GB2419885A

GB2419885A - Thermoresistant molding or spinning material

Info

Publication number: GB2419885A
Application number: GB0600707A
Authority: GB
Inventors: Reiner Buettner; Frank Wendler; Gerhard Graness; Frank Meister; Waldemar Dohrn
Original assignee: Thueringisches Institut fuer Textil und Kunststoff Forschung eV
Current assignee: Thueringisches Institut fuer Textil und Kunststoff Forschung eV
Priority date: 2003-07-11
Filing date: 2004-06-09
Publication date: 2006-05-10
Anticipated expiration: 2024-06-09
Also published as: AT504005B1; WO2005007946A1; GB0600707D0; DE10331342A1; GB2419885B; GB2419885C; DE10331342B4

Abstract

The invention relates to a method for producing thermally stable molding or spinning solutions containing cellulose, an aqueous stable tertiary amine oxide, preferably N-methylmorpholine-N-oxide (NMMO), a non-solvent for cellulose, especially water, stabilizers, and property-modifying additives. Said molding or spinning solutions are spun into cellulosic fibers according to the dry-wet extrusion process or drawn into films. The invention is characterized in that one or several stabilizers are provided at quantities of at least 0.01 percent by weight relative to the spinning solution, said one or several stabilizers containing polymer-bound groups for binding metal ions and/or aldehyde in a sufficiently alkaline spinning solution.

Description

Thermostable molding or spinning compound

Description

The invention relates to a method of producing thermostable molding or spinning solutions that contain cellulose, an aqueous stable tertiary aminoxide, preferably N-methylmorpholine-N-oxide (NMMO), a nonsolvent for cellulose, particularly water, stabilizers, and optionally various additives for modifying properties and that are spun into cellulosic fibers or drawn into sheets in a dry-wet extrusion process. S..

S S..

Tertiary aminoxides have been known as solvents from US patent 2,179,181. These aminoxides are not very thermos table. For example, Nmethylmorpholine--N-oxide decomposes into N-methylmorpholine, morpholine, N- formylmorpholine, formaldehyde, and CO2. Stability can be further reduced by heavy metal ions such as iron and copper (Ferris et al, J. Org. Chern., 33, page 3493 (1968), Taeger et al, Formeln, Faserstoffe, Fertigware, 4, pp. 14 - 22 (1985)) . However, metal ions cannot be excluded due to the raw materials and the design of the plant used.

This set of general conditions can pose a certain risk to the manufacturing and molding of aminoxide cellulose solutions, typically performed at temperatures in the range from 90 to 130 C, in that uncontrolled exothermic reactions may occur that are determined by additives, reaction products, and environmental conditions (exothermics). This problem is significantly increased if additives are intermixed with the molded article to modify its properties. For example, a weakly acidic ion exchanger was added to the spinning solution to produce an ion exchange fiber. Thermostability of this solution was substantially lower than that of a non-modified solution. A similar observation was made when producing a fiber modified with activated carbon.

The criterion used for assessment was onset temperature.

In the cases mentioned above, onset temperature sank by approximately 20 C to approximately 130 C. Onset temperature is the temperature that indicates the point at which the spinning solution starts to disintegrate.

In addition to risks posed by process engineering aspects, increased thermal instability of the aminoxides also causes economic setbacks when recycling the solvent.

Not only aminoxide is decomposed but cellulose as well, which adversely affects the properties of the molded pieces.

DD 158656 describes a method for reducing cellulose decomposition in aminoxide-containing cellulose solutions. Substances are added to the solution or aminoxide that have a aminoxide-reducing effect. Amines, urea, hydroxylamine, hydrazine, sulfites, thiosulfates, dithionites, thiourea, sulfur, aldehydes, and reducing sugars are named as suitable substances here. Using these substances does not result in sufficiently stable spinning solutions.

To reduce the decomposition of cellulose in aminoxide- containing solutions, DE 3034685 proposes adding organic compounds having a minimum of four carbon atoms, a minimum of two conjugated double bonds, and a minimum of two hydroxyl and/or amino groups with at least one unsubstjtuted hydrogen atom and/or containing glyceraldehyde. DE 3034685 mentions propyl gallate as the most effective stabilizer.

