After the injection molding, the film and plastic are integrated. The wear-resistant material is on the outside. This process is mostly used in the mobile phone display screen. The plastic materials are mostly PC, PMMA, PBT, etc., which mainly have the function of wear resistance and scratch resistance. There is also a technology called IML (in-mold-lable), which is roughly the same as IMD, except that flim is pulled out like a punched tape after injection molding, which just transfers the printed pattern to the plastic parts, also known as in mold transfer.
There are two main types of IMD. One is PC and single chip. The other is pet, chain like (like film or printed instant noodle pockets).
The former finished product is merge PC chip, the latter only takes the ink on the pet chain, but PET material (chain, also known as foil) is not imported into parts by merge.
The former can only be screen printed because of the thick PC, so the effect is rough. For example, the front shield shape of Motorola v66 is already very delicate, while the latter can be printed with offset plate due to its thin pet, which is very fine, especially electroplating and transparent, fine metal and surface texture are very good, such as the front electroplating and black texture effect of Motorola V60.
For example, the control panel on Matsushita rice cooker mold is a typical IMD, which puts a silk screen printed PET film into the injection mold for injection molding. The materials are PC, transparent ABS and PMMA. After injection molding, the film and plastic are combined into one.
Nowadays, most of the outer screen lenses of mobile phones adopt IMD technology, and the cost is correspondingly increased. The requirements of mobile phone molds, especially transparent molds, are more stringent.
Generally speaking, there are two background reasons for using IMD,
- Some effects of injection molding are difficult to simulate, such as the walnut automobile dashboard (car parts mold).
- It is very difficult to integrate several effects on small pieces of parts. For example, the front triangle of moto V60 mold concentrates on electroplating, transparency and screen printing, but it also requires delicacy. Imagine that it is very difficult to use real plating, injection molding and splicing of transparent pieces.
Another method is to make the outer surface smooth and the inner surface rough, but there are some requirements for the mold.
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