Carbon Black, which is also known as furnace black, is colloquially often called soot but has very little in common with the familiar, unwanted by-product occurring in all incomplete combustion processes. Soot known from smoking chimneys or from the exhaust system of older cars significantly differs from carbon blacks manufactured in accordance with stringent quality standards.
Carbon blacks are produced in different manufacturing processes according to the requirements of the end user. Due to the use of defined raw materials and a purposeful control and surveillance of the production processes, it is possible to manufacture reproducible qualities, which are clearly defined by their specifications.
For ensuring the properties requested a wide range of different carbon black specifications has been created with respect to the wide variety of requirements based on the final applications.
Our long experience in the market and the close co-operation with different manufacturers allow us to provide you with the appropriate types of all manufacturing processes even in different preparation forms.
The furnace process allows the manufacturer to influence the development of carbon black particles in various ways.
It is possible to control the particle size as well as the resulting particle structure.
The furnace process is used to manufacture both carbon black for rubber and pigment grades. Apart from this, it is possible to produce conductive carbon blacks featuring a very high structure.
Channel black process
The crude oil is vaporized in the channel black process and is fed to the burners together with the carrier gas.
A specific influence on the structure of the carbon blacks produced in this way is not possible.
Nowadays, the channel black process is primarily used to manufacture carbon black pigments with very fine particles, which are above all distinguished by their high content of oxygenic surface groups.
Lamp black process
The oldest process for the production of carbon black provides hardly any possibility to influence the resulting particles.
The raw material is burnt in a pan separating the resulting lamp black.
Lamp black is distinguished from other types of carbon black by the wide range of particle sizes. This particle size distribution range is the result of the different burning zones within this process.
Thermal black process
The discontinuous thermal decomposition of natural gas leads to the development of thermal black.
Developing thermal black is a relative slow process, in which very coarse carbon black particles are developed featuring hardly any structure.
Thermal blacks are distinguished by their particle size and by the structure. They are furthermore characterized by their special purity.
Product properties and delivery forms of carbon blacks
Size of the primary particle
The primary particles create a firmly linked aggregate which even cannot be separated by dispersion. The size of the primary particles does not allow a direct indication on the size of the aggregate.
The structure describes the branching that is resulting from the fusion of the primary particles. This structure is stable and does not change when the pigment is processed.
The surface is the result of the interaction of size of the primary particle and structure.
The surface area of carbon black is the result of the primary particle size, the structure and the porosity. The outer surface area of carbon blacks can be determined by special methods, enabling omitting structure and porosity depending on the requirement. The respective values provided by various methods (STSA, IOD, CTAB) give information on the characteristics and the processing in the respective application.
The specific surface area of carbon black is determined by the BET method. The inner structures as well as the porosity of the particles are also determined in this process. The surface area allows conclusions on the binding agent demand of the particles. In addition to this, it is possible to draw further conclusions on the characteristics in correlation with the above mentioned determinations of the outer surface area.
Carbon black as powder shows an extreme dust emission and is therefore not easy to handle. Despite the tendency to agglomeration, carbon black powder can be dispersed very easily.
However, it is not possible to provide all types in powder form.
Carbon black in beads
Carbon black is further processed to beads in a downstream cylindrical rotary granulator. In this process, water or oil, mostly in combination with an additive, serves as a binding agent.
Grades in beads create lower dust than powder grades. However, they are neither free-flowing nor dust-free owing to the fines content which can account for up to 15%.
When producing spray-dried granules, carbon black is processed to an aqueous dispersion, the particles are completely disaggregated and stabilized by additives.
The subsequent spray granulation leads to a dust-free, free-flowing granule (GrapaCarb), which can be adjusted to numerous requirements with the aid of various additives. This allows to ensure easy dispersion in the respective application medium.
Water-based preparations (Euronyl® CB) are manufactured by grinding in bead mills using various kinds of dispersing and wetting agents.
They are adjusted to different fields of application ensuring maximum efficiency owing to perfect dispersion.
Fields of application
Carbon black pigments are used in adhesives in order to colour the adhesive compound deep black, to make it conductive and to make the material ageing resistant to UV light. There are, in particular, very high demands on the adhesives and the carbon blacks in the field of high-tech adhesives and in the automotive sector.
The paints and varnish industry imposes several requirements on the carbon black pigments. Lamp black types are frequently used for tinting paints and primers. Furnace and channel blacks are used for coatings of higher qualities.
Due to our large product range, we are able to provide you the right type of carbon black for all requirements.
Carbon black pigments play an important role in the field of printing inks. Owing to the large number of carbon black types available, that are different in structure, particle size and surface chemistry, there are optimized carbon black pigments for any formulation and all printing methods.
Carbon black pigments can be used to colour plastics in the requested shades of grey and black. Apart from this, the use of carbon black pigments minimizes the photo-oxidative degradation of plastics caused by UV light. An antistatic finish or electrical conductivity of the plastics can be achieved by means of a highly structured furnace carbon black or special high-performance carbon blacks. Special requirements imposed on plastics coming into contact with food can be met by special carbon black pigments. These grades are characterized by particularly low PAH values and a low degree of impurity.
Carbon black pigments are widely used in metallurgical applications:
The pore density of refractory materials is reduced. In addition, Carbon blacks have the effect of reducing slag which improves the life cycle of the materials.
Carbon blacks are used for special alloys as casting powder and cover powder which allows regulating the lubricating effect, the thermal insulation and a controlled release of slag formers.
The structure and particle size are very important for these particular applications. In special cases, it is an advantage to use carbon blacks with oxidic surfaces, i.e. channel blacks or non-oxide furnace blacks.
For the colouring of paper, it is recommended to use pre-dispersed carbon blacks in liquid preparations (Euronyl® CB). For nuanced mass colouration of pulps or for film coating, we offer appropriate preparations based on furnace black pigments or channel blacks featuring a particularly small particle size that provides for a special colour depth. For electrical conductivity purposes, we offer a series of special carbon blacks and preparations adapted to such requirements.
Anionically or cationically stabilised liquid preparations are available as an option.
Our especially adjusted liquid preparations (Euronyl® CB) qualify for the colouring of technical textiles, in particular fleeces. Depending on the requirements, they provide for a purposeful increase in UV or IR absorption, conductivity or just a particularly high colour depth. A wide range of available additive systems enables us to adapt the compatibility with the aid of binding agents in order to avoid system-related agglomerations and incompatibilities.