MaterialTPE/TPR Coated ABS Concept

TPE/TPR overmolding ABS refers to the process of first injecting ABS plastic in the injection molding process, then placing the finished ABS product into another mold, and injecting TPE/TPR material onto the surface of the ABS part. This process is typically completed within two injection molding machines, with the mold for injecting the soft TPE being called the overmolding mold. Today, more advanced two-color and multi-color injection molding machines have maturely been applied, suitable for scenarios where products require composite injection molding with multiple materials. Two-color injection molding shortens the injection molding process time compared to traditional overmolding secondary injection molding.

Material Characteristics of TPE/TPR Coated ABS

Hardness — Different product applications require varying levels of material hardness. Considering the adhesion of TPE to ABS and the tactile feel of the material, the hardness range for ABS plastic with TPE/TPR overmolding is typically between 30-90A Shore.

b. Basic Physical Properties — The TPE elastomer material used for bonding ABS should possess necessary adhesion to ABS, good flow processing properties, and moderate surface wear and scratch resistance. Depending on the differences in customer product design and performance requirements, the physical properties of TPE may vary. TPE suppliers (Dongguan Aodili Plastic Raw Materials Co., Ltd.) generally provide *suitable* and cost-effective TPE modified materials based on customer sample requirements.

Analysis of the reason for poor adhesion between TPE/TPR and ABS coatings:

a. Concerns regarding TPE/TPR compound formulations. We recommend that customers, particularly those new to TPE/TPR materials, collaborate with established TPE, TPR manufacturers. Some traders may not fully understand TPE/TPR themselves, and the TPE/TPR compound they provide may inherently have poor adhesion to ABS jacketing.

b. The temperature used for secondary injection molding and overmolding is inappropriate. Low temperatures result in insufficient TPE/TPR plasticization and poor flowability, which not only affects the appearance but also significantly impacts the melting and bonding performance at the contact surface between TPE/TPR and ABS. Suitable processing temperatures are related to the TPE/TPR material formula, mold design, and other factors. It is recommended to consult the supplier during processing and make adjustments according to the actual production conditions.

Additional: CoatedABS injection molding temperature for TPE/TPR is 160~220°C, with a hardness range of 30~90A. Generally, under comparable conditions, TPE with SEBS base material requires a secondary injection molding temperature that is higher than that of TPR with SBS base material.