Difference between PE liquid filter bag and PP liquid filter bag?
PE filter bag is made of polyester fiber filter cloth, PP filter bag is made of polypropylene fiber filter cloth, PE and PP are deep three-dimensional filter materials, and 100% pure fiber is made by acupuncture to form a three-dimensional, highly fluffy three-dimensional depth and tortuous filter layer. It is characterized by loose fiber structure, which increases the capacity of impurities; The product belongs to the compound closure mode, which can effectively remove solid and soft particles, that is, large particle impurities are intercepted on the fiber surface, while fine particles are captured in the deep layer of the filter material to ensure that they will not be damaged due to pressure increase during use, and has high filtration efficiency; In addition, the outer surface of the product is treated by high-temperature surface heat treatment, that is, the application of instantaneous sintering technology / calendering treatment can effectively prevent the loss of fiber due to the high-speed impact of liquid during filtration, which not only ensures that there is no filtrate pollution caused by fiber separation, but also avoids the excessive blockage of filter hole caused by traditional rolling treatment and shortens the service life of filter bag. At the same time, the pressure difference is small and does not affect the flow rate.
PE and PP are two different materials; PE polyester fiber has good performance at room temperature and is the main filter material in bag filter. It can withstand an operating temperature of 130 ℃ under dry conditions; if it works continuously above 130 ℃, it will harden; fading; brittle, temperature will also weaken its strength. Accuracy range: 1-300 microns. PP polypropylene has good wear resistance and high elastic recovery rate. It is an excellent thermoplastic fiber. The precision range of polypropylene is 0.1-500 microns, and the maximum temperature is 94 degrees. Before dyeing, PE is milky white, opaque, hard and not easy to extend. It burns stone cured meat. The flame is low blue, sharp yellow and the tail smoke should be thicker. PP is white and translucent before dyeing, with petroleum smell after combustion. The material after combustion is clear and transparent is PP and blackened is PE.
Polypropylene, abbreviated as PP, is a thermoplastic resin prepared by polymerization of propylene. There are three configurations: isotactic, random and syndiotactic. Industrial products take isotactic as the main component. Polypropylene also includes copolymers of propylene and a small amount of ethylene. It is usually a translucent colorless solid, odorless and non-toxic. Due to its regular structure and high crystallization, the melting point is as high as 167 ℃, which is heat-resistant, and the products can be sterilized by steam. With a density of 0.90g/cm3, it is the lightest general-purpose plastic. Corrosion resistance, tensile strength 30MPa, strength, rigidity and transparency are better than polyethylene. The disadvantage is poor low-temperature impact resistance and easy aging, but it can be overcome by modification and adding antioxidant respectively.
Polyethylene, abbreviated as PE, is a thermoplastic resin prepared by polymerization of ethylene. In industry, it also includes ethylene and small amounts α－ Copolymers of olefins. Polyethylene is odorless, non-toxic and feels like wax. It has excellent low temperature resistance (the minimum service temperature can reach – 70 ~ – 100 ℃), good chemical stability, can resist the erosion of most acids and bases (not resistant to acids with oxidation properties), is insoluble in general solvents at room temperature, has small water absorption and excellent electrical insulation performance; However, polyethylene is very sensitive to environmental stress (chemical and mechanical action) and has poor heat aging resistance. The properties of polyethylene vary from variety to variety, mainly depending on molecular structure and density. The products with different densities (0.91 ~ 0.96g / cm3) can be obtained by different production methods. Polyethylene can be processed by the molding method of general thermoplastic plastics (see plastic processing). It is widely used to make films, containers, pipes, monofilaments, wires and cables, daily necessities, etc. it can also be used as high-frequency insulating materials for TV, radar, etc
PE: Polyethylene properties (forming):
- The crystalline material has small moisture absorption, does not need to be fully dried, and has excellent fluidity. The fluidity is sensitive to pressure. High pressure injection should be used during molding. The material temperature is uniform, the filling speed is fast, and the pressure is fully maintained. Direct gate should not be used to prevent uneven shrinkage and increase of internal stress Pay attention to the gate position to prevent shrinkage and deformation
- Large shrinkage range and value, obvious directionality, easy to deform and warp. The cooling speed should be slow. The die is equipped with cold material cavity and cooling system
- The heating time should not be too long, otherwise decomposition will occur
- When soft plastic parts have shallow side grooves, they can be demoulded by force
- Melt fracture may occur and should not be in contact with organic solvent to prevent cracking.
PP: Polypropylene properties (Molding):
- Crystalline material has low hygroscopicity, is prone to melt fracture, and is easy to decompose in long-term contact with hot metal
- Good fluidity, but large shrinkage range and value, prone to shrinkage Dents, deformation
- The cooling speed is fast, the pouring system and cooling system should dissipate heat slowly, and pay attention to controlling the forming temperature. When the material temperature is low and high pressure, it is easy to be oriented. When the mold temperature is lower than 50 ℃, the plastic parts are not smooth, which is easy to produce poor fusion and flow marks, and warpage deformation is easy to occur above 90 ℃
- The plastic wall thickness must be uniform to avoid lack of glue and sharp corners to prevent stress concentration Precautions PE polyethylene is widely used in the manufacture of plastic bags, plastic films, milk cans and other products. It is resistant to a variety of acid and alkali corrosion, but not antioxidant acid. PP polypropylene has high impact resistance, strong mechanical properties, and resistance to a variety of organic solvents and acid-base corrosion.
Widely used in industry, PP has good chemical stability. In addition to being eroded by concentrated sulfuric acid and concentrated nitric acid, it is relatively stable to other chemical reagents and has good anti-corrosion effect. However, low molecular weight aliphatic hydrocarbons and aromatic hydrocarbons can soften and swell PP sdrgenddfbr.