DE3311707A1 - DEVICE AND METHOD FOR CHEMICAL TREATING A CLOTH - Google Patents

Description

State of the art

In the textile industry, the treatment of cotton cloth is to improve its dyeability and known for its shine. Sodium hydroxide is a chemical that is used for this purpose and this type of treatment is generally referred to as mercerization. There are many and different Variants of the mercerization process. Alone in the US

'"there are currently around 150 to 200 mercerising companies, who use the vacuum washing method. The commonly used procedure of this kind includes the impregnation of cotton and cotton blend cloths with a sodium hydroxide solution of

5 15 to 25% at speeds in the range of 45.72 to 137.16 m / min. The cloth is impregnated with the sodium hydroxide and then squeezed out.

Normally the cloth leaves the ^{nip rollers} with an uptake of between 60 to 70%. After remaining in the cloth for a few seconds, the sodium hydroxide is then removed by washing after it has reacted with the cotton to improve its dyeability and gloss. 25th

The washout is done in several different ways. The cloth can be used several times in a wash bath immersed and then squeezed to remove the remaining sodium hydroxide solution.

Alternatively, the washing process can be carried out using a vacuum and a tenter frame. The tenter frame is a common device for maintaining the dimensions of the cloth when it is by means of Water is washed over a vacuum. The cloth will

held in a frame and held around its edges by suitable anchoring means

to eliminate any shrinkage problems.

3 ""

Sodium hydroxide is expensive and the known method generally tries as much as ^ possible to recover and concentrate back to the 15-25% solution for reuse.

In known devices where a vacuum is used to perform the dehumidification process support, the cloth is generally washed on a tenter frame that covers a series of Vacuum boxes are located, each of which has a vacuum slot through which a low vacuum is applied the cloth is applied to aid the dehumidification process when water is applied to the cloth and this is washed. The accumulated liquid including the sodium hydroxide is then used directed to an evaporator. A recuperator consists of a large box that comes with

Steam and water is filled, through which the cloth alternates vertically between and over free-running rollers moved up and down and then subjected to the squeezing pressure of pressure rollers to remove the sodium hydroxide and reclaim the water. At this

According to the type of procedure, about 151.4 liters of fresh water are added to the recuperator per minute. That Fresh water flows in countercurrent from the recuperator and flows into the first cascade on the stenter frame Spot where the vacuum slot is for the first

Vacuum box is located., It is through the vacuum slot collected and fed like a waterfall to the next washing station, where the next vacuum box is located is located. At each successive station is the recovered water and sodium hydroxide are fed to the cascade of the next washing station. at this type of process leaves the sodium hydroxide

the sixth recovery cascade generally at a concentration of 2 to 4%. At this Concentration, the 151.4 liters of solution must be evaporated in order to bring the solution to a concentration ^ Bring back 15 to 25%, which is reintroduced into the station, where more cloth with sodium hydroxide to be impregnated. In fact, about 10 886 kg of steam per hour are required so that it is quite an expensive operation. It should be noted that the low concentration the sodium hydroxide in this type of process is caused in part by the fact that, if the water from washing station to washing station is contaminated with sodium hydroxide, it will be disposed of further sodium hydroxide is less effective. Another factor contributing to the low Percentage of recovered sodium hydroxide contributing is the fact that currently a low one Vacuum now currently used to dehumidify the cloth

is used.

It can be seen that a certain need for a more effective. and there is a more economical mercerization process.
25th

Summary of the invention

Against this background, one of the main objects of the invention is to provide an improved Vacuum washing device for a textile process, in particular a mercerization process, in which cloth made of cotton and cotton blends are impregnated with sodium hydroxide for treatment purposes and the sodium hydroxide is then removed and used for

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its reuse is processed.
1

It is an object to provide a device in which the cloth is impregnated with a sodium hydroxide solution, squeezed to remove a certain percentage of the chemical solution, and left in that state for a short period of time so that the Sodium hydroxide can act on the cloth and improve its dyeability and gloss. Thereafter, the sodium hydroxide from ¹ ^ is the cloth was removed by a vacuum washing process.

