Paper machines are the giants in the machine construction sector: many of them are 200 meters long and 10 meters wide. In just a single minute, nearly 2000 meters of paper fly through the machine over rolls and cylinders at a speed of 120 km/h. The rolling bearings installed in such a machine must meet extreme requirements: moisture, very high temperatures, shaft deflections, high speeds and long running times. Only bearings that work with a very high degree of reliability make it possible to produce paper of the highest quality.

Forming section
The forming section consists of the headbox and the wire section. It is a critical section of the paper machine, since it is here that the quality and structure of the finished product is determined. However, for bearings, the operating conditions are not too challenging - except for the water and moisture present in the process. As in all paper machine applications, reliability is critical to ensure continuous production.

Breast, drive, guide and stretch wire rolls
Breast, drive, guide and stretch wire rolls are not particularly demanding applications from a bearing perspective. The main issue is the amount of process water present and consequent problems relating to corrosion and lubrication. However, like most applications in a paper machine, these rolls are subject to misalignment and axial expansion of the shaft, and the bearings must accommodate this.

Suction rolls
Suction rolls are used for dewatering the web. Like most applications in a paper machine, they are subject to misalignment and axial expansion of the shaft and the bearing arrangement must accommodate this. In addition, of all the rolls in a paper machine, suction rolls have the highest speed demands. As production capacity is pushed further and further, speed requirements are likely to increase even more in the future. The operating conditions for this application are therefore considerable, placing high demands on the machinery components.

HCH bearing for pulp and paper machinery
Bearings in pulp and paper machinery often operate under high-temperature conditions, vulnerable to problems such as fracturing of the inner ring, which can result in work stoppages. Excellent durability under high temperature conditions including moisture and dust laden environments can result in longer life, high limiting speed and dramatically enhanced productivity. Operating difficulties often put great demands on the bearing solutions in pulp and paper machinery.