Requirements of rubber products for fillers and functions of various carbon black in rubber (2)


Carbon black generally refers to carbon particles, generally due to the inadequate combustion of organic matters, in which hydrogen and oxygen elements are converted into water, and if carbon elements are not fully burned, they will break away from molecules and form carbon black. Carbon black with almost all particle size ranges 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. Generally speaking, the varieties with fine particles have narrow particle size distribution. The finer the pigment black is, the more contact points between the carbon black aggregates will be. As a result, the stronger the cohesion between them will be. When the pigment black is added into the material, i.e. the initial carbon black is evenly distributed, the work to be done for dispersion will be greater, so as 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 true density, which is determined by the element and structure (or crystal structure) of carbon black. In the absence of special description, the density of carbon black refers to true density; the other is pour density or apparent density, which varies with the processing conditions of carbon black and needs to be determined frequently. Apparent density mainly provides basis for volume calculation of engineering equipment, packaging, storage and transportation containers.






The carbon black with small particle size and high structure has low pour density. Carbon black with small particles, high structure, pure surface and high surface roughness has good conductivity. Rubber technology network learned that when preparing conductive rubber, the amount of carbon black should not be less than a certain critical value, otherwise, too little carbon black in the rubber can not form a conductive channel or cause field emission, so that the conductivity of the rubber can not meet the requirements.






The role of carbon black in rubber


1. Increase the wear resistance and service life of rubber products (reinforcing agent)


2. Cost saving. Generally, rubber products are made of two parts of rubber and one part of carbon black (filler)


From: Rubber Technology Net