A multi-layered drip irrigation pipe wherein its core layer made from one of the materials selected from group of materials consisting of paper, paper pulp, board, sawdust, wood, wood chippings, bamboo, bagasse, oil palm stem, popula, wood flour, fruit hull powder, moss, peat, mulch, grasses, straw, hay, cotton, starch, seeds, seed husks, silage, cereal and cereal husks, kernels, bread, flour, skin, feces, manure, dung, fish cartilage, leaves of various flora, bark of various flora, plant stems, seaweed and other naturally growing flora, bone, bone meal, vegetables, fruit, fiber, hair, fur, feathers, clay, shell, ash, rags, felt and other commercially produced fabrics and mixtures of any of the preceding materials.

A multi-layered drip irrigation pipe wherein its core layer made from one of the materials selected from group of materials consisting of paper, paper pulp, board, sawdust, wood, wood chippings, bamboo, bagasse, oil palm stem, popula, wood flour, fruit hull powder, moss, peat, mulch, grasses, straw, hay, cotton, starch, seeds, seed husks, silage, cereal and cereal husks, kernels, bread, flour, skin, feces, manure, dung, fish cartilage, leaves of various flora, bark of various flora, plant stems, seaweed and other naturally growing flora, bone, bone meal, vegetables, fruit, fiber, hair, fur, feathers, clay, shell, ash, rags, felt and other commercially produced fabrics and mixtures of any of the preceding materials.

A hemp-winding composite pipe including a lining layer, a reinforcement layer winding on the lining layer, and an external protective layer, in that order from the inside to the outside in the radial direction. The reinforcement layer is a hemp bast layer, including continuously connected hemp basts.

A hemp-winding composite pipe including a lining layer, a reinforcement layer winding on the lining layer, and an external protective layer, in that order from the inside to the outside in the radial direction. The reinforcement layer is a hemp bast layer, including continuously connected hemp basts.

A duct includes a polymeric duct wall that circumscribes a fluid-conveyance passage. The polymeric duct wall includes, relative to the fluid-conveyance passage, an inner surface and an outer surface. An electrically conductive coating is disposed on at least one of the outer surface and the inner surface.

A duct includes a polymeric duct wall that circumscribes a fluid-conveyance passage. The polymeric duct wall includes, relative to the fluid-conveyance passage, an inner surface and an outer surface. An electrically conductive coating is disposed on at least one of the outer surface and the inner surface.