Extrusion International 6-2022-USA

74 Extrusion International 6/2022 RUBBER TUBE EXTRUSION Time and Cost Savings in the Production of Rubber Tubes Exact wall thicknesses are of particular importance in the production of rubber tubes. If the wall thickness is too thin, quality is compromised – but if the wall is too thick, more material is needed in the production process. KraussMaffei’s self-centering tube dies equipped with a wall thickness gauge provide an excellent solution to tackle this problem. They precisely correct any deviations in the ongoing extrusion process. In addition, maximum repeatability is ensured when it comes to frequent batch changes. A s compared to conventional solutions, customers ben- efit from substantial material savings when using the self-centering tube dies combined with a wall thickness measuring system. Regardless of the production speed, the system automatically controls and optimizes the hose wall thickness and the concentricity during the extrusion pro- cess. The wall thickness tolerance range is thus reduced by 0.05 mm, which ensures material savings of up to 2.5 %. Due to the input material reduction, the investment pays off after just a few weeks in 24/7 production. “Further savings potential can be found in the set-up times of the hose ex- trusion lines. Instead of wasting time with die changes, ad- justments or start-up/shut-down processes, the extruders or extrusion lines equipped with self-centering tube dies reach production mode much faster, which saves time for further operations,” explains Dr. Gerard Nijman, Global Application & Product Owner Tire & Rubber at KraussMaffei. Automatic correction of setpoint variations Self-centering tube dies are available for single or multi- layer tubes with or without fabric reinforcement in the diameter range of 3 to 120 mm and suited for different ex- trusion pressures. Thanks to the automatic adjustment, the floating die inside the extrusion head can be displaced in any required direction. In the event of batch changes, new head parameters are set at the push of a button. Any setpoint de- viations in terms of wall thickness and concentricity are im- mediately corrected and displayed on the control panel. The system stands out for highly professional and reliable pro- duction combined with maximum product quality. KraussMaffei Extrusion GmbH An der Breiten Wiese 3-5, 30625 Hannover, Germany www.kraussmaffei.com tomers are already using the new sen- sor that operates at a distinctly higher resolution and is therefore able to cov- er a much wider product range than its predecessor. MABRI.VISION has developed the new sensor not only for plastic pack- aging, but also for other products whose functionality depends on the quality of thin coatings. The new system can be used, for example, to measure coating thicknesses in blown film extrusion processes and of multi- layer flat foils used in food packaging as well as for medical products, such as transdermal plaster and coated medical tubing. It is also suitable for inspecting hoses produced in co-ex- trusion and multilayer extrusion pro- cesses and for composite materials. MABRI.VISION GmbH Philipsstr. 8, 52068 Aachen, Germany www.mabri.vision Self-centering straight-through and crosshead dies for the production of mono-layer or multi-layer tubes Extruder with self-centering tube die and downstream X-ray system to detect and correct wall thickness and concentricity