Hi guys,

One of the setters called me to show that the screw bottoms out when processing PA6. We did a static nonreturn valve test and the result was that it leaks. I repeated the same procedure for PP and there was no leak at all. The screw and barrel were regenerated a few months ago - the ID of the barreal and OD of the screw were increased by 0,2 mm as one of the maintenance guys told me.

Do you think there might be too much clearance between the check ring OD and the barrel ID? What are the recommendations for these clearances? The screw is 60 mm in diameter. Except for this clearance I know there might be other causes, but I would like to check the clearance when we take out the screw.

Robert