Elastomer Engineering Ltd - Elastomer Engineering Ltd

The properties of Hydrogenated Nitrile Rubber (HNBR) depend upon the acrylonitrile content and the degree of hydrogenation of the butadiene copolymer. They have rather better oil and chemical resistance than Nitrile Rubber and can withstand much higher temperatures.

HNBR has excellent resistance to sour oil and gas, steam, hot water and ozone. Physical properties (e.g. tensile and tear strength, elongation, abrasion resistance, compression set, etc.) are also excellent and compounds exhibit good dynamic behaviour at elevated temperatures. Like EPDM, HNBR can either be cured with sulphur or peroxide, depending upon which properties are the most important. Components in HNBR offer an excellent range of performance at a cost between Nitrile rubber and Fluoroelastomers.

We have several high shot volume, computer controlled vertical injection moulding machines. We designed these to take large moulds beyond the scope of conventional injection moulding machines. With their high injection pressures, they have the unique ability to produce very long mouldings and bulky items that it would be impracticable to manufacture in any other way.

Injection tooling is usually regarded as very expensive. However, our long experience with this type of equipment has shown that our moulds are only slightly more expensive than the equivalent compression versions and certainly cheaper than a comparable transfer mould. The only extra features required are sprue bushes, special runners and press platen attachments.

Faster cycle times are possible with the injection moulding leading to lower unit prices. The process is also ideal for bonding as the metal parts are positively clamped within a closed mould.

Fluoroelastomers or Fluorocarbons, widely known as Viton®, are among the most suitable rubbers for continuous use at temperatures of 200°C and up to 300°C for short periods. Various grades are available depending upon whether compression set, flexibility (as in diaphragms) or chemical resistance is the prime concern. Fluoroelastomers have excellent resistance to ozone and weathering, oils and most chemicals.

They are, however, very expensive, unsuitable for use with phosphate esters and ketones and have poor low temperature capabilities.

Typical applications include: accumulator bladders, diaphragms, gaskets, O-rings and seals operating in especially harsh environments.

Viton® is a registered trade mark of DuPont Performance Elastomers