According to KraussMaffei, MuCell can do everything that's currently in demand—generate savings on material, energy and investment costs—and noticeably reduce the CO2 footprint of products. Plus, used in the automotive industry, the lightweight items produced via the MuCell process will later on also reduce fuel consumption. The new universal screw plays an important part in this.
For the MuCell process, KraussMaffei has created the new HPS-Physical Foaming screw with a longer three-zone area. The screw can be universally used for all plastics (with and without fibre reinforcement) and an up to 30 percent increased plasticizing capacity. As a result, smaller screw diameters may be used, which significantly reduces the investment and operating costs for the plasticising unit. This increased plasticising capacity also results in a higher output without making any change in screw size.
The process is demonstrated on an all-electric PX 321-1400 machine equipped with the APCplus machine function that has also evolved and is now being used with a gas-charged melt for the first time. APC plus keeps the production process constant, even if parameters change due to external influences, shifting the changeover point and the holding pressure profile from shot to shot based on the measured melt viscosity. The result is extremely weight-constant components.
The trade show application, a storage table for trucks and commercial vehicles, features a few more technical highlights, demonstrating that physical foaming is of interest even in areas that may have seemed off the radar until now. It is a project that combines the efforts of KraussMaffei and a team of partners. The mould was provided by Wirth Werkzeugbau and features special mould cooling channels to ensure uniform cooling at the surface—without variothermal technology—and safely prevent hot spots. The graining by Reichle (Bissingen/Teck, Germany) contributes to achieving perfect exposed faces on the foamed components. Material from LyondellBasell also helped to achieve the streak-free surface aesthetics required. Jurke Engineering provided the efficient machine-side Orca temperature control system. Orca measures the speed and quantity of the flow by ultrasonic means—from the outside and without contact with the medium. The precise temperature control optimises the cycle time.
And a partner since 2001, Trexel supplied the metering system, which is It is fully integrated into the KM MC6 control system, ensuring very easy, intuitive handling. If necessary, even satellite solutions are offered that allow multiple machines, all fully integrated, to be supplied with the necessary gas using only one compressor.
An LRX 150 linear robot from KraussMaffei picks up the blank film from a drawer , which can contain up to four different film types. The robot puts down the selected film on the cleaning station, where all particles and/or contaminants are removed using a cleaning brush from Wandres (Stegen, Germany) and the matching extractor system from ESTA (Senden, Germany), two more partners. The robot gripper executes a turn concurrently with the cleaning process so that clean suction devices pick up the cleaned film again.
The "stack gripper" inserts the film into the mould, and the finished part is demoulded. Demoulding is followed by the handshake transfer to a second robot for a foam structure test of the component by means of a testing system from Teratonics (Orsay, France). The testing system specifically allows users to visualise the compact outer layers and the spatial distribution of the MuCell foam in the interior of the component, to check that no bubbles have occurred. The component is then placed on a conveyor belt and transported out of the automated system.
The easyTrace 2.0 systems collects all data related to the injection process and the structural test shot by shot and displays it on a screen. In addition, a QR code appears under which all process parameters for this individualized component have been stored. Here, easyTrace 2.0 acts as an interface system that gathers all data of all process nodes and functions as an interpreter for existing customer-side MES or ERP systems.