| 摘要 |
1456744 Extrusion blow moulding multilayered container TORAY INDUSTRIES Inc 8 March 1974 [13 March 1973] 10486/74 Heading B5A [Also in Division B8] A multi-layered blow moulded thermoplastics container comprises at least one layer 22 composed of a mixture of (i) 55 to 99% by weight of polyamide and (ii) 3 to 45% by weight of an ethylene copolymer containing 0À1 to 10% by mole of at least one compound selected from unsaturated carboxylic acids or amides, esters, anhydrides or metal salts thereof, and one or more layers 21 and 23 composed of an olefin polymer, the thickness of the layer(s) composed of the mixture being 2 to 30% of the total thickness of the lamination and the melt streams forming the layers being combined within a common extrusion die prior to blow-moulding. The container may comprise a double treble, or quadruple-layer construction. As shown, a triple-layer wall construction is formed by combining polymer melt streams within a composite die having three coaxial annular passages between parts 6, 7, 8 and 13, the inner and outer passages being fed with the olefin polymer stream by a screw extruder 3 and the intermediate passage being fed with the mixture. Combining the streams within the die to form a composite tube is said to result in improved bonding between the layers. The tube may be blown subsequently or immediately in a two-part mould 11 to form the container. The olefin polymer layer or layers may be constituted by low, medium, or high density polyethylene, polypropylene, polybutene-1, and olefin copolymers, such as ethylene-propylene copolymer. The polyamide utilized in the "mixture" layer may be nylon-6, nylon-66, nylon-12, nylon-11, nylon- 10, nylon-610, nylon-612 or combinations thereof. The ethylene copolymer of the "mixture" may be in any form, i.e. graft, block or random, and is preferably copolymer consisting of 90 to 99À9% by mole of ethylene and 0À1 to 10% by mole of a metal salt of acrylic or methacrylic acid, zinc methacrylate being preferred. Fillers, such as glass fibres, talc, asbestos, may be incorporated.
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