JPH01272943A - Method of measuring mixing concentration and mixing ratio of polyvinyl alcohol and start in aqueous solution - Google Patents

Abstract

PURPOSE:To enable exact and rapid measurement with a min. amt. of boric acid and iodine to be added by adding the boric acid and iodine to a dilute liquid of an aq. glue soln. to color said soln. and detecting the degree of the coloration from a transmission quantity. CONSTITUTION:The liquid detergent in a liquid detergent tank is partly introduced into a measuring instrument at the time of continuously swashing cloth. This liquid is diluted to about 5-30ppm mixing content of PVA (polyvinyl alcohol) and starch in said liquid for the purpose of a discoloration effect. The liquid is then bisected. The color tone of the liquid changes according to the concn. of the PVA and starch when the boric acid and iodine are added to one thereof. The colored liquid is obtd. by adding 50ppm iodine to the other liquid. These two colored liquids are irradiated by specified light. The quantity of the light transmitted through these liquids is detected by a photodetecting sensor and the concn. of the PVA and starch contained in the liquid detergent contg. the PVA and starch which is a test soln. is exactly measured.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is directed to a continuous desizing process for fabrics, in which polyvinyl alcohol that has fallen into a cleaning tank for cleaning performed in a process prior to applying a desizing agent is removed. This invention relates to a polyvinyl alcohol starch concentration measuring method for controlling the polyvinyl alcohol RYSj concentration in the cleaning tank by continuously measuring the content of starch (sizing agent).

[Conventional technology]

Pre-treatment of long length fabrics for industrial production and processing involves first washing the burnt fabric in a cleaning solution, then applying a desizing agent to the washed fabric for the desired desizing process. It is common to do this.

(Problem to be solved by the invention) However, in the conventional desizing cleaning tank, the desizing is only done in boiling water at 90 to 95°C while water is supplied based on experience based on the degree of contamination inside the tank. However, there is no way to measure the amount of glue that has fallen into the cleaning solution due to contamination during desizing, and to supply water that is appropriate for the content (degree of contamination). Excessive water supply results in wasted water resources or wasted thermal energy to raise the temperature of excess water to 90-95°C. Furthermore, due to changes in the type of processed fabric or processing speed, cleaning The degree of contamination of the liquid in the tank fluctuates and sometimes the degree of contamination with the size agent becomes severe, making it impossible to perform effective and uniform desizing. The problem is that the balance is disrupted, leading to waste liquid pollution.

In particular, recent fabric glues often contain a mixture of polyvinyl alcohol and starch, so it is necessary to know the mixing ratio of polyvinyl alcohol and starch during washing. That is, when polyvinyl alcohol in washing water is recovered and reused, it is not possible to determine the amount of polyvinyl alcohol recovery agent to be used, so the greater the starch mixing ratio, the more the recovery agent is wasted. For this reason, it is necessary to detect the content of polyvinyl alcohol and starch in the cleaning solution, and to measure the mixing ratio of polyvinyl alcohol and starch by sequentially supplying an effective amount of clean water according to the contamination concentration of the cleaning solution. . Conventional methods for measuring the glue content include a discontinuous method for separating polyvinyl alcohol using formalin, but all of these measurement methods require a long time to detect the measured value; It was impossible to detect. Also, is there a colorimetric method that measures the size content at 50 to 500 PPM? In this case, since the fabric contains a surfactant other than the size agent, the surfactant may drop into the liquid in the washing tank. In order to generate bubbles, the glue content must be 50%.
-500 PPM, the amount of light transmitted changes due to the bubbles, making it impossible to continuously and accurately measure the content of the sizing agent.

[Means to solve the problem]

The present invention has been made in view of the above, and in order to save water, resources, and energy when desizing and cleaning fabrics, the present invention detects the concentration of sizing agent in the cleaning liquid in the desizing tank. The object of the present invention is to provide a method for measuring the concentration of a polyvinyl alcohol starch aqueous solution.

(Function) That is, the present invention detects the concentration of polyvinyl alcohol and starch in a polyvinyl alcohol starch (wood) aqueous solution produced by continuously washing a long fabric.
First, the aqueous solution is diluted so that the shelf material content is 5 to 30 PPM, and then 1. Seagull, iodine 5
0 PPM is added to color the liquid, and the degree of coloring of this colored liquid is detected by the amount of permeation, and the amounts of polyvinyl alcohol and starch are measured. Separately, 50P of iodine is added to the above diluted solution to color only the starch.
When PM is added, the degree of coloring is detected and measured by the amount of light transmitted, which is the difference in coloring density between the former colored liquid and the latter colored liquid, or the concentration of polyvinyl alcohol. In this way, the concentration is continuously measured, and it is effective in conserving water resources by sequentially adding and supplying the minimum amount of fresh water suitable for cleaning the cleaning solution in the desizing cleaning tank. Since thorough cleaning can be performed and the mixing ratio of polyvinyl alcohol can be detected and measured, there is no waste of the polyvinyl alcohol recovery agent.

〔Example〕

Examples of the present invention will be specifically described below.

