K 2013: Machine, screw, and color change advances for Sumitomo (SHI) Demag
By K Advisor Staff | August 26, 2013
High-speed packaging, single step touch-screen production, new pigment dosing system for fast color changes, and a low-feed plastification compression screw (minus the compression) are among the K 2013 highlights for Sumitomo (SHI) Demag (Hall 15 Stand D 22). A Systec SP (Speed Performance) 280 fast cycling packaging injection molding machine will mold 1.2-liter polypropylene buckets (84g) cycling at 5.3 seconds. The buckets will be labelled with parallel part removal and IML label insertion. The Systec SP combines an electric motor for dosing procedure and hydraulic motors for mold and injection movements.
Elsewhere, a fully automated injection molding IML/IDL production cell will produce 5-inch touchscreen displays. The IML screen foil is handled and inserted into a lacquer decorated molded frame, in a single step to ISO Class 7, with the whole process managed by a suspended 6-axis industrial robot. In each cycle, the robot takes one conductive inmold label (IML) and positions it onto the fixed half of the single cavity mold. At the same time, the inmold Decoration (IMD) carrier on the closing side above the moving mold half, positions a carrier foil with individual images for decorative coating. The narrow frame is injected and decorated using inmold decoration in black piano lacquer finish. Once the mold is closed, the display is injection molded in polymethyl methacrylate (PMMA) using a film gate and variotherm mold temperature control. Next, a CO2 laser removes the part from the film gate, and it is then cured under UV to harden the topcoat.
Quicker color changes
The activeColourChange pigment dosing system allows pigment to be dosed directly into the melt-filled metering zone of the plastification unit. Designed for up to 5 colors, the upstream feed and compression zones remain free of pigment allowing a shorter screw length to be rinsed during color changes. Uniformly colored pieces can be collected after only a few cycles of new pigment being added, enabling processors to benefit from less waste and reduced change over time. Sumitomo (SHI) Demag said the set up is ideal for cap and closure manufacturing.
Compression-zone-free compression screw
The company will also highlight its SL plastification system, which uses a low feed plastification compression screw without a compression zone. The result? Elimination process variations and for technical precision molded parts, like optical components. Material feed is controlled using an upstream dosing screw and the optimum filling level is determined by material properties and process parameters. The added granulate is melted almost exclusively by cylinder heating. At the show, the company will make a double molded smartphone case with an injection weight of 45g and cycle time of 25 seconds. The SL plastification sytem is currently available as an option on the fully-electric SE-EV Series with a clamping force of 500 to 1800 kN.