| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for treating the internal surface of a fluororesin tube which enables continuous treatment, is excellent in productivity and workability, causes neither a deterioration in a treating soln. nor a treatment spot, and in addition enables the treatment to be carried out using a liq. ammonia solution of an alkali metal having large treatment effect. SOLUTION: A fluororesin tube 2 is closed at two points by means of closing members 3, 4 to form a treatment zone 5, a treating soln. 6 of an alkali metal in liq. ammonia is filled into the tube in the treatment zone 5, and the tube 2 is travelled while cooling the treatment zone 5 to a temperature of the b.p. of ammonia or below to continuously treat the internal surface of the fluororesin tube. Particularly pref., a plurality of treatment zones 5, 12, 15, 17 are continuously provided, and a detergent 18 is filled into the treatment zones 12, 15, 17 located downstream of the treatment zone 5 filled with the treatment soln. 6 to wash the internal surface of the tube 2. |
