Suction roller surface
Suction rollers are used in challenging corrosive environments in the so-called backwater of the paper machine, which contains chlorites (100 –200 ppm) and possibly some other chemicals, such as thiosulphates.
The temperature of the water is approximately +50°C. The surface of the suction roller is also subjected to simultaneous repetitive, straining mechanical stress.
Powder metallurgy
The solution is a powder metallurgical (P/M) suction roller surface. The material is a super duplex steel, Duplok 27, which combines strength and corrosion resistance.
We have manufactured several suction roller surfaces using the P/M method. Due to better durability than that achieved with competing methods, the production rate of the paper machine can be increased.
Winder blades
The winders used in the paper industry mostly wear due to the additives in paper (e.g. kaolin, calcium carbonite). The typical life span of the blade is less than 10 days.
Four-fold service life
The P/M material developed for this application (Ralloy WR6) achieves a longer life span. P/M together with the HIP method guarantees a stable microstructure that prevents even the slightest changes in measurements during use and storage. The life span of the optimised and superfinished blade may be up to 40 days.