JPS6071202A - Chemical treatment method of woody veneer - Google Patents

Abstract

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

Description

[Detailed description of the invention] The present invention relates to a method for chemically treating wood veneers.

Conventionally, various types of natural wood veneers have beautiful grains and colors, and are therefore useful as decorative surface materials for decorative laminated boards used for furniture, walls, floors, and other construction materials.

However, since the natural wood veneer is a natural wood, it has drawbacks such as color unevenness and discoloration, and iron contamination may occur during the veneer manufacturing process.

Since such defective veneers cannot be used as they are, the discolored and contaminated areas are removed by chemical treatment using various bleaching agents, and if necessary, the uneven color areas are uniformly colored with a dye coloring agent. By converting it into a precious wood veneer, it is recycled into a veneer of precious wood.

In addition, in recent years, due to the difficulty in obtaining high-quality natural wood, low-grade wood is often used, that is, low-grade veneer is subjected to chemical treatments such as bleaching or coloring to produce knots that resemble precious wood veneers.

The various chemical treatment operations mentioned above include applying chemicals directly to the surface of the veneer, or immersing the veneer in a chemical bath.The immersion method is usually used from the viewpoint of work efficiency and cost. ing.

However, even in the immersion method, the veneer to be treated is 0.
Since it is in the form of an extremely thin sheet of approximately 2 mm to 1 mm, it is difficult to uniformly and efficiently treat a large number of veneers at once.

For this reason, much research has been carried out on how to efficiently chemically treat veneers using the immersion method, as described in Japanese Utility Model Publication No. 54-43014. Methods such as those found in Japanese Patent Publication No. 5B-2001 and Japanese Patent Application Laid-Open No. 55-15030 have been proposed, but these methods are still insufficient in terms of workability, processing capacity, processing cost, effectiveness, etc. be.

The present invention was devised in view of the above-mentioned problems, and is a method for chemically treating wood veneers, which enables efficient and uniform treatment of a large amount of veneers through simple operations, and which is inexpensive in processing cost. The purpose is to provide

In order to achieve this objective, the chemical treatment method of the present invention involves raising and lowering the chemical level of the chemical bath by discharging and injecting the treatment chemical when applying various chemical treatments such as bleaching and dyeing to wooden veneers by dipping. The outline is as follows.

The present invention will be explained in detail below.

In the present invention, the chemical treatment refers to hydrogen peroxide,
These include bleaching treatment using a bleaching agent such as sodium chlorite, and dyeing treatment using a coloring agent, staining agent, etc.

In carrying out the single-stick chemical treatment method, first, the veneers to be treated are stored side by side in a veneer holder with the width direction of the veneers facing up and down, and then the bleaching agent and the coloring agent are applied.

It is immersed in a processing bath containing a processing chemical solution such as a dyeing agent, that is, a chemical bath.

The treatment chemical solution used may be at room temperature or heated depending on the properties of the column, the type of the veneer to be treated, etc.

Next, while the veneer holder housing the polygonally treated veneer is immersed in the chemical, a portion of the treatment chemical is discharged from the treatment bath.

The level of the chemical liquid in the chemical bath is lowered by the above-mentioned draining operation.

The discharged processing chemical is reinjected into the chemical bath after a certain period of time.

By the above injection operation, the level of the drug solution in the drug bath rises.

That is, the level of the chemical solution in the chemical bath rises and falls due to the above-mentioned discharge and injection operations of the processing chemical solution. In other words, since the treatment chemical fluid flows while contacting the veneer surface, the treatment chemical has a strong medicinal effect and acts between the surfaces of each veneer.

Furthermore, this vertical movement of the chemical liquid surface prevents air bubbles generated in the chemical liquid from adhering to the surface of the veneer.
The concentration of the chemical solution is always constant.

In this case, as a means for discharging the chemical solution from the processing bath and injecting the chemical solution, a diaphragm solenoid valve method, a pressure differential pump supply method, a siphon method, etc. are used as appropriate depending on the veneer processing capacity of the processing bath. .

In addition, the cycle of discharging and injecting such a chemical solution varies depending on the type of chemical treatment and the degree of treatment, but for a normal bleaching machine, 5 to 6 cycles per hour is appropriate, and the discharge and injection rate of the chemical solution at that time is appropriate. Although it depends on the volume of the treatment bath, it is preferably about 300 u/min.

As described above, in the method for chemically treating wood veneers according to the present invention, the discharge of the treatment chemical from the chemical bath and the vertical movement of the chemical surface by injection into the chemical bath improve the contact of the treatment chemical to the veneer. ing.

Therefore, according to the chemical treatment method of the present invention, a large amount of veneer can be treated uniformly and efficiently, and the treatment cost can be reduced accordingly. has extremely high industrial effects both technically and economically.

Below, actual examples and comparative examples of the present invention will be shown.

Example 1 Discolored cypress veneer (J!X 0.25mm, width 120mm
, length 4000mm) After storing 450 boards in a veneer holding device, add 20% (wt%) sodium chlorite aqueous solution 4
00 sentences.

It was immersed in a treatment bath containing 621 warm water, a pH adjuster, a buffer, and a penetration aid, and a bleach solution with a pH of 5.7, and the solution temperature was 40°C9, and the discharge and injection rate was 301. The bleaching process was carried out for 60 minutes with a discharge/injection cycle of 5 cycles per hour.

Next, the veneer holder containing the treated veneer was immersed in a 40'0 hot water bath for 30 minutes, neutralized with sodium sulfite, and further desalted and dried.

Cypress veneer 42 from which the discolored portion has been completely removed after drying
I got 5 plates.

Comparative Example 1 Example 1 except that the bleaching solution in the treatment bath was stirred at a rotational speed of 3° per minute instead of the discharge and injection operation in Example 1.
Bleaching treatment was carried out under the same conditions.

Table 1 shows the bleaching results of the treated veneers obtained by repeating the same experiments as in Example Work and Comparative Example 1.

Table 1 Example work Comparative example 1 Total number of treated veneers 2834 pieces (100%) 2781 pieces (
100%) Excellent veneer 2607 sheets (920%) 129
5 pieces (46.4%) defective veneer 227 pieces (8.0%) 2
85 sheets (102%) Reprocessed veneer None 1211 sheets (4
3.4%) Table 1 demonstrates the superiority of the chemical treatment method of the present invention.

Applicant: Sanyo Kokusaku Pulp Co., Ltd. Agent Patent Attorney Funabashi Kuniyoshi

Claims (1)

[Claims] 1. A method of chemically treating a veneer holder in which a plurality of wood veneers are housed side by side is immersed in a chemical bath, characterized by raising and lowering the chemical level of the chemical bath by discharging and injecting the treatment chemical. Chemical treatment method for wood veneer.