IMD is resin-moulding system that has been rapidly developing recently. In a broad sense, IMD means whole insert-moulding In a narrow sense, it means the system in which the preliminarily-moulded film is insert-moulded.
The process is: printing – preliminary-moulding – trimming – injection moulding – finished product. There are three kinds of preliminary moulding : high-pressure moulding, vacuum moulding and press-moulding with metal dice. Preliminarily-moulded film is trimmed and adhered to the resin in the injection moulding machine. The unprinted side of the film generally comes on the surface of the finished product face up, which means that the printed ink is sandwiched between the film and resin. As the ink is covered with the film, abrasion resistance becomes good.
The ink which is used for IMD must have conflicting properties: flexibility to cope with moulding and the resistance to heat and pressure of injection process.