Vulcanisation

The vulcanisation process involves several steps:

• Raw material preparation: the raw rubber is mixed with crosslinking agents (e.g. sulphur, peroxides) and additives (e.g. fillers, plasticisers).

• Shaping: the mix is brought into the desired shape, e.g. by pressing or extrusion.

• Crosslinking: under heat (approx. 140 to 200 °C) and pressure, chemical bonds form between the polymer chains. This step defines the final material properties.

Depending on the crosslinking agent and process used, vulcanisation can be divided into different categories:

Type	Crosslinking agent	Properties	Typical applications
Sulphur crosslinking	Sulphur	High elasticity, good abrasion resistance	Tyres, conveyor belts
Peroxide crosslinking	Organic peroxides	Heat resistance, low rebound resilience	Heat-resistant seals, hoses
Electron beam crosslinking	Electron radiation	Exact control, no chemical additives	Cable insulation, engineering plastics
Siloxane crosslinking	Siloxanes	Biocompatible, temperature-resistant	Medical technology, sealants

Vulcanised materials have specific properties that make them ideal for technical applications:

• Elasticity: the material returns to its original shape after deformation.

• Abrasion resistance: suitable for heavy-duty applications.

• Thermal stability: resistant to high temperatures.

• Chemical resistance: resistant to oils, solvents and chemicals.

• Longevity: high resistance to ageing and environmental influences.

Vulcanisation is a key technology in many industries:

Automotive industry

• Tyres: vulcanised rubbers provide longevity, elasticity and grip.

• Seals: use in engines and car bodies for optimum sealing.

Mechanical engineering

• Conveyor belts: vulcanised materials are robust and resistant to abrasion.

• Vibration dampers: reduction of vibration and shocks.

Medical technology

• Implants: biocompatible silicones for use in the human body.

• Tubing: vulcanised rubber tubing for medical devices.

Construction industry

• Sealants: for use in windows, doors and facades.

• Elastomer floor coverings: slip-resistant, durable floor coverings.

Vulcanisation offers numerous advantages:

• Higher load-bearing capacity: improved mechanical and thermal properties.

• Longer service life: high resistance to ageing and environmental influences.

• Adaptability: suitable for a wide range of applications and materials.

Although vulcanisation offers many advantages, there are also challenges:

• Exact process control: temperature, pressure and time must be precisely controlled to achieve optimum results.

• Environmental impact: vulcanisation processes can pollute the environment if emissions are not controlled.

• Choice of material: not all polymers are suitable for every type of vulcanisation.

• Which materials can be vulcanised? Natural and synthetic rubbers and certain plastics such as silicones.

• What distinguishes vulcanisation from other crosslinking processes? Vulcanisation is based on chemical reactions that create permanent bonds, usually by adding sulphur or peroxides.

• Can vulcanised rubber be recycled? Yes, vulcanised rubber can be reprocessed mechanically or chemically, but with limitations in material quality.

• What role does vulcanisation play in tyre production? It gives tyres the necessary elasticity, abrasion resistance and heat resistance.

Vulcanisation is an essential process in the manufacture of elastomers and rubber products. It significantly improves the mechanical, thermal and chemical properties of materials and makes them suitable for a wide range of applications. Thanks to innovative processes and materials, vulcanisation remains a central part of modern manufacturing technology.