BASE MATERIAL FOR EXPANSION MOLDED PRODUCT AND MANUFACTURE OF EXPANSION MOLDED PRODUCT

PROBLEM TO BE SOLVED: To obtain efficiently a molded product requiring an opening at a specific position by omitting the number of excess man days without complicating a shape by a method wherein a small piece part to be inserted for blocking a recessed opening part is separably formed in a base material main body having partially the recessed opening part. SOLUTION: A recessed opening part 15 for storing or equipping other parts such as a console box, a register for air-handling, etc., is formed by being recessed to a rear side at a required position of a surface 12 of a base material main body part 11. A small piece to be insert 21 is for the purpose of blocking the recessed opening part 15 of the base material main body 11 in expansion molding, and separably molded at a specific position of the base material main body part 11. A formed position of the small piece to be insert 21 is allowed to be an underside of a peripheral edge of an opening for a meter 18, and connected to the base material main body part 11 with a connection part 26. By cutting the connection part 26, it is enabled to be separated from the base material main body 11. Since the base material main body is integrated with the small piece to be insert 21, the expansion molded product can be remarkably efficiently manufactured.