Shanghai Daoqin Plastics Co., Ltd.

 一, brief introduction

thermoplastic property plastics features is in add hot rear 膨胀, cooling rear shrinkage. add pressure rear 体积也 will shrink small. in injection molding process in will melt plastics injection mold type inner, 充填结束 rear material cooling solid 化, from mold in 取出塑 parts 时即出现 shrinkage, shrinkage is molding shrinkage. parts from mold to stability this time inner, dimensions still 会出现 micro small 变化, types is shrinkage, types is certain wet property plastics wet 而出现膨胀, is its in main/primary function is molding shrinkage.

二, 塑 parts structure and property effect/influence

for/regarding molding parts thick 说, generally due to thick cooling time relatively long, shrinkage rate relatively large . for/regarding generally parts 说, 当沿熔 material direction dimensions and 垂直于熔 material flow direction dimensions relatively large 时, shrinkage rate 差异也 relatively large . from material flow 距离 看, gate separation pressure loss large, 因而该处 shrinkage rate ratio gate large . 因 add strong/high 筋, 孔, and and other tool has shrinkage resistant force, this shrinkage rate relatively small.

1） plastics structure for products shrinkage rate effect/influence

(1)  thick parts ratio thin parts shrinkage rate large (但 large more plastics 1mm thin made parts ratio 2mm shrinkage rate large, this is due to melt in mold cavity inner retardant force increase large 缘故);

(2) 塑 parts upper belt/tape parts ratio belt/tape parts shrinkage rate small ;

(3) 塑 parts complex ratio simple shrinkage rate need small ;

(4) 塑 parts high degree direction generally ratio water direction shrinkage rate small ;

(5)  fine long parts in long degree direction upper shrinkage rate small ;

(6) 塑 parts long degree direction dimensions ratio thick degree direction dimensions shrinkage rate small ;

(7)  inner shrinkage rate large, outer shrinkage rate small.

2） plastics property for products shrinkage rate effect/influence

(1)  crystallization type plastics shrinkage rate large 于无定形 plastics ;

(2)  flow property good plastics, molding shrinkage small ;

(3)  plastics in add filling material, molding shrinkage obvious decline ;

(4)  different amount same plastics, molding shrinkage same.

三, mold structure effect/influence

gate for shrinkage rate has effect/influence. use small gate 时, holding pressure 结束之 front gate solid make parts shrinkage rate increase large. injection molding mold in cooling structure is mold design in key/critical. cooling design 不当, 则因塑 parts temperature degree 不均衡而 generate shrinkage 差, its is make parts dimensions or deformation. in thin separation, mold temperature degree distribution for shrinkage rate effect/influence more is obvious. small summary below/following 四点:

(1)  gate dimensions large, shrinkage rate decrease small ;

(2) 垂直 gate direction shrinkage rate decrease small, gate direction shrinkage rate increase large ;

(3) 远离 gate ratio gate shrinkage rate small ;

(4)  has mold made parts separation shrinkage rate small, made parts separation shrinkage rate large.

四, molding process for plastics products shrinkage rate effect/influence

（1） material temperature degree : material temperature degree relatively high 时, pressure relatively good make shrinkage force decrease small. use small gate 时, gate solid 化早而 make shrinkage rate still relatively large. for/regarding thick parts 说, make temperature degree relatively high, its shrinkage rate still relatively large.

（2）补 material : in molding conditions in, amount decrease/reduce material make parts dimensions maintain stability. material 不足则无 method maintain pressure, make shrinkage rate increase large.
（3） injection pressure : injection pressure is for shrinkage rate effect/influence relatively large factors, especially is 充填结束 rear holding pressure pressure. in generally lower, pressure relatively large 时候因材 material density large, shrinkage rate relatively small.
（4） injection speed degree : injection speed degree for shrinkage rate effect/influence relatively small. for/regarding thin parts or gate non small, and use strong/high material 时, injection speed degree add fast shrinkage rate small.
mold temperature degree: usually mold temperature degree relatively high shrinkage rate relatively large. for/regarding thin parts, mold temperature degree high material flow resistant retardant small, shrinkage rate relatively small.
（5） molding cycle : molding cycle and shrinkage rate 无直接关系. attention/notes, add fast molding cycle 时, mold temperature degree, material temperature degree and other 必然也发生变化, from effect/influence shrinkage rate 变化.

