carbon-black  
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FAQ

 

1. What is carbon black?
Carbon black is a particulate form of elemental carbon, similar to graphite in its microstructure.
2. What are the various uses of carbon black?
Carbon black is used in rubber as a reinforcing agent and in plastics, printing inks, coatings, sealants, and a variety of other products for pigmentation, electrical conductivity, rheology control and UV protection.
3. What is meant by carbon black reinforcement?
It is the ability of carbon black to enhance the properties of elastomers, such as tensile strength and abrasion resistance or wear and is widely used in tyre and rubber products.
4. How does carbon black affect the opacity of the final product?
Carbon black is a superior opacifier for a wide variety of applications. This characteristic stems from the ability of carbon black to absorb radiation across the spectrum of visible light. This excellent absorbing ability allows strong reductions in transmitted and reflected light.
5. How does carbon black impart electrical conductivity to polymeric systems?
Carbon black is more conductive than polymers, resins, or rubber. Addition of carbon black reduces the electrical resistivity by forming a conductive network through the polymeric matrix. Grades of carbon black have been developed to optimize conductivity at lower loadings while meeting all other critical performance requirements for conductive applications.
6. Which carbon black factors affect UV protection in plastic compounds?
The four main factors that influence the UV protection of a plastic compound are: carbon black particle size, carbon black structure, carbon black dispersion quality in the plastic matrix, and carbon black loading in the plastic formulation.
7. Are there any substitutes for carbon black?
There are no known substitutes for carbon black.
8. Are their different types of carbon black?
Yes. Carbon black properties, such as colour, degree of rubber reinforcement, or ease of dispersion, are tailored to suit specific applications. The properties of carbon black are most often controlled by varying its surface area and/or structure.
9. Do you supply grades of carbon black like 'N326'?
Codes like 'N326' or 'N###' are general industry classifications for carbon black grades. These industry classifications do not give information on the purity, cleanliness or analytical consistency. These specific attributes and others are available in PCBL carbon black grades. We have carbon black equivalents for all such grades, many of which are provided in both fluffy and pelleted form.
10. What is the difference between fluffy and pelleted carbon blacks?
Pelletized products are easier to store, handle and convey than fluffy products. They are cleaner to handle and produce fewer housekeeping problems because they are less dusty. The major drawback to the use of pelleted grades is that they are typically more difficult to disperse in comparison with their corresponding fluffy grades. The decision to use fluffy black is generally made because available equipment is inadequate to disperse pellets.
11. How does carbon black structure affect dispersion rate?
Higher structure carbon blacks are generally more easily dispersed than low structure carbon blacks of similar surface area. A high structure carbon black is one in which the aggregates are composed of many prime particles clustered together with considerable branching and chaining. As a result, the aggregates pack more poorly reducing the inter-aggregate attractive forces. Low structure carbon blacks are more compact, allowing closer packing and thus greater inter-aggregate attractive forces which makes dispersion more difficult. However, while more energy is necessary to disperse lower structure carbon blacks, their higher density allows them to 'wet' or incorporate easier because there is less occluded air to displace.
12. How does carbon black surface chemistry affect dispersion rate?
Some grades of carbon black are post treated to increase the amount of chemisorbed oxygen on their surfaces. In some end use applications, this improves the rate of dispersion by improving the rate of wetting. Dispersion stability of the carbon black also increases and product viscosity is reduced.
13. What is undertone?
Undertone relates to a secondary colour property of carbon black and is dependant on carbon black primary particle size. Depending on the size of the primary particle and level of dispersion, a grade of carbon black can have either a brown or blue undertone.
14. What should I consider when selecting a pelleted versus a fluffy carbon black to use in my application?
Pelletized products are easier to store, handle and convey than fluffy carbon blacks. They are cleaner to handle and produce fewer housekeeping problems because they are less dusty. Pellets are also less expensive than the corresponding fluffy carbon black. The major drawback to the use of pelleted grades is that they are more difficult to disperse than the corresponding fluffy carbon black. The decision to use a fluffy carbon black is generally made because available equipment is inadequate to disperse pellets.