IML(In-mold label), also known as in mold insert injection molding, is a molding method in which ink is printed on the inner surface of a sheet, and the printed sheet is hot pressed into a 3D shape. The outer shape and inner hole are then punched and cut, and then placed into the injection mold cavity. The injected resin is then injected into the metal mold cavity and bonded with the sheet to form a solid product.
IML(In-mold label) has the advantages of surface corrosion resistance, wear resistance, non shedding, bright colors, replaceable color patterns, and excellent surface decoration effects. It is widely used for surface decoration of products such as mobile phones, 3C, home appliances, and instruments.
IML’s process procedures
Cutting – Flat printing – Ink drying and fixing – Applying protective film – Punching positioning holes – Hot forming – Cutting peripheral shape – Material injection molding process flow is shown in the following figure: Specific instructions are as follows:
1) Cutting: Cutting a roll of thin film into square blocks of predetermined size for use in printing and molding processes.
2) Flat printing: Produce a film mesh according to the required icons and text, and print the icons and text on the cut square blocks of the film.
3) Ink drying and fixation: Place the printed film square in a high-temperature oven to dry, with the aim of fixing the IML ink.
4) Applying protective film: To avoid scratching the surface of the already printed film during the punching and positioning process, it is sometimes necessary to apply a single or double layer protective film.
5) Punching positioning holes: Hot formed positioning holes must be punched accurately. The positioning holes for the cutting process sometimes need to be punched in advance.
6) Hot forming (high-pressure or copper mold): After heating the printed film, it is formed using a high-pressure machine or copper mold in a preheated state.
7) Cutting the outer shape: Cutting off the waste of the formed three-dimensional film.
8) Material injection: Put the film with the same solid shape as the front mold after molding onto the front mold to inject the IML finished product.
