Five factors to choose for plastic filler selection
Fillers are generally powdery materials and are inert to the polymer. The purpose of adding fillers in the preparation of plastics is to improve the molding processability of plastics, to improve certain properties of the products, to give new properties to plastics and to reduce costs. The main factors to consider when choosing a filler are:
1, low price
The price of fillers has a significant impact on the cost of plastics. The specific gravity of the filler-added polyvinyl chloride plastic is 2 to 3 times that of the filler. Therefore, the specific gravity of the polyvinyl chloride plastic added with the filler increases rapidly with the addition amount, so the calculation cost based on the weight is not as good as the volume. The calculation cost is exact, and the volume cost must be considered in terms of application. The small specific gravity of the filler is advantageous for the volume cost.
2, oil absorption
That is, the ability of the filler to absorb the plasticizer. It depends on the fineness of the filler and the variety of fillers and plasticizers, and the cost of the plastic increases as the oil absorption increases.
3, electrical performance
The addition of calcined clay can improve the electrical insulation of the plastic. The calcined clay removes the crystal water and other impurities during the calcination process. The calcination temperature affects the electrical insulation of plastics, generally at 600~700 °C, which gives the best results. Fillers can also improve the thermal deformability of cable materials, adding a small amount of carbon black to improve the weather resistance of plastics. A large amount of carbon black is added to lower electrical insulation and to prepare a semiconductor polyvinyl chloride plastic. A filler having a small water absorption is advantageous for electrical insulation.
4. Influence on physical properties
In soft polyvinyl chloride plastics, as the amount of filler increases, tensile strength, tear strength and elongation decrease, and hardness increases. When a filler having a larger particle size is used, the loss of tensile strength and tear strength is large, and when a filler having a fine particle size is used, the elongation is largely lowered.
The clay hardens the polyvinyl chloride plastic more than the calcium carbonate, that is, the hardness increases greatly and the elongation decreases. The effects of various fillers on the physical properties of plastics are also different due to differences in plasticizer absorption, specific gravity, hardness, dispersibility, particle size and particle size distribution.
5, purity
Since the plastic may react with impurities in the filler, there is a certain requirement for the purity of the filler. It has been confirmed that metal impurities have a counteraction to the lanthanum/cadmium type stable system, and trace amounts of iron, manganese, copper and a relatively small amount of aluminum have a great influence on the efficiency of the plasticizer. The presence of sulfur is due to the formation of sulfides by vulcanization, which contaminates the lead stabilizer. When calcium carbonate is used in white or other light-colored polyvinyl chloride products that are susceptible to infection, the content of trace elements is recommended to be limited to the following:
Fillers widely used in the processing of polyvinyl chloride plastics are calcium carbonate, clay, barium sulfate, titanium dioxide and the like. Barium sulfate, titanium dioxide, calcium carbonate and the like are mainly used in hard plastics. Calcium carbonate clay is mainly used in soft plastics. It is advantageous to add calcined clay in the insulation grade cable section. Calcium carbonate is mainly added to the sheath grade cable material, and aluminum hydroxide, calcium carbonate and talc powder are also added to the film to reduce the cost.
The development direction of the filler is to surface coat the filler in various ways during the preparation process. The main benefits of surface treated calcium carbonate are: reducing the tendency of calcium carbonate to agglomerate and improve processing properties, which is beneficial for the development of plastic processing to continuous high speed extrusion processes. Other benefits of calcium carbonate coated with a surface of stearate are: small oil absorption, reduced plasticizer dosage; satisfactory and effective hydrophobicity and a moderately low plasticizer content, thus improving electrical properties The thermal stability is improved due to the supplemental stabilizing effect of calcium stearate in the coating layer; the addition of a lubricant in the plastic processing can simplify the compounding process.
Copper is a versatile and important material in various industries. It is a soft, malleable, and ductile metal that is a good conductor of electricity and heat. Copper has been used by humans for thousands of years, and it still plays a critical role in modern society.
One of the main advantages of copper is its excellent electrical conductivity. It is used extensively in electrical and electronics applications, such as wiring, power transmission, and printed circuit boards. Its thermal conductivity is also very high, making it suitable for heat exchangers and cooling systems.
Copper is also important in the construction industry. Its corrosion resistance, durability, and aesthetic appeal make it an ideal material for roofing, gutters, and plumbing systems. Copper is also used in architectural features such as decorative panels, wall cladding, and sculptures.
Copper is also an essential material in the manufacturing of various products. Its mechanical properties and workability make it ideal for manufacturing pipes, tubes, wires, and other hardware components. Copper alloys, such as brass and bronze, are used to make a wide range of products, including musical instruments, jewelry, and coins.
Moreover, copper is an environmentally friendly material. It is completely recyclable, and recycled copper can be used to manufacture new products without any loss of quality. Recycling copper also saves energy and reduces the need for mining, thereby conserving natural resources and reducing greenhouse gas emissions.
In conclusion, copper is a versatile material with many advantages. Its excellent electrical and thermal conductivity, durability, workability, and recyclability make it an essential material in various industries.
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