When producing oil resistant rubber products with reclaimed nitrile rubber as the main raw material, the rubber compound shall have good heat resistance to oil aging, low compression set and necessary physical and mechanical properties; Carbon black is the most commonly used reinforcing filler, in which the variety and amount of carbon black directly affect the processing properties of NBR reclaimed rubber, especially the Mooney viscosity, scorch resistance and extrusion performance of rubber compound. Xiaobian would like to share with you the skills of using carbon black in nitrile reclaimed rubber products from these three aspects today.
1. Carbon black affects mooney viscosity of reclaimed butadiene acrylonitrile rubber compound
Theoretically, when carbon black is added to the reclaimed NBR, the Mooney viscosity of the compound will increase, and the activated carbon black can give a higher viscosity value to the NBR compound; The smaller the carbon black particle size and the higher the structural degree, the greater the Mooney viscosity value of the NBR reclaimed rubber. The influence of carbon black on Mooney viscosity of NBR compound from large to small is: medium and super wear-resistant furnace black>high wear-resistant furnace black>fast pressing furnace black>fine particle furnace black>semi reinforced furnace black>fine hot cracking carbon black>medium hot cracking carbon black>non carbon black. The Mooney viscosity of NBR compound can also be improved by increasing the amount of carbon black.
2. Carbon black affects the scorching performance of reclaimed butadiene acrylonitrile rubber compound
When carbon black is added to the reclaimed butadiene acrylonitrile rubber, the scorching time of the rubber compound will be reduced in varying degrees, and the surface properties of carbon black and the particle size of carbon black will affect the scorching performance of the rubber compound. In actual production, the alkaline carbon black has a tendency to shorten the anti scorching time of reclaimed butadiene acrylonitrile rubber 2ELYY1220. In the carbon black produced by oil furnace method, the PH value is within the range of 6-9. The main factors affecting the time of the reclaimed butadiene acrylonitrile rubber compound are the carbon black particle size and structural degree: the smaller the carbon black particle size, the higher the structural degree, and the greater the degree of shortening the scorch resistance time of the reclaimed rubber.
3. Carbon black affects the extruding and calendering properties of nitrile reclaimed rubber compound
The properties of carbon black directly affect the extruding and calendering properties of NBR reclaimed rubber when carbon black is used for reinforcement. The influence of carbon black on the extrusion process of NBR reclaimed rubber is mainly shown in the expansion rate (shrinkage) of the extrusion mouth, the extrusion speed and the appearance of the semi-finished products. When high structural carbon black is used in nitrile rubber, carbon black gel is easy to be produced in the rubber compound, which greatly limits the movement of rubber macromolecules and increases the relaxation time of molecular structure, so the expansion rate of the extrusion die or the shrinkage of the calendered film is small.
The influence of carbon black of various varieties on the extrusion expansion rate of NBR reclaimed rubber from small to large is: high structural high abrasion furnace black ＜ fast extrusion furnace black ＜ high abrasion furnace black ＜ general furnace black ＜ medium super abrasion furnace black ＜ semi reinforced furnace black ＜ fine particle furnace black ＜ medium particle hot cracking carbon black ＜ fine particle hot cracking carbon black. With the increase of carbon black content, the extrusion expansion rate and deformation rate of NBR reclaimed rubber vulcanizate decreased gradually.
When using reclaimed butadiene acrylonitrile rubber or butadiene acrylonitrile rubber/reclaimed rubber to produce rubber products such as oil resistant rubber hose, oil resistant rubber boots, oil resistant rubber plate, oil resistant shock absorption block, you must select the right type of carbon black. Later, Xiaobian will continue to share with you the impact of the type and amount of carbon black on the physical and mechanical properties of butadiene acrylonitrile reclaimed rubber vulcanizate.
Exclusive original article [commercial authorization] reprint, excerpt and excerpt in any form are prohibited without written authorization. Focus on Hongyun rubber: learn the process formula and raw material technology of producing rubber products from recycled rubber to help you reduce costs and increase profits