（6） mold temperature degree : mold temperature degree high, shrinkage rate large

五, commonly used plastics shrinkage rate

below/following is commonly used plastics shrinkage rate

PA6 series molding shrinkage

名称 and molding shrinkage % 备注

15% glass fiber reinforced PA6 0.5-0.8 PA6G15

20% glass fiber reinforced PA6 0.4-0.6 PA6G20

30% glass fiber reinforced PA6 0.3-0.5 PA6G30

40% glass fiber reinforced PA6 0.1-0.3 PA6G40

50% glass fiber reinforced PA6 0.1-0.3 PA6G50

25% glass fiber reinforced flame retardant PA6 0.2-0.4 Z-PA6G25

30% glass fiber reinforced flame retardant PA6 0.2-0.4 Z-PA6G30

30% glass fiber reinforced flame retardant PA6 0.2-0.4 Z-PA6G30

无卤 flame retardant PA6 0.8-1.2 Z-PA6

30% mineral filled flame retardant PA6 0.5-0.8 Z-PA6M30

30% glass beads filling PA6 0.8-1.2 PA6M30

30% glass fiber (GF) material composite/compounding filling PA6 0.3-0.5 PA6M30

40% glass fiber (GF) material composite/compounding filling PA6 0.2-0.5 PA6M40

30% mineral filled PA6 0.6-0.9 PA6M30

40% mineral filled PA6 0.4-0.7 PA6M40

PA6 generally injection molding grade 1.4-1.8 PA6

PA6 fast speed molding 1.2-1.6 PA6

PA6 generally toughened 1.0-1.5 PA6

PA6 in and other toughened 0.9-1.3 PA6

PA6 ultra- toughened 0.9-1.3 PA6

MoS2 filling wear resistant PA6 1.0-1.4 PA6

PA66 series molding shrinkage

名称 and molding shrinkage % 备注

15% glass fiber reinforced PA66 0.6-0.9 PA66G15

20% glass fiber reinforced PA66 0.5-0.8 PA66G20

25% glass fiber reinforced heat resistant 油PA66 0.4-0.7 PA66G25

30% glass fiber reinforced PA66 0.4-0.7 PA66G30

30% glass fiber reinforced hydrolysis resistant PA66 0.3-0.6 PA66G30

40% glass fiber reinforced PA66 0.2-0.5 PA66G40

50% glass fiber reinforced PA66 0.1-0.3 PA66G50

25% glass fiber reinforced flame retardant PA66 0.2-0.4 Z-PA66G25

30% glass fiber reinforced flame retardant PA66 0.2-0.4 Z-PA66G30

30% mineral filled flame retardant PA66 0.2-0.4 PA66M30

无卤 flame retardant PA66 0.8-1.2 Z-PA66

30% mineral filled flame retardant PA66 0.4-0.7 Z-PA66M30

30% glass beads filling PA66 0.8-1.2 PA66M30

30% glass fiber (GF) material composite/compounding filling PA66 0.2-0.5 PA66M30

30% mineral filled PA66 0.6-0.9 PA66M30

40% mineral filled PA66 0.4-0.7 PA66M40

generally injection molding grade PA66 1.5-1.8 PA66

fast speed molding PA66 1.5-1.8 PA66

generally toughened PA66 1.2-1.7 PA66

in and other toughened PA66 1.2-1.6 PA66

ultra- toughened PA66 1.2-1.6 PA66

MoS2 filling wear resistant PA66 1.2-1.6 PA66

PA/ABS series molding shrinkage

名称 and molding shrinkage % 备注

10% glass fiber reinforced PA/ABS 0.3-0.6 PA/ABSG10

20% glass fiber reinforced PA/ABS 0.2-0.5 PA/ABSG20

30% glass fiber reinforced PA/ABS 0.1-0.3 PA/ABSG30

20% glass fiber reinforced flame retardant PA/ABS 0.2-0.5 Z-PA/ABSG20

resistant impact PA/ABS 0.5-0.8 PA/ABS

high impact PA/ABS 0.8-1.0 PA/ABS

PP series molding shrinkage

名称 and molding shrinkage % 备注

20% slip powder filling PP 1.0-1.5 PPM20

30% slip powder filling PP 0.8-1.2 PPM30

40% slip powder filling PP 0.8-1.0 PPM40

20% slip powder filling toughened PP 1.0-1.2 PPM20

20% carbon acid filling PP 1.2-1.6 PPM20

10% glass fiber reinforced PP 0.7-1.0 PPG10

20% glass fiber reinforced PP 0.5-0.8 PPG20

