How to making PP corrugated hollow sheet？
PP Corrugated Plastic Sheet is a twin wall profile extrusion, connected by a series of vertical ribs, also called Coreflute,
Corflute, Correx Sheet,Corex Sheet, PP coroplast Sheet. The PP corrugated sheet can be widely used in packaging, advertising,construction, agriculture, hardware, layer pad industry and others.
The raw material of the plastic hollow board is PP plastic, which is polypropylene plastic, which is non-toxic and does not harm the human body. The most important link in the production process of the hollow board is to adjust the parameter settings such as the molding temperature and heating conditions of the PP material. The settings that need to be paid attention to in the whole process are as follows:
1. The PP material of the hollow sheet will start to deteriorate from around 280 °C, so the heating temperature should be operated below 270 °C, its molecular orientation is very strong, and it is easy to be warped and twisted due to the molecular orientation during low temperature molding, which should be paid attention to.
2. A high pressure forming machine must be used for high pressure forming.
3. Back off tilt may magnify. The runner and gate must be designed according to the fluidity. Pay attention to control the material temperature and mold mold.
4. The molding shrinkage rate is about 0.35%, the heating temperature is 180~300℃, the mold temperature is 20~80℃, the material tube temperature is 220~270℃, the ejection temperature is 210~280℃, the injection pressure is 400~1000kg/cm², the lowest The operating temperature is 200°C.
5. The gate design must pay attention to the adhesion of the molded product. Molded products must be designed to prevent dents and deformations. The forming shrinkage rate is about 0.8~1.5%.
6. The drying temperature is 60~90℃ with hot air, it takes 1 hour, and the temperature of the first section is 240~250℃; the second section is 190~250℃; the third section is 170~230℃; the fourth section is 170~230℃; The segment is 150~210℃; the mold surface temperature is 20~60℃.
7. Temperature setting: nozzle 200~220℃, front section 190~215℃, middle section 190~210℃, rear section 185~200℃; screw speed 120~max rpm, mold temperature 20~70℃, injection pressure 700~ 1800℃, extremely long pressure holding 30~70%, back pressure 120~200kg/cm².
8. Density 0.90~0.91g/cc, specific gravity 0.9~0.92, linear expansion coefficient 0.000058~0.0001/℃, molding shrinkage rate 1.0~2.5%, thermal deformation temperature 57~63℃ (96~110℃).