TPE Overmolding onto Nylon(mainly PA6, PA66 and defibrillators modified nylon engineering plastics) often used in handles of kitchen utensils and electric drill tools, electrical accessories, etc. The hardness of TPE can be adjusted by modified formulation. The hardness range for TPE which overmolding onto nylon: Shore 40A~Shore 80A, the most common hardness is Shore 60A.
Injection moulding machine or two-colour injection machine are often used where Thermoplastic Elastomers is molded onto nylon. Injection moulding machine need two sets of mold, a set of mold for nylon parts injection, another set of mold for tpe overmolding onto nylon, it requires two steps. Two-colour injection machine complete the entire production process in one machine, thus shortening the molding cycle, improving work efficiency.
Manufacturers often encounter poor bonding capability where TPE is molded onto nylon. How to improve the situation?
2.Provide appropriate tpe injection molding temperature. During processing, it is necessary to make tpe and nylon having a close processing temperature. For example, nylon injection molding temperature is 250 to 260 degrees, then tpe overmolding temperature need to be 240 to 250 degrees, approaching but slightly lower than nylon injection temperature.
3.Preheat nylon parts before overmolding. Heat nylon parts and put them into the injection molding machine before it goes cold, then tpe materials molded onto nylon immediately. Thus can improve the adhesion properties of tpe and nylon.
4.Create better product design. Perforate nylon parts in some inconsequential position or set zigzag groove at the edge of soft cover, by insert molding or increasing the contact area between the TPE and nylon can improve their adhesion.
Injection moulding machine or two-colour injection machine are often used where Thermoplastic Elastomers is molded onto nylon. Injection moulding machine need two sets of mold, a set of mold for nylon parts injection, another set of mold for tpe overmolding onto nylon, it requires two steps. Two-colour injection machine complete the entire production process in one machine, thus shortening the molding cycle, improving work efficiency.
Manufacturers often encounter poor bonding capability where TPE is molded onto nylon. How to improve the situation?
1.Change formulation and improve the compatibility of tpe with nylon, so as to enhance their adhesion. There is a big gap between the two materials’microscopic molecular polarity. Poor compatibility between them make it difficult for tpe bonded to nylon. We can improve adhesive property between tpe and nylon by introducing a graft material.
3.Preheat nylon parts before overmolding. Heat nylon parts and put them into the injection molding machine before it goes cold, then tpe materials molded onto nylon immediately. Thus can improve the adhesion properties of tpe and nylon.
4.Create better product design. Perforate nylon parts in some inconsequential position or set zigzag groove at the edge of soft cover, by insert molding or increasing the contact area between the TPE and nylon can improve their adhesion.
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