Title of Invention	A METHOD AND A DEVICE FOR THE CONTINUOUS PRODUCTION OF AN EXTRUSION SOLUTION
Abstract	ABSTRACT IN/PCT/2002/00471/CHE A process and a device for controlling the composition of solution (s) The present invention relates to a process and a device for controlling the composition of solution (s) for the manufacture of cellulosic shaped bodies, comprising (a) mixing cellulose pulp and a water containing aminoxide with formation of a suspension, (b) forming a cellulose solution from the suspension by evaporation of water, (c) extruding the cellulose solution through an air gap into a precipitation bath, containing an aqueous aminoxide solution, and the cellulose solution coagulates there to form shaped bodies, (d) conducting the shaped bodies through an aqueous washing solution in which remaining aminoxide is washed out from the shaped bodies, (e) returning aqueous aminoxide solution from stage (c)and/or (d) after concentration to stage (a), in which a property of the solutions is measured and according to the measured value the composition of the solutions is controlled, characterized in that at least one non-optical property of one of the said solutions is measured and the deviation(s) from the measured value respectively values from a predetermined reference value is used for the regulation of the composition(s) of these solutions, in which the property of the solution is chosen from the relative permittivity, the inductive conductivity, microwave absorption, the density, the water content and the ultrasonic speed.

Title of Invention

A METHOD AND A DEVICE FOR THE CONTINUOUS PRODUCTION OF AN EXTRUSION SOLUTION

Abstract

ABSTRACT IN/PCT/2002/00471/CHE A process and a device for controlling the composition of solution (s) The present invention relates to a process and a device for controlling the composition of solution (s) for the manufacture of cellulosic shaped bodies, comprising (a) mixing cellulose pulp and a water containing aminoxide with formation of a suspension, (b) forming a cellulose solution from the suspension by evaporation of water, (c) extruding the cellulose solution through an air gap into a precipitation bath, containing an aqueous aminoxide solution, and the cellulose solution coagulates there to form shaped bodies, (d) conducting the shaped bodies through an aqueous washing solution in which remaining aminoxide is washed out from the shaped bodies, (e) returning aqueous aminoxide solution from stage (c)and/or (d) after concentration to stage (a), in which a property of the solutions is measured and according to the measured value the composition of the solutions is controlled, characterized in that at least one non-optical property of one of the said solutions is measured and the deviation(s) from the measured value respectively values from a predetermined reference value is used for the regulation of the composition(s) of these solutions, in which the property of the solution is chosen from the relative permittivity, the inductive conductivity, microwave absorption, the density, the water content and the ultrasonic speed.

