Capsule FillerThere are many types and varieties of capsule fillers, mainly including the following categories: Calcium carbonate: Calcium carbonate is a common and inexpensive filler material. Calcium carbonates of different origins and properties are as follows: Ordinary calcium carbonate (chalk): White crystals or powder, specific gravity 2.70-2.95, soluble in acid, insoluble in water. When heated to 825°C, they decompose into calcium oxide and carbon dioxide. Naturally occurring calcium carbonate minerals include limestone, calcite, whiting, and tian stone, which are ground into powder and called ordinary calcium carbonate. They are dry-sol and wet-milled, with particle sizes ranging from 1.5 to 44 microns, dry-milled particle sizes greater than 20 microns, and wet-milled particle sizes less than 20 microns. Precipitated calcium carbonate: Powdery calcium carbonate precipitated by the flow of carbon dioxide into limewater or sodium carbonate solution and limewater.

　　The precipitated calcium carbonate of the capsule filler has a particle size of 1.0~16 microns, a specific surface area of 5~25M/G, a refractive index of 1.49, a pH of about 10, is insoluble in water and alcohol, releases carbon dioxide when encountering acid; slight hygroscopicity. Active light calcium carbonate of capsule filler: It is a light calcium carbonate with a layer of fatty acid soap adsorbed on the surface of the particles. Tasteless and odorless white powder.

　　Capsule FillerIncludes various carbon blacks. Carbon black is a product produced by the partial combustion or thermal decomposition of liquid or gaseous hydrocarbons under insufficient air conditions. The elemental composition of carbon black is mainly carbon, with only a small amount of hydrogen and oxygen, which is a black powder material with a "quasi-graphite crystal" structure and a colloidal size range. Due to different production processes, carbon black can be divided into many grades, but the following two are commonly used in the plastics industry: Natural gas tank black: Black powdery substance, rough surface, easy to absorb moisture in the air. Average particle size 23-30NM, specific surface area 130-160M/G.

　　Mixed gas tank black: This is a type of carbon black made by gasifying coal tar and natural gas with added anthracene oil and naphthalene oil. The "structure" of carbon black in the capsule filler refers to the tendency of carbon black to aggregate into clusters, which plays an important role in the rheological properties of the carbon black polymer system. "High-structure" carbon black promotes the extrusion of polymers with characteristics of high viscosity, high elastic modulus, low flow rate, and smooth low swelling. Adding carbon black to polymers not only prevents photodegradation and thermal oxidation, but also improves the hardness of plastic products.

　　Cellulose paper pulp: Kraft paper, white paper, colored paper, etc. are used as filler paper. Generally, the paper is soaked in resin, dried, sliced, and then pressed into thin sheets as materials. Wood powder: Widely used in thermosetting resins, high impact strength, low shrinkage rate, good electrical properties, and low price. The wood powder particles should be uniform in size, and larger particles such as wood chips and bark should be removed. Cotton pieces are made by cutting cotton or purifying cotton spinning. The impact resistance of plastic products filled with cotton scraps is improved, and the volume is large.

　　Peanut shell is an inexpensive capsule filler with high phenol content and abundant sources. Peanut shell powder can appropriately improve the performance of PS and PP and reduce costs. The surface of peanut shell powder is generally non-polar. Its water absorption is also smaller than wood powder. Walnut shell: Walnut powder is waste produced during the processing of walnut kernels. Because it contains a large amount of wood resin and ceresin, it does not have water absorption. Glass fiber; mainly used for plastic reinforcement.