In-mould decoration

Adapted from Wikipedia: http://en.wikipedia.org/wiki/In-mould_decoration

In-mould decoration, a special type of plastic moulding, is used for decorating plastic surfaces with color and/or with an abrasion resistant coat.

Principle

A carrier foil is placed inside the opened mould. It carries the dried paint layers which are supposed to be transferred to the plastic part, the paint facing the gate. After filling with plastic the paint sticks to the plastic, and therefore is removed from the carrier when opening the mould. For the next cycle the carrier foil is moved one picture further.

Mould construction

The mould has to be constructed in a way to let the back side of the carrier foil rest against a flat wall. The plastic foil can be bent slightly, but the more it is bent, the more the risk of wrinkles. The filling only takes place on the other side, the side the carrier is covered with paint. The part has to stay on the side of the gate (= ejectors on gate side). The tips of the ejectors are usually bent a little bit to ensure the parts stick to them)

Carrier foil feeder

To be able to place pictures as fast as possible inside the mould, the carrier tape is wound on a coil: the unused, full one on top of the mould, the used, empty on the bottom. Usually the foil feeder is attached to the moving side of the mould, to enable demoulding when opening the mould.

Cleaning of the parts

Leftovers from the paint ("flakes") on the edges have to be removed from the parts. This usually works by rotating brushes.