Obvious crease mark at the outside of the cup bottom and only 260g have such problem.
Cause Analysis
After analysis and discuss with our techincal team , it is confirmed that this problem should be No matching between the mold and the thickness of the cup bottom board.
Cup Bottom Mold
Based on our experience, the mold size grade varies from 20g to 30g per coated cupstock gramme.
The mold size varies from 30-40um.
Normally speaking FK1 240gsm and 260 gsm should share the same set mold, please double check the mold.
If using the wrong mold , the mold and the cupstock is not matching, it will cause the crease mark and cracking problem.
CAPA - Using Suitable Cup Bottom Mold
Cracking Of Cup Bottom
NAUP cup stock has high bulk & high stiffness.
If the gap between the male ejection head and female mould is un-suitable for paper's thickness, it is easily caused cracking defect around the cup bottom.
Suggest to consult with the cup macking machine manufacturer for suitable mold to solve the problem.
CAPA - Using Suitable Cup Bottom Mold
Cracking at cup's bottom ejection process-- Please use the suitable mold to do the cup bottom.
It is necessary to properly adjust the male ejection head to hold & push the paper up through female mould when making the cup bottom piece.
If the gap between the male ejection head and female mould is un-suitable for paper's thickness, it is easily caused cracking defect around the cup bottom piece by the extrusion friction.
Shouguang Sunrise Industry mainly produce and deal in paper products, Specialized in producing PE coated paper, cup fans, lids and more for your sourcing selection.
