JPH05261707A - Method for predrying veneer - Google Patents

Abstract

PURPOSE:To systematically, efficiently and economically perform the predrying of veneer peeled off by a rotary race by the sun's rays and the waste heat from a facility heat source. CONSTITUTION:The roof of a factory is made of glass or plastic pervious to the sun's rays, and a guide rail for drying and transporting veneer is arranged under the roof over a wide range and veneer peeled off by a rotary race is successively guided to the area under the roof by the guide rail and circulated under the roof to be subjected to predrying by the sun's rays and the waste heat from the facility heat source in the factory.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is to systematically, efficiently and economically preliminarily dry a veneer peeled by a rotary race with sunlight and heat discharged from a heat source of equipment. By adopting the preliminary drying step, the subsequent main drying can be efficiently performed.

[0002]

2. Description of the Related Art At present, a veneer made by peeling a log with a rotary lace is placed in a dryer exclusively for wood and dried. However, since the moisture content of each part of the log is different, it is dried simultaneously under certain conditions. Even so, the dried veneer may be insufficiently dried or over-dried, and the insufficiently dried veneer is passed through the dryer again.

It is also conceivable to stack the veneers indoors and allow them to dry naturally, but this requires a large space and a long number of days. Furthermore, it may be possible to spread it outdoors and dry it with sunlight, but it requires a large vacant lot and rain, sand dust, etc. will adhere. The effort of spreading and incorporating is also difficult.

When a veneer laminated material or plywood is made by using a veneer that is insufficiently dried, the finished material is warped,
Deformation troubles such as twisting often occur.

[0005]

The problem to be solved by the present invention is to systematically, efficiently and economically determine the type of heat source used for single-plate predrying, the place of use and the method of use. By introducing the preliminary drying step of the present invention,
Conventionally, it is possible to prevent troubles such as insufficiently dried products occurring when dried in a dryer for exclusive use of wood and the re-drying.

[0006]

According to the present invention, the roof of a factory is a glass or plastic roof through which sunlight passes, and a wide range of equipment for drying and transporting veneers under the roof is installed. Then, guide the veneer peeled off by the rotary race under the roof by the guide of the drying and transportation equipment, and pre-dry with the sunlight and the heat exhausted from the heat source in the factory while circulating under the roof. Is a method for predrying a single plate. The present invention will be described in detail below.

The veneer used for the veneer laminated material and plywood is made by cutting logs from the pile as it is, or after dipping in hot water, continuously peeling it with a thickness of several mm while rotating it with a rotary race to obtain an appropriate length. Cut into pieces and make. A veneer laminated material or plywood is formed by drying the veneer, applying an adhesive to the adhesive surface, stacking several dozen to several sheets, and press-bonding. Here, it is important to dry the veneer, and a veneer laminated material or plywood made by using a veneer that is not sufficiently dried often causes deformation trouble such as warp or twist of the finished material.

Here, the cause of insufficient drying of the veneer will be described. Generally, as a property of one log, the core material (central portion) and the sap material (outer peripheral portion) have different moisture contents. .. The core material has a high water content, and the sapwood has a low water content. (For some types of logs, the moisture content of the core and sapwood may be the opposite of the above). Therefore, even the veneer peeled by the rotary lace has a high moisture content in the core veneer and a low moisture content in the sapwood veneer. When such veneers are uniformly placed in a wood dryer to dry, veneers that have been dried include those that are insufficiently dried and those that are overdried. If the product is insufficiently dried, it is passed through the dryer again. In some cases, the core material having a high moisture content and the sapwood having a low moisture content are separated from the beginning and passed through a wood dryer under different drying conditions.

The present invention relates to a method for solving the above problems of high and low moisture content after drying. That is, the pre-drying process is adopted, and the feature is that the type of heat source used for pre-drying, the place of use and the method of use are systematic, efficient, and
It's about doing it economically. Next, these will be described in detail.

The dry heat source used in the present invention is characterized by the combined use of sunlight and heat exhausted from equipment heat sources. The natural drying of veneers using these heat sources has a high drying efficiency for veneers with a high moisture content and a low drying efficiency for veneers with a low moisture content. First, there is an advantage that variations in the moisture content of each veneer after preliminary drying are reduced. Therefore, there is no problem of insufficient drying of the veneer that has been subjected to subsequent main drying, and there is little variation in the moisture content. In addition, there are advantages such as effective use of sunlight, which is economically costly, and exhaust heat from the heat source of equipment in the factory.

Next, regarding the pre-drying place adopted in the present invention, it is under the roof of a factory where sunlight is often exposed and the exhaust heat of the facility heat source can be efficiently used. Of course, the roof of the factory must be made of glass or plastic to allow sunlight to enter this part. In addition to the above, the advantage of having the pre-drying place under the roof of the factory is that a large space with no obstacles can be obtained, so the pre-drying capacity is sufficient, and the layout of the pre-drying equipment can be changed as desired. There is also something that can be designed.

Next, the preliminary drying equipment that can be used in the present invention will be described. First, the roof of the factory where the pre-drying process is performed is made of glass or plastic that allows sunlight to pass over a wide area. Next, under the roof, a wide range of equipment for drying and transporting veneers is installed. The equipment may be shaped like a roof or may be flat. As an example of such equipment, a large number of pairs of guide rails with a single plate width extending from one end to the other under the roof are provided in a wide range, and both ends of each guide rail set are adjacent to each other. The equipment will allow the veneer to move to the guide rail assembly. With such equipment, the veneer coming out of the rotary race is guided to the entrance of the guide rail and guided under the roof one by one, and the sunlight and the heat exhausted from the equipment using the heat source in the factory are generated while circulating under the roof. Can be pre-dried. It is also effective to blow air with a blower to increase the drying capacity while circulating under the roof.

