even line force

increased line force right

increased line force centre

increased line force at the edges

Hot S-Roll - the Principle

A steel tube rotates around the fixed axle. The annular gap is separated by two seals into two semi-circular chambers.
The chamber facing the nip is hydraulically pressurised by oil. In this way an oil pressure is generated that stands in linear ratio to the cylinder forces.
This allows the Hot S-Roll to adapt against the cournter roll ideally, ensuring an even and infinitely variable line force across the full roll width.
In the nip no friction whatsoever occurs, as the rolls rotating against each other are absolutely cylindrical. In addition, the variable adjustment of the line force (purposely uneven, too) allows for an active correction of the product.

Hot S-Roll Variants

All Hot S-Roll variants (200 / 250 / 275) have been especially adapted to the current production processes. Their distinguishing feature is the attainable maximum roll surface temperature. Due to the counterflow principle all three Hot S-Roll systems possess a temperature accuracy of ± 1° C and are designed for a production speed of up to 1000 m/min and for a line force of up to 150 N/mm (in case of special applications even up to 300 N/mm and more).
All roll systems are designed for a roll surface width of up to 7000 mm (in case of special applications even wider). In special cases such as polyamides, bicomponents (BiCo) or blends the design of the system is individually adapted.

Profiles in Comparison

X-Crossing	Single Roll Bending	Hot S-Roll

MD tensile strength profiles of PP spunbonded nonwoven 15 g/m² over the whole material width