Abstract: A method for producing a transfer mixture by the direct dissolution method in a thin film evaporator (D) having a feed, a housing and a discharge, wherein the feed introduces a product consisting essentially of cellulose, water and a functional liquid into the housing, wherein an evaporator shaft (5) situated in the housing (4) rotationally wipes the product over the heated interior of the housing (4), wherein the product heats up and some of the water evaporates, so that the transfer mixture is obtained, wherein (a) the transfer mixture is discharged before the product substantially overheats; and (b) all heating surfaces of the thin film evaporator in contact with the product are subjected to a heating temperature, which is at least 20K above the temperature of the product.

Abstract: The invention relates to a thin film evaporator (D) for producing a transfer mixture according to the direct dissolution method, having a feed (1), a housing (4) and an outlet (2), wherein the feed (1) introduces a starting material, made of cellulose, water and a functional fluid, into the housing (4), wherein an evaporator shaft (5) situated in the housing (4) rotatingly sweeps the starting material over the heated interior of the housing (4), wherein the product is heated and some of the water evaporates so as to result in the transfer mixture, which flows to the outlet (2) together with a supply stream, wherein the through-flow capacity of the outlet (2) is greater than the supply stream.

Abstract: Mixing kneader for processing a transfer mixture into a molding solution, according to the direct dissolution method, having a feed, a housing and a discharge, wherein the feed introduces a product consisting essentially of cellulose, water and a functional liquid into the housing, wherein a kneader shaft situated in the housing rotationally mixes and kneads the product and sweeps wipes it over heated inner surfaces of the mixing kneader, wherein reducing the amount of undissolved particles in the product and the size of the particles are reduced, and evaporating some of the water evaporates to produce form a molding solution, wherein the process volume of the mixing kneader is determined only by the requirements of a molding solution flow capacity.