| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a forming method of a thin-walled molded product capable of forming a light guide plate for a liquid crystal of a medium or larger size. <P>SOLUTION: A thin-walled molded product is formed by using an injection device (2) composed of a heating cylinder (5) and a screw (6). Firstly, dies (20, 21) are placed in a state of being opened by a predetermined amount, and a screw (6) is driven in the axial direction to inject molten resins in cavities. The dies (20, 21) are clamped to compress the injected molten resins. During compression, the screw (6) is retracted by a predetermined time to lower the resin pressure of the molten resins in the cavities. Thereafter, a driving force in the axial direction is applied to the screw (6) to perform the pressure application of applying the predetermined resin pressure to the molten resins. The drive of the screw (6) during the pressure application may be subject to speed control, and then, switched to pressure control. <P>COPYRIGHT: (C)2012,JPO&INPIT |
