Screen Printing Large Coroplast Signs

loyglenn

I could use some help troubleshooting some problems I am having printing coroplast signs.
Setup:
Screen - 305 mesh, inner dimensions are 76"H x 66"W, print are about 46"H x 46"W
Substrates - 4mm and 10mm coroplast

I can't seem to get the print right. The screen sticks to the coroplast in the middle of the print (does not peel enough) with what should be the proper off-contact (1/32" to 1/4"). If I increase the off-contact, I have to compensate with higher squeegee pressure, yet the top and bottom don't receive the proper print resulting in un-printed lines in the valleys of the coroplast. I am fairly new at this so I'm sure many things could be wrong (improper screen size/print area ratio, wrong off-contact for print size, etc.) Any help is greatly appreciated.

tonypep

Most likely improper screen tension

loyglenn

Looks like you are correct...I measured the tension at around 14 newtons. That is center and corners. From what I can find it should be around 20 or 21 newtons. Sending frames back to be re-stretched and will see if that solves the problem. Thanks for the reply as I'm not sure I would have ever checked that.