Wittmann Battenfeld: Liquid silicone injection molding of micro parts

MicroPower 15/10H/10H „Combimould“ mit LSR-Dosierpumpe (Bild: Wittmann Battenfeld) / MicroPower 15/10H/10H „Combimould“ with LSR dosing pump (Photo: Wittmann Battenfeld)

Stützring mit Silikonmembran aus PC und LSR (Bild: Wittmann Battenfeld) / Support ring with a silicone membrane made out of PC and LSR (Photo: Wittmann Battenfeld)

At the Compamed, the international trade fair for the medical manufacturing supplier market and product development hold in Düsseldorf from 15 to 18 November 2021, WITTMANN BATTENFELD produced a micro support ring with a silicone membrane to demonstrate its expertise in the field of liquid silicone processing.

Laying out injection molding machines for liquid silicone processing has a long tradition at WITTMANN BATTENFELD. This type of technology has been used for many years not only on conventional machines, but also on the MicroPower, a machine specially designed for micro parts injection molding.

On this machine, thermally homogeneous melt is injected via a two-step screw-and-plunger injection unit, with shot volumes ranging from just a few mm³ to 4 cm³. In this way, it has become possible to make top-quality parts in an absolutely stable production process and with short cycle times.

The multi-component version of the MicroPower, known as MicroPower COMBIMOULD, is equipped with two horizontally positioned injection aggregates and a rotary disk integrated in the machine. The rotary disk takes care of turning the part towards the second injection unit and back. The machine is also laid out for clean-room injection molding. Its rotary disk is completely encapsulated. All connections for heating aggregates, temperature sensors, water tempering, core pull pneumatics and sensors, as well as the blow-through valve, are installed close to the rotary disk. The resulting short connection lines to the mold enhance the machine’s user friendliness.

At the Compamed, WITTMANN BATTENFELD demonstrated its know-how in the field of LSR processing in micro part production by manufacturing a support ring with a silicone membrane from PC and LSR on a MicroPower 15/10H/10H COMBIMOULD. The materials to be used for this purpose are polycarbonate (Macrolon) from Covestro and a self-adhesive LSR (Silopren) supplied by Momentive. The mold has been constructed in co-operation with Nexus. The LSR metering device actually comes from Nexus and is equipped with a new Servomix liquid dosing unit for LSR with an OPC-UA interface (Euromap 82.3).