Voelkl with CM65 conical twin-screw extruder pipe 110 32 molding process conditions are as follows:
Barrel temperature / C 175/165/150/140
Connectors die temperature / C 160
Die temperature / C 175/175/165/190/200
Screw Temperature / C 130/135
Screw speed / (r / min) 30.5
Motor torque utilization /% 95
Vacuum / MPa 0.09
Screw fullness /% 100
Melt pressure / MPa 24.5 (measured at the connector)
Melt plastic box temperature / C 193 (measured at the connector))
Yield / (kg / h) 250
Xu Shoujian with CM80 conical twin-screw extruder production sound pipe 225 6.6 pipe process conditions are as follows:
Barrel temperature / C plastic case 175/165/150/140/150
Die temperature / C 175/180/180/180/185
Melt pressure / MPa 15
Melt temperature / C 200
Screw speed / (r / min) 26
Motor torque value /% 78
Twin-screw extruder with a general machining process plastic package of the tube under the following conditions:
Barrel temperature / C 175 ~ 180/165 ~ 170/155 ~ 160/140 ~ 150
Die temperature / C 160 (connection) / 170 ~ 175/180 ~ 185/185 ~ 190/180 ~ 185/173 (punch)
Screw Temperature / C 60 ~ 80
Screw speed / (r / min) 20 ~ 30
Screw clamshell packaging vacuum / MPa 0.08 ~ 0.09
Pulling speed faster than the extrusion rate of 1% to 3%
In order to better control plastic trays the twin-screw extrusion process, the need for a twin-screw extruder functions each stage of understanding. According Leingartner papers, he pressed a particular processing function, can be twin-screw feed section is divided into sections, plastic sections, current limiting, venting and metering zones into five sections. The role of the feed section is pvc dry mixture at a predetermined speed of delivery to the plastics segment, while the material is preheated. Plastics segment is the role of the material further heated and agglomerate into blocks. The role of limiting the exhaust section of the sealing and facilitate the material melting section. The main function of the exhaust section is to eliminate volatiles, and pre-plasticized material entrained in the air. The role of the metering section is to complete the melting process, the material homogenization, and generate sufficient pressure to overcome the resistance of the die. The five functions are the geometry of each section by the screw to achieve the change.
In controlling the molding condition, first, to control the temperature. Barrel temperature distribution from high to low, the feed section and the section of the plasticizing temperature of the material to be heated in the exhaust section to achieve a certain degree of gelation, junction block and the material density packaging company of about 1.0g/cm3, density is clear plastic box too low there will be withdrawn from the vent powder phenomenon. In the metering section lower temperature due to friction heat, melt temperatures up to 190 C. In the die temperature was gradually increased, as shown in Figure plastics products 2-10. Die out at temperatures up to 250 C, so that the PVC gel instantaneously achieve the desired degree without degradation.
Second, we must packaging design control the feedstock. To meet the twin screw extrusion process stability requirements, you can choose for full metering section C-shaped chamber is less sensitive to the number of process conditions, ie a higher plastic packaging screw speed, the lower the resistance of the feedstock and the lower die. The feedstock generally make the exhaust section of the spiral groove is half full. In addition, the screw should be lower than the rated torque. For conical twin-screw, torque up to 95% of the rated value is safe.