| 摘要 |
PROBLEM TO BE SOLVED: To prevent warp deforming of a multilayer wall due to a difference of shrinkage factors of primary and secondary plastic materials in a multilayer dichroic molding. SOLUTION: This molding comprises recesses 3, 4 partitioned by a partition wall 5 on front and rear surfaces of a surface wall of a molding wall 1. The recesses 3, 4 are filled with forming plastic materials, and a front wall 7 and rear wall 8 of the same shape and size are formed. And, a stress generated between the walls 7 and 5 is brought into coincidence with a stress generated between the walls 8 and 5 to cancel both the stresses to one another. |