Full Text	The invention relates to a process and a device for controlling the composition of solution(s) in the production of cellulosic shaped bodies, in which (a) cellulose pulp and an aminoxide containing water are mixed under formation of a suspension, (b) a cellulose solution is formed from the suspension under the evaporation of water, (c) the cellulose solution is extruded through an air gap into an aqueous precipitation bath and there coagulates to form mouldings, (d) the form mouldings were conducted through an aqueous washing solution, in which remaining aminoxide is washed out of the form mouldings, and (e) aqueous aminoxide solutions from stage (c) and/or (d) after concentration leads back to stage (a), in which a property or physical behavior of the solution is measured, and on the basis of the measured value the composition of the solutions are regulated. The invention also relates to a device for the performance of this process with a mixing apparatus equipped with metering elements, a dissolving and evaporation device connected to the mixing apparatus, and an extrusion device connected via a line to the dissolving and evaporation device, with a downstream precipitation bath, at least one washing bath, containing a strongly diluted, aqueous aminoxide solution, a device for the measurement of one property of the solutions with the purpose of controlling their composition. When mention is made in general in the present invention of a property to be measured of the cellulose solution, this should also be understood to include a measurable physical behaviour of the solution. The properties of the cellulosic mouldings manufactured in accordance with the aminoxide process, in particular the textile physical properties of the spun fibres and filaments, depend to a large degree on the composition of the extrusion solution. In .order to maintain the optimum properties it is therefore desirable for the composition of the solution to be monitored and for fluctuations to be kept within narrow limits. In a continuous process like the present Aminoxide-Process its monitoring is of importance for an economic running. It is important , to measure also the concentration of the aminoxide solutions in stage (c) , (d) and (e) and to regulate the composition of the solution. From WO 94/28212 the principle is known of taking a sample from time to time of the spinning solution flowing to the extrusion apparatus, and of measuring its refractive index, which at 60 °C should lie in the range from 1.4 890 to 1.491, in order to obtain extrusion products with satisfactory-properties. It is also known to keep the refractive index of the aminoxide solution in certain limits. Thereafter the refractive index of the aqueous aminoxide solution of the precipitation bath at 60 °C could lie in a range of 1,3644 to 1,3708, whereas for the concentrated aminoxide solution for the formation of the cellulose suspension the refractive index could lie in a range from 1,4620 to 1,4628, without activation of the metering elements or changings in the evaporation conditions. The monitoring of the refractive index of the solution in a more or less wide range does not allow the exact regulation of the composition of the solution. In addition this process does not work in case of solutions with strong lightabsorbtion and /or -diffraction. The SP 0254 803 shows a process for the production of an aqueous, pure N-Methylmorpho line -N- oxide -solution by reaction of Methylmorpholine with an aqueous Hydrogen peroxide, in which mixtures of Methylmorpholin and water were destillated, the aceotrop of Methylmorpholine and Water at temperatures from 60°C to 100°C was reacted with an aqueous Hydrogenperoxide- solution and the reaction solution is afterwards concentrated to the desired N-Methylmorpholine-N-oxide content. The concentration of the so obtained endproduct can be monitored through measurement of the refractive index or density, in which the endproduct is slightly yellow coloured and as unpurities, nearly undetectable amounts of peroxide, Methylmorpholine and carboxylic groups could be present. The objective on which the present invention is based is of creating a process for the manufacture of cellulosic mouldings according to the aminoxide process, in which the composition of the spinning solution can be precisely monitored. The regulation of the composition of the spinning solution should be more precisely than it is possible to do this on the basis of a range of refractive indices. In addition to this, a process is to be created for the manufacture of cellulosic mouldings according to the aminoxide process in which the composition of the spinning solution can be regulated with the shortest possible delay, so that any fluctuations which arise in the composition can be kept within narrow limits. Especially a process is to be V^^Acreated for the manufacture of cellulosic mouldings ~ v according to the aminoxide process, in which the composition of the different solutions occuring during the course of the process could be regulated even when the measurement of the refrative index is useless, because the light absorbtion or -diffraction of the solutions is to strong. Finally, a device is to be created to carry out the process, by means of which the changes in the composition of the solutions of the aminoxid process, in fact both the spinning solutions and the cellulose free, aqueous aminoxide solutions, could be kept in narrow limits or be eliminated.Further advantages can be derived from