Seals help avoid flavour transfer

These products are available from Dichtomatik UK, exclusive provider for Freudenberg’s food and beverage related products in the UK.

The different flavourings consist of a variety of aromatics, whose effect on elastomers has not been researched in depth to date. Depending on the composition and chemical characteristics of these individual aromatics and the mixture ratios, the resistance of the elastomer to these substances, as well as its absorption and release rates with regard to them, can be assessed; the assessments can in turn be reinforced by the results of the exposure tests. 

In the processing industry, elastomers should ideally be able to withstand corrosive cleaning media, be resistant to all products offered by the bottler in question, and offer a long service life – criteria some perfluoroelastomer products certainly fulfil. These sealing compounds are used in the chemical industry for applications where, for example, concentrated corrosive chemicals are used. In contrast, the food and beverage industry primarily uses cleaning media that are diluted and can therefore be satisfactorily withstood by more economical materials.

Freudenberg’s 70 EPDM 291 provides good resistance to almost all conventional cleaning media. Cleaning at 82°C in CIP media and sterilisation at 149°C is possible, while heat resistance in water up to 180°C (short-term to 210°C) is said to provide a substantially higher resistance to water steam compared to other EPDM compounds.

The Achilles’ heel of EPDM materials however, is their poor resistance to fatty media, which can cause rapid swelling. An alternative material for the production of non-polar products is Fluoroprene XP 41, a material suitable for the entire processing industry. This combines very good performance in cleaning media with a high level of resistance to oils and fats,and remains stable in temperatures from -15 to +200°C.