Characteristics, classification and physical properties of fillers Plastic sheet production line
DATE：2021/3/2 14:27:31 / READ： / SOURCE：This station
Characteristics, classification and physical properties of fillers
Plastic sheet production line
The fillers for plastics modification have the following characteristics:Solid matter with a certain geometry can be inorganic or organic.
Generally, it does not react with the filled matrix resin, that is, it is a relatively inert substance.
3 the mass fraction in the filled plastics shall not be less than 5%.
Fillers are different from additives commonly used in plastic processing, such as pigments, heat stabilizers, flame retardants, lubricants and other solid powder substances, and also different from other liquid additives and plasticizers. In the past, the main function of fillers was "increment". However, with the development of filling modification technology and the deepening of the understanding of fillers, combined with the changes brought by filling modification to the properties of plastic products, people have gone from simply pursuing cost reduction to improving some aspects of physical and mechanical properties of plastic products through fillers, especially functional fillers, or giving new functions to plastic products. Fillers have become indispensable for plastic modification It is one of the most important raw materials in the world. Plastic sheet production line www.handern.com
Spherical, massive, flaky, fibrous, etc. Since most of the fillers used at present are processed from natural minerals, sometimes the fillers are separated from organic fillers. According to the function of fillers, they can be divided into ordinary fillers and functional fillers. According to the geometric shape of fillers, there are many kinds of classification methods for fillers, which are generally divided into four categories: oxide, salt, elemental matter and organic matter. Fillers can also be called non-metallic mineral fillers according to inorganic.
The geometric shape, size distribution, physical properties and chemical properties of filler particles will directly affect the material quality of building and filling materials. The shape of the filler has a significant effect on the mesh number of the sieve. Item is an English unit, day is the number of round holes per square inch. Plastic sheet production line www.handern.com
The physical properties of fillers are as follows:
Don't worry. It's going to be big. The apparent density mainly affects the operability of fillers in the preparation of filled modified plastics. Medium density has true density and false density (apparent density). Due to the gap between the particles of the filler, the particle size and distribution of different shapes are different. When the mass is the same, the volume of the pile is different, the apparent density is different, and there is time difference
2 oil absorption value in many occasions, the filler and plasticizer are used together, if the plasticizer is absorbed by the filler, the plasticizing effect on the resin will be greatly reduced, so the influence of the filler itself on the system is very obvious due to the different oil absorption value when the filler is filled in the same amount. The benefits are offset by the wear of the processing equipment. But on the other hand, the higher the hardness of the filler, the greater the wear of plastic processing equipment. People do not want to use filler to bring abrasiveness. Mohr's hardness is a measure of the relative comparison of notching ability between materials. The Mohs hardness of human fingernails is 2. It can carve marks on talc, but it can't do anything on calcite. The Mohs hardness of common fillers is: Graphite 0.5 ~ 1, talc 2, kaolin 2, calcite 3, barite 3.3, wollastonite 5, quartz 7. In addition, the difference of hardness between the two materials is also related to the wear strength. Generally, the screw material of plastic extruder is 38CrMoAI alloy steel. After nitriding treatment, its Vickers hardness is 800 ~ 900, and the hardness of fly ash, glass bead or quartz sand is higher. The wear of nitriding steel is very serious. After processing dozens of tons of materials, the nitriding layer of screw does not exist in the plastic plate production line (the nitriding layer is about 0.4mm thick) www.handern.com
four Conductive metal is a good conductor of electricity, so the use of metal powder as filler can affect the electrical properties of filled plastics. However, as long as the amount of filler is small and the resin group can wrap each metal filler particle, the change of electrical properties will not change abruptly. Only when the amount of filler is increased to make the metal filler particles reach the degree of contact with each other, the electrical properties of filled plastics will decrease The volume resistivity will decrease significantly. The fillers made of nonmetallic minerals are electrical insulators. Theoretically, they will not affect the electrical properties of the plastic matrix. It should be noted that due to the influence of the surrounding environment, a layer of water molecules will agglomerate on the particle surface of the filler. According to the different properties of the filler surface, the combination form and strength of this layer of water molecules with the filler surface are different. The electrical properties of the fillers dispersed in the resin matrix may be different from those of the fillers when they exist alone. In addition, in the process of grinding and grinding, due to the breaking of valence bond, the fillers are likely to carry static electricity and form mutually adsorbed aggregates, which is more likely to occur in the production of fine fillers with extremely high fineness.
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