SKF in the paper industry: bearings for dryer cylinders, rollers, and housings

In a paper mill, bearings are exposed to moisture, steam, and temperature, especially in dryer cylinders. Therefore, choosing the right bearing is key. SKF in the paper industry offers specific solutions for each position: press rollers, table rollers, and dryer cylinders. We stock SKF bearings for these applications and help you identify the exact code.

Dryer cylinders operate with high-temperature steam, which causes expansion of the shaft and housing. A bearing that does not accommodate this displacement can generate unwanted axial loads. That is why spherical roller bearings and CARB toroidal roller bearings are used, as they absorb misalignment and allow axial displacement. We distribute these series and quote the code you need.

To order a bearing, it is advisable to have the code engraved on the part or the shaft and housing dimensions. If you don't have the code, send us a photo of the bearing and housing, and we will indicate the alternative. In the paper industry, each position has different requirements: press rollers support high radial loads, while dryer cylinders need C3 internal clearance due to temperature.

SKF spherical roller bearings are the most used option in the paper industry due to their load capacity and tolerance to misalignment. In dryer cylinders, they support the weight of the cylinder and steam loads. We stock codes such as 23130, 22325, 22328, and 22336, which adapt to different shaft diameters and loads.

These bearings have two rows of rollers and a spherical raceway in the outer ring, allowing them to self-align. In a paper machine, where frames can deform due to temperature, this property prevents edge overloading. They are also used in press rollers, where loads are high and humidity is constant.

When ordering a spherical roller bearing, check whether the bore is cylindrical or tapered. The K suffix indicates a tapered bore, which is mounted on an adapter sleeve. In dryer cylinders, tapered bores are common to facilitate mounting and dismounting. If in doubt, send us the complete code and we will quote it.

SKF CARB toroidal roller bearings are a specific solution for positions where the shaft expands due to temperature. Unlike a traditional bearing, the CARB toroidal roller bearing allows internal axial displacement without generating additional loads. In dryer cylinders, this is essential: the cylinder heats up and expands, and the bearing must accommodate that movement.

We stock codes such as C 2220, C 3130, C 2222, and C 3232, which are used on the free side of the cylinder. The fixed side usually has a spherical roller bearing, and the free side a CARB toroidal roller bearing. This combination prevents stresses in the housing. We distribute both series so you can order the complete pair.

When ordering a CARB toroidal roller bearing, it is important to indicate whether it is for the fixed or free side, and the shaft diameter. It is also advisable to know the internal clearance: in high-temperature applications, C3 is recommended. If you are unsure, send us the dimensions and we will advise you.

SAF split housings are the base where bearings are mounted in a paper machine. Their two-piece design allows inspection and replacement of the bearing without dismounting the shaft. We stock SAF housings for spherical roller bearings and CARB toroidal roller bearings, such as SAF 220, SAF 222, SAF 322, and SAF 520.

In the paper industry, SAF housings are used in dryer cylinders, press rollers, and table rollers. They must withstand moisture and steam, so they are selected with appropriate seals and correct lubrication.

When ordering an SAF housing, you need the code of the bearing inside and the shaft diameter. It is also advisable to indicate whether the housing is foot-mounted or flanged, and the seal type. If you have the old housing, a photo helps identify the exact model. We distribute SAF housings and quote the complete assembly.

Lubrication is critical in bearings of a paper machine. In dryer cylinders, high temperature requires special greases or oil with adequate viscosity. Depending on the position and lubrication method, the seal type and whether the bearing is greased or oiled are chosen.

In press rollers, where there is water and pulp, additional seals are used to prevent contaminant ingress. When ordering a bearing, indicate whether it is grease or oil lubricated, and if it needs a seal.

C3 internal clearance is common in bearings for dryer cylinders because temperature reduces normal clearance. If the bearing operates at high temperature, request C3 to prevent blockage. If you don't know what internal clearance your machine requires, consult us with the current bearing code and we will guide you.

To order an SKF bearing for the paper industry, the most practical is to have the code engraved on the part. For example, 22325 or C 3130. If the code is blurred, measure the inner diameter, outer diameter, and width, and we will help identify it. A photo of the bearing and housing also helps.

In paper machines, bearings often have suffixes indicating special features. The K suffix means tapered bore, 2RS rubber seal on both sides, 2Z metal shield on both sides, and C3 increased internal clearance. Other suffixes are validated with MR's technical team to ensure exact replacement.

When you write to us via WhatsApp or email, indicate the code, brand, and mounting position. If it is an SAF housing, send us the housing and bearing codes. We will respond promptly with a quote. We work with SKF and distribute their bearings for the paper industry in Buenos Aires, Argentina.

A common mistake is ordering a deep groove ball bearing for a dryer cylinder. That position needs a spherical roller bearing or CARB toroidal roller bearing, which supports high radial loads and misalignment. Another mistake is not considering thermal expansion: if both sides are fixed, the bearing becomes overloaded. That is why one fixed side and one free side are used.

Another mistake is not verifying internal clearance. In high-temperature applications, C3 clearance is necessary to prevent blockage. If you mount a bearing with normal clearance in a dryer cylinder, it can seize and damage the housing. When ordering, specify if the position operates hot.

Finally, do not ignore sealing. In areas with water and pulp, a bearing without adequate sealing contaminates quickly. SAF housing seals protect the bearing. If you have doubts about which bearing goes in your machine, consult us with the data from the plate or the old bearing.