JPS60250902A - Method of adjusting moisture content in 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 [Technical Field] The present invention relates to a method for adjusting the moisture content of a veneer, which is performed when obtaining a dyed veneer or the like.

[Background technology]

To obtain dyed veneers for the production of artificially decorated veneers, a decolorizing solution is applied to the raw veneers, and steam is heated while the veneers are loaded.
The applicant has developed and implemented a method in which a staining solution is then applied to the decolorized veneer and heated with steam while the veneer is loaded.

The decolorized veneer has a temperature of nearly 100°C due to the heat treatment described above. Therefore, if this is allowed to cool naturally,
Surface drying of the veneer occurs, and this surface drying may cause insufficient penetration of the dye in the next step of coating dyeing, resulting in poor dyeing. That is, a minimum of 70% is required for dye penetration.
This is because a water content higher than that is required.

[Purpose of the invention]

Therefore, an object of the present invention is to provide a method for adjusting the moisture content of a veneer, which avoids poor dye penetration in coating-type dyeing by maintaining the moisture content of high-temperature wood veneers after coating-type bleaching. be.

[Disclosure of the invention]

In order to achieve the above object, the present invention is characterized in that when cooling a heat-treated wood veneer, the surface of the wood veneer is cooled by bringing it into contact with a cooling roll immediately after the heat treatment is completed. The gist of this article is how to adjust the moisture content of veneer. This will be explained in detail below based on drawings showing examples thereof.

FIG. 1 shows an example of a process for producing a dyed veneer, including a method for adjusting the moisture content of the veneer, according to the present invention. Prepared material veneer 1
On the other hand, a decoloring liquid is applied using a roll coater 2.

Thereafter, the obtained veneer 1' coated with the decolorizing solution is loaded and heated by applying steam 3. This steam heating promotes penetration of the applied decolorizing liquid and increases the decolorizing effect. This coating type decolorization method has advantages over the conventional immersion type decolorization method, such as requiring less amount of decolorizing agent and eliminating the need for waste liquid treatment. Conventionally, the decolorized veneer panels that have been steam-heated in this manner are left to cool naturally while being loaded. Then, the dye was applied using a flow coater or a roll coater, and the veneer was loaded again and heated with steam to dye the veneer. 4 is passed between cooling rolls 5, 5, and brought into contact with each other to rapidly cool it. Although the type of cooling roll does not matter, it is preferable to use a metal roll and keep the temperature below 20°C. After cooling, the decolorized veneer 4' is directly sent to the dye coating process. That is, the dye solution is applied by passing it between the dye application rolls 6.6, and then the obtained dye-coated veneer 7 is loaded and steam 3 is applied, thereby increasing the dyeing effect of the spread-type dyeing method. That's what I do.

In the present invention, as described above, the high-temperature veneer after decolorization is immediately cooled by the cooling roll, thereby preventing rapid drying from the surface of the veneer. Therefore, the moisture content of the bleached veneer is maintained at 70% or more.

Next, an embodiment will be described together with a conventional example.

A comparison is shown below between coated decolorized veneers dyed using a conventional method and those treated and dyed using the method of the present invention.

The coated decolorized veneer was obtained as follows. The moisture content was 77.3% (σ Yuichi, = 5.8), the decolorization method was hydrogen peroxide, and the veneer temperature was 100℃ (
It is considered to be equal to the above steam temperature. ), the material is agathis wood with a thickness of 1.0 mm and a sapwood of 50 cm x 50 cm. For cooling after decolorization, in the conventional method, the loaded state is left to cool, but in the processing method of the present invention (example), a stainless steel cooling roll with a diameter of 25 cm is used, and the temperature is 0. The temperature was adjusted to ±5°C and cooling was performed at a feed rate of 0.25 m/sec (Example).

Dyeing was done by a paint dyeing method. The dye solution is Suminol Milling Brown 5 R (Sun+1nol
Milling Broivn 5R) 0.4%. The coating amount was 150±l Og/rd, and the subsequent heat treatment consisted of exposing a stack of 25 sheets to steam at 100° C. for 5 hours and heating with steam.

The results obtained are shown in Table 1, and while the conventional method had poor dyeing unevenness, the method of the present invention yielded dyed veneers with almost no dyeing unevenness.

(Hereafter, extra white) Next, in parentheses is σ, -2.

〔Effect of the invention〕

As described above, this invention uses cooling rolls to perform cooling after heat treatment, so it is possible to avoid drying of the surface of the veneer, and it has the advantage of avoiding poor dye penetration in coating dyeing methods. is obtained.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram illustrating a coating dyeing method including an embodiment of the method of the present invention. 4... Veneer after steam heating 5... Cooling roll agent Patent attorney Takehiko Matsumoto

Claims (1)

[Claims] (11) In cooling the heat-treated wood veneer, the surface of the wood veneer is cooled by bringing it into contact with a cooling roll immediately after the heat treatment is completed. (2) The cooling roll is a metal roll, and the roll temperature is 2.
The method for adjusting the moisture content of a veneer according to claim 1, wherein the temperature is 0°C or less. (3) The method for adjusting the moisture content of a wood veneer according to claim 1 or 2, wherein the heat treatment is steam heating after applying a decolorizing agent to the wood veneer.