Abstract: A wiper blade rubber is provided, which has low sliding resistance against a glass surface, hardly generates creak and chatter, has good flexibility and bending property at low temperatures, has excellent durability, and has good design property. The wiper blade rubber has a main body, at least an outer surface of which is coated with a silicone rubber, and a wiping layer comprising a high-hardness organic rubber provided by on a tip portion of the main body at a contact side to a glass surface.

Abstract: A casting method and apparatus using a resin core wherein a portion of a wall of the resin core that receives a greater heat and/or load than other portions of the wall of the resin core, is increased in thickness. As a result, even if the resin core receives more heat and/or load in places, a local deformation or breakage of the resin core is effectively prevented.

Abstract: A casting method is disclosed in which a resin core is fabricated by using a resin which maintains a mechanical strength satisfying a shape accuracy required for a cast product until solidification of molten metal in contact with the core and is softened when heated beyond the core temperature at which the molten metal in contact with the core was solidified. The removal of the resin core from the cast product after the cast product containing the core from a die, includes a step of forcedly cooling the cast product containing the core down to a predetermined temperature at which the resin core can be removed from the cast product without being broken apart by pulling one of its ends, and a step of withdrawing the core at the predetermined temperature from the cast product having been forcedly cooled down. It is thus possible to cool the core down to a predetermined temperature suited for the withdrawal and preclude the inconvenience that the core being pulled is broken apart.