Extrusion International 4-2024

36 Extrusion International 4/2024 FOAM EXTRUSION Risk-free Process Optimization – Testing System Precisely Meters Different Blowing Agents Even with Fluctuating Extruder Pressure A lower density, better mechanical and insulating properties and significantly reduced raw material consumption. Given these advantages, it is no wonder that foamed plastics have taken the market by storm in recent years. They are mainly used as packaging components and for shock absorption, thermal insulation and soundproofing. However, the variance in blowing agents and their process conditions, such as high pressure or deviating temperatures, require specified systems and quickly make the extrusion process relatively complex. The LEWA ecofoam metering system provides a remedy. A fail-safe complete solution for all known blowing agents, it is characterized by consistently precise metering even for fluctuating parameters. T he LEWA ecofoam testing system offers users a cost-efficient op- portunity to see the reliable quality of the extruder system and the end products for themselves in everyday operation without obligation. Depending on the intended use and desired properties of the plastic product, different blowing agents are used in foam extrusion. For ex- ample, they can be carbon diox - ide, propane, butane, pentane or halogenated hydrocarbons such as Freon 152a. Although the dis- charge pressures and temperatures of these media differ from one an - other, the metering of the blowing agent into the plastic melt must be consistently precise in order to achieve a homogeneous and high- quality end product. The proven LEWA ecofoam metering system was therefore specially designed to meter all common blowing agents precisely and reliably. Universal extruder system for testing with all blowing agents To ensure the required constant foam quality, the quantity of blow- ing agent in the LEWA ecofoam is adjusted proportionally to the ro - tation speed of the extruder. The smart control technology developed by LEWA itself comes into play here. It continuously compares the signal from the flow meter with the guide signal and regulates the rotation speed of the drive motor accord - ingly. Due to the pump's pressure- stiff characteristic curve, metering remains constant even for fluctuat- ing extruder pressure. At its core, the hermetically tight and therefore low-maintenance system consists of a LEWA ecoflow With the LEWA ecofoam metering system, the Leonberg pump manufacturer offers a fail-safe complete solution for all known blowing agents. It is characterized by consistently precise metering even for fluctuating parameters. (Pictures: LEWA) The LEWA ecofoam testing system offers users a cost-efficient opportunity to see the reliable quality of the extruder system and the end products for themselves in everyday operation without obligation