Classification of black carbon

Carbon black is an amorphous form of carbon. Light, loose and very fine black powder with a very large surface area, ranging from 10-3000m2 / g, is the product of incomplete combustion or thermal decomposition of carbon-containing materials (coal, natural gas, heavy oil, fuel oil, etc.) under the condition of insufficient air.

Carbon black  generally refers to carbon particles, generally due to insufficient combustion of organic matter, in which hydrogen and oxygen elements into water, and carbon combustion is insufficient, will be separated from the molecules, the formation of carbon black. Almost all particle size ranges of carbon black can be obtained by furnace black production process.

The particle size of carbon black of the same variety is not exactly the same, showing a particle size distribution range. In general, the finer particles of the variety, the size distribution is narrower. The finer the pigment black, the more contact points between the carbon black aggregates, and the stronger the cohesion between them. When the pigment black is mixed into the material, that is, the uniform distribution of the initial carbon black is started, the greater the work to disperse, in order to separate the carbon black particles, and finally achieve the highest blackness and coloring.

There are two kinds of density of carbon black, one is the true density, that is, by the composition of carbon black elements and structure (or crystal structure), in the absence of special instructions, the density of carbon black refers to the true density; The other is the pour density or apparent density, which varies with the processing conditions of carbon black and needs to be measured often. The apparent density mainly provides the basis for the volume calculation of engineering equipment and packaging, storage and transportation containers. The pouring density of carbon black with small particle size and high structure is small. The carbon black with small particles, high structure, pure surface and high surface roughness has good conductivity.

According to the use can be divided into two categories: rubber carbon black, pigment carbon black

1. Classification of carbon black for pigment
Internationally, carbon black is usually divided into three categories according to its coloring ability, namely high-pigment carbon black, medium-pigment carbon black and low-pigment carbon black. This classification system is often represented by three letters. The first two letters indicate coloring capacity and the last one indicates production method.

2.Classification of carbon black for rubber
The naming system takes into account the vulcanization rate and structure of carbon black material, and consists of four systems. The first letter represents the vulcanization rate of the rubber. N represents normal curing rate and S represents slow curing rate. The first letter of the last three letters represents the surface area of carbon black nitrogen. The second and third numbers reflect different degrees of structure.

N220 is suitable for all kinds of rubber, wear resistance is 10%-20% higher than N330, can give colloidal rubber high tensile strength and tear strength, and has a certain electrical conductivity. It is mainly used for tread rubber of truck tire, passenger tire, and rubber products with high strength and high wear-resisting.

N330 is a kind of carbon black with good reinforcement properties, which can give the colloidal particles good strength and elongation, tear resistance, wear resistance and elasticity. Mainly used for tire tread, cord rubber, tire side and various rubber industrial products.

N550 is suitable for natural rubber and all kinds of synthetic rubber, easy to disperse, can give the rubber material high stiffness, fast press out speed, mouth expansion is small, press out surface smooth. The vulcanized rubber has good high temperature and thermal conductivity, as well as good reinforcing properties, elasticity and resilience. It is mainly used in tire cord glue, tire side, inner tube, extrusion and calendering products.

N660 This product is suitable for all kinds of rubber, compared with semi-reinforced carbon black, has higher structure, finer particles, easy to disperse in the rubber material, vulcanized rubber tensile strength, tear strength and fixed elongation stress is higher, and small deformation, low heat generation, elasticity and resistance to flexure. Mainly used for tire curtain tape, inner tube, bicycle, rubber hose, tape, cable, shoes and calendering products, model products, etc.

Pyrolysis method of carbon black: rubber carbon black N990 series of carbon black using natural gas as raw material, in the isolation of air under the condition of flame combustion, cracking generation, said thermal cracking method of carbon black, carbon black N990 its basic performance and furnace method of carbon black has a big difference.

The main advantages of carbon black N990 are as follows:
1.Particle size and distribution. The average particle size is 280nm, nitrogen surface area is 7-11 square meters/g, sulfur absorption value is 10 g/kg, and CTAB surface area is 9 square meters/g.
2.Second, the particle aggregation degree is very small or the structure is very low, showing many individual spherical carbon black particles, the base part is composed of a few fused particles, compared with other varieties of carbon black, the overall aggregation degree is very low.