Powdered food hoses

Trelleborg Industrial Hose has launched a compound for food hoses that prevents the accelerated wear usually associated with static dissipation when transferring powdered foodstuffs. Following extensive laboratory tests and in applications with end-users, the company can offer a white food-grade compound that is conductive enough to dissipate static electrical charges, according to ISO 8031, while meeting the requirements of FDA 21 CFR 177.2600. Critical tests with sugar have given good results, proving the service life of the hose is increased tenfold when compared to a non-conductive white food-grade hose.

One of the main reasons for failure of rubber hoses used for transfer of powders is electrical sparks. Electrical charges created by powder particles during transfer can reach extreme levels, depending on the media being processed and its speed of transfer. These charges will attempt to dissipate and, if the hose acts as an insulator, the electrical charges will rupture the molecular chains of the rubber hose. This diminishes the elastic quality of the rubber hoses, reducing abrasion resistance and accelerating wear of the hoses.

The common black hoses used for non-food powders are conductive and can therefore dissipate electrical charges effectively along their structure or to the ground. However, white rubber is usually preferred for transfer of food products and to meet food regulations, such as those of the FDA in the US, there are strict limitations on the type of ingredients used in rubber compounds. Most of those that usually make rubber conductive are restricted for use in contact with food stuffs. This means that the life of white hoses transferring food stuffs is lowered.

The new white compound is available in two hose types, each with a black, outer protective cover: Supervrac for bulk tank truck unloading and Trellvac for either stationary or mobile vacuum systems

In addition, as the hoses are conductive through the hose itself, its cover and in-between, they can safely be used in an explosive atmosphere environment meeting the European Union ATEX directive, provided the usual earthing safety measures are taken.