DE2420812A1 - METHOD AND DEVICE FOR THE RAPID TREATMENT OF PULP TISSUE WITH SALMIA SPIRIT - Google Patents

Description

Cluett, Peabody & Co., Inc.
433 River Street, Troy
fiew York V.St.A.

Method and device for the rapid treatment of cellulose tissue with ammonia

Conventionally, many fabrics have been subjected to an aqueous caustic treatment to fiberize the fabrics mercerize, whereby the pasers swell and are made porous and more accessible, so that the absorption capacity for paints, flammability-reducing substances, resins and the like is improved. However worsen Caustics are many fibers, so there is a need for a more delicate treatment which is the desired Provides mercerization results without fiber deterioration. A caustic mercerization also requires a sustained washing to remove the caustic, and this washing was a disadvantage. Also are suitable from For various reasons, cotton wool and ribbed velvet are not suitable for caustic mercerization.

Ammonia has been used, and is (as in the United States patents

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3,511,591 and 3,347,963) are used been made to make pulp fibers more suitable for shaping close. Attempts at treating pulp tissues with ammonia are in DAS 1,063,572 and in the USA patent 1 998 551 mentioned, but without giving irute results were obtained. In U.S. Patent 3,406,006, ::: it have ammonia treated pulp tissue caused excessive tissue shrinkage. In U.S. Patent 3,560,140 Yarns and threads were treated with ammonia and then stretched to improve strength.

In US Pat. No. 3,664,158, fabrics were treated with ammonia and subjected to transverse stretching to reduce shrinkage, but this attempt to limit fabric shrinkage when treated with ammonia was far from successful. Unfortunately, the application and control of such transverse stretches, especially in the treatment of iifirk goods, were not feasible. Even with fabrics, the tensions required to keep the fabric from shrinking to two percent ( $ 2) were not really feasible, and the difficulty was compounded by the meshing of the fabrics. Ba has been difficult to maintain the width of the fabrics, both because of ammonia shrinkage and because stretching in the warp direction exacerbates the loss of width. In the methods currently used, the tensioning has proven to be unsatisfactory for limiting the shrinkage in the ammonia treatment of cellulose fabrics.

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- 35 -

The simple result aes Yorsteilender "was that Wonn also wässerip-it ATrroniak ÖE: r apparently" useful ^p ÜR an I erzerisatioh of pulp ^ eweben (especially ^ ar .- wanted ^ riliich ^υϊ '- & iM.O-. .ensanrt), a kercerization with aqueous ammonia -is su of the present invention had not yet achieved any economic application.

The task of i-ierization of cellulose fibers n.it 3alü.iak / roist is f as in riinselnen is explained in more detail in the roof hurrying) on particularly new, expedient, iceinenwers obvious and easy way

been elost. It has been found that in one. I'usainmen- ";rin.'T-in of cellulose -weave rait ammoniacal ammonia the G-eweave fibers first swell radially and become porous without any significant shrinkage, whereupon the fibers soon shrink a '" ¹ "' to ^ e. I The present invention provides a method and apparatus for kercerizing pulp webs with aqueous ammonia by soaking the tissues in the ammonia ice and then rapidly removing the ammonia skeleton from the tissues (within about 0.6 to about 9 seconds, preferably within 1.8 to about 3.6 seconds) before the fibers of the fabrics have had any substantial degree of shrinkage.

Accordingly, it is an object of the invention to provide aqueous ammonia instead of an aqueous caustic solution to kercerize To use pulp fibers, so that the fabrics of it one better stretching (or stretching), increased resistance

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BATH ORIGINAL

ochrum oven and wrinkles (or folds) as well, an improved absorption capacity for dyes, the flammability Depressants, resins and the like without deterioration of fibers are obtained.

Another aim of the invention is to achieve certification many fabrics, such as drilled cotton and ribbed velvet, which practically cannot be mercerized by using aqueous caustic solutions.

Yet another aim of the invention is to provide kerzerization to enable knitted fabrics through liquid ammonia.

Another object of this invention is to reduce shrinkage (especially knitted fabrics) with the kercerization To control ammonia.

Veiter it is a goal of the invention, a device of the proposed type to create which one-establishment for the operator to adjust the feed rate of the fabric, and has a device to use the length of the path of the fabric from the impregnation the liquid, i.e. the ammonia, to refine until the beginning of the removal of the ammonia.

Another object of the invention is to reduce voltage requirements so that mechanical requirements of the device are simplified. A reduction of the tensions also reduces the raftbedarf ^ Vo rri CHT un _f ~.

