SML is broadening its extrusion equipment range with a co-rotating twin-screw extruder, which the company is presenting at K 2025. The new twin-screw extruder is aimed at applications requiring high output capacities in polyolefins and polyesters, complementing SML’s cast film technology portfolio. According to Hans-Jürgen Luger, Head of Research and Development at SML, the extruder has been designed in-house to match the specific requirements of the company’s extrusion lines. “Our in-house-designed co-rotating twin-screw extruder is tailor-made for the specific requirements of our extrusion lines, contributing to an exceptional film quality,” he said.
The design focuses on compactness and energy efficiency. Compared with a large single-screw extruder at the same throughput, the processing unit is shorter and occupies a smaller footprint, which reduces the heating power needed to maintain barrel temperatures. Using starve feeding, the drive operates at high torque throughout the output range, where it achieves maximum efficiency. Melt temperature can be controlled by adjusting the degree of filling. Tests on a CPP line at SML’s Technology Centre showed that the specific energy input was 10 to 15% lower than for a comparable single-screw extruder. In addition, a web inspection system recorded up to 20% fewer gels on a standard CPP film.
The performance profile positions the unit for packaging film processors who seek higher throughput with tighter quality control. In this context, SML targets integration with its high-performance cast film lines while keeping operating costs and maintenance effort contained through practical component choices.
Applications and throughput
One primary area of application is SML’s cast film lines. “With throughputs in the range of 1,000 to 2,000 kg/h, the TSE is ideal for our high-performance cast film lines with end film widths of up to 6.5 metres,” said Elias Mayrhofer, Product Manager at SML.
Design and maintenance
The extruder features a swivel-mounted barrel that enables rear screw extraction for quick changeovers. Barrel temperature control uses ceramic heaters combined with air cooling, providing precise, cost-efficient and low-maintenance operation. SML offers pre-configured, single-piece barrel designs in different lengths, with venting ports available depending on the application. For screws, customers can choose single-piece designs or segmented-shaft configurations.
PET and PLA processing without pre-drying
In combination with SML’s high-performance vacuum unit, the twin-screw extruder supports processing of PET or PLA without pre-drying. The configuration also enables high proportions of regrind or flakes and supports in-line compounding for material conditioning directly on the extrusion line.
