INJECTION MOLDING METHOD

PROBLEM TO BE SOLVED: To provide an injection molding method capable of producing a molded body of a thermoplastic resin or a thermoplastic resin composite material with high appearance at a high cycle.SOLUTION: Provided is an injection molding method comprising: a first step where, using a die 100 including first temperature adjustment means 13, 23 capable of at least cooling cavity faces 31, 32 and second temperature adjustment means 14, 24 capable of at least heating the cavity faces at the sides opposite to the cavity faces of the first temperature adjustment means, the cavity faces are heated up to a heating temperature more than the melting point or glass transition temperature of a thermoplastic resin, and the thermoplastic resin is filled into the die; and a second step where, after the first step, it is temperature-reduced to a cooling temperature below the melting point or glass transition temperature of the thermoplastic resin to cool and solidify the thermoplastic resin, and subsequently, the die is released to take out a molded body, in which the temperature increasing rate in the first step is controlled to 80°C/min or more, the temperature decreasing rate in the second step is controlled to 100°C/min or more, and also, a difference between the heating temperature and the cooling temperature is controlled to 50°C or more.SELECTED DRAWING: Figure 1 【課題】熱可塑性樹脂または熱可塑性樹脂複合材料の成形品を外観良く、ハイサイクルで製造することができる射出成形方法を提供する。【解決手段】キャビティ面31,32を少なくとも冷却することができる第一の温度調節手段13,23と、第一の温度調節手段のキャビティ面とは反対側に、キャビティ面を少なくとも加熱することができる第二の温度調節手段14,24とを備える金型100を用い、キャビティ面を熱可塑性樹脂の融点又はガラス転移温度以上の加熱温度まで昇温して熱可塑性樹脂を金型内に充填する第一の工程と、第一の工程後、熱可塑性樹脂の融点又はガラス転移温度未満の冷却温度まで降温して熱可塑性樹脂を冷却固化し、その後、金型を開放して成形体を取り出す第二の工程とを備える射出成形方法であり、第一の工程における昇温速度を80℃/分以上とし、第二の工程における降温速度を100℃/分以上とし、かつ加熱温度と冷却温度との差を50℃以上とする。【選択図】図１