| 摘要 |
PURPOSE:To efficiently and effectively purge resin from an extruder in a short period of time by extruding aromatic polyester resin, the melt viscosity of which is higher than that of thermoplastic resin and which is mixed with water. CONSTITUTION:In order to purge wholly aromatic polyester resin from an molder, the mixture of polyester resin and water is extruded in succession to said polyester resin. The employed aromatic polyester resin is the polyester, which consists of terephthalic acid, isophthalic acid or the like and bivalent diol and the logarithmic viscosity index of which depends upon the resin to be extruded and preferably lies within the range of 0.2-2.0. In addition, the mixing ratio is 0.1-2.0pts.wt. of water to 100pts.wt. of aromatic polyester resin. If the water is less than 0.1pt.wt., enough purging effect is not obtained. On the contrary, if the water exceeds 2.0pts.wt., the intrusion of the mixture to the screw of the molder becomes poor and the purging effect vanishes. Further, the execution of the above-mentioned method after the first purging by wholly aromatic polyester resin containing no moisture may also be done well and can obtain more favorable effect. |
