Abstract

A length of plastic with a copper powder adhered to a surface thereof along its length for control of growth of algae and the like, and method and apparatus for producing such a product. A multi-chamber drip irrigation hose for distributing water and the like having a larger primary tube and a smaller secondary tube of flexible water impermeable material and joined at a common wall having passages facing the interior of the primary tube in communication with the interior of the secondary tube and having passages leading from the interior of the secondary tube to the exterior, with a copper powder adhered to at least one inner surface along the length of the tube, with the powder being in a continuous layer or in a non-continuous layer. In one embodiment the copper powder is applied from a reservoir onto a plastic film by brushing directly onto the film or by transfer from a rotating wheel carrying the copper powder. In other embodiments, the power is applied during the formation of the plastic film as by extruding, blowing or molding.