2.1.1 Viscosity Factors (Flow Factors) in the Mold.

PE, PS, PP = 1
PA              = 1.2 - 1.4
CA             = 1.3 - 1.5
ABS           = 1.3 - 1.4
PMAA       = 1.5 - 1.7
PC             = 1.7 - 2.0

The factors are guide values for the previously mentioned clamping force calculation tables whereby the following factors naturally must be taken into account :

• shape of part.
• type of injection.
• feed position melt temperature.
• various other factor.

Example no 2 :
- projected injection surface = 200 cm2
- flow path (max lenght) = 90 mm Ratio  =  70:1
- wall thickness = 1.25 mm
- material = PC

The diagram shows a spesific internal mold pressure of approx 175 kp/cm2.

Clamping force for this case :

200 x 175 = 35,000 kp x 1.7 - 2 = 70,000 kp
                                                    = 700 kN = 70 Mp