sandwich conveyor systems can be sized to convey virtually an infinite volume of bulk materials. The sandwich principle, with load carried (and sealed) between two belts, allows materials to be gently secured for upward transport at any angle of inclination required. Materials like granulated particles and smooth lumps as well as primary crushed rock or ore are easily and positively lifted. Conversely, cleaning of the belts is no problem when the job requires conveying sticky materials such as clay, sludge or filter cake because the belts are completely flat and may be scraped, brushed or reverse bent as required. Sticky products that will not release from cleated belts, sidewall belts or bucket elevators are routinely and satisfactorily conveyed.