Moisture and heat put paper mill machinery at risk. Filtering oil and keeping it clean means fewer breakdowns, higher efficiency, and longer equipment life. Solutions such as CJC filters make it possible to keep oil clean and dry, ensuring efficiency, productivity, and extended equipment lifetime
Pulp and paper manufacturing plants are complex production systems operating in extremely humid environments, where equipment reliability is crucial to maintaining high output. Across the production line, a wide range of subsystems are in use — many of which are exposed to water or heat, such as gearboxes, bearings, and hydraulic systems.
Due to the high level of water ingress and elevated ambient temperatures, it is essential to keep oil clean and dry while removing oxidation residues.
If the complex and diverse systems used to produce pulp and paper do not operate optimally, costly downtime, efficiency losses, and reduced production can result. Gearboxes, bearings, and hydraulic components are all at risk of contamination by water and oxidation residues caused by heat. This can lead to unexpected failures and the need to purchase expensive replacement parts with long lead times.
If the oil contains oxidation residues, equipment cannot operate at peak performance — resulting in increased wear and higher energy consumption.
Oil contamination in the dryer section
Contaminants found in lubricating oils used in the paper industry are typically composed of water, depleted additives, paper dust, and/or oxidized oil by-products caused by heat (sludge/varnish).
Oil analyses occasionally reveal traces of other contaminants such as residues from previously used paper machine oils, rust inhibitors, or similar materials.
Contaminants tend to settle at the bottom of tanks, in feed and return lines, and on bearings, gears, and hydraulic components. The layer of contaminants that accumulates at the bottom of the tank usually results from long settling times and a high water content. When such deposits are found, the tank must be cleaned — typically every two to four years if no fine filtration is used.
Due to the detergent nature of most paper machine oils, it is rare for deposits to accumulate inside pipelines. When they do occur, the cause is usually poor pipeline design or excessive contamination (from process water, steam condensate, or high temperatures caused by low flow rates).
In some cases, system design errors prevent proper oil circulation.
Oil contamination in internal gears
Since most paper machines have internally lubricated gear systems, deposits can form in the return troughs. Oil collects here before returning to the main return manifolds.
If the flow rate is too low, deposits accumulate and can eventually overflow into the main tank. Inspection plates are usually available and can be removed to assess the severity of the issue.
Cleaning this component of the machine can be quite complex.
Oil contamination in bearings
Bearings in the dryer section are exposed to high temperatures (up to 125 °C) for extended periods. Operating conditions for these bearings are therefore very demanding.
The ever-increasing requirements for larger, faster machines and higher steam temperatures add stress to lubricants and lubrication systems in general.
The bearings of these rolls are lubricated with circulating oil, and the general oil requirements for this section are dictated by the demands of the dryer cylinder bearings. To achieve proper lubrication, large volumes of water-free oil with suitable viscosity are required.
In modern machines with isolated bearings, it is generally possible to maintain bearing temperatures below 90 °C. However, since so many factors influence the oil requirements, they must be determined for each specific dryer section.
Deposits in bearings are among the most common and often hardest to explain contamination problems — and oil condition is almost always the root cause of bearing failures.
The CJC Solution
The solution is often simpler than one might expect: a filter.
Benefits of Installing Oil Filters:
- Keeps both wet-end and dry-end process machinery in proper operating condition
- Maintains low water levels in lubricating oils for gears and bearings
- Ensures high process stability and productivity
- Reduces the risk of failures and unplanned maintenance
- Extends lubricant life by a factor of 3–4
When CJC Oil Filter solutions are installed in pulp and paper production systems, they provide highly efficient oil filtration and powerful water removal — ideal for systems with high levels of water ingress.
Technically, CJC filters are designed to keep oil clean, dry, and free of oxidation residues, as demonstrated through years of operation and multiple installations in pulp and paper plants.
By choosing a CJC Oil Filter, you ensure low oxidation residue levels and longer service life for gearboxes, bearings, and hydraulic equipment. Maintenance costs are reduced, and unexpected failures are avoided.
Oil condition can even be monitored remotely from the central control room using the Oil Contamination Monitor (OCM).
Depending on the type of contamination to be removed, CJC offers various tailored solutions.
To remove emulsified water, the recommended setup combines a Desorber with a CJC Filter using a filtration cartridge rated at 3 µm absolute / 0.8 µm nominal.