According to DD-A-02l8104, this method has disadvantages as the cellulose solution changes its color or reaction products of the additives mentioned above accumulate in it during aminoxide recycling. Furthermore, these additives do not effectively prevent additional cellulose decomposition catalyzed by iron compounds and other "S contaminants. * 2 I..

According to DD-A-0229708, cellulose solutions in Nmethylmorpholine-N-oxjde can be stabilized to withstand * thermooxidative decomposition by adding substituted * phenols, preferably 2,6-di-tert.-butyl-p-cresol. The stabilizing effect however does not make the spinning solution stable enough.

According to E-P-A-0l11518, cellulose solutions in Nmethylmorpholjne-N-oxide can be thermally stabilized by adding phosphoric acid and phosphonic acid or salts thereof. According to DD-A-0229708, this stabilizing effect is not sufficient.

It is known from DD-A-02l8l04 that thermostable cellulose aminoxide solutions can be obtained by adding one or more alkaline substances in quantities between 0.1 and 10 percent by weight in relation to the cellulose solution to the aminoxide. Recommended substances are alkali hydroxides such as sodium hydroxide, alkaline salts such as Na2CO3 as well as organic nitrogen bases.

WO 95/23827 explains that increased thermostability of the spinning solution can be obtained using an aqueous aminoxide solution set to a pH value in the range from 10.5 to 13.5 using sodium hydroxide for dissolving the cellulose.

EP 0670917 Bi discusses that adding alkaline substances will not prevent cellulose decomposition if the thermal load acts for a longer period of time. - I..

Thus alkaline stabilization as such is not suitable to meet both requirements, i.e. to prevent aminoxide decompositions and cellulose decomposition.

EP 0670917 Bl proposes to stabilize the spinning solution by adding one or several stabilizers that have an antioxidative effect on cellulose and a sufficient alkaline effect.

The solutions proposed in the patents mentioned above for stabilizing spinning solutions exclusively refer to spinning solutions that do not contain extra additives for modifying the molded pieces.

Adding such additives often makes the spinning solution more unstable and therefore increases the risk of exothermjc reactions of the spinning solution.

Tests with spinning solutions modified with weakly acidic ion exchangers that were stabilized according to the state of the art using propyl gallate and sodium hydroxide solution showed a reduced onset temperature and caused exothermjc reactions during the extruding process.

Spinning solutions modified with activated carbon led to similar results. In addition to the reduction of the onset temperature, the viscosity of the spinning solution also drops considerably due to cellulose decomposition.

It is not possible to subject these solutions with their known stabilization status to a spinning process.

It is the object of this invention to develop a method for producing thermostable cellulose-amjnoxjde solutions 41* modified with additives that effectively suppresses the See, * 20 risk of exothermjc reactions of the molding or spinning solution, to produce molded regenerate cellulose pieces * with a sufficiently high degree of polymerization, and to * keep aminoxide decomposition low. C. JC

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This object of the invention is achieved by adding one or several polymerbound stabilizers with binding properties for metal ions alone and/or aldehyde-binding properties in quantities of at least 0.01 percent by weight in relation to the cellulose solution to a molding or spinning solution containing cellulose, an aqueous tertiary aminoxide, a nonsolvent for cellulose and optionally additives for property modification and being set to a sufficiently alkaline pH. These stabilizers can be used alone or mixed with other complexing agents and alkaline substances. The invention is based on the finding that the binding of metal ions such as Fe2, Fe3 and Cu, Cu2 and the binding of formaldehyde can significantly reduce the decomposition of NI'INO and cellulose and therefore the risk of exothermic reactions.

These substances are preferably added when the molding or spinning solution is prepared. The alkali salts of weakly acidic chelating iminodiacetjc acid bound to styrene- divinylbenzene copolymer or polymer-bound carboxyl groups or alkali salts thereof are used as polymer-bound stabilizers for the selective binding of metal ions. A benzylamine bound to styrene-divinylbenzene copolymer is used to bind aldehydes, in particular formaldehyde.

Sufficient alkaline pH setting of the molding or spinning solution is achieved using alkali hydroxides, alkaline I...

earth hydroxides and alkaline salts as well as organic nitrogen bases.

