Patent ID: 7676854

Claim:
A method for manufacturing a rigid helmet liner comprising: assembling a first mould comprising a flexible slip mould with secondary, relatively rigid and outward protruding forms arranged on an essentially rigid head-shaped main mould; arranging a softenable and/or flexible, tight film or foil on said first mould; forming said flexible, tight foil on said first mould to a helmet liner shaped product with a quantity of hollow protrusions and cavities, in which said helmet liner shaped product exhibits undercut relative to said first mould; consolidating said helmet liner shaped product with a quantity of protrusions and cavities on said first mould to form a consolidated helmet liner shaped starting product; removing said consolidated helmet liner shaped starting product and said flexible slip mould with said outward protruding forms from said rigid head-shaped main mould; collapsing and removing said flexible slip mould with said outward protruding forms from said consolidated helmet liner shaped product.