The Rubber is an elastomer with great features. EThere are two main kinds of rubber, natural and synthetic.
- In view of UNI 7703 standard, natural rubber is obtained by coagulating latex taken from particular plants after having made an incision in their trunks. The mechanical features are excellent, but rubber derived from natural latex has poor resistance to atmospheric agents, temperature variation and chemical agents.
- Synthetic rubber is obtained from the polymerisation of simple hydrocarbons from which artificial rubbers are obtained and are subsequently coagulated. There are different kinds of artificial elastomers with mechanical and chemical features of different values.
The latex produced with coagulation, is vulcanised with a process which includes the heat-treatment of the rubber mixed with particular additives like sulphur, carbon black, inert fillers, plasticisers, etc; after the vulcanisation process, the product takes the name of the compound.
During the vulcanisation phase, the rubber reticulates, and molecular bonds are created to prevent molecule slipping; in this way the rubber loses it plasticity features and takes its final shape.
According to the product to be made, the vulcanisation process is done either in closed moulds which creates the moulding process, or among rotary cylinders which creates the so-called calendaring process, or in extruders.
Applications of rubber
The finished product is found in the shape of moulds, drawn items, and die-cut items. Some of the rubber wide range of applications are:
- Seal rings
- Taps and fittings
- Metal rubber items
- Various components
- Suction caps
- Cable glands
Rubber classification Rubber elastomers can be classified as follows:
- dienic polymers and co-polymers
- isoprene polymers (natural rubber)
- polybutadiene; styrene rubber; nitrile rubber; butadiene-vinyl pyridine co-polymer
- chlorobutadiene co-polymers (neoprene)
- mono-olefin polymers and co-polymers
- isobutene polymers
- polyethylene elastomers
- fluoro-olefin elastomers
- acrylic elastomers
- ethyl acrylate and butyl acrylate polymers and co-polymers
- fluoro-acrylate polymers
- polysulfide rubber
- polyester rubber
- silicone rubber