As a useful filter medium, filter paper has been widely used in various fields. The function and use of filter paper are different according to the different fiber types of filter paper. There are general filter paper for general occasions, glass fiber filter paper for high temperature, and ultra-clean polypropylene filter paper.
The filter paper structure is a labyrinth structure composed of fibers and channels. This structure, together with the physical forces associated with the fluid, constitutes the filter function of the filter paper. The filtering mechanism is as follows:
Direct capture or intercept
During this process, some people mistakenly thought that it was the only element that constituted filtration, and believed that the dirt particles were blocked in the surface or labyrinth of the inflow surface only because they were larger than the pore size. Actually, otherwise, there are:
Adsorption
When the filtered fluid passes through the maze, although some particles have a diameter much smaller than the pore size, they are also adsorbed to the filter paper under the effect of electrostatic attraction. Therefore, some filter media are specially charged with static electricity during the manufacturing process.
Shock
In this process, due to the connection of the flow rate, the particles fall directly into the filter paper fiber surface instead of staying in the filter paper pores, and are adhered to it by the adsorption force and the fluid activity force, thus also blocking some smaller particles
Filter cake
With the continuous accumulation of dirt particles on the surface of the filter paper, it constitutes a filter layer itself, thereby capturing smaller particles in the pores between the large particles. Block or reach the differential pressure.
Production of filter paper
The filter paper is produced, it is very simple to say, it is nothing more than a variety of fibers soaked in a water-based binder to completely disperse it, and then form a tightly connected connecting paper roll on the silk screen, after drying, dipping and drying Acceptable humidity level.
But in fact, to manufacture highly efficient filter paper, insisting on batch-to-batch, roll-to-roll and even year-to-year functions will require a narrow scale of change in weight, looseness, air permeability, strength, etc.
Filter media in the filter
The filter material in the filter is necessary to prevent the filter system from being damaged by harmful particles. Together, it allows the fluid to pass through to prevent cavitation in the pump, work cylinder and combustion chamber. In theory, a perfect filter should filter out 100% of the contaminated particles while providing consistent breathability. But in fact this is impossible.
The design of the filter paper needs to do its best to strike a balance among various indicators to effectively maintain the system to be filtered. The requirements of the oil filter on the filter paper will be higher than that of the air filter, mainly due to the sudden change of the oil concentration under a sudden temperature change, which will affect the filtration flow of the oil.
The filter paper of a high-quality oil filter can filter impurities and ensure a sufficient flow rate under drastic temperature changes. If low-cost filter paper is used to manufacture the filter element, due to its large pore size, poor uniformity, and low filter power, it cannot effectively filter out harmful impurities to the engine, which will cause premature engine wear.
Post time: Apr-15-2020