the following description. This objective is achieved with the process described in the preamble, according to the invention, that a non-optical property of, at least one of the mentioned solutions is measured and the deviation(s) of the measured value from a certain reference-composition is used for regulating the composition(s) of this/these solution(s). Differing from the above mentioned process including the measurement of the refractive index, according to the invention the deviation of the measured value is given in a narrow limit of tolerance. Deviations of the measured value to the reference value directly set off an intervention at the metering elements of the regulating circuit. The process according to the invention accordinly allows for a substantially stricter regulation of the solution composition than is possible, when the regulation is just activated, when the measured value is leaving the tolerance limit. The measurement of a non-optical property of the solutions does not require the transperancy of the solutions for the wavelength used. So also spinning solutions, which contain defined proprotions of additives, such as titandioxide, colour or filling material and aminoxide solutions obtained in course of the process, which are deep coloured because of the impurities, could be controlled and regulated in concern to their concentration. According to the preferred embodiment of the process according to the invention, the non-optical property of the solution is selected from among the dielectricity constant, the (electric) conductivity, the microwave intensity and -speed, the density, the water content, and the ultrasonic speed. In Process, transparent and non-transparent solutions could be controlled by the measurement of the same property, so the expenditure of measurement and regulation is minimized.The water content can be determined according to the Karl Fischer method. According to the preferred embodiment of the process the temperature of the cellulose solution is measured at or shortly before or after the measurement of one of the mentioned properties of the solution and the measured value is compensated on the basis of the measured temperature. Because the temperature of the spinning solution may variate, the measured values must be converted to the reference temperature at which the property values or behaviour values of the spinning solution of the reference composition are known, with which the measured values are to be compared. This reference temperature, to which the measured values are converted, is, for example, 50 °C or 60 °C. For preference the property of the solution is measured in¬line. The in-line measurements allow not only for a rapid determination of the composition of the solution, but also reduce the safety risk engendered by the propensity to decomposition of the solution, due to the possible onset of runaway reactions in hollow spaces of the line (for example in the pipe for taking samples). In one embodiment of the process according to the invention, recourse is made to the regulation of the composition of the solution in the metering of the components in stage (a),(b) respectively(d) . If, for example, a change in the composition of the spinning solution is determined by measurement of the properties, intervention in the metering system of the components cellulose and/ or solvent NMM0/H20 is necessary. For the correction of the composition of the precipita.tion bath solution, it could be necessesary .to make a recourse of the metering system of the introduced washing solution or to change the dosage of water to the washing solution. In another embodiment, recourse is made to the operating conditions of the stage (b) or/and stage (e) regulating the composition of the solution. If the results disclose a shift in the proportion .of NMMO/HaO, this can be corrected in the stage (b), by the water evaporation being throttled or increased in this stage. The concentration of the aqueous aminoxide solution to be led back in stage (a) , can also be regulated by a recourse made in stage of concentration, respectively evaporation. The objective is further resolved with the device according to the invention, referred to in the preamble, in that in line or in a container, containing the solution to be controlled, a measuring device for the measurement of a non-optical property of the solution is arranged, and that the measuring device together, in line with metering elements or the evaporation device forms a regulating circuit for regulation of the composition of the solution. The measuring device delivers a measured value of the solution, for example the dielectricity constant or the density, which is transformed into signals for the manipulation elements , for example the metering speed of metering elements or the change in the heat performance of the evaporation apparatus. For preference, the measuring device comprises a device for measuring the temperature of the solution and for temperature compensation of the measured values of the measuring devices. The measuring device accordingly delivers measured values which are already temperature-compensated so that a direct comparison is possible with the property values of the spinning solution of the reference composition, related to a specific temperature. The invention is described in greater detail hereinafter on the basis of the drawing. The single Figure shows the schematic flow chart of an embodiment of the device according to the invention. Cellulose pulp containing