China Plastics Network tells about the molding process of TPV

1 Hollow molding

Hollow molding is a resin-specific molding method, and general vulcanized rubber molding cannot be applied, and TPV materials can be used in this manner. For example, automotive rack and pinion shrouds, TPV instead of neoprene, hollow molding method can reduce the cost of the component by 30% to 40%, and can be lightweight, product performance is also improved; for automotive purification The air venting tube adopts three-dimensional exchange blow molding technology to cut off TPV and polypropylene while blowing air extrusion (TPV is used at both ends of the tube to improve sealing; the other abdomen of the tube uses fully cross-linked TPE to improve flexing Fatigue and softness; in order to reduce the cost and maintain a certain rigidity, PP is used in the straight part of the pipe. In the past, the parts used in combination of several workpieces can be replaced by one workpiece, which can greatly reduce the combination process. In addition, the hollow molding technology also Based on the general blown extrusion technology, we have developed new technologies such as injection blow molding and compression blow molding with good molding precision.

2 injection molding

Compared with vulcanized rubber, TPV injection molding has a short molding period (unlike vulcanized rubber, which needs to be kept for a certain period of time). TPV can be used to prepare simple injection molded articles or to prepare two-color molded articles in common with other olefin materials. Since TPV has an alkene hard segment and is highly miscible with other olefins, it does not require a special adhesive layer (by fusion bonding), and it is easy to carry out embedding with an alkene material such as PP/TPO/TPE, that is, double injection. Molding makes the product as solid as possible and has a long service life. It can also realize two-color molding with polar materials such as polyamide.

TPV is used for injection molding of automotive sealing strips. It can be used for injection molding of sealing strips, melt-solidification of glass and thermal bonding of the two into a production line, which makes the sealing strip and glass become a solid whole and greatly improves the sealing performance. .

3 extrusion molding

(1) Tubular extruded products

The tubular finished product has a simple tube, a double extruded tube and a coating of a wire. The simple tube has a food tube, a printing rubber roller, and the like. Multi-extruded tubes are represented by automotive fuel delivery lines. The inner side of the pipe is required to be resistant to gasoline and low in permeability, and polyamine can be used, and the outer layer is required to be heat-resistant, weather-resistant and flame-retardant, and a TPV flame-retardant blend can be used, and the two materials can be co-extruded. Tubular finished product.

(2) Profile extrusion

Since the TPV finished product has excellent shape stability, the molding shrinkage after extrusion is small, and it can be used for extruding products having various cross-sectional shapes. For example, extruded water foaming, the process of TPV extrusion foaming without the use of harmful chemicals, can produce extruded profiles with a density as low as 0. 2 g / cm3. Compared with sponge rubber molding, it has the advantages of simple process (eliminating the curing cycle), process waste recycling, product color and design flexibility, and small impact on the environment.