Abstract: Hose structure suitable for transport of highly abrasive media including at least two concentric tube layers of elastomeric material. The radially innermost tube layer material is of greater abrasion resistance than a tube layer radially outwardly thereof. A radially outer tube layer material is of greater resilience than that of the radially innermost tube layer. The tube layers may be made visually distinguishable, for example, by being of different colors, so as to serve as a wear indicator.

Abstract: A plurality of lengths of at least one flattened flexible polymeric tube disposed in superposed relation. Each length in cross section includes enlarged folded edge portions with a flat center portion between the edge portions. Means such as a separator or spacer having substantial thickness is inserted between or within the tube lengths to support the weight of at least a substantial part of the center portion of each length to prevent the formation of edge creases longitudinally along the edges of the tube lengths. The invention is particularly useful in the processing of uncured or unvulcanized rubber tubes either in a stacked or rolled condition.