Various types of In-Mold Decoration (IMD) processes
Various types of In-Mold Decoration (IMD) processes
Plastic materials are widely used in various aspects of our lives, such as automobiles, home appliances, laptops, consumer electronics, and medical devices. When using plastic materials as product appearance parts, we usually apply various surface decorations. However, due to environmental considerations and other factors, traditional processes such as spray painting and water transfer printing cannot meet current demands. Therefore, the environmentally friendly and visually rich In-Mold Decoration (IMD) process has become increasingly popular.
In-mold decoration (IMD) is a process that can complete the decoration process inside an injection mold. Its products have the advantages of high clarity, good three-dimensional effect, and surface scratch resistance, and have been widely used in fields such as automotive, home appliances, consumer electronics, and medical electronics.
IMD technology was developed by foreign manufacturers, and various process names have emerged according to the characteristics of their respective products. On the other hand, this technology first entered Taiwan and then was introduced to mainland China, and the process name was translated from English, resulting in various names and definitions such as in-mold injection, in-mold transfer, in-mold labeling, insert molding, etc., such as IMD, IMR, IML, FIM, INS, and so on.
Several common concepts related to In-Mold Decoration (IMD):
According to Wikipedia, IMR which is stands for "In-Mold Decoration by Roller" (sometimes explained as "In molding release" in part) , and is a type of IMD (In-Mold Decoration) technology. It is a roll-to-roll process that can be fully automated and is particularly suitable for the surface decoration of product exterior and functional panels. It has been widely used in laptops, early mobile phones, home appliances, and cars. The characteristic of the IMR process is that the outermost layer of the film is a release film, usually made of PET material. After production, the product can be separated from the base film to form continuous roll-to-roll production.
IML stands for In-Mold Label (sometimes also referred to as In-Mold Lamination), and is commonly known as in-mold insert molding or in-mold labeling. It is a technique that involves placing a pre-printed label or decorative film inside a mold cavity before injection molding the material around it. This results in a product with a high-quality, integrated decoration that is both durable and scratch-resistant. IML has been widely used in industries such as home appliances, automotive, and medical electronics. Examples include IMD control panels for air conditioners and washing machines, covers for robotic vacuum cleaners, and dashboards and center consoles for cars.
The significant feature of in-mold labeling (IML) process is that there is a hardened, transparent film layer on the surface, followed by a printed pattern layer in the middle, and a plastic layer on the back. As the ink is sandwiched in the middle layer, the product is resistant to scratches and wear, and the color remains vivid for a long time without fading. Unlike IMR, the IML film remains on the product surface as a whole.
The film substrate used in IML varies depending on the application and specific requirements. It can be made of PET, PMMA, ABS, PC, PMMA/PC, or ABS/PMMA. In the automotive industry, PC and PC/PMMA are commonly used.
One important step in the IML process that distinguishes it from IMR is the film forming method. There are two methods: hot pressing and air pressure. Generally, air pressure provides better results and causes less damage to the appearance of the film.
- processing" generally refers to low-stretch products with poor edge wrapping effect, which may require post-processing such as CNC after processing. This term is more commonly used by domestic manufacturers. Foreign manufacturers may have other terms, such as "FIM" used by Mektec.
INS is a proprietary term for high-stretch in-mold injection molding in the automotive industry. Generally, it refers to the inlay injection molding process. This process uses thermoforming or high-pressure forming to stretch the pre-printed ABS film or ABS+PMMA three-dimensionally, then cut the inlay accurately according to the product shape, and finally place the inlay accurately into the injection mold cavity for injection molding. Some manufacturers also call it IMF (In-Mold Forming), which refers to high-stretch IML.
- main products: automotive interior decoration, instrument panel decoration strip, auxiliary instrument panel, door decoration strip, rear armrest, nameplate, etc.
The INS film is an ABS film or ABS+PMMA, generally 0.5mm thick, with PMMA accounting for approximately 25%, or 0.125mm. Because PMMA has better scratch resistance than ABS, composite material films of ABS+PMMA are more commonly used in automotive interior decoration.
INS process flow: pre-thermoforming of film - high-pressure forming - punching out excess film edge - in-mold injection molding.
The INS process is basically the same as IML in terms of technology, but with higher stretching degree and different choices of film materials. The reason why it is introduced separately is mainly because this technology is widely used in the automotive industry, and the film is mostly imported, which distinguishes it from conventional IML.
IMR/IML/INS process comparison
IMR, IML, and INS are all IMD processes, but there are differences in the process, film material, and effect. INS and IML have similar processes, but with different stretching degrees.
New emerging IMD technologies:
IMT: Inner Molding Translate label (developed for the mobile phone industry, mainly refers to 3D texture in-mold transfer, the processing process is similar to IML, but the film has a release layer. It is mostly used for imitating glass or ceramic texture.)
- In Mold Electronics (refers to the traditional IMD decoration in the mold, the technology combines with flexible printed circuits, and can integrate touch, decoration, lighting and other functions. It has become a new concept popular in recent years, and can be widely used in automotive, home appliances, consumer electronics, medical equipment and other fields.)
- This technology completes the decoration of plastic parts through in-mold transfer during the injection molding process, and then injects PU (polyurethane) into the same mold cavity, so that it can achieve exquisite design with crystal clear and high-gloss surface.