It is to be noted that the veneer peeled off in the rotary race is automatically guided to the entrance of the guide rail one by one, and can be circulated under the roof by the guide rails installed in a wide area, that is, the rotary race and the preliminary drying equipment. The connection method is efficient. In addition, it is also efficient to connect the guide rail outlet that automatically guides the veneer that has been pre-dried to the subsequent wood dryer and the wood dryer.

As the veneer material to which the method of the present invention can be applied, all types of veneer such as pine, cedar, cypress, oak, beech, and lauan can be used.

[0015]

The feature of the present invention is, firstly, that the drying heat source adopted is a combination of sunlight and heat exhausted from the facility heat source. The natural drying of the veneer using these heat sources has a high drying efficiency for the veneer with a high water content and a low drying efficiency for the veneer with a low water content. There is an advantage that the variation of the moisture content of each veneer after the preliminary drying is reduced. Therefore, there is no problem of insufficient drying of the veneer that has been subjected to subsequent main drying, and there is little variation in the moisture content. In addition, there is an advantage that the heat emitted from sunlight and the heat source of equipment in the factory does not require utility costs. Secondly, the pre-drying place is under the roof of the factory, where sunlight is good and the heat emitted from the heat source of the equipment can be used efficiently. Of course, the roof of the factory must be made of glass or plastic to allow sunlight to enter this part. In addition to the above, the advantage of having the pre-drying place under the roof of the factory is that a large space with no obstacles can be obtained, so the pre-drying capacity is sufficient, and the layout of the pre-drying equipment can be changed as desired. There is also something that can be designed.

[0016]

EXAMPLES The model test of the present invention was carried out by the following method. First of all, we will use a glass greenhouse as a solar power facility,
A hot air heater was brought in and used as exhaust heat from the facility heat source.

The test veneer was obtained by peeling a cedar thinning log having a diameter of 20 cm and a length of 1.2 m with a rotary lace machine to obtain a veneer having a thickness of 2.5 mm, a width of 1.2 m and a length of 0.5 m. A large number of plates were prepared. The average moisture content of the produced veneer was 80% for the log sapwood and 140% for the core material.

Among the produced veneers, 3 veneer veneers and 3 veneer veneers were selected, hung with a wire at a position 50 cm below the roof of the greenhouse, arranged in parallel to the roof, and exposed to sunlight. .. Heat from a warm air heater was applied from the bottom. Furthermore, the front and back of the veneer were returned three times every two hours, and the surface exposed to sunlight was changed. The average moisture content of the veneer subjected to the above treatment for 8 hours was 45% for the sapwood and 55% for the core material, and the difference in moisture content was small. The pre-dried veneer was dried at 170 ° C. for 7 minutes with a wood dryer. After the treatment, the moisture content of the veneer was 10% or less for both the sapwood and the core material.

Next, an adhesive was applied to the adhesive surfaces of the above six veneers, and the veneers were laminated and pressed to form a veneer laminate. The thus prepared single plate laminated material having a thickness of about 15 mm was not deformed such as warped or twisted immediately after the production and after a lapse of more than half a year.

[0020]

[Comparative Example] Separately, three sapwood veneers and three core veneers were selected from the veneers produced in the examples, and dried with a wood dryer at the same time as the examples. After the treatment, the average moisture content of the single plate was 9% for the sapwood and 45% for the core material, and there was a difference in the moisture content of both.
It was necessary to pass the core material through the wood dryer once more to make the content 10% or less.

Next, an adhesive was applied to the adhesive surfaces of the above-mentioned six veneers, and the veneers were laminated and post-pressed to form a veneer laminate. The veneer laminated material having a thickness of about 15 mm produced in this way had a considerably remarkable warp deformation immediately after the production.

[0022]

EFFECT OF THE INVENTION Since the heat source of the present invention is naturally dried by using sunlight and heat exhausted from the facility heat source, even a single plate having a high moisture content has high drying efficiency, and the core material and the sap material are skipped. The variation in the moisture content of each veneer after preliminary drying is small. Therefore, there is no problem of insufficient drying of the veneer that has been subjected to subsequent main drying, and there is little variation in the moisture content. In addition, there is an advantage that utility costs are not required because the heat emitted from sunlight or the heat source of equipment in the factory is effectively used. Further, in the present invention, since the under roof of the factory is used as a predrying place, sunlight is often radiated and the exhaust heat of the equipment heat source can be efficiently used. A large space without obstacles can be obtained, so that the predrying capacity is sufficient. It also has the advantage that the layout of the preliminary drying equipment can be designed as desired. Also in the final product, the veneer laminated material and plywood made from the veneers pre-dried by the method of the present invention do not have deformation troubles such as warping and twisting.

Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location F26B 9/02 Z 9140-3L 23/00 B 9140-3L

Claims (2)

[Claims] 1. A roof of a factory is a glass or plastic roof through which sunlight passes, and a facility for drying and transporting veneers is installed under the roof over a wide area and peeled off by a rotary race. A guide for the veneer, which is guided by the drying and transporting equipment under the roof, and is pre-dried by sunlight and heat exhausted from a heat source in the factory while circulating under the roof. Drying method. 2. A veneer peeled off by a rotary race is placed on a pair of guide rails extending from one end under the roof to the other end, and is then moved to an adjacent guide rail. Move from one end of the rail to the other,
The method for predrying a single plate according to claim 1, further comprising predrying with sunlight and heat exhausted from a heat source of equipment in a factory while circulating between adjacent guide rails.