Patent ID: 8795566

Claim:
A multi-component injection moulding method for producing a sleeve-shaped preform ( 1 ) which has at least two layers ( 2 , 2 a , 2 b , 3 ) and an open end and an opposing closed end wherein the closed end comprises an outer surface, said method comprising at least two process steps including at least two cavities and at least one injection mould core that can be used for both cavities, said method characterised in that: during the first process step, the first layer ( 2 , 2 a , 2 b ), which has at least one first ( 2 a ) and at least one second area ( 2 b ) extending partially in the circumferential direction of the preform, is injected onto the injection mould core within the first cavity, wherein the first cavity has at least one depression to form at least one protrusion of the first area ( 2 a ), wherein said at least one depression extends from an inner surface of the cavity essentially in a radial direction towards the outside of the cavity and said at least one protrusion extends outward from surrounding surfaces of the first area, with the second area ( 2 b ) having a substantially lower layer thickness than the first area ( 2 a ), and during the second process step, in the second cavity the second layer ( 3 ) is deposited on the first layer ( 2 , 2 a , 2 b ) which is located on the injection mould core in the second cavity in such a way that only the second area ( 2 b ) of the first layer ( 2 , 2 a , 2 b ) is completely covered by the second layer ( 3 ) and the first area ( 2 a ) is formed by the at least one protrusion, wherein the closed end of the preform comprises a continuous region of both the first layer and the second layer, and wherein the second layer constitutes the outer surface of the closed end of the preform.