Process for the manufacture of a composite molded structure, and especially of a ski

A process for manufacturing a ski from substantially flat stock materials, said ski having a distinct cross-sectional shape and consisting of a plastic foam core and upper and lower half-casings formed on respective upper and lower peripheral surfaces of said plastic foam core, said upper half-casing unitarily forming upper and side surfaces of the ski, said process comprising:

• arranging in a lower portion of a mold a first substantially flat sub-assembly which forms said lower half-casing;
• arranging in said mold a second substantially flat subassembly which forms said upper half-casing;
• arranging at least one flexible plastic membrane between said first sub-assembly and said second sub-assembly, said at least one membrane being adherable to said plastic foam core and to said half-casings;
• closing said mold, such that when said mold is closed, said at least one flexible plastic membrane forms a sheath within said mold between the first and second sub-assemblies;
• pressure injecting into said sheath reactants which react to form a foam which expands in situ, until said sheath substantially fully urges the sub-assemblies against upper and lower inner surface walls of the respective upper and lower portions of said mold, wherein said edges of said upper sub-assembly slide within said mold to allow the sub-assemblies to be urged substantially fully against inner surface walls of said mold;
• cooling all contents within the mold to form said ski;
• and
• opening the mold to remove said ski.