The vacuum washing process involves the use of a series of vacuum boxes running in the direction of travel are arranged and aligned with a tenter frame. The cloth is grasped and placed in the tenter frame that lies over the vacuum boxes, with a small amount of fresh water attached to each one selected number of washing stations is applied, so that at each selected station a print

takes place through the vacuum or suction box if there is a lot of fresh water that is already in the cloth Water and impurities such as sodium hydroxide are removed.

The recovered chemical solution is sent to an evaporation station where suitable means, such as steam, can be applied to evaporate the water and the chemical concentration on the desired height so that the solution too

returned to the impregnation station and can be used again with the cloth that is treated later.

It is an object of the invention to regulate the water pressure at each of the fresh water nozzles that are on each of the selected stations are arranged so

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that the volume or amount of water that is applied to the cloth corresponds to the mass of the cloth is proportional. In this way, a heavier cloth will be exposed to a larger amount of water. One The means by which this can be achieved is to vary the pressure with speed. Since the speed of the process is a function of the weight, towels will be heavier in weight moves slower and moves lighter weight cloths faster. Hence, on a faster moving one Cloth applied less water.

In accordance with the present apparatus, it is also provided that an improved vacuum washing process is performed Using a relatively high vacuum in the range of 0.254-0.2794 mm can be achieved. In this way, the solution can be more efficiently removed from the wipe at each washing station.

It is also an object to provide a facility in which the first of the series of washing stations, which has the first vacuum box, to the evaporation station is connected in parallel because the concentration removed from the cloth at the first station

is essentially the same as that originally applied to the cloth. As a result of this, the recovered sodium hydroxide solution at the first station can immediately be sent to the impregnation station

be returned.
30th

In this embodiment, the next group the vacuum boxes for each of the next group of stations, e.g. B. five stations, all together connected and connected to the evaporation station

where the concentration of the last mixture of the recovered solution on the con-

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'' centering for reuse in the impregnation station can be returned.

Of course, the number of washing stations is a matter of choice, with the goal being that Remove sodium hydroxide from the cloth and complete the wash. The cloth can then other known and common workstations

are fed.
10

Of course, in the present invention, the air and liquid mixture contained in each Vacuum box is accumulated exposed to a suitable conventional type of separator, so that the '5 Air can be removed from the solution before the Solution is passed to the evaporation station or returned to the impregnation station.

In summary, a vacuum washing device for ^ is provided a textile process for the chemical treatment of a cloth by impregnation of the cloth with a chemical solution of specific concentration and a subsequent partial dehumidification of the cloth. The vacuum washer comprises several oc

Washing stations, which are arranged so that shortly after the impregnation the cloth in one of the vacuum boxes superimposed layer so that the deposited through a slot in each of the vacuum boxes Vacuum will remove the liquid from the cloth.

A fresh water supply is located at each of a selected number of vacuum washing stations where a Vacuum box is arranged to supply fresh water to each of the selected work stations and that Washing the cloth as well as removing the chemical

to ease off the cloth. An evaporation station is between the selected washing stations

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switches so that the liquid removed from the cloth can be exposed to the evaporation agents, the chemical solution recovered from the cloth to the specific concentration for its reuse to reduce.

Taking into account the above mentioned task, reference is now made to the attached Drawings referenced.

Brief description of the drawing

The single figure shows a schematic view of the textile process using the vacuum washing device according to the invention.

Detailed description

The device 20 according to the invention is illustrated in schematic form in the drawing. As the

Arrows indicate, the sheet enters and occurs from the left side of the drawing when viewed to the right at the end of the procedure. In the present mercerization process, the cloth is treated with a sodium hydroxide solution of certain concentration, and the sodium hydroxide will be taken out removed from the cloth after a certain period of time by means of a washing process. The sodium hydroxide reacts with the cloth, e.g. cotton and cotton blends,

and improves the dyeability and gloss of the 35th

Cloth.

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HO

The cloth 22 is fed by means of a pair of feed rollers 24 and 26 and over a guide roller 28 in moves a tank 30 at an impregnation station 32. The tank 30 contains a sodium hydroxide solution 34 or a known common replacement solution. The sodium hydroxide solution has a concentration of about 15 to 2 5%.

