Joining structure of bubble board, information display means, educational toy and double box

摘要

PROBLEM TO BE SOLVED: To provide a new junction structure of a foam board, using a foam board itself, and information display means, an intellectual training toy and a double box each having the junction structure of the foam board.SOLUTION: A junction structure 1 of a foam board includes a foam board 2 with a projection, having a back sheet 21 and a cap sheet 22, and having a projection 24 comprising a cap 23 of the cap sheet 22, and a foam board 3 with a recess, having a liner sheet 31 and a cap sheet 32, and having a recess 34 comprising a cap 33 of the cap sheet 32, and is so constructed that the foam board 2 with the projection and the foam board 3 with the recess are joined by inserting the projection 24 into the recess 34.