Press

From micro to max: Solid and liquid silicone processing

06.06.2018
– Smaller than ever before: The new PX 25
with 250 kN clamping force
– Micro-injection molding with LSR
– New AZ 50 material feeding unit for solid silicone on the CX 200
– Double-digit growth rates for silicone processing
From micro to max: Solid and liquid silicone processing - Picture Main

(Munich, June 6, 2018) Intelligent materials, intelligent processing: take silicone with its enormous growth rates, for example. At the Competence Forum, KraussMaffei is demonstrating liquid and solid silicone processing. The new, small PX 25 manufactures sealing rings made from LSR by micro-injection molding. HTV sealing mats are formed on the reliable CX 200. The new AZ50 material feeding unit completes the material conveying. APC Plus ensures the most consistent component weight on both machines.

World premiere for the small PX 25

Applications for silicone processing include everything from baby pacifiers and baking pans as well as lenses for LED or components in the engine bay. The market for silicone processing is growing by double digits worldwide because the material has excellent chemical properties along with flexibility and temperature resistance. It is resistant to aging, fire and bacteria. Competence Forum visitors can observe both the liquid silicone (LSR) and solid silicone (HTV) processing.

With the PX 25, KraussMaffei is exhibiting a machine with only 250 kN clamping force for the first time and with it, is targeting products with low shot weight for use in medical technology, for example, or for precision components such as clocks, gears or gearbox elements. "The current application with a cycle time of just 14 seconds illustrates that. A radial seal made from LSR with an intricate undercut and a weight of only 0.15 grams—a product in the micro-injection molding business area—is being produced," explains Jochen Mitzler, Manager of Market Intelligence and Product Management at KraussMaffei. Specifically for the project, a new plasticizing unit with an especially small screw (12 millimeters in diameter) was developed. A servomotor-controlled SPX 10 sprue picker completes the system. Competence Forum visitors can delve into the application virtually with a HoloLens, which visualizes all of the important customizing functions on the machine and the mold. Truly, this is a live performance of Industry 4.0.

Partners in this exhibit are Dow Silicones (material), ACH Solution GmbH (mold), AVR Tech Innovations GmbH (HoloLens) and gwk Gesellschaft Wärme Kältetechnik GmbH.

Solid silicones on the rise in the United States and Asia

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 will produce 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," says Mitzler. 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. "Whether solid or liquid, KraussMaffei makes silicone processing safe and simple," summarizes Mitzler.

Partners in this exhibit are Rico Group (mold), Wacker Chemie AG (material) and Regloplas AG (heat-balance).

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.

 
From micro to max: Solid and liquid silicone processing - Picture 1
From micro to max: Solid and liquid silicone processing - Picture 2
From micro to max: Solid and liquid silicone processing - Picture 3