# 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
Top

# Injection Molding Clamping Force Calculation

Class Plastic Material Constant K
1 PS,PE,PP X1.0
2 PA,PBT,PETP X1.3-1.35
3 CA,CAB,CAP,EVA,PEEL,PPVC X1.35-1.45
4 ABS,ASA/AAS,POM X1.45-1.55
5 PMMA,PC/ABS,PC/PBT X1.55-1.70
6 PC,PES,PSU,PEEK,UPVC,PEI X1.70-1.90

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

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.

`form_structure_1=[[{"name":"fieldname2","index":0,"title":"K:viscosity coefficient (constant K)","userhelp":"","dformat":"number","min":"","max":"","predefined":"","ftype":"fnumber","csslayout":"","required":false,"size":"medium","formats":["digits","number"],"form_identifier":"","fBuild":{},"shortlabel":"","userhelpTooltip":false,"predefinedClick":false},{"name":"fieldname6","index":1,"title":"Po:average Pressure of Cavity(bar)","predefined":"","ftype":"fnumber","userhelp":"","csslayout":"","required":false,"size":"medium","min":"","max":"","dformat":"digits","formats":["digits","number"],"form_identifier":"","fBuild":{},"shortlabel":"","userhelpTooltip":false,"predefinedClick":false},{"name":"fieldname7","index":2,"title":"S:projected area of runner and parts (CM2)","ftype":"fnumber","userhelp":"","csslayout":"","predefined":"","required":false,"size":"medium","min":"","max":"","dformat":"digits","formats":["digits","number"],"form_identifier":"","fBuild":{},"shortlabel":"","userhelpTooltip":false,"predefinedClick":false},{"name":"fieldname8","index":3,"userhelp":"","title":"","ftype":"fSectionBreak","csslayout":"","form_identifier":"","fBuild":{},"shortlabel":"","userhelpTooltip":false},{"name":"fieldname4","index":4,"readonly":true,"title":"Clamping Force (F)=","predefined":"","userhelp":"Note: you could ask for the L/T from your plastic material supplier,then check the chart to have the u0022average pressure of cavityu0022,and this result is just for your reference,","eq":"fieldname2*fieldname6*fieldname7/1000","ftype":"fCalculated","csslayout":"","required":false,"size":"medium","form_identifier":"","fBuild":{},"shortlabel":"","userhelpTooltip":false,"toolbar":"default|mathematical","optimizeEq":true,"eq_factored":"(fieldname2*fieldname6*fieldname7/1000)","suffix":"","prefix":"","decimalsymbol":".","groupingsymbol":"","dependencies":[{"rule":"","complex":false,"fields":[""]}],"hidefield":false}],{"0":{"title":"Clamping force calculator","description":"This calculator is designed by u003Ca title=u0022www.myplasticmold.comu0022 href=u0022https://myplasticmold.comu0022u003Ewww.myplasticmold.comu003C/au003E","formlayout":"left_aligned"},"formid":"cp_calculatedfieldsf_pform_1"}];`

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 <60 60-110 110-170 170-240 240-340 340-450 450-560
HIPS <60 60-110 110-160 160-230 230-330 330-420 420-520
PP <70 70-130 130-180 180-250 250-380 380-500 500-650
PE <80 80-150 150-220 220-300 300-430 430-580 580-700
POM <50 50-100 100-150 150-210 210-310 310-420 420-500
ABS <50 50-100 100-150 150-200 200-300 300-400 400-500
AS <40 40-80 80-130 130-180 180-250 250-350 350-450
PC <35 35-70 70-110 110-160 160-200 200-280 280-370
August 17, 2020 plastic mold