Sorry fo the misunderstanding.
The customer does not mind the brown spot on the label, but it is my concern to solve the issue. All lids come with the spot - so in that sence it is 100% rejects.
Dear Patprimmer,
Thank you for your attention and suggestions.
Well, I fully understand and appreciate what you say about the gate and the ball, etc. I already decided to increase the gate diameter to reduce shear heating at the gate which might be overheating the melt, remove the gate internal...
Dear Compositepro,
Thank you for your suggestion. Indeed the problem is the jet of plastic melting through the label.
I missed to say that the gate was modified not in diameter as you suggest but a part of sphere was introduced to give material filling route other than direct to the label...
Dear Demon3,
Thank you for your suggestions.
Lowering the temperature does not eliminate the spot - already tested.
Reducing cycle time will not help either, and injecting from a different position is not feasile.
Melt flow rate is already high enough abt.40
However, I have seen similar lids...
Product: PP round flat Lid, dyed dark brown. Injection gate on the male mould side to allow for the label to be applied on the female mould.
Label material: Multilayer PP white 65 microns
Since PP material is dyed dark brown and being injected opposite the white label, it fuses into the label...