear Low Density Polyethylene	LLDPE - Linear Low Density Polyethylene	2.000	2.500
MABS	Transparent Acrylonitrile Butadiene Styrene	0.400	0.700
PA 11 30% Glass fiber reinforced	Polyamide 11 30% Glass fiber reinforced	0.500	0.500
PA 11 conductive	Polyamide 11 conductive	0.700	2.000
PA 11 flexible	Polyamide 11 flexible	1.400	1.800
PA 11 rigid	Polyamide 11 rigid	0.700	2.000
PA 12 conductive	Polyamide 12 conductive	0.700	2.000
PA 12 fiber reinforced	Polyamide 12 fiber reinforced	0.700	2.000
PA 12 flexible	Polyamide 12 flexible	0.700	2.000
PA 12 glass filled	Polyamide 12 glass filled	0.700	2.000
PA 12 rigid	Polyamide 12 rigid	0.700	2.000
PA 46	Polyamide 46	1.500	2.000
PA 46 30% GF	Polyamide 46 30% glass fiber	0.300	1.300
PA 6	Polyamide 6	0.500	1.500
PA 6-10	Polyamide 6-10	1.000	1.300
PA 66	Polyamide 6-6	0.700	3.000
PA 66 30% GF	Polyamide 6-6 30% glass fiber	0.500	0.500
PA 66 30% mineral filled	Polyamide 6-6 30% mineral filled	0.600	1.000
PA 66 IM 15-30% GF	Polyamide 6-6 impact modified 15-30% glass fiber	0.200	0.600
PA 66 impact modified	Polyamide 6-6 impact modified	1.200	3.000
PAI	Polyamide-Imide	0.600	1.000
PAI 30% GF	Polyamide-Imide 30% glass fiber	0.100	0.300
PAI low friction	Polyamide-Imide low friction	0.100	0.500
PAN	Polyacrylonitrile	0.200	0.500
PAR	Polyarylate	0.900	1.200
PARA 30-60% GF	Polyarylamide 30-60% glass fiber	0.100	0.400
PBT	Polybutylene Terephthalate	0.500	2.200
PBT 30% GF	Polybutylene Terephthalate 30% glass fiber	0.200	1.000
PC 20-40% GF	Polycarbonate 20-40% glass fiber	0.100	0.500
PC 20-40% GF FR	Polycarbonate 20-40% glass fiber flame retardant	0.100	0.500
PC high heat	Polycarbonate high heat	0.700	1.000
PC/PBT	Polycarbonate/Polybutylene Terephthalate blend	0.600	1.100
PCTFE	Polymonochlorotrifluoroethylene	0.500	1.500
PE 30% GF	Polyethylene 30% glass fiber	0.200	0.600
PEEK	Polyetheretherketone	1.200	1.500
PEEK 30% CF	Polyetheretherketone 30% carbon fiber	0.000	0.500
PEEK 30% GF	Polyetheretherketone 30% glass fiber	0.400	0.800
PEI	Polyetherimide	0.700	0.800
PEI 30% GF	Polyetherimide 30% glass fiber	0.200	0.400
PEI mineral filled	Polyetherimide mineral filled	0.500	0.700
PEKK– Low cristallinity grade	Polyetherketoneketone– Low cristallinity grade	0.004	0.005
PESU	Polyethersulfone	0.600	0.700
PESU 10-30% GF	Polyethersulfone 10-30% glass fiber	0.200	0.300
PET	Polyethylene Terephtalate	0.200	3.000
PET 30% GF	Polyethylene Terephtalate 30% glass fiber	0.200	1.000
PET 30/35% GF Impact modified	Polyethylene Terephtalate 30/35% glass fiber impact modified	0.200	0.900
PET G	Polyethylene Terephtalate Glycol	0.200	1.000
PE-UHMW	Polyethylene -Ultra High Molecular Weight	4.000	4.000
PFA	Perfluoroalkoxy	3.000	5.000
PHB - Polyhydroxybutyrate	Polyhydroxybutyrate	1.200	1.600
PI	Polyimide	0.200	1.200
PLA-injection molding	Polylactide-injection molding	0.300	0.500
PMMA	Polymethylmethacrylate (Acrylic)	0.200	0.800
PMMA high heat	Polymethylmethacrylate (Acrylic) high heat	0.200	0.800
PMMA Impact modified	Polymethylmethacrylate (Acrylic) impact modified	0.200	0.800
PMP	Polymethylpentene	1.600	2.100
PMP 30% GF	Polymethylpentene 30% glass fiber	0.300	1.200
PMP mineral filled	Polymethylpentene mineral filled	1.400	1.700
Polyamide 66 (Nylon 66)/Carbon Fiber, Long, 30 % Filler by Weight	Polyamide 66 (Nylon 66)/Carbon Fiber, Long, 30 % Filler by Weight	0.300	0.300
Polyamide 66 (Nylon 66)/Carbon Fiber, Long, 40 % Filler by Weight	Polyamide 66 (Nylon 66)/Carbon Fiber, Long, 40 % Filler by Weight	0.300	0.300
Polyamide 66 (Nylon 66)/Glass Fiber, Long, 40 % Filler by Weight	Polyamide 66 (Nylon 66)/Glass Fiber, Long, 40 % Filler by Weight	0.300	0.300
Polyamide 66 (Nylon 66)/Glass Fiber, Long, 40 % Filler by Weight	Polyamide 66 (Nylon 66)/Glass Fiber, Long, 40 % Filler by Weight	0.300	0.300
Polyamide 66 (Nylon 66)/Glass Fiber, Long, 50 % Filler by Weight	Polyamide 66 (Nylon 66)/Glass Fiber, Long, 50 % Filler by Weight	0.300	0.300
Polyamide 66 (Nylon 66)/Glass Fiber, Long, 50 % Filler by Weight	Polyamide 66 (Nylon 66)/Glass Fiber, Long, 50 % Filler by Weight	0.300	0.300
