Different substrates in the market should choose different materials for the wrapping material, different TPE has different wrapping materials, and different TPE wrapping is also the only material to do different substrates.

　　For example, the package PP material can not package ABS, package ABS material can not package PA, etc.. Now the market TPE wrapping, can be divided into the following categories: PP wrapping class, ABS wrapping class, PETG wrapping class, PC wrapping class, PA wrapping class and so on.

　　The thickness of the TPE cover:

　　In most TPE overmolding applications in the market, the wall thickness range of 1.5-3.0mm will ensure a good bonding effect, if the TPE bit is too thin, injection is more difficult, the bonding strength is lower, and the feel is poor. If the TPE adhesive bit is too thick, on the one hand, the cost is higher, on the other hand, it is easy to produce shrinkage, bubbles and other defects.

　　The wall thickness of the TPE adhesive bit should be as uniform as possible to achieve the best molding cycle. The transition between different wall thicknesses should be gradual to reduce problems arising from fluid flow, such as air lines and bubbles.

　　TPE Covered Casters:

　　Curvature (minimum radius of 0.5mm) should be used at sharp corners to reduce local stresses. Deeper closed air chambers or arched parts that cannot be exhausted should be avoided, and sufficient exhaust slots (0.015-0.025mm) can be added at the end of the TPE covered rubber bit if necessary. Insufficient venting may cause air trapping, glue burning, insufficient adhesion and other undesirable phenomena.

　　Adding buckle on the substrate or making some properly designed deeper concave and convex part is helpful to improve the adhesion effect of TPE.

　　Treatment of mold surface:

　　The mold should be polished to get a smooth or clear surface. A rougher mold surface is needed in order to produce that lusterless appearance of thermoset rubber surfaces. Generally speaking, the rough surface produced by electrical discharge machining (EDM) of the mold cavity will produce a good appearance of the part and make release easier. Abrasive methods such as steam blasting, sand blasting or shot blasting, and chemical etching can also be used to produce a surface with a different gloss and appearance.