Treatment of flexible webs with liquids cong. reagents - including preheating of web before impregnation

摘要

Sheet matls. in web form, e.g. paper, pulp, fabric, felt or other non-woven matls. are impregnated with substances in soln., dispersion or emulsion form after preheating to temps. substantially higher than that of the treating medium. Impregnating liq. penetrates more deeply and more rapidly into the inner structure of the web. In addn. the process has appreciable economic advantages, since the preheating can be used e.g. to dry, heat set or preshrink the web. When heat-sensitive matls. are being applied, an appreciable shortening of the coagulation time is achieved and economy in heat at this stage is achieved.