Polyamide 66 (Nylon 66)/Glass Fiber, Long, 60 % Filler by Weight	Polyamide 66 (Nylon 66)/Glass Fiber, Long, 60 % Filler by Weight	0.300	0.300
Polyamide 66 (Nylon 66)/Glass Fiber, Long, 60 % Filler by Weight	Polyamide 66 (Nylon 66)/Glass Fiber, Long, 60 % Filler by Weight	0.300	0.300
Polypropylene Homopolymer (PP Homopolymer)/Glass Fiber, Long, 30 % Filler by Weight	Polypropylene Homopolymer (PP Homopolymer)/Glass Fiber, Long, 30 % Filler by Weight	0.400	0.400
Polypropylene Homopolymer (PP Homopolymer)/Glass Fiber, Long, 40 % Filler by Weight	Polypropylene Homopolymer (PP Homopolymer)/Glass Fiber, Long, 40 % Filler by Weight	0.300	0.300
Polypropylene Homopolymer (PP Homopolymer)/Glass Fiber, Long, 40 % Filler by Weight	Polypropylene Homopolymer (PP Homopolymer)/Glass Fiber, Long, 40 % Filler by Weight	0.300	0.300
Polypropylene Homopolymer (PP Homopolymer)/Glass Fiber, Long, 50 % Filler by Weight	Polypropylene Homopolymer (PP Homopolymer)/Glass Fiber, Long, 50 % Filler by Weight	0.300	0.300
Polypropylene Homopolymer (PP Homopolymer)/Glass Fiber, Long, 50 % Filler by Weight	Polypropylene Homopolymer (PP Homopolymer)/Glass Fiber, Long, 50 % Filler by Weight	0.300	0.300
POM	Polyoxymethylene (acetal)	1.800	2.500
POM impact modified	Polyoxymethylene (acetal) impact modified	1.000	2.500
POM low friction	Polyoxymethylene (acetal) low friction	1.800	3.000
POM mineral filled	Polyoxymethylene (acetal) mineral filled	1.500	2.000
PP 10-20% GF	Polypropylene 10-20% glass fiber	0.300	1.000
PP 10-40% mineral filled	Polypropylene 10-40% mineral filled	0.600	1.400
PP 10-40% TALC	Polypropylene 10-40% talc	0.900	1.400
PP 30-40% GF	Polypropylene 30-40% glass fiber	0.100	1.000
PP copo	Polypropylene copolymer	2.000	3.000
PP homo	Polypropylene homopolymer	1.000	3.000
PP impact modified	Polypropylene impact modified	2.000	3.000
PPA	Polyphthalamide	1.500	2.200
PPA – 30% mineral	Polyphthalamide– 30% mineral	1.000	1.200
PPA – 33% glass fiber	Polyphthalamide – 33% glass fiber	0.500	0.700
PPA – 33% glass fiber – high flow	Polyphthalamide– 33% glass fiber – high flow	0.740	0.760
PPA – 45% glass fiber	Polyphthalamide– 45% glass fiber	0.100	0.300
PPE	Polyphenylene Ether	0.500	0.800
PPE 30% GF	Polyphenylene Ether 30% glass fiber	0.100	0.400
PPE FR	Polyphenylene Ether flame retardant	0.600	1.000
PPE impact modified	Polyphenylene Ether impact modified	0.600	1.000
PPE mineral filled	Polyphenylene Ether mineral filled	0.300	0.700
PPS	Polyphenylene Sulfide	0.600	1.400
PPS 20-30% GF	Polyphenylene Sulfide 20-30% glass fiber	0.200	0.500
PPS 40% GF	Polyphenylene Sulfide 40% glass fiber	0.200	0.500
PPS conductive	Polyphenylene Sulfide conductive	0.300	1.000
PPS GF & mineral	Polyphenylene Sulfide glass fiber & mineral	0.300	0.700
PS 30 % GF	Polystyrene 30% glass fiber	0.200	0.200
PS crystal	Polystyrene crystal	0.100	0.700
PS high heat	Polystyrene high heat	0.200	0.700
PSU	Polysulfone	0.700	0.700
PSU 30% GF	Polysulfone 30% glass fiber	0.100	0.600
PSU mineral filled	Polysulfone mineral filled	0.400	0.500
PTFE	Polytetrafluoroethylene	3.000	6.000
PTFE 25% GF	Polytetrafluoroethylene 25% glass fiber	1.800	2.000
PVC 20% GF	Polyvinyl Chloride 20% glass fiber	0.100	0.200
PVC plasticized	Polyvinyl Chloride plasticized	0.200	4.000
PVC plasticized filled	Polyvinyl Chloride plasticized filled	0.800	5.000
PVC rigid	Polyvinyl Chloride rigid	0.100	0.600
PVDC	Polyvinylidene Chloride	0.500	2.500
PVDF	Polyvinylidene Fluoride	2.000	4.000
SAN	Styrene Acrylonitrile	0.300	0.700
SAN 20% GF	Styrene Acrylonitrile 20% glass fiber	0.100	0.300
SMA	Styrene Maleic Anhydride	0.400	0.800
SMA 20% GF	Styrene Maleic Anhydride 20% glass fiber	0.200	0.300
SMA FR V0	Styrene Maleic Anhydride flame retardant V0	0.500	0.500
TPS-Injection General Purpose	Thermoplastic Starch GP	0.600	1.500
TPS-Injection Water Resistant	Thermoplastic Starch WR	0.600	0.900
XLPE - Crosslinked Polyethylene	XLPE - Crosslinked Polyethylene	0.700	5.000

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