water and a NMMO/HjO mixture are introduced via metering system 1 into a continuous pulping device 2. The device 2 may be a multi-shaft device, such as has been described in DE-C 198 37 210.8. Connected downstream of the device 2 is a dissolving device 3, in which the suspension formed in 2 is transformed into a solution by the addition of heat and under-pressure, under water evaporation.A suitable process for this is known from DE-A 44 41 468.8. Connected to the dissolving device 3 via a line 8 is an extrusion mould 4, through which the spinning solution is extruded via an air gap into a precipitation bath 5. Depending on the type of the extrusion mould and the operations which follow, films, fibres, filaments, or other moulding can be obtained. The moulding 6 acquired in this way is conducted via a withdrawal element 7 for a washing stage 10, in which remaining aminoxide is washed out of the moulding 6. According to the invention, a measuring device 9 is arranged in the line 8 between the dissolving device 3 and the extrusion mould 4 for the measurement of a non-optical property, for example dielectricity constant or the density of the solution. The measuring device delivers a temperature-compensated signal to a microprocessor 12, which detects deviations from the reference solution and gives manipulation signals via signal line 13 to the metering element la for cellulose and via signal line 14 to the dissolving and evaporation device 2. It is obvious from the drawing , that the washing solution coming from the washing stage 10 via line 24 is introduced into the precipitation bath container 5- A measuring device 11 in this line is detecting the composition of the used washing solution in line 24 and regulates via signal line 18 with the microprocessor 16 the valve 17 for the addition of water to washing stage 10. The used precipitation solution is introduced via line 19, which is also containing a cleaning device (not shown), into a evaporation stage 20, in which the the solution is evaporated to a given aminoxide-concentration. The concentration of the evaporated solution is, via measurement of a property by a measuring device 21 and comparison of measured with the reference value via processor 22, transformed into a manipulating signal, which is used for manipulation of the evaporation conditions in evaporation stage 20 via signal line 23. WE CLAIM: 1. A process for controlling the composition of solution (s) for the manufacture of cellulosic shaped bodies, comprising (a) mixing cellulose pulp and a water containing aminoxide with formation of a suspension, (b) forming a cellulose solution from the suspension by evaporation of water, (c) extruding the cellulose solution through an air gap into a precipitation bath, containing an aqueous aminoxide solution, and the cellulose solution coagulates there to form shaped bodies, (d) conducting the shaped bodies through an aqueous washing solution in which remaining aminoxide is washed out from the shaped bodies, (e) returning aqueous aminoxide solution from stage (c)and/or (d) after concentration to stage (a), in which a property of the solutions is measured and according to the measured value the composition of the solutions is controlled, characterized in that at least one non-optical property of one of the said solutions is measured and the deviation(s) from the measured value respectively values from a predetermined reference value is used for the regulation of the composition(s) of these solutions, in which the property of the solution is chosen from the relative permittivity, the inductive conductivity, microwave absorption, the density, the water content and the ultrasonic speed. 2. The process according to claim 1, wherein the temperature of the solution is measured at or shortly before or after the measurement of the property and the measured value of the property is compensated on the basis of the measured temperature. 3. The process according to claims 1 and 2, wherein the property is measured in-line. 4. The process according to claims 1 to 3, wherein recourse is made to the regulation of the composition of the solution in the metering of the components in stage (a), (c) or(d). 5. The process according to claims 1 to 4, wherein recourse is made to the operating conditions in stage (b) and/or (e) for the regulation of the composition of the solutions. 6. A device for carrying out the process according to any of the claims 1 to 5, comprising a pulping device (2) equipped with metering elements (la, 1^), connected to a dissolving and evaporation device (3), an extrusion {device (£) connected via a line (8) to said dissolving and evaporation device (3), with a downstream precipitation bath (5), at least one washing bath, containing a diluted aqueous aminoxide solution, and devices for the measurement of a property of the solution(s) to control their composition, characterized in that, that in the line (8, 19, 24) or in a container, containing the solution to be controlled, a device (9, 21, 11) for the measurement of a non-optical property of the solution is positioned, and that the measuring device together with upstream metering elements (la, lb; 17) or evaporation devices (3; 20) forms regulating circuits (13, 14, 15; 18; 23) for the regulation of the composition of the solution. 7. The device according to claim 6, wherein the measuring device (9, 11, 21) comprises a device for measuring the temperature of the solution and a temperature compensation of the measured value of the measuring device.