409886/0358 ORIGINAL BATHROOM

Also an object of the invention is the use of a device of the proposed type with a small treatment volume, so that the necessary starting and stopping periods be kept to a minimum.

Finally, it is another object of the invention to provide a device of the proposed type to create, which are economical to build and operate and in the rest of theirs is well adapted to its intended use.

The device is used to carry out a treatment of cellulose fabrics on an industrial basis. In order to This treatment can be carried out, it is necessary that the device is able to handle large lengths of Fabrics with consistent and uniform results safe to process. It is also important that the device be able to weave a wide variety of G, light and heavy, with low or high pulp content, loosely woven or knitted, and tightly woven and knitted, au process.

The drawing shows an embodiment of the invention:

Fig. 1 is a somewhat simplified longitudinal section through a device for carrying out a mercerization of cellulose tissues with aqueous ammonia, Fig. 2 is a somewhat simplified plan view of the device according to Fig. 1,

Fig. 3 is an enlarged schematic side representation a voltage control that has a -i-'eil of the Device forms,

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Έΐξ. 4 shows temporal relationships for shrinkage?: And treatment in the warp direction for a cotton fabric at different tensions,

Fig. 5 shows temporal relationships for shrinkage and treatment in the direction of entry for a cotton weave at different voltages,

Figure 6 shows the barium activity number as a function der - "Ehandlunrszeit with watery Ar.ir.oniak for a cotton fabric,

Figure 7 is a photomicrograph of fibers from an untreated Cotton fabric,

FIG. 8 is a photomicrograph similar to that of FIG. 7 of FIG a 1 second lanp · treated 3au: .woll? e'.vebe,

FIG. 9 is a photomicrograph similar to that in FIG. 7 one Construction roll fabric that treats for 5 seconds was, and

Fig. 10 is a photomicrograph similar to that in ^£ \ i ?. 1 of a cotton fabric treated for 30 seconds.

When a Zellstpffaser in rialmaikzeist - is elegt ^r, the pulp in a similar lioiiie viie swells a pulp aser, which was elegt in an aqueous caustic ", and thereby elicits a Ivierzerisation The characteristic beans form of a pulp fiber turns into a more cylindrical shape. the walls of the fiber become thicker. In this state, the fiber is more receptive to dyes, deflaning retarders, resins and the like and, for the rest, better suited for further processing.

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./erden 7. Al l material fibers are spun into yarn and these yarns are made. If fabrics are woven and then these fabrics are immersed in ammonia, a shrinkage of considerable length takes place. .The shrinkage of most of the commercially available fabrics is un. · "- · asymmetrical with a stronger shrinkage in the warp direction as a puncture of the duration ier .iali.iai'f'eistbohandlung, whereby various tensions are transferred to the Lette for a cotton'-ewebe J-. The curves before; ier 10 if and-load (ΐ, kg) ice -Only 1 pound - "'cl ^ ot'-uig (0.45 kp;) have been empirically determined and found to be on. tensions of 10 nsi (0.7 kp / cm) to:; u 1 psi ( 0, U7 kp / cm) of the fabric width.

The curve referred to as the "unloaded" curve is an extrapolated estimate of the shrinkage that would occur with the "0" load. The ^a round for a zero-load curve that was not determined experimentally was that a non-tensioned tissue sharply folds when it is passed into aqueous ammonia, and therefore a shrinkage is extremely difficult to determine. The Fol ^ to chan "· from FIG. 4 is that a shrinkage are dpannen of iewebes disregard ^r- ehalten can. A similar effect is from Pi .- /. 5 for the shrinkage as a function of the duration of the oalmiak ^£ travel treatment at different tensions in the weft direction for a building wool fabric. Ks reveals that shrinkage is much less sensitive to tension and time in the weft direction than in the warp direction, and this is of great benefit because it is difficult to detect tension in the

409886/0358 BAD ORJGlNAL

To transmit the weft direction. However, it must be taken into account that the general character of the curves in Pig. 4 and 5 are similar, indicating that a similar controller for shrinkage in the weft direction is possible.

The treatment of a cellulose fabric in ammonia can result in undesirable shrinkage, but it also has a mercerization effect. The consequence of swelling of the fibers during mercerization is an increased accessibility of the cellulose, because it is more porous and thus makes you more responsive. The practical advantages of this increased accessibility are a higher capacity for dyes, resin and the like, which (along with other benefits likewise obtained) normally with a Mercerization go hand in hand with aqueous caustic solution ·.

