JPH0473261A - Method and apparatus for continuous bleaching of fabric - Google Patents

Abstract

PURPOSE:To obtain a bleached fabric of good quality without creases by impregnating and applying a hot inert sodium chlorite solution into a continuous running fabric of continuous length, then applying an activator for the sodium chlorite thereto and transferring the resultant fabric through wet heat-treating chambers under tension. CONSTITUTION:A fabric of continuous length 2 is continuously introduced into a liquid bath 1 and dipped in a hot inert sodium chlorite solution and the excess solution is then squeezed with squeezing rolls 5 and further guided into wet heat reaction chambers 6. The fabric is then initially sprayed with an aqueous solution such as an organic acid, e.g. formic or acetic acid or an inorganic acid, e.g. sulfuric or hydrochloric acid capable of activating the aforementioned sodium chlorite from activator sprays 8 while being transferred through plural guide rolls 7 internally installed in the above-mentioned chambers 6. Thereby, wet heat treatment is subsequently carried out at a prescribed temperature. The aforementioned steps, as necessary, are continuously repeated plural times.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method and apparatus for continuous bleaching of fabrics, which are configured to effectively carry out continuous bleaching of fabrics while saving energy and shortening processing time. It is related to.

[Prior Art] Sodium chlorite bleaching of long fiber fabrics that are continuously processed and produced industrially involves applying an aqueous solution of sodium chlorite activated with an organic or inorganic acid to the fabric to be bleached, Next, this liquid-impregnated fabric is fed into a wet heat reaction treatment chamber to continuously perform the desired bleaching treatment. More specifically, regarding this type of conventional bleaching method, the sodium chlorite aqueous solution applied to the fabric to be bleached has a pH of 3 to
4, the fabric is continuously passed through this aqueous solution to impregnate it, and then squeezed with a squeezing roll to obtain an appropriate amount of liquid content. A moist heat reaction treatment is carried out over a long period of about 40 to 60 minutes while maintaining the temperature at 80 to 90 DEG C., thereby achieving the continuous bleaching of the long fabric.

In other words, loading the fabric inside the reaction chamber causes differences in temperature distribution and reaction rate between the inside and outside of the loaded fabric, and the bleaching process has to be adjusted to the longest part of the process, so the process takes about 40 to 60 minutes. Processing time is required.

[Problem to be solved by the invention] However, in such a conventional method, the timing of the wet heat reaction treatment of the fabric impregnated with an aqueous solution of sodium chlorite requires about 40 to 60 minutes as described above. In the moist heat reaction chamber, since the fabrics are sequentially loaded into the reaction chamber, horizontal wrinkles occur in the fabrics due to the stacking pressure, and uniform and good bleaching cannot be expected.

In particular, if the fabric to be bleached is a high-quality product such as a fine-count high-density fabric or a high-twist fabric, once wrinkles form, it is impossible to correct the wrinkles. It was necessary to avoid a bleaching process that applies pressure in a moist heat reaction chamber.

Therefore, in order to transfer the fabric within the reaction chamber without applying pressure during wet heat treatment of the fabric, it is possible to adopt a kite roll transfer means, but this continuous fabric transfer means using guide rolls is not suitable. , the number of guide rolls to be arranged in the moist heat reaction chamber increases, and the total volume of the reaction chamber becomes enormous. That is, when the residence time of the fabric to be subjected to moist heat reaction in the reaction chamber is 40 to 60 minutes,
For example, if the machining speed per minute is 100 m, the calculation is 4
This requires a group of Kiterolls capable of accommodating 000 to 6,000 m of fabric and a volume of the heat-and-moisture reaction chamber, which results in an enormous size of the heat-and-moisture reaction chamber, making it practically difficult to equip such a large-scale heat-and-moisture reaction chamber. Therefore, the inventor first applied for patent application No. 2-125
No. 880 and Japanese Patent Application No. 125881/1999 disclose a method and apparatus for bleaching fabrics that can save energy and shorten processing time. The present invention provides a continuous bleaching method and apparatus.

[Means for Solving the Problems] A feature of the present invention is that the fabric to be bleached is sufficiently impregnated with the hot liquid of an inert chlorite sorter. In this case, the sodium chlorite is not activated, so there is no generation of chlorine dioxide scum that causes bad odors, so the sodium chlorite in the solution is not consumed, and the scale and equipment are not affected by the chlorine dioxide gas. It has the advantage of not corroding. Next, an aqueous solution of an activator of sodium chlorite, such as an organic acid such as formic acid, acetic acid, and oxalic acid, an inorganic acid such as sulfuric acid, and hydrochloric acid, and a galvonyl compound such as formaldehyde and glyoxal, is added to the wet heat reaction chamber while being sprayed. By spraying the bleaching activator using a booster, the sodium chlorite impregnated into the fabric effectively achieves the bleaching purpose on the fabric without detaching. The amount of bleach that oxidizes and decomposes the dye on the fabric is only a small portion of the sodium chlorite used, and most of it becomes chlorine dioxide gas upon activation and leaves the fabric. If this chlorine dioxide gas is separated from the fabric, it cannot be expected to be very effective in a short period of time.If bleaching is to be carried out in a short period of time, the amount of activator and sodium chlorite must be increased, resulting in rapid gasification. Since the available chlorine dioxide on the fabric is severely consumed, the chlorine dioxide escapes from the fabric in the form of gas while the dye is not decomposed, let alone bleaching the fabric. Furthermore, in the present invention, extremely effective bleaching can be achieved by repeating the process multiple times so that chlorine dioxide can effectively act on the fabric.
It is done in energy saving and short time.

