US Patent 7798806 Two-piece bottom insert for a mold cavity

A bottom insert for an injection mold, which insert is of a two-part configuration having a hot part which has a recess of the hot side and a cold part which has a recess of the cold side, wherein the cold part is arranged at least partially within the hot part so that the hot part at least portion-wise surrounds the cold part. The two parts of the bottom insert are preferably separable and the. hot part preferably has an opening in opposite relationship to the recess of the hot side for receiving the cold part. Further, the cold part and the hot part are desirably sealed off relative to each other, desirably by O-rings. In general, all surfaces which are provided for contact with the molding to be produced are arranged at the cold part. An insulating coating, an insulating membrane and/or a spacing element is desirably provided at the contact surface between the hot part and the cold part.