高速ヒートサイクル成形（RHCM）では，金型温度を成形樹脂の Tg もしくは HDT より高くすることで金型の転写性や光沢レベルを向上するだけでなく，型内圧力を制御することによりシンクマークやウェルドの消去が可能である．工業的に高速かつ省エネルギーのヒートサイクルを達成するためには，蒸気や加圧水，また誘導加熱が用いられている．これらのうち前記の 2 種類は原理的に同じものであり，加熱もしくは冷却された媒体を交互に用いることによりヒートサイクルを達成する．蒸気は最大 200℃と加圧水の 180℃より高くかつ流量が大きく取れることに特徴があるが，加圧水は元々金型との熱伝達が高いため，結局両者の総括的な熱伝達係数は同等のものとなる．これらの方法は金型の最高到達温度が媒体の温度に制限されることと，媒体からの熱流束が金型温度の上昇にしたがい低下するために均一加熱が難しいという短所を持つ．

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The mechanical properties of poly(lactic acid) (PLA)/polycarbonate (PC) blend were improved considerably by addition of both poly(butylene adipate-co-terephthalate) (PBAT) and dicumyl peroxide (DCP) as a radical coupling agent for PLA and PBAT. In this work, the authors aimed to grasp meltdown properties of PLA/PBAT with/without DCP by (1) clarifying the effect of addition of DCP on the melt viscoelatsic properties of PLA/PBAT, and make this ternary system more suitable by (2) optimizing additive contents and (3) investigating the effect of fabrication processes on mechanical properties and morphologies of the blends. The growth curves of G' and G'' for PLA/PBAT (70/30) (wt/wt) with/without DCP measured by a rheometer suggested that branching and cross-linking structures were formed by hetero-and/or homogeneous radical coupling reactions. The elongation at break of the ternary reactive blend with DCP 0.30 phr (PLA/PBAT/PC blend with DCP) increased up to 160%, which was much better than that with other DCP contents. Moreover, the value of standard deviation for the ternary reactive blend was smaller. Furthermore, PLA/PBAT/PC ternary polymer blends were prepared through a twin-screw extruder with an L/D ratio of 75, and their physical and meltdown properties were investigated. The domain size of the reactive blend with an L/D ratio of 75 was smaller than that of 45, however, the impact strength of the blend with an L/D ratio of 75 decreased with increasing rotation speed of the extruder. Moreover, the MFR of the blend increased with increasing rotation speed of the extruder as well. As the MFR of PC prepared under same condition of blending did not change, so this suggested that PLA/PBAT components of the ternary blends were degraded in higher shear rate. As a result, the impact strength of the ternary blends decreased as well.

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