| 摘要 |
PURPOSE:To produce the titled film which is uniformly dyed even in the width direction, by heat-treating a hydrophilic polymer film with a difference in temperature in the width direction and then dyeing the film. CONSTITUTION:Part of a hydrophilic polymer film such as cellophane is cut off in the width direction and dyed without heat-treating it. Unevenness in dyeing depth in the width direction is measured and the relationship between the heat treating temperature and the heat treating time in the width direction is established on the basis of the measured values. The hydrophilic polymer film is heat- treated with such a distribution of temperature in the width diretion that the temperature is higher with an increase in the dyeing depth and the temperature is lower with a decrease in the dyeing depth. The film is then dyed by immersing it in a dyeing soln. contg. a natural and/or synthetic edible color, and dried. |