The cloth 22 is through the tank 30 and the sodium hydroxide solution 34 therein over a series moved by spaced free-running rollers 36, so that the cloth on a vertically alternating back and forth Bahn is passed through the tank and the sodium hydroxide in it. The cloth moves through the tank at a speed of about 45.7-137.2 m / minute.

The cloth 22 is then moved out of the tank and engaged by a pair of nip rollers 38 (padder),

which squeeze the cloth that the nip rollers 38 picked up at about 60 to 70 percent by weight Solution leaves.

The towel 22 is then passed through a treatment station 40

passed through, which is basically a time setting station which controls the cloth for a certain period of time so that the sodium hydroxide works properly react with the cloth and the desired chemical reaction can be achieved. It was called

effectively found the cloth in the treatment station left for a period of 40 seconds. A number of suitable, time-controlled ones Cam rollers 42 is used to keep the cloth in the treatment station for the predetermined length of time to handle and control.

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The cloth is then fed from treatment station 42 to a vacuum washing stage, which is a series of of vacuum washing stations, which are arranged one behind the other in the direction of movement. The establishment can be provided so that a part of the reaction time of about 40 seconds can be used, while the cloth moves to the vacuum washing station and is being prepared for the washing treatment. To that To avoid the problem of shrinkage, the edges of the fabric are attached to a tenter frame 44 during the washing stage held.

Each wash station includes a vacuum box and there are six vacuum boxes in the embodiment shown intended for the six washing stations. They include vacuum boxes 46, 48, 50, 52, 54 and 56. All vacuum boxes are connected to a suitable vacuum source, not shown, and have a slot on the top of the cloth

opposite so that the liquid and air can be drawn off through the slot in the vacuum box, to make it easier to dehumidify the cloth and wash the sodium hydroxide solution out of the cloth.

The first wash station in the direction of travel comprises a vacuum box 46 and that accumulated therein Solution is passed through line 58 into tank 30 as part of the solution 34 therein. A conventional air / liquid separator 60 in the

Line 58 is used to separate the air and the liquid that has accumulated in the vacuum box 46 so that the air can be discharged and the liquid can be directed into the tank 30. The ones from the cloth Liquid removed by vacuum box 46 has not been diluted and therefore essentially has that same chemical concentration as the solution in the tank

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► · · I

30 retained. Therefore it can be immediately returned to the tank for reuse.

A nozzle arrangement located above the remaining five washing stations is used to introduce Fresh water showers in each of the separate washing stations. The nozzle arrangement 62 is above the Vacuum box 48, the nozzle arrangement 64 lies above the vacuum box 50, the nozzle arrangement 66 lies Above the vacuum box 53, the nozzle arrangement 68 is above the vacuum box 54 and the nozzle arrangement 70 is above the vacuum box 56. The nozzles are designed so that a small amount of water through this from a fresh water source 23

'5 is directed directly onto the cloth in each washing station will.

The liquid accumulated in each washing station after the first washing station is turned into a common

^ Line 72 passed and mixed when it is introduced into an evaporation chamber 74 in an evaporation station 75. As a result, the liquid-air mixture accumulated in the vacuum box 48 is passed through the line 78, the air and liquid being separated in a conventional separator 80 so that the liquid flows into the line 72 and finally into the evaporation chamber 74. The liquid-air mixture collected in the vacuum box 50 flows through the line 82 and after

the separation of air and liquid in a conventional separator 84, it also flows into the Line 72. Similarly, the liquid and air mixture contained in vacuum box 52 flows is accumulated through line 86 to the separator

88, with the liquid emerging from the separator flowing into line 72. The air-liquid

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Mixture accumulated in vacuum box 54 is fed through line 90 to separator 92, from which the separated liquid flows into line 72. Finally, the liquid and air mixture accumulated in the vacuum box 56 ^{u is} fed through the line 94 to a separator 96, and the liquid leaving the separator enters the line 72 and finally into the evaporation chamber

74 a.
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The percentage of sodium hydroxide in the solution accumulated in the evaporation chamber 74 is substantial reduced and less than the concentration required in the impregnation station. As a result, the water in the solution in tank 74 must be evaporated in order to keep the concentration up bring back from about 15 to 25%. This is done by a conventional vaporization process using steam achieved, with the steam from a usual, not

source shown in the evaporation chamber and the chemical concentration of the sodium hydroxide can be properly adjusted. The ones in the evaporation tank 74 solution present in the necessary concentration is then passed through line 76 in

returned to tank 30 for reuse.

