The injection plastic parts must be removed from the mould after the completion of plastic injection moulded products.

If the injection mould cannot be opened, it cannot be removed either. So a set of plastic moulds must be divided into the mould and down mould, or the left and right mould.

However, the injection moulding parts is a crack in the combined mould position because the plastic injection time must be the pressurized plastic filling of the mould, So no matter how close the mould is, with today’s technology, the plastic is more or less bound to be squeezed into the gap. When the mould comes out of the mould, it leaves a mark in the gap, which in the plastic world is called a mark.

Looking at this trace carefully, you will find that the parts have a bit more plastic out of them. The injection parts have too much plastic called “Sometimes the mould is poorly designed, or the mould is worn and neglected so that the two moulds can not wholly fit together, resulting in dislocation, and an obvious step will be formed.

Because the plastic line is due to the joint formed by the mould, so in the mould design will be decided at the beginning of the plastic line, but also because the location of the PL will affect the follow-up mould opening position, so avoid because mould corner (undercut) cannot refund mould problem, such as a plastic cup in hand, parallel to the parting surface is best to handle, In case the hand is still buried in the mould after parting.