Manufacturing method for double walled container

A manufacturing method of double walled container, comprising:

• preparing a parison having a rigid outer layer and a flexible inner layer,
• enclosing the parison within a mold including split mold halves, thereby forming a molded parison including a pre-blow cylindrical section, a pre-blow bottom section, a bottom projection, and a lower parison excessive burr,
• blowing gas into an inside of the molded parison, thereby forming a blown parison including a cylindrical section and a conical bottom section, the conical bottom section including the bottom projection, and
• removing the lower parison excessive burr from the blown parison,
• wherein the flexible inner layer is fixed to the rigid outer layer in the bottom projection, and
• wherein the split mold halves comprise mold cylindrical sections for forming the cylindrical section, mold conical bottom sections for forming the conical bottom section, mold bottom projection forming sections for forming the bottom projection, and parison excessive burr receiving recesses for receiving the lower parison excessive burr.