Processes & Products
Solid silicones: New material feeding unit
| Petra Rehmet
Live demonstration at the Competence Forum
Intelligent materials, intelligent processing: take silicone with its enormous growth rates, for example. At the Competence Forum (June 6 to 7), KraussMaffei was demonstrating liquid and solid silicone processing. The new, small PX 25 manufactured sealing rings made from LSR by micro-injection molding. HTV sealing mats were formed on the reliable CX 200. The new AZ50 material feeding unit completed the material conveying. APC Plus ensured the most consistent component weight on both machines.
Along with LSR, solid silicones are being used more and more, as is shown by trends in the United States and Asia. Therefore, at the Competence Forum, a CX 200 was producing a sealing mat made of HTV and weighing 72 grams in an 8-cavity mold. It is about transporting the tough material, without air voids, to the plasticizing unit. The new AZ 50 material feeding unit with stuffing pressure control takes on this task. It processes the blocks of material in a rotating hopper and pulls the HTV downward using a continuously downward-moving stuffer screw. Using rear ventilation, the air can escape upwards, which is unlike other system concepts that use a forced piston, which inevitably traps the air and thus keeps it in the injection barrel, the mold and finally in the component.
APC Plus for LSR and solid silicone
The APC Plus machine function ensures the most weight-consistent components. It regulates the changeover point from the injection to the holding pressure phase individually for each shot and levels out the viscosity fluctuations in the melt. The specific property patterns for various materials are stored in the machine in a database, as are the low-viscosity LSR and solid silicone. APC Plus adjusts the injection process precisely to the application and the material within the same shot.
"Whether solid or liquid, KraussMaffei makes silicone processing safe and simple"Jochen Mitzler, Head of Market Intelligence and Product Management
Partners in this exhibit were Rico Group (mold), Wacker Chemie AG (material) and Regloplas AG (heat-balance).