JPS6335870A - Production of sheet impregnated with chemical liquid - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application - This invention relates to a method for manufacturing fibrous sheets such as paper and nonwoven fabric impregnated with disinfectants, preservatives, aromatics, and other chemicals. The present invention relates to a method which is particularly suitable for producing a child-like sheet impregnated with a solvent in a wet state.

-Prior Art- Conventionally, a method using an impregnating machine 20 as shown in FIG. 8 is known as a method of manufacturing a wet fibrous sheet impregnated with a chemical solution. The impregnating machine 20 impregnates the sheet with the chemical solution 6 by continuously passing the sheet 1 wound into a roll through a dipping tank 21 containing a solution 6 in which the chemical to be impregnated is unwound. Generally, after impregnating the sheet with the chemical solution 6, the solvent is evaporated with a dryer 22 to obtain a dry sheet. In order to obtain a wet sheet using this device, the sheet that has passed through the impregnated layer 21 is squeezed with nip rollers 23 to form a product without passing through the dryer 22, or the sheet that has been dried with the dryer is re-solvated. A wet product is obtained by spraying the product with a sprayer or the like.

The reason why the wet chemical liquid-impregnated sheet is manufactured by the above method is mainly to ensure uniformity of the chemical concentration and solvent concentration impregnated into the sheet, and the sheet is processed while being spread over the entire surface. Therefore, the concentration distribution of chemicals and solvents on the sheet surface can also be made uniform.

Problems to be Solved by the Invention - A sheet impregnated with a medicinal solution in a wet state is required mainly because the sheet is impregnated with a volatile solvent to promote the volatility of the medicinal ingredient and make the medicinal effect more powerful. This is a case where you want to make the most of it. Such wet chemical liquid-impregnated sheets are usually required to have side-shaped sheets, and for convenience of transportation and handling, a certain number of sheets are required to be bundled together. If you only manufacture sheets,
The easiest method is to squeeze the sheet after passing through the impregnation tank 5 of the impregnating machine with the nip roller 23 to remove excess chemical solution, but in this method, the wet sheet is cut into a certain size. Post-work is required to neatly stack and bundle the sheets, and it is extremely difficult to automate such work, and even if it is done manually, it is very troublesome and time-consuming.

Conventionally, when obtaining a 1000-sized sheet in a wet state, the sheet impregnated with the chemical solution 6 is once dried with a dryer and then cut into strips, and the cut sheet is again sprayed with a solvent. The method of laminating the layers had to be adopted, which resulted in a large loss of equipment and increased manufacturing costs due to the increase in the number of steps.

The purpose of this invention is to provide a method for easily manufacturing side-like chemical liquid-impregnated sheets that are bundled into a certain number of sheets without compromising the uniformity of the chemicals and solvents impregnated into the sheets. It is said that

-Means for Solving the Problems- The method of the present invention involves cutting a fibrous sheet such as paper or nonwoven fabric to a desired size in advance to be impregnated with a chemical solution, and stacking a plurality of sheets in a flat stack. After bundling and immersing this in a solution containing a chemical, it is rotated at high speed with the stacking direction as the direction of the rotation axis, that is, the sheet surface is a plane perpendicular to the rotation axis, and the excessively impregnated chemical solution is removed. It is characterized by removing liquid by centrifugal force.

Effect 1 In the above method, the amount of the chemical solution impregnated into the sheet is adjusted by the rotational speed of the liquid removal tank and the processing time during centrifugal liquid removal. It was predicted that if a sheet impregnated with a chemical solution was manufactured using such a method, non-uniformity in the amount of chemical solution impregnated onto the sheet would be unavoidable, but as a result of experiments conducted by the applicant of the present invention, it was found that the impregnation process It was possible to obtain a sheet impregnated with the chemical solution as uniformly as that produced by the conventional production method using a machine. According to the above method, the sheets can be cut in advance and processed in a bundle, so the process of cutting wet sheets and stacking them can be eliminated.

One Embodiment - Fig. 1 shows a manufacturing process of the present invention in a process diagram. In the method of the present invention, a fibrous sheet 1 to be impregnated with a chemical is cut into a certain size, and as shown in FIG. Numerous through holes 3, manufactured according to cutting dimensions.
. . 3 and placed in a storage container 4 made of, for example, wire mesh or punched metal, stacked horizontally, and immersed in the chemical solution 6 in the immersion tank 5. Then, when the chemical solution has sufficiently permeated the sheet 1, the sheet 1 is pulled up together with the storage container 4, and the stacking direction of the sheet 1 is aligned with the direction of the rotation axis A in the centrifugal deliquification tank 8 which is rotated around the axis A by the motor 7. and set it in a flat state. In the figure, a bundle of sheets 2 is placed in the center of the deliquid layer 8.
Although the state in which the liquid removal layer 8 is stacked and set in one is shown, if the liquid removal layer 8 is large, it is also possible to stack and set in multiple pieces. By rotating the centrifugal dewatering tank 8 for a set time at a rotation speed set according to the required impregnation concentration, the excessively impregnated chemical solution is removed by centrifugal force to obtain a product.

The deliquified chemical solution is recovered from the centrifugal deliquid tank 8 and returned to the immersion tank 5 again.

The following tests were conducted to confirm that the product obtained in this way has the same performance as a product manufactured using a conventional impregnation processing machine, and that the chemical solution is evenly distributed and impregnated into the sheet. I did it.