A test method for determining the Merzerisationsgrades is in AATCG 89-1958T containing test check based on the ^x 'atsache that mercerized cotton absorbs more barium than untreated cotton, and therefore barium hydroxide can be used to the G-rad of Maerzerisation quantitatively determine . In using this test, it is important that no other barium ion absorbing materials, such as finishes or other fibers, are present. Carefully washed and cleaned pieces from a sample (and a non-mercerized control piece) are placed in a bath of 0.25 n-barium hydroxide, an alkali, in .einer k

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BATH ORIGINAL

30 cm for two (2) hours at 21 ° C. Ten (10) Each solution is then titrated with 0.1 η hydrochloric acid. The mercerized cotton sample absorbs a greater amount of barium hydroxide than the control sample; therefore if the amount of barium hydroxide that remains in the solution is less, and the amount of hydrochloric acid required for neutralization is smaller. This way it is responsible for neutralization The amount of hydrochloric acid required is a quantitative measure of the amount of barium absorbed. The ratio of from of the mercerized sample results in barium absorbed by the non-mercerized sample, multiplied by 100, the barium activity number. Values from 100 to 105 indicate no mercerization. A number over 150 shows essentially complete mercerization at. Intermediate values usually show an incomplete Reaction or a too weak mercerising bath.

Typically mercerized samples should have a barium activity number of 150 to 160 to be considered properly mercerized. In FIG. 6 isteine envelope of values of designed barium act ivitätszahlen, the materials WUR taken _T to which differently, with ammonia were treated long. Assuming that the curve representing the information obtained falls in the middle of the envelope curve, the designed mean curve approximates it between 0 and 30 seconds.

Because the tests were carried out with samples of cotton fabrics that were larger than

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are moderately large, the specimens actually have, on average, activity for all of their larae, and hence also for the fibers of their irrobes. The microphotographs of the Fip> 7-10 were made of any yarns selected from the respective samples. This G-arne were embedded in a medium carefully selected so as not to interfere with the swelling of the pulp fibers. The samples were then cut into slices in planes perpendicular to the Faaer axis and photographed at five hundred magnifications using light transmitted through the samples.

The photomicrograph of an untreated control pit is in Fio ·. 7 and gives the typical bean shape of cotton fibers again. Some of the fibers appear to be swollen to be and not have the bean shape; but the number of these fibers is small compared to the total number the number of fibers shown in the photomicrograph. The microphotography A coarse yarn that has received ammonia treatment for one (1) second, as shown in Fig. S it shows a number of fibers on the outer surface of this yarn can be seen as swollen fibers, while fibers in have retained their classic bean shape near the center. An examination of the yarn that took five (5) seconds had been treated for a long time, as shown in FIG. 9, and des Yarn treated for thirty (30) seconds as shown in Figure 10 leaves a greater number of fibers antler outer surface appear swollen. The yarns of Figs. 7, 8, 9 and 10 were taken from fabrics containing the

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Points 0, 1, 5 and 30 of the time coordinate in FIG. 6 correspond. There is a significant difference in the degree of swelling (Fiercerization effect), as it is with watery Ammonia treated cotton fibers can be observed when compared with untreated cotton fibers will. That pointer and the steep rise in barium activity versus the duration of the Salm ^ j -kireistbehandlungskurve in Fig. 6 led to a conclusion which was subsequently empirically proven, namely that an advocate Cardiac erosion without undesirable dull effects can be achieved if the duration of the ammonia treatment of the cellulose fibers is kept short enough.

A preferred arrangement of apparatus for carrying out the method according to the invention is in the ig *. 1, 2 and 3 shown. A cream 11 made of cellulose tissue is continuously fed through an ammonia treatment chamber 12 in which a dip box 13, a steering roller 14, a pair of guide rollers 15, a tension regulator 16, a delay system generally designated 17 and a dryer 18 are accommodated Fabric web 11 is led through an entrance closure 19, around a Ketx roller 21 and under a net roller 22 into a container 23 with aqueous ammonia in the immersion box 13 The switch 26 is part of a solenoid 27 which actuates a valve 28 in a line 29. The line 29 feeds the immersion box 13 via a line 31 which opens into a housing 32 surrounding the chamber 12.

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det. During normal operation, a valve 33 is opened and another manual valve 34 is closed. To turn it off, the valve 33 in the line 29 is closed and the valve 34 in the line 31 is opened. If the ammonia in the dip tank 13 has to be changed quickly, the contents can be emptied via a valve 35 and a line 37 into a trough 37 which is provided with a heating coil 38 to allow the ammonia to be drained via the line 39 and an outlet 41 to an incinerator (not shown) or to evaporate. The immersion box 13 can be raised or lowered (as indicated by dashed lines in FIG ^{. 1} Ig. 1) in order to regulate the immersion of the water path 11 in the container 23 with ammonia.

