How Much Do You Know About The Filter Paper?
Filter paper is frequently seen in various industries. Different fiber filter papers have different performance and usages, such as there are normal ones for general occasions, glass fiber filter papers for high temperature, and polypropylene filter papers for ultra-clean, etc. It provides an effective means for removing as many contaminating particles as possible from liquids and air and has a small resistance limit.
In the actual design of the filter paper, every effort must be made to balance the various indicators to effectively protect the system to be filtered. Then the filtration principle of filter paper is reflected in the following aspects:
1. Filtering agglomerates—-as the dirt particles accumulate on the surface of the filter paper, it forms a filter layer itself, thereby capturing smaller particles in the pores between the large particles. as the particles continue to Increase, the resistance is also continuously increased until the end is completely blocked or reaches the pressure difference.
2. Adsorption—–When the filtered fluid passes through the labyrinth, although some of the particles are much smaller in diameter than the pore size, these small particles are adsorbed onto the filter paper by the electrostatic attraction. Therefore, static electricity is specially added to some filter materials during the manufacturing process.
3. Fall-into—-In this process, due to the flow rate, the particles directly fall into the surface of the filter paper fiber rather than staying in the pores of the filter paper and are held by the adsorption force and the fluid force of the fluid, thereby blocking some smaller particles.
Design and production
It seems that the production of filter paper is simple, nothing more than immersing a variety of fibers in a water-based binder to completely disperse them, then forming a tightly bonded connecting roll on the screen, drying, dipping, and drying again to achieve acceptable levels of humidity.
But actually making efficient filter paper is not that easy, as different fiber types, weights, and thickness combinations will produce different filtration characteristics. Different batches of wood pulp have different characteristics, but filter paper production must be consistent with batch and batch, volume and volume and even year and year performance, requiring a narrow range of weight, porosity, air permeability, strength, etc.
A theoretically perfect filter should filter out 100% of the contaminated particles while providing consistent air permeability. In fact, this is impossible. The design of the filter paper must be done with the best efforts to balance the various indicators to effectively protect the system to be filtered. After the filter paper is immersed, it is often pressed and twisted in order to obtain the desired stiffness of the communication, and then dried to a suitable degree.
Do you know what is the precaution for filter paper when it is filtered? The following needs to be considered when not choosing the qualitative and quantitative analysis filter paper.
1. Generally, we will choose natural filtration, using the filter paper’s ability to retain solid particles, to separate the liquid and solid;
2. Due to the mechanical strength and toughness of the filter paper, it should minimize filtration by suction filtration. If the filtration speed must be increased, in order to prevent filtration failure caused by penetrating filtration, when the air pump is filtered, 2 to 3 layers of filter paper can be stacked in the funnel according to the pumping force. First, a layer of dense filter cloth is placed, and then the filter paper is filtered on the top to prevent leaking when vacuuming filtration.
3. It is better for filter paper to not filter hot concentrated sulfuric acid or nitric acid solution.