[Test 1] A product in which 26 g/m of rayon paper was impregnated with a chemical solution using water as a solvent, using essential oil purified from tree sap and denatured to be soluble in water, was tested using a conventional impregnation processing machine. Six test pieces were randomly taken from each of the products manufactured by the method of the present invention and the products manufactured by the method of the present invention, and the impregnation with the chemical solution was measured to obtain the following data. The unit of measurement for the amount of chemical solution impregnated is .mu./m'.

The impregnated amount of products produced by conventional impregnating machines (conventional machine products in the table) is distributed in the range of 40 to 62 ■/I.
The impregnation amount of the product produced by the method of the present invention (the product of the present invention in the table) is 4
The impregnated amount of the product obtained by the method of the present invention is slightly higher, but the distribution range is narrower, and it can be seen that a more homogeneous product is obtained. Incidentally, the impregnation l of the product according to the method of the present invention can be reduced overall by increasing the rotational speed of the liquid removal tank 8 during centrifugal liquid removal.

[Test 2] Next, as fibrous sheets, ■26 g/m rayon paper, 050 g/m bleached kraft paper, ■80
Chemical liquid impregnated sheets were manufactured using three types of sheets of unbleached kraft paper of g/rd, and the uniformity of the impregnated chemical liquid concentration was confirmed for each sheet. 0.125% essential oil as medicinal solution
Using a dissolved ethanol solution, the cutting size of the sheet is 1
500 sheets are made into one bundle with 10mX I Q Q + n, 3 bundles are stored in the storage container 4, and after soaking in the chemical solution, 280 Or
Centrifugal dehydration was performed for 2 minutes at , p, m. Select two sample sheets from each of the bundles 2a, 2b, and 2e (Fig. 4) stored in three tiers, and measure the impregnation of the chemical solution in the central part 11 and edge part 12 (Fig. 7) of the sheets. I obtained the following data. The unit of the numerical value indicating the amount of impregnation in the table is .mu./m'.

■ Rayon paper of 26 g/rK ■ Bleached kraft paper of 50 g/rd In the chemical liquid impregnated sheets produced by the conventional technique described above, the non-uniformity of the chemical liquid impregnation concentration is approximately within ±20%. According to the above test results, the variation in density is within ±13% of the average value, except for one example when using 80 g/rd unbleached kraft paper (measured values marked with *). It is settled in.

Since unbleached kraft paper is rarely used in chemical solution impregnated sheets, and rayon paper or bleached kraft paper is usually used, the method of the present invention can be practically used as a substitute for the conventional method using an impregnation processing machine. confirmed.

Above, tests were conducted on chemical liquids in which essential oils were dissolved in water or ethanol, but even when the chemical is an aromatic agent other than essential oil, such as a fragrance, a preservative, or a disinfectant, or when the solvent is an organic solvent, etc. Since there is no essential difference in the permeation of the chemical into the fibrous sheet and the release of excess chemical through centrifugal dehydration, the method of the present invention can also be used to produce chemical-impregnated sheets using these chemicals and solvents. It is clear that it can be done.

In addition, methods other than the present invention include a method in which the material is soaked in a chemical solution, dried once, cut into 1,000-sized pieces and tied, and then soaked in a solvent such as ethanol and centrifuged to remove liquid;
Attempts have been made to release excess chemical by squeezing a stack of 1,000-sheet sheets dipped in chemical liquid up and down using a press, but these methods have not been able to produce chemical liquid-impregnated sheets with a sufficiently uniform impregnation concentration. I couldn't.

- Effects of the Invention - According to the method of the present invention explained above, fibrous sheets are cut in advance to the dimensions of the final product, the number of sheets to be shipped is stacked and bundled, and the sheets are immersed in a chemical solution in that state. By centrifugal dehydration, it is possible to produce a sheet with a uniform concentration of chemical solution impregnated in each laminated sheet and in the center and edges of the sheet surface, so no special equipment is required for production. First, the manufacturing process is shortened, and a fibrous sheet impregnated with a chemical solution at a desired concentration can be easily and inexpensively manufactured. In addition, by adjusting the rotation speed and dewatering time of the centrifugal deliquid tank, it is possible to accurately control the amount of chemical impregnated, and since the manufacturing process does not include a drying process, the evaporation of the chemical liquid during the drying process is prevented. This is particularly effective when the chemicals are highly volatile or when the chemicals and solvents are expensive.

[Brief explanation of drawings]

1 to 6 are diagrams showing an embodiment of the present invention,
Fig. 1 is a block diagram showing the manufacturing process, Fig. 2 is a perspective view showing cut and bundled fibrous sheets, Fig. 3 is a perspective view showing a container for storing the bundle of fibrous sheets, and Fig. 4 is a perspective view showing the fibrous sheet bundle. FIG. 5 is a sectional view showing the fibrous sheet housed in the container, and shows the state of immersion in the chemical solution. FIG. 8 is a side view schematically showing an impregnating machine used in the conventional method. In the figure,

Claims (1)

[Claims] A plurality of fibrous sheets cut to a predetermined size are laminated into a bundle, which is immersed in a chemical solution for a predetermined time, and then centrifuged to remove liquid with the lamination direction set as the rotation axis direction.
Method for manufacturing a chemical liquid impregnated sheet.