Full Text

The invention relates to a process and a device for controlling the composition of solution(s) in the production of cellulosic shaped bodies, in which (a) cellulose pulp and an aminoxide containing water are mixed under formation of a suspension, (b) a cellulose solution is formed from the suspension under the evaporation of water, (c) the cellulose solution is extruded through an air gap into an aqueous precipitation bath and there coagulates to form mouldings, (d) the form mouldings were conducted through an aqueous washing solution, in which remaining aminoxide is washed out of the form mouldings, and (e) aqueous aminoxide solutions from stage (c) and/or (d) after concentration leads back to stage (a), in which a property or physical behavior of the solution is measured, and on the basis of the measured value the composition of the solutions are regulated.
The invention also relates to a device for the performance of this process with a mixing apparatus equipped with metering elements, a dissolving and evaporation device connected to the mixing apparatus, and an extrusion device connected via a line to the dissolving and evaporation device, with a downstream precipitation bath, at least one washing bath, containing a strongly diluted, aqueous aminoxide solution, a device for the measurement of one property of the solutions with the purpose of controlling their composition. When mention is made in general in the present invention of a property to be measured of the cellulose solution, this should also be understood to include a measurable physical behaviour of the solution.

The properties of the cellulosic mouldings manufactured in accordance with the aminoxide process, in particular the textile physical properties of the spun fibres and filaments, depend to a large degree on the composition of the extrusion solution. In .order to maintain the optimum properties it is therefore desirable for the composition of the solution to be monitored and for fluctuations to be kept within narrow limits. In a continuous process like the present Aminoxide-Process its monitoring is of importance for an economic running. It is important , to measure also the concentration of the aminoxide solutions in stage (c) , (d) and (e) and to regulate the composition of the solution.
From WO 94/28212 the principle is known of taking a sample from time to time of the spinning solution flowing to the extrusion apparatus, and of measuring its refractive index, which at 60 °C should lie in the range from 1.4 890 to 1.491, in order to obtain extrusion products with satisfactory-properties. It is also known to keep the refractive index of the aminoxide solution in certain limits. Thereafter the refractive index of the aqueous aminoxide solution of the precipitation bath at 60 °C could lie in a range of 1,3644 to 1,3708, whereas for the concentrated aminoxide solution for the formation of the cellulose suspension the refractive index could lie in a range from 1,4620 to 1,4628, without activation of the metering elements or changings in the evaporation conditions. The monitoring of the refractive index of the solution in a more or less wide range does not allow the exact regulation of the composition of the solution. In addition this process does not work in case of solutions with strong lightabsorbtion and /or -diffraction.

The SP 0254 803 shows a process for the production of an aqueous, pure N-Methylmorpho line -N- oxide -solution by reaction of Methylmorpholine with an aqueous Hydrogen peroxide, in which mixtures of Methylmorpholin and water were destillated, the aceotrop of Methylmorpholine and Water at temperatures from 60°C to 100°C was reacted with an aqueous Hydrogenperoxide- solution and the reaction solution is afterwards concentrated to the desired N-Methylmorpholine-N-oxide content. The concentration of the so obtained endproduct can be monitored through measurement of the refractive index or density, in which the endproduct is slightly yellow coloured and as unpurities, nearly undetectable amounts of peroxide, Methylmorpholine and carboxylic groups could be present.
The objective on which the present invention is based is of creating a process for the manufacture of cellulosic mouldings according to the aminoxide process, in which the composition of the spinning solution can be precisely monitored. The regulation of the composition of the spinning solution should be more precisely than it is possible to do this on the basis of a range of refractive indices. In addition to this, a process is to be created for the manufacture of cellulosic mouldings according to the aminoxide process in which the composition of the spinning solution can be regulated with the shortest possible delay, so that any fluctuations which arise in the composition can be kept within narrow limits. Especially a process is to be V^^A*created for the manufacture of cellulosic mouldings *~ v according to the aminoxide process, in which the composition of the different solutions occuring during the course of the process could be regulated even when the measurement of the refrative index is useless, because the light absorbtion or -diffraction of the solutions is to strong. Finally, a device is to be created to carry out the process, by means of which the changes in the composition of the solutions of

the aminoxid process, in fact both the spinning solutions and the cellulose free, aqueous aminoxide solutions, could be kept in narrow limits or be eliminated.Further advantages can be derived from the following description.
This objective is achieved with the process described in the preamble, according to the invention, that a non-optical property of, at least one of the mentioned solutions is measured and the deviation(s) of the measured value from a certain reference-composition is used for regulating the composition(s) of this/these solution(s). Differing from the above mentioned process including the measurement of the refractive index, according to the invention the deviation of the measured value is given in a narrow limit of tolerance. Deviations of the measured value to the reference value directly set off an intervention at the metering elements of the regulating circuit. The process according to the invention accordinly allows for a substantially stricter regulation of the solution composition than is possible, when the regulation is just activated, when the measured value is leaving the tolerance limit. The measurement of a non-optical property of the solutions does not require the transperancy of the solutions for the wavelength used. So also spinning solutions, which contain defined proprotions of additives, such as titandioxide, colour or filling material and aminoxide solutions obtained in course of the process, which are deep coloured because of the impurities, could be controlled and regulated in concern to their concentration.
According to the preferred embodiment of the process according to the invention, the non-optical property of the solution is selected from among the dielectricity constant, the (electric) conductivity, the microwave intensity and -speed, the density, the water content, and the ultrasonic speed. In Process, transparent and non-transparent solutions could be controlled by the measurement of the same property,