The mash-modified molding or spinning solution is * *1 preferably set to a pH value between 11 and 12. If molding or spinning solutions are modified with additives for achieving special fiber characteristics, the pH value of the mash may be lower than 11 to 12. If the molding or spinning solution is charged with weakly acidic ion exchangers such as acrylic acid-divinylbenzene copolymer with bound carboxylic acid groups for producing ion exchange fibers, the pH value is at 9 to 10. Similar conditions exist when producing fibers that show increased water retention capacity called superabsorbers, which is achieved by incorporating weakly cross-linked polyacrylic acid neutralized by up to 60% with sodium hydroxide solution.

As is known, a drop in pH value results in destabilization of the N-O bond in NMMO and increased decomposition as well as a significantly increased risk of exotherrnjc reactions (EP 0670917 Bl).

Modification of the molding or spinning solution with activated carbon also results in increased formation of acids that reduce the pH value and can therefore make the molding and spinning solution very unstable.

Increased thermal decomposition of NNNO and decrease of the DP of cellulose is taking place in these molding or spinning solutions.

It turned out that the stability of modified spinning solutions can be improved considerably by the stabilization of the spinning solution with polymer-bound stabilizers for selective binding of metal ions and aldehydes. Pro-rata addition of other complexing agents such as propy]. gallate, ethylenediamjne tetraacetic acid dipotassiurn salt and glycine as well as organic bases such as hydroxylamine or benzylamine can enhance the : effect of the polymer-bound stabilizers.

Studies have also shown that adding a polymer-bound * stabilizer for binding metal ions causes a significant * 30 improvement of the stability of the molding or spinning solution if the latter is set to a sufficiently alkaline pH. The same applies for the polymer-bound stabilizer that binds aldehydes, in particular formaldehyde. Both stabilizer types should be combined for best results. Use of the stabilizers according to the invention significantly increases the thermostability of modified molding or spinning solutions.

Only the use of these stabilizers and reduction of the risk of exothermic reactions makes it possible to subject the molding or spinning solutions modified with weakly acidic ion exchangers, superabsorbers such as partially neutralized weakly cross-linked polyacrylic acid, with activated carbon and other neutral adsorbers to a spinning process.

In addition, this reduces the loss of NNNO that is being recycled. Another advantage is that the stabilizers according to the invention reduce the decomposition of cellulose accordingly when it is dissolved in N1iNO and processed, especially when using additives such as weakly acidic ion exchangers, activated carbon and superabsorbers on the basis of polyacrylic acids whose carboxylic groups may in part be neutralized with sodium or potassium ions.

The invention is described in more detail with reference to the examples below which however do not limit the * invention in any way. The testing methods used for assessing the stability of the cellulose solutions will briefly be outlined below.

* 30 Testing methods for assessing the thermostability of spinning solutions: ** S * S S * S a S.....

S

Dynamic viscosity Dynamic viscosity (zero shear viscosity) was measured using a Rheostress 100 rheometer with a TC 500 temperature control unit by Haake (85 C reference temperature) . The measurements were performed immediately after preparing the molding or spinning solution.

Mini autoclave The molding or spinning solutions were tested for accelerated exothermic decomposition reactions using RADEX safety calorimeters by System Technik Deutschland GmbH. Both temperature and the increase in pressure are measured. 2 g of the molding or spinning solution are weighed into a closed steel vessel (test pressure 100 bar, burst disk).

Two methods of measurement were used to track temperature and pressure development: 1. dynamic method The sample is heated via a ramp (heating rate 0.75 cal/mm) from room temperature to 300 C The lowest Tonset temperature at which the substance to be tested shows a visual increase in pressure (dp/dt) is : . determined to assess sample stability. a... *e * S I 555

2. Isoperiboljc method (long-term test) The sample is kept at a constant temperature of 140 C for 24 hours. Thermostability is characterized using the pressure curve. The maximum increase in *..SSS

I

pressure dp/dt in bar/mm over time in h at which the peak occurs is recorded.

UV/VIS method UV/VIs spectroscopy was the chosen method to evaluate kinetic changes in molding or spinning solutions. The absorption spectroscopic changes were examined as a function of temperature at a wavelength range from 200 to 600 nm and as a function of time at a constant wavelength of 400 nm. A cuvette with temperature control was designed for this purpose that met the special requirements of such samples and inserted in a tJV-2401 PC spectrometer by Shimadzu. Thermostability testing was performed using a PID controller (varistor type K, AT 0.1 K) at a heating capacity of the cuvette of 50 W and a thickness of the optical layer of 350 m. The isothermic temperature profile from ambient temperature to 150 C was freely selectable for absorption spectra and time curves.

