1. Overmolded nylon PA, need to choose a specific grade of TPE rubber. Mainly from the polarity of PA nylon and higher melting point, which requires modification of the TPE to meet the TPE and nylon have a strong adhesion. At present, the adhesion of TPE and PA nylon, the industry has made greater progress, usually have a certain number of years and R & D strength of the TPE manufacturers, can provide TPE grades of overmolded PA. Of course, in addition to adhesion, if the user has some other special material requirements, such as surface scratch resistance, flame retardant, etc., the requirements of TPE and more stringent, sometimes need TPE manufacturers in addition to customize special TPE rubber.

　　2.TPE overmolded nylon material processing technology and considerations.TPE overmolding, you can use two-color injection molding machine and ordinary injection molding machine to achieve. Two-color injection molding machine molding fast, just by rotating the die head, no need to take out the nylon rubber parts, directly in an injection molding machine can be completed overmolding. If you use ordinary injection molding machine, you need to inject the nylon rubber parts first, and then use another set of overmolding molds, embed the nylon parts into the overmolding molds in advance, and then inject the TPE into the surface of the nylon parts to complete the overmolding.

　　For two-color machine molding, because the whole overmolding process is fast, the nylon parts are overmolded while they are hot, and the adhesion effect with TPE is very good. For ordinary injection molding machine overmolding nylon, because the nylon parts and TPE parts are separated from the individual molding. For nylon parts, one is to ensure that the surface clean before overmolding, and the second is due to the low surface temperature of nylon parts before molding, it is generally recommended to preheat the surface of the rubber parts before overmolding and baking (generally 130~140 ℃ baking for 2 hours) processing, and then immediately put the preheated nylon parts to overmolding molds for the second injection of TPE overmolding. Whether it is a two-color machine or ordinary injection molding machine, when the overmolding, it is necessary to achieve sufficient injection molding temperature, general TPE overmolding nylon, overmolding temperature is about 220 ~ 260 ℃ between the specific can be consulted with the supplier, and according to the actual overmolding situation properly adjusted. For some of the overmolded surface is larger, more complex structure of the product, whether it is two-color machine and ordinary injection molding machine molding, it is recommended to use multi-point into the glue, in order to facilitate the overmolding.

　　3.TPE overmolded nylon material summary

　　As the saying goes, strike while the iron is hot. In this case, it should be said while the heat is wrapping. Sufficient temperature is to ensure that the TPE overmolded nylon smoothly the most important process conditions. Above both nylon parts preheating, multi-point into the glue or overmolding molding temperature selection, are around the molding temperature needed to carry out. Sufficient temperature can provide the energy needed for overmolding, prompting the formation of a fusion layer between the TPE and the nylon parts, and then form a strong bond.