Process for producing a product

Abstract

A method for production of a molded article from a base substance in a device for mixing of the base substance with a solvent is provided. The method includes mixing a base substance to produce a molding solution with the solvent and at least partially removing the solvent from the mixture; and feeding the molding solution to a device for further processing of a product and diluting the molding solution before further processing. In embodiments, the diluent is introduced to the device before a discharge device and/or in the discharge device.

Claims

1. A method for production of a molded article from a base substance, the method comprising: mixing a base substance and a solvent in a reactor to produce a molding solution; at least partially removing the solvent from the molding solution in the reactor; and diluting the molding solution with a diluent to decrease a viscosity of the molding solution; wherein, after at least partially removing the solvent from the molding solution, the diluent is introduced to the molding solution toward an end of the reactor adjacent to a discharge device or in the discharge device of the reactor; and the diluent is introduced to the molding solution prior to a pump associated with the discharge device pumping the molding solution from the discharge device and prior to the molding solution being at least temporarily stored in a buffering vessel; and the diluent is not removed from the molding solution.

2. The method of claim 1, wherein the diluent is introduced to the molding solution toward an end of the reactor adjacent to the discharge device or in the discharge device of the reactor, and the molding solution is held up after the discharge device.

3. The method of claim 1, wherein the concentration of the molding solution or the concentration of the diluent is monitored via an optical index.

4. The method of claim 1, wherein the concentration of the molding solution and the diluent are monitored via an optical index.

5. The method of claim 3, wherein the optical index of the diluent is monitored before introduction to the molding solution or the optical index is monitored in the molding solution after dilution.

6. The method of claim 4, wherein the optical index of the diluent is monitored before introduction to the molding solution and the optical index is monitored in the molding solution after dilution.

7. The method of claim 3, wherein the optical index of the diluent or the molding solution lies at or between 1.40 and 1.50.

8. The method of claim 4, wherein the optical index of the diluent and the molding solution lies at or between 1.40 and 1.50.

9. The method of claim 1, wherein an additive is supplied to the molding solution before the discharge device, in the discharge device, or before the discharge device and in the discharge device.

10. The method of claim 9, wherein the additive is fed together with the diluent.

11. The method of claim 9, wherein the additive is an inorganic material suspended in the diluent.

12. The method of claim 9, wherein the additive is an organic material suspended or dissolved in the diluent.

13. The method of claim 9, wherein the additive is a mixture of different organic and inorganic materials.

14. The method of claim 13, wherein the additive mixture is suspended in the solvent or suspended in the diluent.

15. The method of claim 9, wherein the additive is ground before addition with or without diluent.

16. The method of claim 14, wherein the additive mixture is ground before addition with or without diluent.

17. The method of claim 1, wherein the diluent is tertiary amine oxide.

18. The method of claim 1, wherein the diluent is an aqueous tertiary amine oxide.

19. The method of claim 1, wherein an additive or an additive mixture is supplied to the molding solution before the discharge device, in the discharge device, or before the discharge device and in the discharge device; and the additive or additive mixture is chosen so that it also deliberately influences the properties of the molding solution.

20. The method of claim 1, wherein the diluent is introduced toward the end of the reactor adjacent to the discharge device and in the discharge device of the reactor.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) Additional advantages, features and details of the invention are apparent from the following description of preferred practical examples and with reference to the drawing; the drawing and its only FIGURE shows a block diagram for the process according to the invention for production of molded articles from a base substance, especially from renewable raw materials.

DETAILED DESCRIPTION

(2) The cellulose necessary for this is fed to a kneading reactor 2 by a feed line 1. Such horizontal kneading reactors are known, for example, from DE 199 40 521 A1 or DE 41 18 884. The invention, however, is not restricted to these kneading reactors. All treatment devices in which renewable raw materials can be subjected to treatment for later spinning are embraced by the invention.

(3) In the present practical example treatment of the renewable raw material occurs by means of a solvent, preferably amine oxide monohydrate, which is fed to the kneading reactor via an additional feed line 3.

(4) Intensive mixing of the raw material with the solvent with supply of heat occurs in the kneading reactor 2 and also evaporation of the solvent so that a relatively highly viscous spinning solution is formed. The spinning solution is then optionally fed to a buffer vessel 5 via a discharge device 4. There it is temporarily stored, if necessary, with addition of heat.

(5) However, according to the invention this relatively highly viscous spinning solution is to be diluted before it is optionally fed to the buffer vessel 5 or directly to final processing. According to the invention this occurs in the discharge device 4 or even just before the discharge device 4 in the kneading reactor 2 toward the end of the kneading reactor. A combination of both addition locations is also contemplated.

(6) An additional feed line 6 is provided to add the diluent to the discharge device 4, in which a pump 7 is incorporated. An additional or other feed line for the diluent is indicated by reference number 8. A pump 9 is also incorporated in this feed line 8.

(7) Another pump 14 is incorporated between a discharge 4 and the optional buffer vessel 5 by means of which the molded solution is held up after the discharge.

(8) The method according to the invention is conducted as follows:

(9) Introduction of the base substance, especially the renewable raw material, and the solvent to kneading reactor 2 occurs via feed line 1 and feed line 3. With supply of heat intense mixing occurs, in which case heat supply can occur from the outside by means of a heating jacket, through heated kneading shafts and/or heated kneading elements (disk elements). Further mechanical heat input occurs during mixing itself through the corresponding shear energy. Through the evaporization of the solvent the forming solution (spinning solution) will be concentrated up so that it has such a high amount of the base substance toward the end of the kneading reactor 2 shortly before the discharge device 4, that it is too highly viscous for a later spinning. It is now diluted with a diluent, which is supplied via feed line 8 and/or feed line 6. The concentration of the molding solution and/or the diluent is then monitored via the optical index. This optical index is also referred to as refractive index. It characterizes the refraction (change in direction) and reflection behavior (reflection and total reflection) of electromagnetic waves on encountering an interface between two media.

(10) In the present case the optical index of the diluent before introduction to the molding solution and the optical index in the molding solution after dilution are preferably monitored. The optical index of the diluent and/or molding solution should lie at 1.40 to 1.50.

(11) It is also conceived to supply an additive to the molding solution/mixture before discharge or in the discharge, optionally also via feed line 6 or 8. The additive can also be fed together with the diluent.

(12) As soon as the spinning solution is used, removal of the diluted spinning solution occurs from the buffer vessel 5 and by means of a pump 13 it is forced through a spinning solution filter 10. Homogenization of a spinning solution occurs on this account. The spinning solution can then be temporarily stored in another buffer vessel 11, if necessary. Actual spinning then occurs in a device 12.