JP2849775B2 - Surface treatment method for wood products - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to an improvement in a method for processing the surface of wood, and in particular, to harden, polish, and prevent discoloration of the surface of wood products containing a high resin content such as pine. About things.

[Prior Art] Wood, especially softwoods such as pine, cedar, and cypress are generally soft and easy to be damaged, and are difficult to use for floorboards and the like. However, pine is somewhat harder than other softwoods, but is also easily scratched.

Therefore, conventionally, these softwood materials have been subjected to plastic material processing to improve the quality of the materials and surface hardening. For example, it is impregnated with vinyl monomers such as MMA (methyl methacrylate) and styrene and cured by heating.
For example, a film such as (polyethylene) or EVA (ethylene-vinyl acetate copolymer) is heated and fused to the surface, or PEG (polyethylene glycol) is injected.

However, such strengthening by plastic treatment increases the specific gravity of wood, and requires a large amount of chemicals and processing, resulting in high costs. In addition, there are drawbacks such as significantly reducing the moisture absorption / exhaustability and the warm touch, which are the excellent points of wood, making the wood slippery when wet with water, and causing the plastic to peel off from the surface after a long time, making it hard to see.

[Problems to be Solved by the Invention] Therefore, a method of increasing the surface hardness and the surface gloss by heating and compressing only the surface layer of wood has recently been developed.
This utilizes the plasticity and permanent set of wood due to heat, moisture and pressure, and the surface layer of wood becomes denser and the strength increases. The degree depends on the type of wood, water content, and processing conditions, but it is said that the surface strength is about 10 to 40% and the wear resistance of the surface is about twice.

However, this processing method has no problem with cedars and cypresses, but in the case of wood containing a high resin content such as pine genus, a large amount of tar leaks out on the material surface due to heating and pressing, making processing difficult. And ruin the lumber again. Even if the tar that has leached on the surface is removed with a solvent or the like, the tarnish gradually discolors due to the tar or the like gradually oozing out from the inside.
Therefore, although there is a great demand, it has been impossible to achieve surface hardening of pine wood by heating and pressing.

Therefore, the present inventor paid attention to the pine content and succeeded in removing the pine content from the pine material and performing surface hardening treatment by heating and pressing.

[Means for solving the problems] Pine genus includes pine (Akamatsu / Kuromatsu etc.), Ezomatsu, Yonematsu,
There are many types such as New Zealand pine, but all of them contain tartar (pine resin). The resin content is
It is roughly composed of oily terpenes and solid resin acid (commonly known as rosin). As time passes, tar stains ooze out on the product surface and gradually change from brown to dull black, There is a drawback to lower. If the solar drying is performed, such a phenomenon occurs more or less. The hardened tar on the surface of the timber cannot be removed and the discoloration can only be bleached with a bleaching agent. However, the bleaching process loses the original taste of the wood or weakens the wood.

Therefore, the present inventor, after sawing pine wood to the required dimensions,
When put into a pressure cooker and heated and pressurized by injecting live steam, the pine in the pine was successfully removed to a level that did not substantially discolor at a later date. A pressure tank horizontal type tank type with several perforated pipes for jetting live steam inside was used, but if it has a structure that can store wood and heat and supply live steam in a closed type Anything is fine.

The descaling process is based on the type of product (plate,
In the case of a board, it depends on whether it is a straight grain or a grain, etc.) and dimensions (especially thickness), but a temperature of about 100 to 130 ° C and a pressure of about 0.5 to 1.5 kgf / cm ² may be applied for about 3 to 8 hours. Is performed day and night.

In the case of a normal plate material, 115 to 130 ° C., more preferably 12
The temperature is about 0 to 125 ° C. and the pressure is about 0.8 to 1.5 kgf / cm ^2, more preferably about 1.0 to 1.4 kgf / cm ^{2, for} about 3 to 8 hours. Of these, it is desirable to raise the temperature and pressure slowly for about 1 to 2 hours and to lower and lower the temperature slowly over about 1 hour. In the case of a straight plate, warping or cracking is unlikely to occur, so that somewhat harsh conditions are acceptable. If the thickness is about 10mm or 20mm, it is possible to completely remove the debris by this treatment.

In the case of products such as thick plates and square materials, especially pillars, which are thick and have a high risk of cracking or deformation, the pressure is 0.5 to 1.3 kgf / c.
It is preferable that the heat treatment is performed gradually over a long period of time (for example, 8 hours or more or one day and night) under mild conditions of m ² and a temperature of about 105 to 1115 ° C. This is to prevent cracking and deformation due to rapid temperature and humidity changes. In this case, the temperature is raised and raised in about 2 to 3 hours. After maintaining this state for several hours, the air is gradually exhausted to normal temperature and normal pressure. However, in the case of a structural material such as a column material, care must be taken because the material is weakened if the die is removed too much. In this case, if the dust is removed from the surface to about 5 to 8 mm depending on the size, discoloration with time hardly occurs and strength deterioration is small, so the degree of removal of the dust is controlled by adjusting the temperature, pressure and time.

