Hard Rubber

... Your Direct Line (+49 911) 6 57 17 -31


...our programme:


Moulded Articles
Bushings, surgical components, filter covers, skittles balls, valve balls, screw joints



Semi-Finished Products

Profile Rods/Pipes
- for electrical- and measurement technology, such as bushings, sleeves, insulators, rivets, swelling rubber, nipples, Contact strips
- for chemical engineering, such as casing plates, spacers, filter

Protective Rubberising
Armatures, tanks, filters, blowers, propellers, pipes

... and much more!

Construction according to your drawings or patterns available!

Data sheet as PDF (1,2 MB)


Production, properties and use

Ebonite is mainly made of natural rubber (NK) and sulfur (S).

For this purpose a mixture of natural rubber and sulfur is melted in a furnace. The molten mixture is poured in a desired metal form and is heated up to the vulcanization for approx. 15 minutes on approx. 200°C. To improve the interlinking of the used materials the form is still removed and the half stuff is submitted to other cycles of the heating and cooling. Ebonite thereby receives his high density and permanence. The used sulfur amounts sway between 30 and 40 weight parts on 100 weight parts natural rubber. Only very unsaturated rubber qualities with many carbon-double connections can be used to reach a high interlinking degree with the sulfur.

Ebonite or hard rubber is no hard rubber, because to no elastic qualities exist. The quality profile of ebonite / hard rubber is comparable rather with plastics.

Ebonite or hard rubber has very good permanence compared with chemicals, nevertheless, changes color with the time by sunlight (UV).  By the development of thermoplastic polymers since the 1960s, the use from ebonite or hard rubber was removed more and more from thermoplastic  polymers, since these are easier to process and cheaper to manufacture.

Actually, ebonite / hard rubber is still used as a mouthpiece for wood blowing instruments or tobacco pipes due to its absolute taste neutrality and its "soft bite".

But also for high-quality combs, the properties of ebonite / hard rubber are unmatched till this day.

Telephone (+49 911) 6 57 17 -31 or E-Mail

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