120 C proved to be the most suitable reference temperature for comparing molding or spinning solutions.

The UV-ViS spectrometer measured sample changes via the extinction change AE.

The assessment criteria used were derived by comparing the extinction curve over time of a stable molding or :,:::. spinning solution with that of accelerated exothermic decomposition reaction: Initial rise (AE/At)50 after 50 minutes and change (AE)400 after 400 minutes. I* * * * * * *

I * I

Measurement of color changes: The color changes that occur in molding or spinning solutions were determined from an eluate with water at a 1: 3 ratio. 10 g of the comrninuted molding or spinning solution were mixed at ambient temperature with 30 ml distilled water and the eluate obtained was measured in extinction after 48 h at a wavelength of 470 nm to determine the E(470) value.

Formaldehyde detection Formaldehyde was detected after preparing the molding or spinning solution. 5 ml of aqueous eluate (see UV/VIS method) were mixed with 4 ml acetonitrile and 0.5 ml 2,4- dinitrophenyl hydrazine solution and filled up to a quantity of 10 ml with distilled water. The solution is measured after one hour using HPLC with a liv 340 diode array detector (by DIONEX).

Stabilization of spinning solutions that were modified with additives: Various additives such as ion exchangers, superabsorbers and neutral adsorbers are added to the molding or ::::. 25 spinning solutions to modify the properties of lyocell fibers. The stabilizing effect of the stabilizers used * according to the invention will be illustrated below with * ***** * reference to selected examples: :. 30 *

S

Modifjcajon with ion exchangers When adding ion exchangers, it was found that particularly ion exchangers with acidic groups such as COOH groups and -503H groups can reduce the thermostability of the molding or spinning solution.

Table 1 shows the stabilizing effect of the stabilizers of the invention using the example of a weakly acidic ion exchanger.

The molding or spinning solutions listed in Table 1 were prepared in a laboratory kneader.

Procedure:

Examples

Example I

227.3 g 49.6% NI1NO (N-methylrnorpholine_N_oxide) were placed in a laboratory-type kneader and 13.9 g spruce cellulose with a residual moisture of 7.5 percent by weight and a degree of polymerization (DP) of approx. 495 and 12.80 g of a weakly acidic ion exchanger are added.

The reactor was closed and the mash was stirred at room temperature for 15 minutes, then a 30 mbar vacuum was applied. The temperature in the kneader was raised in steps to 90 C. The dissolution process was completed : .. after 240 minutes. S... *5*5 * S * S..

The testing methods described such as dynamic viscosity, *..

* a miniautoclave tests and the tJv/VIS method were applied to test the stability of each spinning solution. I. S * S S * .

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The aqueous eluates were measured by absorption spectrometry at a wavelength of 470 nm to evaluate the chromophores that had formed in the molding or spinning solution. Other stability criteria used included the quantity of formaldehyde that had formed and the pH value in the aqueous eluate of the spinning solution.

Example 2

Solution 2 was prepared in a similar way as described in Example 1. 0.06 percent by weight of propyl gallate and 0.04 percent by weight of sodium hydroxide solution in relation to the spinning solution were added for stabilization.

Example 3

Solution 3 was prepared in a similar way as described in Example 1. 0.21 percent by weight styrene-divjnylbenzene copolymer with chelating iminodiacetjc sodium salt(SDI) and 0.21 percent by weight styrenedivinylbenzene copolymer-bound benzylamine (SDB) were used for stabilization. * .. * I * St.. * . e*.

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* S.... * S

II S * S S * a

S

SSSSS a S

Table 1:

Example Dynamic Minlautoclave Viscosity [Pas] dp/dt T0 { C] [bar/mm] t [hi 1 9,423 0.0109 140 2 11,650 0.0124 149 3 12,170 0.0091 156

Table 2:

Examp tJV/VIS 120 C HCHO pH le concen- value tration iE50.ioo LE400 E470 [mg/i] 1 >5 - 0.043 26 7.2 2 >5 - 0.065 19 7.1 3 0.22 1.46 0.014 1.5 7.2 * ** * . * S... __________ _________________ *5 50 * . S...

