PURPOSE: To increase bond strength at the time of molding by a method wherein a movable core is intruded into a cavity in the fusing section of a resin material, the flowing of one resin material is regulated temporarily, the movable core is retreated from the inside of the cavity, and the other resin material is flowed to the fusing section, and fused and unified with one resin material.
CONSTITUTION: One resin material A in a plurality of resin materials injected from a plurality of gates is flowed to a fusing section first, and flowing is regulated by a movable core 3 at a position, where the resin material A is flowed. Consequently, since the resin material A is cooled from a surface brought into contact with mold, viscosity distribution, in which viscosity is increased toward the surface side and viscosity is lowered toward the inside, is generated. The movable core 3 is retreated from a cavity 12 under the state, and the other resin material B reaches the fusing section. Since the flowing of the other resin material is not hindered, an approximately uniform temperature is kept and viscotily is also lowered and equalized and has the kinetic energy flowing. Accordingly, the other resin material is intruded into a section having low viscosity in one resin material and fused and unified.
ITO TOSHIYASU
FUNAHASHI RIICHI
MARUI KOSAKU KK