Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : September 03, 2023 - September 06, 2023
In today's society, plastic products are used everywhere. Injection molding is mainly used for mass production of plastic products. In this process, there is the problem of increased costs due to the time required to cool the resin filled into the mold. If the mold is released with insufficient cooling, adhesion will increase, resulting in defects such as increased roughness, and cracks on the product surface. In this study, a coating was applied to the mold surface to reduce adhesion and prevent product defects. Previous studies have shown that both Si-doped Diamond-Like Carbon (Si-DLC) coated and non-coated steels exert a large force to pull the mold surface and Poly Ether Ether Ketone (PEEK) resin apart. In this work, we further tried boron nitride (BN) coatings, which has a high hardness next to diamond, a high-temperature durability, electrical insulating properties, and chemical stability, being expected to have low adhesion to resins. Adhesin-Peeling tests of h-BN, c-BN, Si-DLC against PEEK showed that the peeling strength of BN coatings was significantly lower (1.64 MPa at the peeling temperature of 80℃) than that of Si-DLC coatings (11.6~22.2 MPa at peeling temperatures from 30 to 100℃). Note that the peeling strength of the Si-DLC coating with release agent was 0.43 MPa at the peeling temperature of 80℃).
