How to distinguish between real and fake TPE overmolding

TPE overmolding is a kind of processing technology to overmold TPE soft rubber material on other hard materials such as plastics and metals through specific process. This is mainly through the two-color injection molding machine to achieve a molding, or the use of ordinary injection molding machine with a special overmolding mold to complete the second injection. The key lies in combining the soft and elastic characteristics of TPE with the robustness of the hard substrate, so as to enhance the product's grip, comfort and aesthetic appearance.

According to the different structure of product overmolding and the required overmolding effect, there are two types of overmolding, usually called real overmolding and fake overmolding.

1.Real overmolding

Real overmolding is a kind of processing way to realize the close combination of TPE soft rubber and other hard plastics or other materials through injection molding process, so that the fusion of materials occurs in the position where the overmolding is needed. It makes use of the compatibility between materials and the characteristics of the injection molding process, so that when the TPE in the molten state wrapped in the surface of the hard plastic, it can be fused with the hard plastic at the interface of the combination. Let TPE soft rubber and hard materials in the molding process to achieve real bonding and fusion, resulting in very difficult to use external forces to separate.

2. False encapsulation

False encapsulation refers to TPE and other hard plastics or other materials do not need to be completed through the fusion effect, it is not through the chemical or physical fusion between the TPE soft rubber and hard substrate to achieve a close bond, but through the mold design or other mechanical means to enhance the adhesion between the TPE soft rubber and hard substrate. Soft TPE, TPR and metal overmolding belongs to the false overmolding, TPE can replace rubber to complete the metal injection molding overmolding, the key lies in the design of the overmolding structure, in general, the higher the hardness of TPE, the more conducive to the formation of a solid overmolding with the metal.

The core of distinguishing between real and fake TPE overmolding is to observe the way of bonding between the materials and the degree of solidity. True adhesive bonding through the molecular level of fusion to achieve integration, with long-lasting durability, anti-peeling characteristics; while the fake adhesive bonding rely on the mold structure or mechanical means, although in the cost and process is more flexible, but the durability is relatively weak. In practice, consumers can determine the type of cover rubber by pulling test and observing the surface bonding details.