Filler specific surface area test - Database & Sql Blog Articles

Fillers are also known as fillers, extenders. Some fillers are also body pigments. The filler of the micro-nucleus has good hiding power and is commonly used in the coatings industry.
Fillers can be used in a variety of polyurethane products, such as polyurethane coatings}, sealants: polyurethane pastes, special elastomers i polyurethane foam. Melamine plant fiber polymerization, soap ginseng polyol, etc., organic filler can be used for polyurethane foam; calcium carbonate kaolin (ceramic, · china clay), molecular sieve powder talc powder wollastonite titanium titanium barite powder (barium sulfate) and other fine Inorganic powder can be used as polyurethane sealant 0 polyurethane soft foam polyurethane elastomer and adhesive. A filler such as a polyurethane coating.
Refers to materials that are filled in other objects. In chemical engineering, a filler refers to an inert solid material contained in a packed column, such as a Pall ring and a Raschig ring, etc., which acts to increase the gas-liquid contact surface and strongly mix them with each other. In chemical products, fillers, also known as fillers, are solid materials used to improve the mechanical properties of the filler (5 sheets), mechanical properties of the product, and/or reduce costs. Among them, fillers which can significantly improve the strength of the product, such as long fibers and whiskers, are often referred to as reinforcing materials, and carbon black is called reinforcing filler. Solid materials and calcium carbonate are often used as fillers in pharmaceutical tablets, cosmetics and detergents, but the purpose is to adjust the dosage and concentration instead of improving the performance, so it should be called diluent. Plastic plasticizers, rubber oil-filled oils, and spinning oils can improve performance and cost, but it is customary to treat these liquid materials as processing aids.
In polymer chemicals, fillers (fillers) are the most widely used additives, and almost all plastics (including thermoplastics and thermosets), natural rubbers and coatings use a large amount of filler. For example, adding wood powder, clay or calcium carbonate when manufacturing plastics can not only improve the mechanical properties of the product, increase the hardness, but also reduce the cost; using graphite, magnetic powder or mica as a filler can improve the electrical conductivity, magnetic permeability and resistance of the plastic. Heat; the addition of carbon black or silica (silica) to the rubber can significantly improve the physical properties of the product; the addition of titanium (titanium dioxide) to the spinning solution can be shaded and dyed. In the coatings industry, white or colored fillers (such as titanium, talc, calcium carbonate, barium sulfate, etc.) are often added to improve the optical, physical and chemical properties of the coating. Fillers (fillers) for such applications are called body pigments or exhibits. Color material.
The performance of the filler mainly depends on: 1 has a large specific surface area (m2 / m3 filler layer) (filler specific surface area test by 3H-2000 series specific surface area test); 2 liquid on the surface of the filler is better Uniform distribution performance; 3 airflow can be evenly distributed in the filler layer; 4 seasoning has a large void ratio (m3/m3 filler layer). In addition, the choice of filler should also consider its mechanical strength, source, manufacturing and price.
The filler of the filler increases the viscosity of the material, especially the fibrous filler increases the viscosity significantly. The filler before the addition is dehydrated to avoid the consumption of a portion of the isocyanate. It must be noted that the formation of carbon dioxide causes foaming of the resin and affects the physical properties of the polyurethane resin.
In order to speed up the wetting rate of the filler while reducing the viscosity of the system, or to add more filler to the polyurethane resin, it is sometimes necessary to add a wetting and dispersing agent to the resin in advance. In-mold lacquer is an additive with three functions of coating, color paste and mold release agent. It is evenly sprayed in the mold, and after the paint film is dried, the polyurethane sole, the self-skin foam, and the polyurethane soft foam can be molded. After the hard foam product is released from the mold, the color paint is attached to the molded product.
Edit the types of fillers in this section There are many kinds of fillers. Metal powders such as aluminum powder, zinc powder copper powder and silver powder can be used as conductive fillers. Cement, fly ash, etc. can also be used as the filler. Vegetable powders such as wood flour and starch can also be used as the filler. Calcium fluoride can be used in small amounts in polyurethane adhesives and sealant systems; it also acts as a carbon dioxide absorber.
In general, fine powder fillers or modified fine fillers, as well as fibrous and flaky fillers, can be used in small amounts to improve their overall performance. For example, for elastic polymers (such as rubber and polyurethane elastomers) Reinforcement, increase modulus, strength, wear resistance, heat resistance, improve dimensional stability, and improve strength and aging resistance for hard products. However, if the amount used is too large, the physical properties are lowered, and the operation is difficult when the filler content is large. The fillers are as follows: depending on the filling method, they can be divided into bulk packing and structured packing.
The specific surface area of ​​the filler is an important parameter. The specific surface area is the surface area per gram of solid material in m2/g; the national standard for specific surface area testers is the BET multi-point method based on BET theory (GB/T 19587-2004). The main point of the specific surface area measured by the nitrogen adsorption BET multi-point method is: in the range of 5-30% nitrogen partial pressure, the adsorption amount of the adsorbent (the powder to be tested) to nitrogen is measured at different partial pressure points of nitrogen, and adsorption is made. The isotherm, the specific surface area of ​​the adsorbent can be calculated by the BET formula to determine the saturated adsorption amount of the monolayer when the surface of the adsorbent is covered with nitrogen molecules to cover the monolayer. 3H-2000BET-A specific surface area measuring instrument is a high-precision analytical instrument based on national specific surface testing standards. It has 7 domestic leading technologies; such as the only integrated in-situ purge processing function in China, for chromatographic specific surface testing The problem of purging treatment between different nitrogen partial pressure points is required, which makes the purging treatment between different nitrogen partial pressure points more convenient and efficient, and reduces the influence of continuous testing on accuracy; the only program-controlled wind-heat assisting device in China After achieving full automation, it is guaranteed to obtain sharp and rapid desorption peaks and reduce background error; the only chromatographic concentration detection system in China makes the nitrogen partial pressure detection accuracy increase by 10 times relative to the flow method; the six-way valve injector program control The only domestic quantitative tube program-controlled switching function; the only domestic particle size report function; the instrument parameter software display, at the same time, the large-screen LCD hardware display on the instrument, making the instrument working state parameters clear at a glance, the operation is more reliable; and the liquid nitrogen temperature monitoring , detector gas shut-off protection, detector thermostat, important part of the sound prompt, make 3H-2000BET-M specific surface meter In terms of test accuracy, stability and safety, and ease of operation, it has achieved and partially surpassed the performance of similar instruments abroad. The 3H-2000 series has a large number of customers in the country, and is a well-known brand of surface-surface instruments.