Patent ID: 8828299

Claim:
A method of injection moulding a plastics component with a slit including providing a first mould member affording a mould cavity, which is defined by an internal surface, and a second mould member with an external surface whose shape is substantially complementary to the shape of the mould cavity, one of the internal surface and the external surface carrying an elongate formation which defines an elongate apex, advancing the second mould member into the mould cavity such that the apex is spaced from the opposed one of the internal surface and the external surface by a predetermined distance of between 0.0075 and 0.075 mm and the internal surface of the first mould member and the external surface of the second mould member together define a mould space, injecting molten polyolefin material into the mould space to substantially fill it and venting displaced air from the space between the apex and the opposed surface during the injection of the polyolefin material, the predetermined distance being so dimensioned that the polyolefin material does not completely fill the space between the apex and the opposed surface, whereby the slit is formed, wherein the width of the slit is sufficiently small or substantially zero, whereby the edges of the slit form a substantial seal.