Reduction in cycle time.
In many cases, increase of melt temperatures by 10 to 15 deg. c. helps in eliminating bubbles.
Processing clarified PP
For injection moulding, the following factors should be considered:
A highly polished mould for the best clarity
Optical finish Draw finish(not recommended)
melt temperature observed. Usually
190 to 210
c. is a good starting point
adjusted to avoid condensation. Raise mould temperature slightly in conjection with melt temperature to solve bubble problems.
Low pressure high speed mould filling is best for low haze. "Packing" can cause haze and some loss of impact properties.
It is obvious from the points discussed so far that the properties of end products are decided by various parameters, viz.,
Temperature, pressure, speed and time set on the machine