The production of tissue paper places the highest demands on machines, components and materials. Low basis weights, very high speeds and extremely short drying times determine the process.
At the same time, expectations regarding energy efficiency, plant availability and product quality are continuously increasing. Against this background, roll covers are increasingly becoming the focus of process optimisation.
Roll covers have a direct influence on drainage performance, running stability and the bulk and softness of the end product. Their use in press roll positions on the Yankee cylinder is particularly demanding. Here, high line loads, high nip frequencies and high thermal loads all come together. Unlike suction contact rolls, the cooling influence of the suction holes is also missing.
The result is increased stress due to the self-heating of the cover, which can lead to material fatigue and limited running times.
Mechanical dewatering is a key lever for reducing energy consumption. A higher dry content after the pressing process directly reduces the energy required for drying. This requires a roll cover that remains elastic even under extreme conditions, generates less internal heat build up and runs stably over the long term.
With the tisQ.R roll cover, SCHÄFERROLLS has developed a material that is specifically designed to meet these requirements. The cover is characterised by a very low loss factor (tan delta). This property stands for high elasticity with minimal heat build up during operation. This allows tisQ.R to be used in pressure roll positions without internal cooling. This not only reduces energy consumption, but also significantly simplifies the operating conditions of the roll.
A specially developed bonding system ensures a reliable connection between the cover and the roll core. The multi-layer, application-specific structure guarantees reliable power transmission even under high dynamic loads. At the same time, the wear properties of the material are impressive.
The hardness remains constant over long operating periods, which supports stable process conditions.
Practical experience confirms this concept. When using tisQ.R in a tissue paper machine with a pressure roll position, the roll could be operated without internal cooling. This significantly reduced the roll weight during operation, lowering operating costs and maintenance requirements.
The machine started up without vibration. Once the dewatering capacity of the felt was reached, the speed could be increased to 2000 m/min. Throughout the entire running time, the vibration level remained low and had no negative impact on product quality or efficiency.
After ten months of operation, the roll cover showed only minimal wear. This confirmed tisQ.R’s suitability for long operating times under demanding conditions.
tisQ.R represents a new approach to pressure roll covers in the tissue process: energy-efficient, thermally stable and process-reliable. For operators, the cover offers an effective way to push performance limits while reducing operating costs – without compromising product quality.
Key properties of tisQ.R for press roll applications
- Hardness: 20–30 P&J.
- Excellent elasticity with low heat generation.
- Operation without internal cooling.
- Outstanding wear resistance and high hardness stability.
- Surface designs available: blind hole/groove.
SCHÄFERROLLS
SchäferRolls, manufacturer of high-quality roll systems and covers, is to present its technological expertise, product solutions and services for improving product quality and machine performance. SchäferRolls roll covers are precisely adapted to the chemical, physical and thermal requirements of the product, roll positions and machine. Services include consulting and digitalisation solutions for roll operation, management and maintenance. The company’s focus is on making paper, cardboard and tissue production more profitable and resource efficient for you.