To prevent ammonia leakage, it is desirable to in the ammonia treatment chamber 12 a light Maintain negative pressure. For this purpose the outlet 41 is provided with a suitable suction device (not shown) establishment in connection. The housing 32 is provided with insulating material 42 between an inner liner 43 and a outer liner 44 encased. The ^ inldfrer conclusion 18 and the outlet closure 45 each have a pair of elastic parts and opposing fixed parts 47. In each of the fasteners 19 and 45, the web 11 is between an elastic Part 46 and a fixed part 47 of each pair detected and the space between the two pairs over the Lines 48 and 49 evacuated.

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After the web 11 with the aqueous ammonia in the Dew box 13 has been moistened, it becomes the castor 14, which spreads and smoothes the web, before it passes between the guide rollers 15. From the G-ewebebahn 11 (both by the action of the guide rollers 15 as well as that of the castor 14) removed excess Salmiakgeist is caught in a trough 52 to be returned to the immersion box 13 by gravity. Ton the guide rollers 15, the web is fed to a roller 53 and from there via a series of alternately fixed rollers 54, 55 and movable rollers 56, 57 delivered. This row of rollers represents the delay system 17. - ^ ie movable Rollers 56,57 are movable vertically, as will be discussed in detail, about the length of the web of fabric 11- between the time you started using ammonia is impregnated in the dip box 13, and the time to regulate the removal of the liquid ammonia by drying the G-ewebebahn begins. From the delay system 17 is the fabric web 11 to the heated, with a support provided dryer 18 delivered via a roller 59, over which they on a runner cloth 61 over a roller 62 runs. The runner cloth 61 is endless and is circulated by means of rollers 63 over a heated drum 64 led. The fabric web 11 leaves the drying device 18 over the outlet rollers 65 and exit gate 54 and exits the ammonia treatment chamber 12 off ο -A spraying of the G-ewebebahn with water or steam and renewed drying can also be used afterwards

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that to remove all ammonia that may be in the G-ewebf- ' is left behind.

Fig. 3 shows a mutual connection between the movable ones Rollers 56, 57 and the voltage regulator 16. The movable rollers 56, 57 sit rotatably between a pair of vertically movable support parts 66, of which only one in £ "ig. 3 is visible. A shaft 67 is in a Sleeve 68 screwed to the back of the support part 66 is attached, so that a rotation of the shaft 67 in one direction a downward movement of the carrier part 66 causes, so that the career of the 'rewebebahn 11 is shortened and the web tension is reduced during rotation shaft 67 moves upward in the opposite direction of the carrier part, so that the path of the fabric web 11 is extended and 'the web tension is enlarged. A bevel gear 69 is attached to one end of the shaft 67 and meshes with a bevel gear 71. The wheel 71 is connected to a motor output shaft 72 of a reversible motor M. The engine is of well-known construction and of a type in which the direction of rotation of the motor depends on the direction of current flow either through the armature or the field windings is determined.

Switching devices are between the voltage regulator 16 and the motor M is provided to change its direction of rotation depending on the degree of tension in the G-web web 11 to excite and control so that the movable rollers 56, 57 are automatically raised or lowered accordingly

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to change the web tension or to keep it within a prescribed range. The retention facilities exist from a two-pole contact switch with a pair of fixed contacts 73 »74, which are connected to a terminal clamp and a pair of field contacts 75, 76 connected to the other I-iotor terminal. A pair of newetlicher contacts 77, 78 are movably seated between den i> .ontal: th 73 and 75 or 74 and 76 for an electrical To establish a connection between them.

The movable contact 77 is connected to a positive voltage source and the movable contact 78 is connected to a negative voltage source via a pair of fixed guide rails. i) The guide rails are rotatably arranged to allow the movable contacts 77, 78 to rotate in contact with the fixed contacts. A lever L movably connects the line rails and is connected to the bearing housing of the voltage regulator 16 at its! As a result of this construction, changes in the tension in the web of tissue 11 result in a compression or relaxation of the movable capsule 79, which are accompanied by a corresponding downward or upward movement of the Lafiiergehiiuses. If the .Bahnspanmmg exceeds a certain Vfert, the flexible capsule 79 is compressed enough to let the lever L bring the movable contacts 77, 78 down into contact with the fixed contacts 75 »74, whereby the motor resets and under tension a current flow in the seal of the arrow 1 * is caused to drive the motor M in the direction of the lower carrier

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to let geils 66 circulate. The lowering of the carrier part 66 lowers the orphans 56, 57 in order to reduce the web tension accordingly, and this continues until the tension is reduced enough to lie in the prescribed range at which point the flexible capsule 79 extends extends enough to bring the movable contacts 77, 78 out of engagement with the fixed contacts 75, 74, so that the motor M turns off.

