| 摘要 |
PROBLEM TO BE SOLVED: To efficiently remove saponification catalyst residues from a water- containing molten or semi-molten ethylene/vinyl alcohol copolymer (EVOH) resin by feeding the EVOH resin into an extruder, pouring a washing fluid into the extruder to wash the resin, and discharging the washing fluid from at least one port downstream of the pour port of the washing fluid. SOLUTION: A water-containing molten or semi-molten EVOH is sent forward by means of a full-flighted section 5, and water as a washing fluid is fed from a washing fluid pour port 2. Next, the EVOH is dehydrated by squeezing excessive water at a fluid removal section 3. During the removal of the excessive water, saponification catalyst residues in the production process are removed by washing. The temperature of the molten resin in the extruder is kept in the range of 70-170 deg.C. The water content of the molten resin in the extruder is adjusted so that the water content of the resin just after discharge from the extruder may be 5-40 wt.%, and the extrudate is cut.
|