The reason why the dust removal is performed immediately after the lumbering is because the bleeding component and the color development on the surface of the lumber progress immediately after the lumbering. Also, the logs in storage gradually change color from the mouth to the inside when dried. Once the material has been discolored, the discolored component cannot be removed even by removing the varnish of the present invention. Therefore, in order to prevent discoloration, it is necessary to always immerse the logs in water or spray water to keep them moist.

By the way, in the above descaling process, dehydration of wood is also performed at the same time. Typically, wood products immediately after sawing have a moisture content of 50
It is about 60%, but this is 20-30%
About. The water or steam condensed water extracted from the wood is discharged as a black and rough waste liquid containing a small amount of lignin and volatile components in addition to tan. Next, it is further dried to a water content of about 10 to 13%. This is because permanent compression strain is less likely to occur when the water content is high in the next heating, pressing and compressing step. Drying may be natural drying such as air drying or solar drying, or artificial drying using various heat sources in a dryer. Once you remove the tarnish,
There is no discoloration due to drying and subsequent aging. After drying, the surface is cut by a plane, finished with a grinder, or subjected to a finishing treatment according to the wood product such as navel cutting.

The pine product that has undergone each of the above processing steps is passed through a pressure roller to compress the surface under pressure. At least one of the pressure rollers is a heating roller, and the temperature is 150 to 230 ° C., particularly,
About 190 to 210 ° C. is preferable. The pressing force (compression force) is controlled by the distance between the upper and lower rollers, and is approximately 85 to 95% of the product thickness. The strength and luster of the product surface layer increase as the pressing force increases and the temperature increases, but if the conditions are too tight, cracking or discoloration occurs, so the above range is desirable. If the moisture content of the product is high, compression strain is unlikely to occur, so that the moisture content of the wood product is set to about 10 to 13% as described above.

Due to this heat and pressure compression, wood grain emerges on the surface of the wood product that is in contact with the heating roller, and the press and heating of the remaining lignin etc. gives a beautiful luster. It changes completely. Even if you do not paint varnish etc. on the wall material etc., it will have a more calm luster, and if it is floor material, it will be glossy and the grain of wood will play a role of non-slip, making it extremely easy to use . Also, if a dyeing solution such as a dye or pigment is applied to the product surface before the heat and pressure treatment,
Various colors, for example, a color resembling a high-grade material or a white background material can be colored reddish, and partial discoloration and color variation can be covered by coloring.

However, the pine wood product which has been subjected to the above-mentioned heating, pressurizing and compression treatment tends to lose its surface hardening and luster due to absorption when exposed to water. In addition, there is also a problem that dirt easily adheres as in general wood products. This is particularly problematic for flooring. Therefore, in order to solve such a defect, a surface treatment material such as a natural fat or oil (for example, a material obtained by dissolving a mixture of a wax and a coloring agent in an oil material derived from vegetable oil or a wax) in a solvent is applied thinly after the above treatment. Then, the moisture resistance and water repellency are improved while keeping the moisture absorption and drainage and the feel of wood as it is, and when polished with a puff or mop, the luster becomes beautiful. The coloring in this case serves the same purpose as the above-mentioned dyeing solution.

On the other hand, when the surface of the pine laminated wood is subjected to surface hardening and glazing by heating and pressing, the bonded portion is hard to be compressed, so that it appears as a streak and lowers the commercial value. Therefore,
First of all, after applying various treatments such as stripping, drying, and slicing to the square lumber, and assembling, at least one of them is lightly pressed with a heated pressure roller (approximately 1/3 to 2/3 of the polishing process) and bonded. After projecting the portion, the surface may be smoothed again by plane finishing, and then pressurized and compressed with a predetermined pressing force to perform surface hardening and polishing of the entire surface. When gluing pine boards or sliced products to the surface of laminated wood (regardless of the type of wood), apply a smoothing process such as pressing and compressing and plane finishing to the pasted side of the laminated wood in advance. If you keep it, the product surface will be beautifully finished without stripes from the glued lumber seam.

[Examples] Next, the present invention will be described in more detail with reference to examples.

Example 1 A 10-cm-wide, 12-mm-thick, 4-m-long sawn pine plate was
Immediately after sawing, a large number of pallets are stacked vertically and vertically via a bar (19 mm square), and the pallets are placed in a pressure cooker.

The pressure cooker has a horizontally long cylindrical shape, and several perforated pipes for spouting live steam are arranged around the inside of the pressure cooker. Temperature rise and pressure rise
Perform gradually over 60 minutes, and keep the condition of 120 ° C. and 1.3 kgf / cm ² for about 2 hours. After that, the air is gradually exhausted to normal temperature and normal pressure over 60 minutes. During the heating and pressurization, a black pigment (e.g., tar) is extracted from the plate together with moisture, and dewatering is performed together with tar removal. No warping or cracking was found in the stripped sheet material. The water content of the board was about 25%.

The plate material taken out of the pressure cooker was further placed in a steam-heated dryer, and dried for 2 to 3 days to a water content of 10%.
Next, finishing processes such as planing and grinder polishing of both surfaces and navel finishing of the butted surfaces were performed.