30% glass fiber reinforced PP 0.4-0.7 PPG30

40% glass fiber reinforced PP 0.3-0.5 PPG40

20% glass beads filling PP 1.2-1.6 PPM20

30% glass beads filling PP 1.0-1.2 PPM20

15% glass fiber reinforced flame retardant PP 0.5-0.7 Z-PPG15

20% glass fiber reinforced flame retardant PP 0.3-0.5 Z-PPG20

30% glass fiber reinforced flame retardant PP 0.2-0.4 Z-PPG30

bromine flame retardant grade PP 1.5-1.8 PP

无卤 flame retardant grade PP 1.3-1.6 PP

high flow high property PP 1.5-2.0 PP

generally toughened PP 1.5-2.0 PP

in and other toughened PP 1.4-1.9 PP

ultra- toughened PP 1.3-1.8 PP

heat resistant aging PP1 1.5-2.0 PP1

heat resistant aging PP2 1.5-2.0 PP2

heat resistant aging PP3 1.5-2.0 PP3

impact resistant resistant 侯PP4 1.5-2.0 PP4

high impact resistance resistant 侯PP5 1.5-1.8 PP5

20% slip powder filling PP6 1.0-1.2 PP6

30% slip powder filling PP7 0.9-1.1 PP7

40% slip powder filling PP8 0.8-1.0 PP8

20% glass fiber reinforced PP9 0.5-0.8 PP9

30% glass fiber reinforced high heat resistant PP 0.4-0.7 PP10

PC series molding shrinkage

名称 and molding shrinkage % 备注

10% glass fiber reinforced PC 0.3-0.5 PCG10

20% glass fiber reinforced PC 0.3-0.5 PCG20

25% glass fiber reinforced PC 0.2-0.4 PCG25

30% glass fiber reinforced PC 0.2-0.4 PCG30

20% glass fiber reinforced flame retardant PC 0.2-0.4 Z-PCG20

25% glass fiber reinforced flame retardant PC 0.2-0.4 Z-PCG25

30% glass fiber reinforced flame retardant PC 0.2-0.4 Z-PCG30

20% glass fiber reinforced flame retardant PC 0.2-0.4 Z-PCG20

30% glass fiber reinforced flame retardant PC 0.1-0.3 Z-PCG30

20% glass beads filling PC 0.3-0.6 PCM20

PC/ABS series molding shrinkage

名称 and molding shrinkage % 备注

20% glass fiber reinforced PC/ABS 0.2-0.4 PC/ABSG20

bromine flame retardant PC/ABS 0.3-0.6 Z-PC/ABS

无卤 flame retardant PC/ABS 0.4-0.7 Z-PC/ABS

resistant grade PC/ABS 0.4-0.7 PC/ABS

35%PC 0.4-0.6PC/ABS

65%PC 0.4-0.7PC/ABS

85%PC 0.4-0.7PC/ABS

PC/PBT series molding shrinkage

名称 and molding shrinkage % 备注

10% glass fiber reinforced PC/PBT 0.5-0.8 PC/PBTG10

20% glass fiber reinforced PC/PBT 0.4-0.6 PC/PBTG20

30% glass fiber reinforced PC/PBT 0.3-0.5 PC/PBTG30

30% glass fiber reinforced flame retardant high heat resistant PC/PBT 0.3-0.5 Z-PC/PBTG30

high impact high heat resistant PC/PBT 0.6-1.0 PC/PBT

PBT/ABS series molding shrinkage

名称 and molding shrinkage % 备注

20% glass fiber reinforced PBT/ABS 0.3-0.5 PBT/ABSG20

30% glass fiber reinforced PBT/ABS 0.2-0.4 PBT/ABSG30

20% glass fiber reinforced flame retardant PBT/ABS 0.2-0.4 Z-PBT/ABSG20

30% glass fiber reinforced flame retardant PBT/ABS 0.2-0.4 Z-PBT/ABSG30

general purpose injection molding grade PBT/ABS 0.8-1.2 PBT/ABS

general purpose flame retardant grade PBT/ABS 0.7-1.1 PBT/ABS

ABS series molding shrinkage effect/influence plastics products shrinkage rate factors

名称 and molding shrinkage % 备注

20% glass fiber reinforced ABS 0.2-0.4 ABSG20

25% glass fiber reinforced ABS 0.2-0.4 ABSG25

30% glass fiber reinforced ABS 0.1-0.3 ABSG30

20% glass fiber reinforced flame retardant ABS 0.1-0.3 Z-ABSG20

generally flame retardant grade ABS 0.4-0.7 Z-ABS

generally injection molding grade ABS 0.4-0.7 ABS

resistant grade ABS 0.4-0.7 ABS