Dynamic check valve study
Software version: 0.0.2 beta - prerealease
Ongoing development - only for beta test!
The purpose of the non-return valve is to allow the metering of material to the front of the screw during plasticizing. It also doesn’t allow the back flow of material down the screw during injection.
If the non-return valve does not close properly or does not seal against the cylinder wall, the material will leak backwards causing variations in shot volume and the parts will alternate between flash, short and full.
This dynamic non-return valve study is done by measuring fill only time and weight at two different working areas for the non-return vale in the injection cylinder.
- Set up a standard optimized process for the mold.
- Remove hold pressure (or set to machine minimum value).
- Adjust shot size until the most filled cavity is approximately 95-98% full.
- Run 10 consecutive shots. Save every shot and record the fill time for each shots.
- Weigh each shot and record the fill only shot weight.
- Move the shot size and the transfer position approximatly 25-30 mm and do the 10-shot study again and save the data in tab "Position 2"
- Evaluate results on tab "Evaluate".
Evaluation
Fill only time variation should be less than 1%.
P1 time variation = %
P2 time variation = %
Evaluation
Fill only weight variation should be less than the normal variation for 10 shots.
P1 weight variation = %
P2 weight variation = %
Evaluation
*
Fill only weight variation between P1 and P2 should be barely noticeable after that the transfer position is moved.
P1-P2 weight variation = %
Evaluation
*