초록 ▼

A multi-layer laminate structure comprises a separate layer of scrap produced from the several thermoplastic resins used in making the laminate structure. In a preferred construction, the multi-layer laminate structure comprises an outer thermoplastic polyolefin layer, an inner thermoplastic polyole

A multi-layer laminate structure comprises a separate layer of scrap produced from the several thermoplastic resins used in making the laminate structure. In a preferred construction, the multi-layer laminate structure comprises an outer thermoplastic polyolefin layer, an inner thermoplastic polyolefin layer and an intermediate oxygen barrier layer preferably made of ethylene-vinyl alcohol copolymer. An adhesive layer bonds the barrier layer to the inner polyolefin layer and a separate scrap layer is disposed interiorly of the outer polyolefin layer. A second adhesive layer bonds the scrap layer to the intermediate barrier layer. Containers having excellent oxygen barrier properties and good transparency are made by forming a parison from the multilayer laminate structure and blow molding the parison to the desired container shape. Apparatus are described for producing multi-layered parisons of polymeric materials for producing such structures in which the relatively thin layers of the structure are formed into a laminate within the apparatus before being joined to a relatively thick layer.

대표청구항 ▼

An apparatus for producing multi-layer parisons of polymeric materials wherein at least two of said layers are relatively thin compared to at least one other layer, said apparatus comprising means including a tubular channel for forming a relatively thick layer of a first polymeric material and lami

An apparatus for producing multi-layer parisons of polymeric materials wherein at least two of said layers are relatively thin compared to at least one other layer, said apparatus comprising means including a tubular channel for forming a relatively thick layer of a first polymeric material and laminate means for forming a laminate of at least two thin layers which is thereafter fed completely around the surface of the thick layer of polymeric material, said laminate means including a segmented die block, each segment being formed with a polymeric accumulation reservoir, the die block being formed around said tubular channel having a first annular passageway of lesser diameter than said tubular channel leading from an accumulation reservoir in a first segment to an outlet orifice and adapted to be charged with a second polymeric material from said accumulation reservoir, a second annular passageway leading from an accumulation reservoir in a second segment to an outlet orifice and adapted to be charged with a third polymeric material from said accumulation reservoir, and a third annular passageway which is an elongated annular member having facing and spaced apart parallel side walls in which said laminate is formed leading from the outlet orifices of said first and second passageways and leading to said tubular channel; whereby a laminate can be formed in said third annular passageway composed of said second and third polymeric material, which laminate is thereafter fed around said first polymeric material. A method of forming a multilayer parison of at least three layers of polymeric materials by co-extrusion with an extrusion head wherein at least two of said layers are relatively thin compared to at least one other layer comprising the steps of forming the thick layer of a first liquid state polymeric material within a tubular passageway and forming a liquid state flow laminate composed of thin layers of a second and third polymeric material within a passageway which is an elongated annular passageway having facing and spaced apart parallel side walls and thereafter feeding said liquid state flow laminate completely around said liquid state thick layer prior to extrusion from said head.