so the expenditure of measurement and regulation is minimized.The water content can be determined according to the Karl Fischer method.
According to the preferred embodiment of the process the temperature of the cellulose solution is measured at or shortly before or after the measurement of one of the mentioned properties of the solution and the measured value is compensated on the basis of the measured temperature.
Because the temperature of the spinning solution may variate, the measured values must be converted to the reference temperature at which the property values or behaviour values of the spinning solution of the reference composition are known, with which the measured values are to be compared. This reference temperature, to which the measured values are converted, is, for example, 50 °C or 60 °C.
For preference the property of the solution is measured in¬line. The in-line measurements allow not only for a rapid determination of the composition of the solution, but also reduce the safety risk engendered by the propensity to decomposition of the solution, due to the possible onset of runaway reactions in hollow spaces of the line (for example in the pipe for taking samples).
In one embodiment of the process according to the invention, recourse is made to the regulation of the composition of the solution in the metering of the components in stage (a),(b) respectively(d) . If, for example, a change in the composition of the spinning solution is determined by measurement of the properties, intervention in the metering system of the components cellulose and/ or solvent NMM0/H20 is necessary. For the correction of the composition of the precipita.tion bath solution, it could be necessesary .to make a recourse of the metering system of the introduced washing

solution or to change the dosage of water to the washing solution.
In another embodiment, recourse is made to the operating conditions of the stage (b) or/and stage (e) regulating the composition of the solution. If the results disclose a shift in the proportion .of NMMO/HaO, this can be corrected in the stage (b), by the water evaporation being throttled or increased in this stage. The concentration of the aqueous aminoxide solution to be led back in stage (a) , can also be regulated by a recourse made in stage of concentration, respectively evaporation.
The objective is further resolved with the device according to the invention, referred to in the preamble, in that in line or in a container, containing the solution to be controlled, a measuring device for the measurement of a non-optical property of the solution is arranged, and that the measuring device together, in line with metering elements or the evaporation device forms a regulating circuit for regulation of the composition of the solution. The measuring device delivers a measured value of the solution, for example the dielectricity constant or the density, which is transformed into signals for the manipulation elements , for example the metering speed of metering elements or the change in the heat performance of the evaporation apparatus.
For preference, the measuring device comprises a device for measuring the temperature of the solution and for temperature compensation of the measured values of the measuring devices. The measuring device accordingly delivers measured values which are already temperature-compensated so that a direct comparison is possible with the property values of the spinning solution of the reference composition, related to a specific temperature.

The invention is described in greater detail hereinafter on the basis of the drawing. The single Figure shows the schematic flow chart of an embodiment of the device according to the invention.
Cellulose pulp containing water and a NMMO/HjO mixture are introduced via metering system 1 into a continuous pulping device 2. The device 2 may be a multi-shaft device, such as has been described in DE-C 198 37 210.8. Connected downstream of the device 2 is a dissolving device 3, in which the suspension formed in 2 is transformed into a solution by the addition of heat and under-pressure, under water evaporation.A suitable process for this is known from DE-A 44 41 468.8. Connected to the dissolving device 3 via a line 8 is an extrusion mould 4, through which the spinning solution is extruded via an air gap into a precipitation bath 5. Depending on the type of the extrusion mould and the operations which follow, films, fibres, filaments, or other moulding can be obtained. The moulding 6 acquired in this way is conducted via a withdrawal element 7 for a washing stage 10, in which remaining aminoxide is washed out of the moulding 6.
According to the invention, a measuring device 9 is arranged in the line 8 between the dissolving device 3 and the extrusion mould 4 for the measurement of a non-optical property, for example dielectricity constant or the density of the solution. The measuring device delivers a temperature-compensated signal to a microprocessor 12, which detects deviations from the reference solution and gives manipulation signals via signal line 13 to the metering element la for cellulose and via signal line 14 to the dissolving and evaporation device 2.