In summary, a small amount of fresh water is contained in applied to each wash station after the first station. For sodium hydroxide removal it is

Fresh water is far more effective than contaminated water is supposed to be. The result is development a material and chemical balance in the washing system. After applying fresh water

immediately tried to get as much of the fresh 35

water and the solution of water and sodium hydroxide that is already in the cloth.

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Thus, if you have a 152.40 cm wide product weighing 271.74 grams per square meter and advancing at about 82.3 meters / minute, 1,534 kg of cloth will be produced per hour. In this • 5 process, 249.48 kg of sodium hydroxide is added to the cloth per hour. In the known system, 80% of the sodium hydroxide is recovered through the use of 151.42 liters / minute, or about 9 072 kg of water per hour. As a result, there is a significantly dilute solution concentration of 2.2% for evaporation.

In contrast, the present system enables 85% of the sodium hydroxide to be removed from the Cloth using 34.07 liters / minute or about 1,361 kg of water per hour. It will be about 0.675 kg of steam per 0.45 kg of water is required for evaporation. While the known system 12 700 kg of steam per hour are required in the present

System only requires 2,390.4 kg of steam per hour. The typical service life of the facility is around 5,000 Hours per year, so the average cost saving is substantial.

It should also be taken into account that the vacuum applied to the vacuum boxes is the same with the present one Facility works more effectively when it is set at 10.47 inches Hg.

When determining the parameters of the system, it must be taken into account that the amount of water added is the Amount of cloth should be proportional- A heavier cloth will require the use of more Water. A cloth weighing 226.80 g would therefore produce water

added at a rate of 1.419 l / minute per nozzle at 15.24 cm center-to-center, while with one

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Product of 85.05 g would only add 0.473 l / minute from one nozzle. The water pressure is regulated and the volume or mass of water is applied proportionally to the mass of the cloth.
5

One way in which this is done is the change in pressure with speed. There The speed of the process is a function of the weight, the heavier the cloths will be moves slower than the lighter weight cloth. Accordingly, progressively less water is applied, when the speed of the cloth increases.

The number of washing stations is a matter of choice. Whether the first washing station with a fresh water source connected or not and the output leads to the evaporation station or back to the impregnation station, is also selectable.

The following is a successful embodiment of the mercerization washing process according to the present system. The experimental conditions include the use of a 35.56 wide sample of a 65/35 polyester / cotton cloth with a base

2

weight of 322 g / m that is moved at a speed of 86.87 m / minute. The cloth came with a Impregnated with 25% sodium hydroxide solution and then squeezed out in squeegee rollers (padder). The sample was then by means of a double herringbone

assigned a 3.18 cm vacuum slot with a 30.48 cm vacuum of mercury extracted. The sample was then washed three times with water at a temperature of 48.9
C at a rate of 1.9 l / minute per 30.48 cm width and extracted after each spray using the extraction procedure mentioned above.
The sample measurements were made by cutting off the samples

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carried out by the tissue after being squeezed out with the nip rollers as well as after each extraction. The percentage of moisture was determined by weighing the wet sample, drying it and then reweighing. Of the The percentage of moisture is the stated basis dry weight of the cloth. That is, wet weight dry weight / dry weight. The percentage of the Sodium hydroxide was determined by titrating the dried cloth samples after they had been in distilled water with 0.1 normal hydrochloric acid up to boiled to a phenothalic endpoint. The percentage the sodium hydroxide is reported on the basis of 100% sodium hydroxide versus the dry weight of the Cloth. The formula used was: cm of 0.1 normal hydrochloric acid X normality of hydrochloric acid X 0.04 / dry weight of the cloth sample.

