Patent ID: 8551778

Claim:
A method for producing a bowl-shaped preform having an inner concave structure made up of a plurality of convex surfaces, comprising the steps of: a) providing a mold made up of at least three submolds, each of which has an exterior side surface, a substantially convex upper surface on an upper end thereof, which substantially convex upper surface forms one of the plurality of convex surfaces of the preform, and at least two contact surfaces on inner sides thereof; b) applying to the exterior side surface, the substantially convex upper surface and the at least two contact surfaces of each of the at least three submolds of step a) at least one fibre layer by electrospinning to form at least three separately electrospun submolds; c) joining together the at least two contact surfaces of the at least three separately electrospun submolds of step b) to form a mold assembly; and d) applying at least one further fibre layer to the exterior surfaces of the at least three submolds of the mold assembly of step c) by electrospinning to obtain the preform.