[Example] The present invention will be described in detail below based on an example shown in the drawings.

Reference numeral 1 denotes a liquid-impregnated tank for impregnating the fabric 2 to be bleached with an alkaline solution. Fabric 2 is supplied and is tension-transferred by guide roll 4
It is liquid-containing. 5 is squeeze roll, 6 is 100
This is a wet heat reaction chamber in which moist heat is maintained before and after the cloth 2, and a large number of guide rolls 7 for tensioning and transporting the fabric 2 are disposed within this wet heat reaction chamber 6. 8 is a sprayer for attaching an active agent to the fabric immediately after being introduced into the wet heat reaction chamber 6, and 9 is a booster placed in the wet heat reaction chamber 6. In this embodiment, two liquid-containing tanks 1 and a heat-and-moisture reaction chamber 6 are arranged alternately in order to repeatedly apply a hot solution of sodium chlorite to the fabric 2 and perform a heat-and-moisture reaction treatment. However, the number of these is not limited to two, and may be more than two.

The above is the configuration of this embodiment.Next, its operation will be described.The fabric 2 to be bleached is placed in the liquid tank 1 at a temperature of 60 to
An inert sodium chlorite solution heated to 95° C. is impregnated. Next, after the excess solution is squeezed out by the squeezing roll 5, the fabric is fed into a heat and humidity reaction chamber 6 maintained at a heat and humidity temperature of, for example, 102°C, and immediately passed through a sprayer 8.
The activator is applied by. This r! j! The spraying of the activator by the W machine 8 can be adjusted to such an extent that the sodium chlorite once attached to the fabric does not run off. Therefore, the fabric to which sodium chlorite is attached is subjected to the action of this activator and moist heat, and the bleaching reaction of the fabric proceeds. That is, liquid 4'! After the inert sodium chlorite hot liquid immersion treatment in chamber 1, a sodium chlorite activator is sprayed in the wet heat reaction chamber 6, and the process is carried out for 30 to 60 seconds while supplementing the moisture content with a booster to produce the desired bleached fabric. However, the amount of sodium chlorite used at this time is 1.2~
It is 1.5kOWF, and some fabrics with especially a lot of hakas may have slight hakas remaining. Therefore, in this example, by repeating the above treatment operation twice, the amount of sodium chlorite used was 0.3 to 0.4960 WF per time, that is, the total amount of sodium chlorite used was 0.6 to 0.8!6. Even thick fabrics can be completely bleached.

In this example, the inert alkaline sodium chlorite solution, which is the bleaching solution to be applied to the fabric, was
By heating the fabric to ~95℃, spraying the activator onto the fabric impregnated with the solution, and performing the wet heat reaction treatment in the wet heat reaction chamber while supplying sufficient moisture with the booster 9, the total The desired bleaching can be achieved with a short moist heat treatment time of about 30 to 60 seconds.

Furthermore, according to this embodiment, since the reaction time in the moist heat reaction chamber is as short as about 30 to 60 seconds, this wet heat reaction chamber can be downsized, and roll transfer is thereby possible. During the wet heat treatment of the fabric, tension transfer means using guide rolls 7 can be adopted as a means for transferring the fabric, and the fabric can be transferred without wrinkles and subjected to bleaching reaction treatment, and a high-quality bleached fabric can be obtained. .

[Effects of the Invention] As described above, the present invention applies an inert hot sodium chlorite solution to a continuously transported long fabric, and then activates the sodium chlorite applied to the fabric. This is a continuous bleaching method and apparatus for fabrics that repeatedly applies an activator to the fabric and transfers the fabric under tension in a moist heat treatment chamber, so it can effectively and instantly bleach the fabric. Can be activated. For example, it is possible to achieve the effect that the bleaching treatment can be completed within a short period of time, such as a total of about 30 to 60 seconds for the wet heat reaction in the wet heat reaction chamber.

Furthermore, since the bleaching process can be carried out in a short time, the wet heat reaction chamber can be made relatively compact, and guide rolls can be used as the means for transporting the fabric in the wet heat reaction chamber. There is an effect that wrinkle-free and high-quality bleached cloth can be obtained without applying stacking pressure to the cloth.

[Brief explanation of the drawing]

The drawing is an explanatory diagram showing an embodiment of the bleaching apparatus according to the present invention. 1...Liquid-containing tank 2...Fabric 3...Treatment liquid 4...Guide roll 5...Squeezing roll
6...Moist heat reaction chamber 7...Guide roll 8...Ejector 9...Booster and 4 other personnel Procedure amendment dated March 7, 1990

Claims (1)

[Claims] 1. Applying an inert hot solution of sodium chlorite to a continuously transported long fabric, and then applying an activator to activate the sodium chlorite applied to the fabric. 1. A method for continuous bleaching of fabric, characterized by repeatedly performing application and tension transfer in a moist heat treatment chamber. 2. A hot liquid tank containing an inert sodium chlorite hot liquid and impregnating a continuously transferred fabric with this hot liquid, and a fabric provided next to this hot liquid tank and to which the hot liquid is applied. Moist heat reaction chambers are alternately arranged, each of which includes an application means for applying an atomized activator, a group of guide rolls to which the activator is applied and tension transfers the applied fabric, and a moist heat application means. A continuous fabric bleaching device characterized by the following: