Abstract: A strip material (1) comprising a support (2) includes on at least one side a plastics layer (5, 6) which is plane on the outside and which is traversed by throughflow passages. In accordance with the invention, the outside (7, 8) of the plastics layer (5, 6) includes embossments (9) provided also between the orifices of the throughflow passages which at least in part inter-communicate and communicate with the throughflow passages. In the production of the strip material, during or after the production of the plastics layer (5, 6), soluble particles are applied onto the outside (7, 8) of the plastics layer (5, 6) and are then pressed into the plastics layer (5, 6), the soluble particles being leachable by a solvent of a type in respect of which the remainder of the strip material (1) is stable whereafter these soluble particles are dissolved out.

Abstract: In a process for the manufacture of a strip material (1) a plastics layer (5, 6) is formed at least on one side of a support (2) from a mixture of plastics materials and particulate soluble corpuscles wherein the soluble corpuscles are leachable by a solvent of a type against which the plastics material is stable. Thereafter the soluble corpuscles are leached out from the plastics layer (5, 6) with the formation of throughflow passages. According to the invention, a plastics powder is prepared as the plastics material, which is mixed with the soluble corpuscles and applied onto the support (2). By heat and pressure treatment a plastics layer (5, 6) including therein the soluble particles, is produced from the mixture of plastics powder and soluble corpuscles, prior to the soluble corpuscles being leached at least in part out of the plastics layer (5, 6).