Email Us

Trial-run Molding

A mould trial is a process by which a new mould is optimised in order to produce the desired products as efficiently as possible. This makes it one of the most important aspects of injection moulding.

Detail of Trial Molding

Trial Molding Process
Trial Molding Process
  1. Set barrel temperature according to recommendations from the material supplier. Middle of recommended in front and lower end of recommended in back, if don’t have date sheet, reference from mold flow report. Record actual melt temp with air shot method. If the customer is to attend the trial, the material data sheet should be printed and present at the machine.

  2. Set mould temperature to the middle of recommended temp span, if don’t have date sheet, reference from mold flow report. Also, make sure the actual mould temp is right during production.

  3. Set clamping force according to Moldflow report, or max clamp of customer specified machine.

  4. Set holding pressure to 0 at first.

  5. Increase the shot size gradually until parts are ~90% full. Check cavity variation. If more than 7% cavity variation, write down in page and mark as the issue needs to improve

  6. Increase the shot size until parts are 100% full, parts can be sink but not short. If the injection plastic parts have flash, burns or air traps, write down in paper comment as the issue needs to fix

  7. Set shot size to 97% full, should be done including an estimated holding time.

  8. Set holding pressure to ½ the actual injection pressure.

  9. Runoff samples and mark them trial number and date, this is very important information for us to find which samples are from the previous trial time, quantity according to customer requirements if parts are ok. 1 balance shot and 2-3 runners should always be sent together with the samples.


Do you need professional Mold Spare Parts and Precision Injection Molds?
Do you need professional Mold Spare Parts and Precision Injection Molds?
Don't hesitate to contact us now.

Related Precision Plastic Injection Molds/Tools