Brief introduction of secondary injection molding of thermoplastic elastomer TPE material.

Time：2021-10-10Hits：1462

Whether insert injection molding or secondary injection molding is selected, thermoplastic elastomer (TPE) is injected on the compatible rigid substrate. This enhances the functionality of "soft-coated hard" goods, such as insulation, chemical resistance, more ergonomic fit, better hand feeling, grip and top-notch aesthetic feeling. Insert molding: In insert molding, a rigid part (usually a relatively hard plastic part) is made first, and then embedded in a mold cavity, and then TPE is used for injection molding on this component, and finally a complete product is obtained. Conventional injection molding equipment can be used for insert molding. Rigid parts can be inserted by manual or mechanical arm. Secondary injection molding: Secondary injection molding is also called secondary injection molding, two-color molding or multi-material molding. In this case, a special machine is used with multiple barrels, which are used to write different data into the same mold. Cohesion in compound injection molding In compound injection molding, the strong cohesion between the substrate and TPE is the key to the success of processing. Poor adhesion may cause doubts such as peeling, bending, wear or delamination. The compatibility between the two materials and the processing temperature are the important factors affecting the bond strength. Data compatibility: Bond strength of different hard/soft data combinations. Processing temperature: It reflects the relationship between TPE melting temperature, rigid substrate temperature and bonding strength. Application of TPE in Compound Injection Molding The thermoplastic elastomer based on polyester (TPE-E or COPE) is produced by DSM engineering plastics. This kind of polyester elastomer combines the strength and processing characteristics of engineering plastics with the function of thermosetting elastomer, and improves the processing, yield and chemical resistance. Most soft compound injection molding applications involve injecting a thin layer of soft materials (TPE) onto a hard substrate. Because TPE generally needs to flow through a long way and thin wall area to fill the mold, TPE must have high fluidity. Low viscosity commodity specifications optimize the adhesion which is very important for double injection molding, and are the first choice for this processing and application. Chemical bonding: TPE can bond well with polar polymers (such as PC, PC/ABS, ABS) used as rigid base materials after double injection molding. Because of this outstanding adhesion, even in the case of very large torque, it will not show the appearance of delamination with the substrate. In the process of selecting exterior elastomers, TPE's excellent layout characteristics and excellent appearance sense function are linked with TPE's outstanding processing function in compound injection molding. Application of physical bonding or adhesive: Mechanical interlocking depiction is often used to improve bonding force between TPE and nonpolar polymer (such as PP) or PA. In addition, adhesive or primer can be used to improve the adhesion between soft TPE and nonpolar polymer.

德创化工 (edit：dechuang)