It is obvious from the drawing , that the washing solution coming from the washing stage 10 via line 24 is introduced into the precipitation bath container 5- A measuring device 11 in this line is detecting the composition of the used washing solution in line 24 and regulates via signal line 18 with the microprocessor 16 the valve 17 for the addition of water to washing stage 10. The used precipitation solution is introduced via line 19, which is also containing a cleaning device (not shown), into a evaporation stage 20, in which the the solution is evaporated to a given aminoxide-concentration. The concentration of the evaporated solution is, via measurement of a property by a measuring device 21 and comparison of measured with the reference value via processor 22, transformed into a manipulating signal, which is used for manipulation of the evaporation conditions in evaporation stage 20 via signal line 23.

WE CLAIM:
1. A process for controlling the composition of solution (s) for the manufacture of
cellulosic shaped bodies, comprising
(a) mixing cellulose pulp and a water containing aminoxide with formation of a suspension,
(b) forming a cellulose solution from the suspension by evaporation of water,

(c) extruding the cellulose solution through an air gap into a precipitation bath, containing an aqueous aminoxide solution, and the cellulose solution coagulates there to form shaped bodies,
(d) conducting the shaped bodies through an aqueous washing solution in which remaining aminoxide is washed out from the shaped bodies,
(e) returning aqueous aminoxide solution from stage (c)and/or (d) after concentration to stage (a), in which a property of the solutions is measured and according to the measured value the composition of the solutions is controlled, characterized in that at least one non-optical property of one of the said solutions is measured and the deviation(s) from the measured value respectively values from a predetermined reference value is used for the regulation of the composition(s) of these solutions, in which the property of the solution is chosen from the relative permittivity, the inductive conductivity, microwave absorption, the density, the water content and the ultrasonic speed.

2. The process according to claim 1, wherein the temperature of the solution is measured at or shortly before or after the measurement of the property and the measured value of the property is compensated on the basis of the measured temperature.
3. The process according to claims 1 and 2, wherein the property is measured in-line.

4. The process according to claims 1 to 3, wherein recourse is made to the regulation
of the composition of the solution in the metering of the components in stage (a), (c)
or(d).
5. The process according to claims 1 to 4, wherein recourse is made to the operating
conditions in stage (b) and/or (e) for the regulation of the composition of the solutions.
6. A device for carrying out the process according to any of the claims 1 to 5, comprising a pulping device (2) equipped with metering elements (la, 1^), connected to a dissolving and evaporation device (3), an extrusion {device (£) connected via a line (8) to said dissolving and evaporation device (3), with a downstream precipitation bath (5), at least one washing bath, containing a diluted aqueous aminoxide solution, and devices for the measurement of a property of the solution(s) to control their composition, characterized in that, that in the line (8, 19, 24) or in a container, containing the solution to be controlled, a device (9, 21, 11) for the measurement of a non-optical property of the solution is positioned, and that the measuring device together with upstream metering elements (la, lb; 17) or evaporation devices (3; 20) forms regulating circuits (13, 14, 15; 18; 23) for the regulation of the composition of the solution.
7. The device according to claim 6, wherein the measuring device (9, 11, 21) comprises a device for measuring the temperature of the solution and a temperature compensation of the measured value of the measuring device.

Documents:

in-pct-2002-0471-che abstract.pdf

in-pct-2002-0471-che claims.pdf

in-pct-2002-0471-che description (complete).pdf

in-pct-2002-0471-che drawings.pdf

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Patent Number

201808

Indian Patent Application Number

IN/PCT/2002/471/CHE

PG Journal Number

05/2007

Publication Date

02-Feb-2007

Grant Date

28-Aug-2006

Date of Filing

02-Apr-2002

Name of Patentee

ZIMMER AG

Applicant Address

BORSIGALLE 1, D-60388 FRANKFURT AM MAIN,

Inventors:

#	Inventor's Name	Inventor's Address
1	NIEMZ, Frank-Günter	Breitscheidstr. 148 07407 Rudolstadt
2	MEYER, Wilhelm	Breitscheidstr. 148 07407 Rudolstadt
3	MAINZER-ALTHOF, Tanja	Breitscheidstr. 148 07407 Rudolstadt

PCT International Classification Number

C08B1/00

PCT International Application Number

PCT/DE00/03409

PCT International Filing date

2000-09-29

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	19947908.9	1999-10-06	Germany