Abstract: A diaphragm- and spring-less check valve for gaseous media comprising an inlet housing (41) having a sealing edge (51), an outlet housing (11) and a closure body (30) disposed in between the housings, which is guided so as to be axially (14) movable and capable of being impressed bilaterally in any desired position and/or state of the valve, wherein the closure body (30) is moveable exclusively on the basis of a differential pressure between inlet (41) and outlet housing (11) in the blocking position against the sealing edge (51) and in the through-put position the sealing edge (51).

Abstract: An article consisting of a base and one or more attachments thereto. The base is made of one thermoplastic polymer and the attachment is made of a second thermoplastic polymer which is at least partially incompatible with the first polymer. Either the first or second polymer contains 5 to 75% by weight of a third polymer which is an olefinic polymer having functional groups thereon. Either of the first two polymers may contain up to 90% of the usual additives. This enables the production of such articles with high interface strength.