Reasons for not wrapping firmly analyzed

　　1 Plastic wrapping difficult to analyze

　　Commonly used plastics are ABS, PP, PC, PA, PS, POM and so on. Each kind of plastic, basically have the corresponding TPE coating material grade. Relatively speaking, PP is the best wrapping; PS, ABS, PC, PC + ABS, PE plastic wrapping second, but the wrapping technology is also very mature, to achieve a solid wrapping without difficulty; nylon PA wrapping difficulty will be greater, but in recent years the technology has made significant progress.

　　2. The main plastic covered TPE hardness range

　　PP overmolding: hardness range 10~95A.

　　ABS, PC, PC + ABS overlay: hardness range of 30 ~ 90A.

　　PS overmolding: hardness range 20~95A.

　　Nylon PA overmolding: hardness range 40~80A.

　　POM (paraformaldehyde steel) overmolding: hardness range TCXH series 50~80A, TSE-ADM series 60~85A.

　　Wrapping other common problems cause analysis

　　1 Layering and peeling at the rubber inlet

　　A Problems of material (improve TPE compatibility).

　　B Fast injection speed and high pressure (reduce the injection speed and pressure appropriately).

　　C Small sprue size (increase the sprue size appropriately)

　　2. Bad demolding of overmolded parts

　　a. Problems of material---

　　Countermeasure: change TPE material

　　b. Mold is too glossy --- Countermeasure: Mould is sunned.

　　Countermeasure: mold sunshine pattern

　　3. White and sticky surface of plastic covered products

　　Small molecule additives precipitation of TPE compatibilizer

　　Countermeasure: pay attention to the amount of additives

　　4 hard plastic parts deformation

　　a Thin hard plastic parts, the second injection temperature is high, softening deformation;

　　b The thickness of the soft rubber package is large, the contraction of the hard plastic parts are pulled deformation.

　　Countermeasures: lower injection temperature, reduce the injection speed, appropriate to strengthen the pressure, if necessary, the mold to do to strengthen the structure of the bar