plastic mold design

clamping tonnage VS shot weight

clamping tonnage(T-吨) shot weight(g-克) shot weight(oz-盎司)
10 7 0.24
20 18 0.64
30 31 1.1
40 48 1.7
50 65 2.3
60 85 3
70 116 4.1
80 128 4.5
90 151 5.3
100 173 6.1
110 199 7
120 224 7.9
130 250 8.8
140 278 9.8
150 307 10.8
160 335 11.8
180 395 13.9
200 457 16.1
220 523 18.4
250 628 22.1
300 809 28.5
350 1003 35.3
400 1210 42.6
450 1426 50.2
500 1653 58.2
550 1889 66.5
600 2133 75.1
650 2386 84
850 3465 122
1000 4374 154
1200 5623 198
1400 6986 246
1600 8435 297
1800 9940 350
2000 11502 405

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Injection Molding Clamping Force Calculation

ClassPlastic MaterialConstant K
1PS,PE,PPX1.0
2PA,PBT,PETPX1.3-1.35
3CA,CAB,CAP,EVA,PEEL,PPVCX1.35-1.45
4ABS,ASA/AAS,POMX1.45-1.55
5PMMA,PC/ABS,PC/PBTX1.55-1.70
6PC,PES,PSU,PEEK,UPVC,PEIX1.70-1.90

LT-ratio

 

 

 

 

 

 

 

 

chart 1.

 

 

A round PC lamp base with 220mm outter diameter,and the wall thickness range from 1.9-2.2mm,the gate is one drop pinpoint gate.What is the clamping force need for this part?

F=Po*K*S

pic1

S:    S=3.14*22*22/4=380CM^2

P0:  L/T=200/1.9=105:1  [200 is  the longest distance of melt flowing=220/2+90(runner lenght)]

check the chart 1. above,the 105 points to the pressure about 165,so the Po  is 160 bar

K:   PC material ‘s constant K is 1.7-1.9,now we choose 1.9 for safe reason,so

F=160*1.9*380=115.5 ton.

IMG_20140526_100858

 

The L/T ratio:

 1.0mm (thickness)1.5mm (thickness)2.0mm (thickness)2.5mm (thickness)3.0mm (thickness)3.5mm (thickness)4.0mm (thickness)
GPPS<6060-110110-170170-240240-340340-450450-560
HIPS<6060-110110-160160-230230-330330-420420-520
PP<7070-130130-180180-250250-380380-500500-650
PE<8080-150150-220220-300300-430430-580580-700
POM<5050-100100-150150-210210-310310-420420-500
ABS<5050-100100-150150-200200-300300-400400-500
AS<4040-8080-130130-180180-250250-350350-450
PC<3535-7070-110110-160160-200200-280280-370