A portion of the cleaning solution in the cleaning solution tank that continuously cleans the fabric is introduced into the measuring device. If the concentration of polyvinyl alcohol (hereinafter referred to as PV8) and starch in this cleaning solution is high, when boric acid and iodine, which will be described later, are added to the cleaning solution, the degree of discoloration will vary depending on the amount added. Since it becomes insensitive and difficult to understand, the cleaning treatment solution is diluted so that the PVA and starch contents are approximately 5 to 30 PPM so that the degree of discoloration relative to the amount of boric acid and iodine added becomes clear.

Next, the PVA and starch-containing cleaning solution thus diluted is divided into two parts, and boric acid and iodine are added to one of the cleaning solutions, resulting in a change in color tone depending on the concentration of the PVA starch. Ru. For example, when a predetermined amount of boric acid and iodine are added to the starch-containing cleaning solution, the degree of discoloration of the cleaning solution changes depending on the PVA and starch content at that time.
PVA starch content is low to high concentration e.g. 0-110
As it becomes 0PP, the color changes from brown to gray to blue. Therefore, the concentration of PVA and starch contained in the cleaning solution can be estimated by looking at the degree of discoloration. However, estimating the PVA starch concentration by visually observing the degree of discoloration due to the addition of boric acid and iodine makes it impossible to accurately measure the concentration due to individual differences in the judgment of the person conducting the test. By irradiating a certain amount of light and detecting the amount of transmitted light with a light-receiving sensor, the test liquid, that is, PVA #
It is possible to accurately measure the concentration of PVA and starch contained in the powder-containing cleaning solution.

As can be seen from this explanation, by adding boric acid and iodine to the cleaning treatment solution containing PVA and R powder, the treatment solution can be
Because it changes color depending on its starch content,
By detecting the color tone of this discoloration using transmitted light, it is possible to measure the Pv8 powder content in the cleaning solution.
If so, the above PVA, R powder content is 5 to 30 PP.
The question is what amount of iodine is desirable to add to the cleaning treatment solution adjusted to M.

In other words, color development on PV does not occur when the amount of boric acid is small, and when the amount of boric acid added to the solution is around 1596, the absorption of light is maximum and the amount of transmitted light is the lowest, and as it becomes darker, the amount of transmitted light decreases. increases, and the sensitivity of the measurement becomes insensitive. Further, as the amount of iodine added increases, the amount of transmitted light decreases, but on the other hand, the sharpness of the color development gradually deteriorates due to the influence of the color of iodine, and the measurement sensitivity becomes dull.

Therefore, in order to determine the appropriate amount of boric acid and iodine to be added, the inventor of the tree added 1 boric acid to a test solution in which the PVA concentration was 5 PPM and the starch concentration was gradually increased from 2.5 to 30 PPM, as shown in Table 1. ．． S*, the transmitted light index when 50 ppm of iodine was added, and the transmitted light index when 50 ppm of iodine alone were measured, and the results were as shown in Table 1.

FIG. 1 is a graph of the numerical values in Table 1.

Table-1 Next, the starch concentration was set to 20 PPM, and PVA? ! 4 degrees from 1 to
Table 2 shows the results of measuring the transmitted light index when 1.5% boric acid and 50 PPM iodine were added to the test solution gradually increased to 110 PP, and the transmitted light index when 50 PPM gi of iodine alone was added. Ta. Figure 2 is a graph of the numerical values in Table-1.

Table 2 Therefore, as can be seen from Tables 1 and 2, the amount of boric acid added at which the degree of discoloration is within the same range at the minimum addition amount of boric acid and iodine, and the difference in transmitted light index at each time of discoloration is within the same range. is approximately 15*, so the PVA concentration is approximately 50 PPM.
, starch 20PPM (7) For test solution, approximately 15*
By adding 50 PPM of boric acid and 50 PPM of iodine, the degree of discoloration caused by transmitted light, that is, the degree of pvBM, can be accurately measured.

Next, in the cleaning treatment solution, the content of PVA and starch is approximately 5 to 30.
The reason for diluting the powder to PPM is to detect the degree of discoloration caused by the addition of boric acid and iodine using transmitted light and to accurately determine the PVA and starch concentrations in the powdered ice solution. It is. i.e. boric acid 1-unit and iodine 50P
It is desirable to have a PVA and starch concentration that matches the transmitted light index width when PM is added.

(Effects of the Invention) As is clear from the above description, according to the present invention, a predetermined amount of boric acid and iodine is added to a PVA-containing fabric cleaning solution (sample solution) diluted so that the degree of discoloration can be easily detected with transmitted light. The concentration of PVA and starch contained in the treatment liquid is detected by adding PVA and starch to the liquid and detecting the degree of color change using transmitted light. This effect allows starch concentration to be measured very accurately and quickly with minimal amounts of boric acid and iodine added.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between starch concentration and transmitted light index, and FIG. 2 is a graph showing the relationship between PVA concentration and transmitted light index. Σ 0゜〇= Σ

Claims (1)

[Claims] 1 The mixed content of polyvinyl alcohol and starch contained in the cleaning solution in the desizing cleaning tank is approximately 5 to 30P.
Boric acid 1.5% is added to this adjusted solution.
%, a colored solution in which the polyvinyl alcohol and starch in the above adjustment solution were colored by adding 50 PPM of iodine, and a colored solution in which 50 PPM of iodine was added to the above adjustment solution to color the starch in the above adjustment solution. A method of measuring the mixing concentration and mixing ratio of the polyvinyl alcohol and starch by detecting and comparing the degree of coloring of both colored liquids using transmitted light.