The DP of the cellulose cannot be measured directly if there are solid particles in the molding or spinning solution. Therefore, the viscosity of the molding and spinning solution must be used as a measure for evaluating the DP decrease of the cellulose. The

SISSSS

S S

viscosity comparison after preparing the spinning solution shows that the stabilizers of the invention according to Example 3 best stabilize cellulose decomposition. Pressure increase is lowest in the minjautoclave and reaches its peak after 10 hours only.

Onset temperature also reaches its highest value at 156 c.

Analysis of Table 2 shows the test using the UV/VIS method. The spinning solutions according to Examples 1 and 2 showed an exothermic reaction after less than 100 minutes while the spinning solution according to Example 3 keeps running until the measurement is aborted after 400 minutes. Figure 1 shows the measured curves.

Measurement of the eluate reveals reduced chromophore formation in Example 3. Formaldehyde formation is significantly lower for spinning solution 3 than for spinning solutions according to Examples 1 and 2.

Formaldehyde release is viewed in the context of NMMO degradation and cellulose decomposition (Th. Rosenau, A. Potthast, H. Sixta, P. Kosma; The chemistry of side reaction and byproduct in the system NNMO/cellulose (Lyoceliprocess), Prog. Polym. Sci. 26., 1763 (2001)) :* 25 Modification with superabsorbers (such as partially neutralized weakly cross-linked polyacrylic acid) * *

Example 4

196 g NMMO (49.6%) and 13.73 g spruce cellulose with a * S S * 30 residual moisture of 7.5 percent by weight and a DP of a.'...

S S

approx. 495 were placed in the reactor and dissolved according to Example 1. When the solution preparation process is finished, 6.59 g superabsorber are suspended in 19.3 g NMMO (80.2%) and added to the spinning solution.

Example 5

Solution 5 was prepared in a similar way as described in Example 4. 0.06 percent by weight of propyl gallate and 0.04 percent by weight of sodium hydroxide solution, in relation to the spinning solution, were added for stabilization.

Example 6

Solution 6 was prepared in a similar way as described in Example 4. Stabilization was performed like in Example 3.

Example 7

Solution 7 was prepared in a similar way as described in Example 4. 0.04 percent by weight sodium hydroxide solution, 0.03 percent by weight propyl gallate and 0.1 percent by weight styrene-divinylbenzene copolymer with chelating iminodiacetic sodium salt (SDI), and 0.10 percent by weight hydroxylamine were added for I'S.

stabilization.

* S *.

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0***II * I The results of the tests are shown in Tables 3 and 4 and in Fig. 2. I* * 8 I S

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Table 3:

Example Dyn. Miniautoclave Viscosity [Pas] dp/dt T0 [ C] [bar/mini t [hi 4 1,092 0.0152 151 7.5 1,288 0.0125 155 6 1,669 0.0166 157 7 1,325 0.0055 163

Table 4:

Example tJV/VIS 120 C HCHO PH value concentra t ion E50_100 iE400 E470 [mg/li 4 0.40 >5 0.046 37 7.7 * I. a S * I.. _______________ 0.04 -- 0.141 15 7.7 * * asia 6 0.13 1.37 0.017 5.0 7.8 * a S __________ 7 0.06 0.91 0.020 0.28 7.5 I. * a S S * * * S*s.

The superabsorber on polyacrylate basis introduced has comparably destabilizing COOH groups. It is shown again (Examples 6 and 7) that cellulose and NNNO decomposition are lowest with the stabilization according to the invention. Thermostability is clearly improved.

Fig. 2 shows the stability curve. An unstabilized spinning solution shows an exothermic reaction after approx. 300 minutes. Inhomogenejtjes that resulted in abortion of the measurement occurred after 180 minutes in the spinning solution stabilized with propyl gallate and sodium hydroxide solution. The spinning solutions stabilizing according to the invention show good thermostability.

Modification with neutral adsorbers (such as activated carbon) Spinning of molding or spinning solutions modified with activated carbon has particularly high stability requirements. Sufficiently stable spinning solutions were obtained only after using suitable weakly reactive activated carbons and performing the stabilization according to the invention. Weakly reactive carbons were selected empirically using the methods listed under Testing methods". Weakly reactive activated carbons were used in the Examples 8 to 11 included here. The results * I....