Test results

location recording
in % sodium
hydroxide
' in % distant
Amount in% Total
velvet ■ i. After the_
Squeeze
roll 69 15.18 2.
I. To
1st slot 42 11.18 26th 26th 3. To
2nd slot 40 7.36 34 52 4th To
3rd slot 40 3.19 56 79

35 5. After

4th slot

2.24

30th

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It can be seen that 85% of the sodium hydroxide was removed after three showers and four vacuum treatments. An investment would normally require 151.42 1 of water per minute to wash this washing procedure ** with a cloth of 1.83 m Broite according to known methods. This procedure requires 1 34.07. This represents a 77.5 reduction in the amount of water. The energy savings would be doubled, namely the savings in heating costs corresponding to the difference of 117.35 l / minute and the savings in evaporation corresponding to the difference of 117.35 l / minute that affect the evaporator.

Substantial cost savings for the system can also be achieved with:

1. the evaporation of the sodium hydroxide solution,

2. the heating of the washing water,

3. by the reduced drying load in the

Cylinder dryers and

4. Chemical savings with higher sodium hydroxide recovery .

In addition, there are lower costs for the energy required to operate the system.

Thus, the various objects and advantages mentioned above are most effectively achieved.

Claims (31)

I) I PL · .- INO. HANS AV. (JIiOENINCi I'AT KNTA K NVA LT A 30-11 Albany International Corp. 1 Sage Road Menands, New York 12204, USA Device and method for the chemical treatment of a cloth Patent claims 1. Device for the chemical treatment of a cloth (22) by impregnating the cloth (22) with a chemical solution (34) of a certain concentration and subsequent partial dehumidification of the cloth (22), characterized by vacuum washers for washing the chemical (34) out of the cloth (22), consisting of a plurality of washing stations which are connected to a suction source and each having a vacuum slot over which the cloth (22) can be moved and through Slot in each station can be dehumidified by a fresh water source (23) for separate supply each washing station and through a recovery station (75) including an evaporator (74) to reduce the chemical solution recovered from the cloth (22) the specific chemical concentration for their reuse. SIKlIKlITSTn, 4 · HOl) O MÜNCHEN 80 · POlI HM0S40 · KAIIKl .: It 11 Kl NI ¹ AIKX T · TKl .. (OhII) 47 107 » · TKl. KX 2. Device according to claim 1, characterized in that the chemical (34) is sodium hydroxide and the chemical concentration is around 15-25%.
5 3. Device according to claim 2, characterized in that that the cloth (22) is impregnated with the sodium hydroxide solution while it is at a speed from about 45.72 - 137.16 m / min and immediately afterwards the fabric is moved by nip rollers (38) and squeezed out until the sodium hydroxide solution (34) is absorbed by about 60-70% will. 4. Device according to claim 3, characterized in that the cloth (22) the first washing station (62) a few Seconds after it was squeezed out by the nip rollers (38). 5. Device according to claim 1, characterized in that that the means for the supply of fresh water at each of the washing stations nozzles (62, 64, 66, 68, 70) for spraying a predetermined amount of fresh water in each station as well as after Applying fresh water a substantial portion of the fresh water, water, and chemical (34) from the cloth (22) through each vacuum slot. 6. Device according to claim 1, characterized in that that the recovery station (75) means for supplying a predetermined amount of steam for the Evaporation of water and for the return of the recovered liquid to the predetermined one Chemical solution concentration includes. 7. Device according to claim 6, characterized in that a device for recycling the recovered Liquid of the predetermined chemical concentration for re-use in impregnation of the cloth (22) is provided. 8. Device according to claim 1, characterized in that that the cloth (22) by an upward and downward movement of the cloth over free-running rollers (36) in one Bath (32) impregnated with the chemical solution (34) and then squeezed out by nip rollers (38) to remove the water and chemical (34) from the cloth (22). 9. Device according to claim 8, characterized in that time setting means the duration of the impregnation of the cloth (22) with the chemical solution (34) control before the cloth (22) the washing process in the Washing stations is suspended.
20th 10. Device according to claim 9, characterized in that the time setting means a plurality of time controllable cam rollers (42) over which the cloth (22) between the point where it is impregnated and is carried away from the washing stations. 11. Device according to claim 1, characterized by a pulling station (46) for receiving the impregnated Cloth (22) before its passage to the first Washing station, through a vacuum slot on the peeling station (46) for receiving the solution (34) the cloth (22) moving over it, through a connecting line (58) to which the solution (34) containing source (32), through a in the 35 Connecting line (58) switched separator (60) to separate the air from the air from the cloth (22) liquid sucked off and returned to the solution source (32). 