Foam

[PVCSKI]

Im looking for ideas to help with Foam running more consistant. I noticed that foam tends to vary shot to shot.From heavy sinking to large bubbling outwards. Im trying to keep it balanced.

[Len]

PVCSKI,
I need some specifics before offering an answer. Large and uneven foam structure is usually caused by early initiation of the blowing agent or poor distribution of the additive.

Questions:
What is your resin/polymer system?
Processing temperature or polymer melt temp @ injection.
Are you using a M/B or straight blowing agent?
What type of blowing agent (azo, Bi-carb, etc.) are you using?
Are you using a foam catalyst?
Are you using a nucleating agent?
Or are a catalyst and/or nucleating agent included in your foam M/B?

There are ways to hasten or retard the "blowing" action of specific blowing agents. Your blowing agent supplier may be a good place to start for help.

Thx,

Len