Next, the finished pine plate material was subjected to surface hardening and polishing by heating and pressing. The heating and pressing was performed by passing through a pair of pressing rollers having a diameter of about 30 cm and a width of about 40 mm. The upper heating roller is heated to about 205 ° C, and the distance between the upper and lower rollers is 10.8mm (compression rate 90%)
Has been adjusted. The feed speed was 1 m / min.

Thus, a glossy plate material was obtained with a hardened surface and a powdery appearance.

Example 2 A rice pine column material sawn to a length of about 12 cm square (four dimensions square) and a length of 3 m,
A large number of pallets were stacked vertically on a pier, and the pallets were placed in a pressure cooker in the same manner as in Example 1 to perform dedusting and dewatering. The condition is 110 ℃, 1.2kg over about 3 hours
The temperature is raised to f / cm ² . In this state, the steam is stopped, and if left overnight, the temperature gradually drops, and after about 16 hours, it becomes normal temperature and normal pressure. During this time, a black pigment (e.g., tar) is extracted together with moisture from the plate material, and dewatering is performed together with tar removal. No cracks were seen in the pillar material from which the resin had been removed, and the resin component had been removed up to about 7 mm from the surface. The water content of the column was about 25%.

The pillars taken out of the pressure cooker were further dried by natural drying for about two months to make the water content approximately 12%. Then
Finished by four planes and grinder polishing.

Next, surface hardening and glazing were applied to all four surfaces of the finished pine pillar material by heating and pressing. The heating and pressurizing is performed by using the upper and lower rollers in the apparatus of the first embodiment.
Performed by heating to ° C. The distance between the upper and lower rollers is 10.2cm
(Compression rate 85%), and the feed rate was 1 m / min. Thus,
The surfaces of all the surfaces were hardened and quail appeared, and a glossy pine pillar was obtained.

Example 3 After performing the same various treatments as in Example 1 on a white pine board having the same dimensions as in Example 1, a reddish dyeing solution (aqueous neoca, diluted 200 times) was applied to one surface, and Air dried for about an hour.

Then, the same heated and pressed compression treatment as in Example 1 was applied to the dyed surface to obtain a reddish and excellent plate material similar to the core material.

Example 4 In Example 1, a surface treatment agent (waterproofing and polishing agent) was applied to the surface of the finally obtained heat and pressure compression treatment agent.
Pine OS color (Distributor: Sunmore Trading Co., Ltd. 15
It was applied at a rate of 2020 cc / m ² and then the surface was puffed. With this finishing, a plate material having a calm color more than the original gloss, a woody feel, moisture absorption and desorption, and water repellency was obtained. This OS color is obtained by dissolving 70% of a mixture of oil and wax derived from vegetable oil and a coloring agent in 30% of alcohol.

Example 5 A pine plate material having a width of 40 mm and a thickness of 13 mm, which was finished in the same manner as in Example 1, was laminated to obtain a laminated material having a thickness of 40 mm and a width of 120 mm. The laminated material was pressed and heated and compressed (roller gap: 38 mm; compression ratio: 95%) in the same manner as in Example 1, and the protruding adhesive portion was plane-smoothed. Then, the roller gap
The thickness was adjusted to 34 mm (85% compression ratio), and the mixture was heated and compressed again to obtain a laminated material having one surface hardened and polished.

[Effects of the Invention] As described in detail above, the present invention puts high-resin content wood, such as pine, into a pressure cooker immediately after sawing, performs steam removal and dewatering with steam, and then dry and planes. After finishing such as above, it is passed through a heated pressure roller to prevent discoloration due to tanning over time and simultaneously cure and polish the surface.

Therefore, it is possible to easily and surely process pine wood products, which have been difficult or impossible to achieve by glazing and surface hardening by heating and compression, and there is no discoloration for a long time. It is a very large place to contribute to. Moreover, since chemicals and the like are not used for removing the dents, there are advantages such as safety and low cost.

Similarly, a pine laminated wood or a decorative laminated wood in which a pine board or a sliced product is bonded to the surface of various wood laminated materials also has the effect of easily and reliably performing surface hardening, glazing, and preventing discoloration.

Claims (4)

(57) [Claims] 1. A wood containing a high resin content, such as pine spp., Is put into a pressure cooker immediately after sawing, and after dedusting and dewatering by steam, further dried, and then subjected to finishing treatment such as planing. A method for surface-treating a wood product, wherein the surface is hardened and polished by passing at least one of them through a heated pressure roller. 2. After the timber of high-resin content wood such as pine is subjected to various treatments such as desiccation, drying and planing, it is assembled.
After at least one side is lightly compressed with a heated pressure roller to make the adhesive part protrude, the surface is finished smooth again,
Then, the surface of the wood product is polished by pressurizing and compressing the surface with a predetermined pressure. 3. A method for processing a surface of a wood product according to claim 1, wherein a dyeing solution is applied to the surface of the wood product before passing through the heated pressure roller. 4. The wood product according to claim 1 or 2, wherein after the surface is hardened and polished with a heated pressure roller, a surface treatment agent is applied to the surface of the wood product to finish the puff. Surface processing method.