Abstract: A method of making a hard multi-tubular structure which comprises; producing a flat hose fabric composed of a plurality of side-by-side abutting hoses, introducing uninflated foil tubes into each of the hoses of the fabric, the tubes being of substantially the same length as the length of the fabric, inflating the tubes for expanding the hoses into formed hollow sections, treating the fabric with a hardening material, and allowing a hardening of the hardening material and a setting of the fabric with the hoses in expanded condition. Therefollowing, the tubes are left after the setting of the hose fabric in the respective hollow sections free of any internal inflating pressure. Alternatively, the tubes may be withdrawn from the hollow sections after the setting.

Abstract: A process for preparing a retort-proof laminate for packaging foodstuffs which comprises laminating an aluminum substrate to at least one polyolefin film selected from the group consisting of high density-polyethylene, polypropylene, ethylene-propylene copolymers and polybutene films using as an adhesive a specific polyolefin resin in melted state prepared by combining together (A) at least one member selected from the group consisting of high-density polyethylene, polypropylene ethylene-propylene copolymers and polybutene, (B) maleic anhydride and (C) aluminum hydroxide, and by rendering said specific polyolefin resin substantially free from unreacted maleic anhydride and low molecular weight maleic anhydide homopolymers.The process also includes preparing a retort-proof coated aluminum substrate for packaging foodstuffs which comprises coating an aluminum substrate with a layer formed from the above-described specific polyolefin resin and thereafter forming a suitable retort packaging container therefrom.