12. The device according to claim 1, characterized in that * that a separator (80, 84, 88, 92, 96) is arranged in the washing station for receiving dos liquid-air mixture, which is collected through the vacuum slot in each washing station, and which the air from of the accumulated liquid which is returned to the recovery station (75). 13. Device according to claim 1, characterized in that a regulating device for regulating the Water pressure is provided so that the amount or volume of water added to the cloth (22) the mass of the cloth (22) is proportional. 14. Device according to claim 13, characterized net that the regulating means control means for changing the water pressure in accordance with the speed of movement of the cloth (22). 15. Device according to claim 1, characterized net that the vacuum device applies a vacuum in the range of 10 to 11 inches. 16. Device according to claim 1, characterized in that the cloth (22) by a clamping frame (44) while it is in the washing stations to prevent shrinkage facilitate. 17. Process for the chemical treatment of a textile ches by impregnating the cloth with a chemical Solution of a certain concentration and other 4 - subsequent partial dewatering of the cloth using the device according to any one of the claims 1 to 16, characterized by the supply of a certain amount of fresh water from a water supply ^ to each washing station, passing the impregnated Cloth through several washing stations via a vacuum slot in each station, leaving water and the chemical is vacuum withdrawn through each slot and recovered the chemical in a recovery station by evaporating what is collected from the wipe Water in the sense of a return of the chemical concentration of the water and the chemical solution, recovered from the wipe to the predetermined chemical concentration for reuse . 18. The method according to claim 17, characterized in that that the chemical is sodium hydroxide and that chemical concentration is around 15 to 25%. 19. The method according to claim 18, characterized in that the cloth is impregnated with the sodium hydroxide solution while dealing with a speed of about 45.72 to 137.16 m / min moves, and that immediately afterwards the cloth of Pinch rollers detected and is squeezed out to an absorption of 60 to 70% sodium hydroxide solution. 20. The method according to claim 19, characterized in that that the cloth reaches the first washing station a few seconds after being squeezed out in the squeezing station. 21. The method according to claim 17, characterized in that that fresh water by spraying a certain Amount of fresh water is applied in each station and that after the application of the fresh water A substantial portion of the fresh water as well as water _ and the chemical from the cloth through each one Vacuum slot can be accumulated through. 22. The method according to claim 17, characterized in that a certain amount of steam in the recovery _{is used in the} station to evaporate water and the recovered liquid is returned to the specific concentration of the chemical solution. 23. The method according to claim 22, characterized in that the recovered liquid of the predetermined chemical concentration is returned to the station where the cloth is impregnated facilitate the reuse of the water and chemical. 24. The method according to claim 17, characterized in that that the cloth for impregnation roll over free running in a bath with the chemical solution upwards and downwards and then squeezed out by squeezing rollers to remove the water and the chemical from the cloth. 25. The method according to claim 17, characterized in that the water pressure is regulated in that the OQ Amount or amount added to the cloth Volume of water is proportional to the mass of the cloth. 26. The method according to claim 25, characterized in that that the pressure is regulated according to the speed of movement of the cloth. ^ 27. Method according to Claim 17, characterized in that that a vacuum in the range of 25.4 to 27.94 cm is applied by means of the vacuum device. ^ 28. A method according to claim 17, characterized in that the length of time during which the cloth is impregnated with the chemical solution before washing the cloth in the washing station is determined by a time setting device.
10 29. The method according to claim 28, characterized in that the time setting device several time-dependent controlled cam rollers, over which the cloth between the point where it is impregnated, ■ 5 and the washing stations is moved. 30. The method according to claim 17, characterized in that the extraction station is in a position to Recording of the impregnated cloth before it ^ Transport to the first washing station is that a vacuum slot is provided at the extraction station for removing the solution from the cloth moving over the slot, through a line extending between the vacuum slot and the solution container, through a separation device between the ends of the line for separation the air from the liquid withdrawn from the cloth and the return of the same to the solution container. 31. The method according to claim 17, characterized in that the separation device in the washing station for Intake of the liquid / air mixture is provided, which through the vacuum slot in each washing station is collected and by separating the air from the accumulated, the recovery station liquid to be supplied.