A similar mode of operation results when the j-ewebesprumng falls below a certain ^T , "/ ert, in which case only the flexible capsule 79 expands in order to move the movable contacts 77, 78 upwards into contact with the fixed contacts 73, 76, whereby the motor M is energized and a current is caused to flow in the direction of the arrow ip in order to let the motor run in the other direction and to cause a lifting of the rollers 56, 57 and accordingly to increase the web tension.

The speed of the fabric web can be adjusted in a suitable manner by regulating the speed of the dryer 18 or preferably the guide rollers 15 are taxed.

The ammonia vapor and the air mixture in the hammer 12 during normal operation is advantageously in a range in which the ammonia vapor forms an excess of ninety (90 %) percent by weight of the mixture. This ninety weight percent (90 #) ammonia vapor is well above the explosive or flammable range

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the mixture of ammonia vapor and air. When the apparatus is put into operation, the treatment chamber is filled with air and a large amount of this air must be purified or removed from the chamber and replaced with ammonia vapor. Conversely, if the system is taken out of service, ammonia and ammonia vapor must be removed from the treatment chamber. Because mixtures of air and ammonia vapor in an area where ammonia vapor is fifteen percent (15 %) to about twenty-five percent (25 "A) by weight of the mixture are explosive (if sufficient heating or a Ignition of the mixture takes place), care must be taken that there is no danger in this area.

It will be apparent to those skilled in the art of fabric processing that modifications of those discussed are preferred Embodiment can be made without departing from the main idea of the invention, as shown in the claims is outlined. For example, other forms of application of ammonia (such as spraying) can be used other types of dryers are used, as well as other systems for speed and halt control can be applied.

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Claims (11)

Expectations : (1 Λ method for the I. Ercerize a cellulosic plastic fabric with ammonia> without significant shrinkage, characterized in that a 3-web web moves steadily forward, impregnated with ammonia and the removal of ammonia from the impregnated web within about 0 6 to about 9.0 seconds after impregnation. 2. The method according to claim 1, characterized in that the Removal of the ammonia from the impregnated web is started within about 1.8 to about 3.0 seconds, after the impregnation was carried out. 3. The method according to claim 1, characterized in that the web is heated for the purpose of expelling the ammonia will. 4. The method according to claim '5, characterized in that the time interval between the impregnation and the beginning of the expulsion of the ammonia is controlled by regulating the linear feed rate of the web. 5. The method according to claim 3, since lurch indicates that the time interval between the impregnation and the beginning of the removal of the ammonia is controlled by Rerein the run length of the web. 409886/0358 6. Apparatus for Aisübunf the method according to claim 1 to 5, characterized in that a device (14, 15 »53, 54, 55, 56, 57, 59, 62) for a steady forward movement the 3-web track (11) together with a net ζ device (22, 23) for coating the web with ammonia and a Means (18, 59, 62, 64) for removing the ammonia from the web in about 0.6 to about 9.0 seconds are provided after the initiation has been effected was. 7. Before rieh do.- ¹ · according to claim 6, durc'- -5; eke? Mzeiohnet that the device for removing the ammonia from the web within about 1.8 to about 3.6 seconds after performing the Irnprä. ^; : nation begins to drive out the ammonia. 8. Vorrichtun: according to claim 7, characterized in that a housing (32) and a l \ etzeinrichtun.T (22, 23) with an immersion box (13) for daH ammonia in the housing for immersing the web are provided, wherein the Means to remove the .anrr.oiiiaks has a heated dryer with a blanket. 9. Vorrichtun "according to claim 8, there -. ^ Rch characterized that a pair of guide rollers (15) housed in the housing (32) * in annex to each other and a facility (16, 17) zuu: Passing the web (11) between the rollers after Leaving the diving box (13) are provided. 10. Apparatus according to claim 9, characterized in that a deflection roller (14) in front of the guide rollers (15) for the 409886/0358 fen the cock (11) is also provided so that the Wipe the web smooth and laid out for one pass Guide rollers is. 11. Device according to claim 10, characterized in that a device (17) to extend the path of the cumulative "Web (11) between the guide rolls (15) and the dryer (18) is provided. 409886/0358 Blank page