Extrusion International 5-2022

78 Extrusion International 5/2022 Smart, Economical, and Sustainable Hose Manufacture Extrusion specialist TROESTER stands for high-quality, German-made, development and production of innovative machines for the rubber industry. Hanover-based TROESTER’s automatic centering straight heads, crossheads, and double crossheads excel at producing high-quality hoses for all applications. Hose manufacturers welcome the benefits of these extrusion systems. Short start-up processes withminimised wastage and the option to save material due to thinner hose walls make production very economical. At the same time, the rawmaterial and energy savings also reflect the environmentally friendly mindset that underpins all TROESTER developments. Wall thickness distribution in the 1/100 mm range TROESTER consistently developed manually adjustable extrusion heads and was able to launch and establish an automatic, single-layer crosshead back in 2010. This prod- uct has been a success story in hose production. Since then, TROESTER has added to its portfolio and customers can now choose between automatically centering straight extruder heads, crossheads, and double crossheads to im - prove the quality of their production and products. TROESTER extruder heads for hose production with au - tomatic wall thickness centering meet all requirements: - Hose wall thickness centering within 1/100 mm - Closed loop control with feedback from the X-ray meter - Greatly reduced start-up scrap due to fast, automatic centering - Guaranteed wall thicknesses allow a decrease in wall thickness - Resource friendly, ideal when materials are expensive - Can be retrofitted and customary tooling systems possible - Less time required due to automated processes - Very quick return on investment (less than a year) for a combination of extruder head, X-ray meter and control How automated extruder heads works The tooling is adjustable in X and Y direction, so that the wall thickness is even. The adjustment options for auto- mated extruder heads are similar to those of conventional systems. The actual adjustment takes place via servo hydrau- lics. Force is either applied with leverage or the tools are mounted with low friction. As a result, small, careful, and fluid movements without jolts are possible. The adjust - ment works as a closed loop in conjunction with a wall thickness gauge. The systems each start with a midpoint setting. As soon as the product has reached the wall thickness gauge, the control system gradually reduces differences in the wall thickness distribution and takes the dead travel between the head and the X-ray meter into account. This initial cen- tering takes place much faster than with conventional ex - Straight head Crosshead Double Crosshead