Ebonit (hard rubber)
Semi-finished products and moulded articles
Ebonite is a material for demanding technical applications such as precision components for volume measuring systems, pump and tank linings, pistons and spinnerets. But also for semi-finished products for the manufacture of technical articles by machining. Due to their exceptionally good resistance to acids and alkalis, ebonite mouldings are used in processes with high chemical stress.
Production, properties and use
Ebonite or hard rubber is mainly made of natural rubber (NK) and sulphur (S). A mixture of natural rubber and sulphur is melted in a furnace. The molten mixture is then poured into a desired metal form and heated to approx. 200°C for approx. 15 minutes for vulcanization. To improve the cross-linking of the materials being used, the mould is removed and the semi-finished product is subjected to further cycles of heating and cooling. Thereby ebonite receives its high density and resistance. The quantities of sulphur used vary between 30 and 40 parts by weight per 100 parts by weight of natural rubber. Only highly unsaturated rubber qualities with many carbon double bonds can be used to reach a high degree of cross-linking with the sulphur.
Ebonite or hard rubber is not a hard rubber, as there are no elastic properties. The quality profile of ebonite/hard rubber is more comparable to plastics.
Ebonite or hard rubber has very good resistance to chemicals, but discolours over time due to sunlight (UV). Due to the development of thermoplastics since the 1960s, the use of ebonite/hard rubber has been increasingly replaced by thermoplastics, as they are easier to process and cheaper to manufacture.
Currently, ebonite/hard rubber is still used as mouthpieces for woodwinds or tobacco pipes due to its absolute neutrality of taste and its "soft bite". But also for high quality combs the properties of ebonite/hard rubber are still unsurpassed.
Properties: low swelling (unhygroscopic), dimensionally stable, tough, impact resistant, electrically insulating
Machining: cutting, turning, drilling, grinding, polishing, bending with very high dimensional accuracy
Resistant to: water, salt solutions, acids, alkalis, petrol, hydrocarbons
From our programme:
Semi-finished products:
Profile rods/pipes:
- for electrical and measurement engineering, such as bushings, sleeves, insulators, rivets, expanding rubber, nipples, contact strips
- for chemical engineering, like cover plates, spacers, filters
Protective rubber linings:
- Armatures
- Tanks
- Filters
- Blowers
- Propellers
- Pipes
Moulded articles:
- Bushings
- Surgical components
- Filter sets
- Skittles balls
- Valve balls
- Screw joints
We also produce according to drawing or sample! –> more info
Phone +49(0)9661 10 90-0 or E-Mail
