摘要 |
For production of a seamless edible cellulose tubing from underivatized cellulose, a solution of the underivatized cellulose in tertiary amine N-oxide, of additives and water, is extruded as tubing from an annular die and conducted through an air gap into a water bath. The cellulose tubing is conducted out of the water bath, cleaned by spraying with heated water and thereafter passed through at least two wash sections and a plasticizing section. After exit from the plasticizing section, the wet cellulose tubing is predried in the laid-flat state, before it is dried to its final moisture. The predryer 13 is arranged vertically or horizontally and consists of an insulated tube to which is fed air heated by a heat exchanger in an accurately metered amount and at a constant temperature of up to 130° C. The main dryer 19 is arranged horizontally and contains tangentially and radially directed air nozzles, the air jets of which keep the inflated cellulose tubing 20 suspended during the drying operation. |