For conveyors intended for the transport of sticky materials the RATAJ® stainless steel duct spiral conveyors (types RRL, RRN) place RATAMID® polyamide plastic inserts, Polyethylene liners (PE) or Polypropylene liners (PP), which have shifted the properties of the spindle-free spiral conveyors to areas of operation previously unknown.
In particular, in some cases, these conveyors can be run idle without the material being conveyed, materials that are easily compacted to form glued and hard crusts, and last but not least, when the conveyor pipe is completely cleaned, the conveyed material can be easily removed from the plastic liner. Wide application of these conveyors is also in the food industry, because plastic inserts have been certified for the possibility of short-term contact with food. The Czech plastic inserts RATAMID® made on the basis of polyamide show several times better properties in tension, toughness, abrasion, mechanical stress and low adhesion coefficient than the polyamides used up to now. The temperature of the conveyed materials using a plastic liner can be up to 140 °C, for a short time up to 180 °C.
Depending on the type of material to be conveyed and the specific technological conditions, combinations of materials are also used.