# How to calculate the injection capacity according to product

//How to calculate the injection capacity according to product

## How to calculate the injection capacity according to product

If the product is made from polystyrene, the injection capacity Wps shall be

Wps=(product weight + total weight of the runner system) / (0.75～0.90)

i.e. Wps=(1.3～1.1) × (product weight + total weight of the runner system)

The larger coefficient is taken when high precision product quality is required.

If the product is made from other plastic (named X plastic), calculate the theoretic injection capacity of the plastic, Wx, based on the aforesaid formula:

Wx=(1.3～1.1) × (product weight + total weight of the runner system)

But you can’t decide the injection capacity of the injection-molding machine simple by Wx, you have to exchange it into Wps. The formula is:

Wps=Wx × 1.05

Vx

In which, Vx represents the specific gravity of certain plastic.

For example: Suppose a plastic product is made from polyethylene (PE), its weight is calculated to be 185g, and the weight of runner system is estimated to be 20g, according to the aforesaid formula:

Wx = 1.2* (185+20) =246g

The specific gravity of PE Vx =0.92

So , Wps =246 ×  1.05

0.92

The machine with DY170 is recommended.

# Other Popular Articles

By |2018-11-11T14:56:47+08:00October 29th, 2018|industry news|Comments Off on How to calculate the injection capacity according to product 