* obtained are shown in Tables 5 and 6 below. * S * S

S 30

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* * 4**l

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Example 8

Solution 8 was also prepared in a similar way as described in Example 1. 227.3 g 49.6% NNNO were placed in a laboratory reactor and 13.9 g spruce cellulose with a residual moisture of 7.5 percent by weight and a degree of polymerization (DP) of approx. 495 and 6.45 g of a weakly reactive activated carbon were weighed in.

Example 9

Solution 9 was prepared in a similar way as described in Example 8. 0.06 percent by weight of propyl gallate and 0.04 percent by weight of sodium hydroxide solution, in relation to the spinning solution, were added for stabilization.

Example 10

Solution 10 was prepared according to Example 8. 0.21 percent by weight styrene-divinylbenzene copolymer with chelating iminodiacetic sodium salt (SDI) and 0.21 percent by weight styrene-divjnylbenzene copolymer-bound benzylamine (SDB) were used for stabilization according

to Example 3.

I'. Example 11 I.. S

Solution 11 was prepared in a similar way as described in Example 8. 0.06 percent by weight propyl gallate, 0.04 SSsIIS * percent by weight sodium hydroxide solution, and 0.21 percent by weight styrene-divinyl copolymer-bound benzylam ne (SDB) were used for stabilization.

The results obtained are shown in Tables 5 and 6 below.

Table 5:

Example Dyn. Miniautoclave Viscosity [Pasi dp/dt T0 [ Ci [bar/mini t [hi 8 1,168 0.0176 142 9 1,372 0.0114 154 1,551 0.00867 156 11 1,409 0.0060 160

Table 6:

Example 1JV/VIS HCHO pH value C concentration E470 [mg/li 8 0.035 46 7.4 I. U * U. 9 0.009 24 8.0 * I a 0.005 2.8 7.8

S

asia sa a S 11 0.004 2.1 8.5 S. S * I * * I a

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Analysis reveals that the stabilizers according to the invention (Examples 10 and 11) produce the highest viscosity of the spinning solution and clearly reduce formaldehyde formation. Reduced formaldehyde formation indicates less NNMO decomposition. The pressure increases over time shown in Fig. 3 are clearly lower for Examples and 11, which indicates improved thermostability of the spinning solutions. * I. * I I S... *111 * S S...

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Claims

Claims 1. A thermostable molding or spinning compound containing

cellulose, an aqueous tertiary aminoxide, a nonsolvent, stabilizers and additives for modifying properties wherein one or several stabilizers that contain polymer-bound groups for metal ion binding and/or aldehyde binding in a sufficiently alkaline spinning solution are contained in quantities of at least 0.01 percent by weight in relation to the spinning solution.
2. The molding or spinning compound according to claim 1 wherein the metal ion binding stabilizer is a styrene-divinylbenzene copolymer with weakly acetic chelating iminodiacetjc groups or alkaline salts thereof bound to the polymer or carboxylic groups bound to the polymer or alkaline salts thereof.
3. The molding or spinning compound according to claim 1 * wherein the aldehyde-binding stabilizer is a styrene- divinylbenzene copolymer-bound benzylarnmine. **** * S
4. The molding or spinning compound according to claim 1 S.....

* wherein the polymer-bound stabilizers are used as stabilizers either alone or in a mixture with hydroxide ions. * 30

**.S..

*
5. The molding or spinning compound according to claim 4 wherein the polymer-bound stabilizers are used in combination with propyl gallate and hydroxylamine.
6. The molding or spinning compound according to claim 2 wherein alkali hydroxide, alkaline earth hydroxide and/or an amine are used as alkaline stabilizers.
7. The molding or spinning compound according to one or several of the preceding claims 1 to 6 wherein N- methylmorpholine-N_oxide is used as a tertiary aminoxide.
8. A method for producing a molding or spinning compound wherein said compound is prepared by suspending cellulose and adding ion exchangers or activated carbon to an aqueous tertiary aminoxide and by adding stabilizers according to one or several of the preceding claims 1 to 7 and by evaporating water using a vacuum in a kneader or filmtruder.
9. A method for producing a molding or spinning compound wherein said compound is prepared by suspending cellulose and adding stabilizers according to one or several of the preceding claims 1 to 8 and by evaporating water using a vacuum and heat up to a * concentration of 75 to 85 percent by weight of tertiary aminoxide, adding the superabsorber, and S... * S

homogenization in a kneader or filmtruder.

S 5.us5 * S *5 5 * S I * .

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