A new suction blow molding machine has been developed for production of 3D parts made of high-temperature materials—i.e., melt temperatures from 250 to 360 C (480 to 680 F). In suction blow (a form of extrusion blow) the parison is conveyed directly from the parison die head into the closed blow mold and is drawn through the mold by vacuum. Once the bottom end of the parison emerges from the blow mold, the parison is pinched off by shutters and then inflated.
The model K3D SB 8 HT machine from Kautex Inc., North Branch, N.J., has an extruder with special screws designed for gentle plasticating and homogenizing of high-temperature materials. The extruder also uses special wear- and heat-resistant steels. Electrical and hydraulic components and related safety devices are designed for processing temperatures up to 360 C. Insulation is provided to minimize heat losses near the die head. Also, the mold is preheated to prevent premature cooling of the parison as it is sucked through the mold.