The key factors for choosing lubricating oil for paper machine

As the paper machine is developing in the direction of large-scale, continuous, and automated, the paper machine's width and paper output speed have been greatly improved, and the bearing speed has increased correspondingly. More and more paper machine customers have begun to choose lubrication in the entire system. Instead of using grease as the lubricating medium for bearings and gears in the system. Therefore, the following factors must be considered comprehensively when choosing paper machine oil:

(1) Hydrolysis stability: Moisture is the biggest hazard in the lubrication system of a paper machine. When tiny cracks on the bearing surface come in contact with moisture, the fatigue rate of the bearing increases, causing pitting, early failure and abnormal shutdown, causing huge losses . High-quality paper machine circulating lubricating oil must have excellent hydrolysis stability. Appropriate oil selection and first-class on-site system maintenance can help reduce water entering the bearing seat and prevent bearing fatigue and early failure.

(2) Filterability: It is time-consuming to replace the filter, and the cost is also high, and the replacement frequency is too high is a signal of poor oil filterability and poor system maintenance. The pall filterability test can provide a relatively reliable reference. The test is divided into two types: dry method and wet method. In the dry test, the oil is heated to 63°C, and the oil is filtered through a filter with a diameter of 3μm at a rate of 20ml/min. When the pressure difference reaches 172.375kPa (25psi), the number of milliliters of the oil passed through is generally considered More than 2000ml is qualified. In the wet test, the oil needs to be added with 1.0t% distilled water, aged at 70°C for 24h, and then placed at room temperature for 24h, and then the above-mentioned pall filtration test is carried out.

(3) Stable viscosity: Because the bearings in the paper machine operate at high temperatures for a long time, it is important to ensure that the oil maintains a stable viscosity during transportation and operation. The key to this is that the composition of the oil must have good oxidation stability and thermal stability. At the same time, the design of the centralized lubrication system must have a heating/cooling device to maintain a relatively constant working temperature of the system and ensure the viscosity of the oil.

(4) Deposition control ability: When oil products age, they will decompose through various mechanisms to form by-products, which will affect the performance of oil products. These by-products will increase the viscosity of the oil and block the filter screen. When they are deposited on moving parts such as bearings, they can increase contact pressure, damage equipment, and even cause downtime. Therefore, the lubricant formulation must have good deposit control capabilities.

The paper machine is a large and continuous mechanical equipment. Under the fierce competition in the industry, the operation reliability of the equipment is required to be high, and abnormal downtime should be minimized. The lubricating oil used as the bearings, gears and other components in the equipment must be well managed.