JPS59209804A - Manufacture of flitch - 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 manufacturing a flitch. [Background Art] As shown in Fig. 1, a conventional flitch has a mold surface that is curved in a convex shape, and is used for high-frequency dielectrics. An upper mold 1 which also serves as a heating anode,
A laminate 3 made of a plurality of wood veneers laminated with adhesive is inserted between the lower mold 2, which has a mold surface corresponding to the mold surface of the upper mold and also serves as a cathode for high-frequency dielectric heating. It is manufactured by pressurizing (pressing) the mold 1 and lower mold 2 while applying high-frequency dielectric heating. However, when manufacturing a flitch in this way, the number of laminated wooden veneers is large (as the impedance of the heated object increases, it is necessary to increase the capacity of the high frequency oscillator. Therefore, A method using a small-capacity high-frequency oscillator has been considered and is being implemented in some cases.
100 sheets are piled up and the small portion is a laminate (called a "book")
This method involves creating a predetermined flitch by sequentially stacking the books. In this case, the book is converted into a flitch as follows. In other words, when a book is placed on a lower mold, another book is placed on top of it with an adhesive layer interposed, and the upper mold serves as an anode for high-frequency dielectric heating, and the lower mold only performs a stamping effect. First, a high-frequency dielectrically heated cathode plate is brought into contact with the side surface of the book, and at the same time as pressing, a high frequency is applied between the anode and cathode plate to dielectrically heat the adhesive layer to accelerate curing. As shown in Figure 2, a new book 4' is stacked with the adhesive layer 6' interposed therebetween, and the abutment position of the cathode plate 8 is changed upward, and the book 4' is stacked by curing in the same manner as above. Gluing is done. In Fig. 2, 4 is a book, 5 is a lower mold, and 6 is a book.
is a laminating agent layer, and 7 is an upper mold. That is, when sequentially laminating and bonding books 4, dielectric heating is performed effectively on the adhesive layer 6' to which a new book 4' is bonded.
The cathode plate 8 is arranged laterally and is configured to be movable up and down. However, when high frequency is applied by bringing the cathode plate 8 into contact with the side surface of the book 4 in this way, the distance between the electrodes differs between the ends and the center of the book stack, so the electric field strength near the cathode plate 8 It becomes stronger at a distance, and becomes weaker at a distance farther than that. Therefore, the center part of the adhesive layer 6' to which the new book 4' is attached is at the target temperature (70 to 90°C).
The temperature of the end portion rises to 100° C. or more before reaching 100° C.), causing problems such as poor adhesion and deformation. Therefore, it has been considered to position the cathode plate 8 further away (lower) than the anode 7 so that the difference in distance between the electrodes between the ends and the center of the book stack becomes smaller. However, there is a limit to lowering the position of the cathode plate in this way, and if the cathode plate is lowered in this way, one book will be heated many times and the temperature will become too high. A problem arose.

[Purpose of the invention]

The purpose of this invention is to reduce the temperature difference between the ends and the center of the adhesive layer as described above, without increasing the capacity of the high-frequency oscillator or lowering the cathode plate. It is.

[Disclosure of the invention]

This invention consists of an upper mold that also serves as one electrode for high-frequency dielectric heating, a lower mold having a mold surface corresponding to the upper mold, and a pair of left and right plates arranged vertically movably between the upper mold and the lower mold. A flitch manufacturing device is prepared which is equipped with an electrode plate that serves as the other electrode for high-frequency dielectric heating, and a material veneer laminate is placed between the upper mold and the lower mold, and the material veneer laminate is Electrode plates are brought into contact with opposing sides via a plate-shaped dielectric material (which has a lower dielectric constant than the material veneer of the material veneer laminate), and the material is heated between the upper and lower molds while being subjected to high-frequency dielectric heating. The feature is that the veneer laminate is compressed to form a flitch.

In other words, by bringing electrode plates into contact with opposing sides of the material veneer laminate via the dielectric as described above, the electric field strength between the ends and the center of the adhesive layer of the material veneer laminate can be reduced. The difference becomes smaller, and the temperature difference force becomes smaller by 11%.

Next, this invention will be explained in detail based on examples.

FIG. 3 is a block diagram of one embodiment of the present invention.

That is, in this embodiment, high-frequency dielectrically heated cathode plates 8 are placed on opposing sides of the book 4, and a material (for example, silicone resin) having a lower dielectric constant than the single plate of material constituting the plate 4 is used.
They are in contact with each other via a plate-shaped dielectric material 9 made of. The rest is the same as in FIG. 2, and the same parts are given the same reference numerals.

With this configuration, the electric field strength is made uniform, and the temperature between the ends and center of the adhesive layer 6' to which the new book 4' is bonded is reduced, which prevents problems such as poor adhesion and deformation. Occurrence will be avoided.

This uniformization of the electric field strength will be explained based on the following equation.

First, when the plate-shaped dielectric 9 is not interposed, the central part (A
), E person'−'J/d 1 end (B), Eg = V/d 2EA/EB =, d2
/di.

Next, when the plate-shaped dielectric 9 is interposed, the central part (A
), then E^= where d3/ε2〉〉d2/ε1d3/δ2〉
If it is d5/ε, then it becomes EA/E8#l.

That is, in order to increase d3/ε2, if the plate-shaped dielectric 9 is made of a material with a small dielectric constant ε2, the electric field strength between the ends and the center can be made uniform.

Next, using a veneer of the following tree species, a silicone resin plate dielectric 9 with a thickness of 51 was interposed between the cathode plate 8 of the above embodiment and the side surface of the book 4, and flitching was performed under the following conditions. I made it.

Wood species used: Agatis veneer size: 303x606x1t (100 pieces) Cathode position: 170B from the anode Cathode size: 60mm width (with fins) High frequency voltage: 1200V High frequency current 70.8A Application time: 5 minutes In this case, the center temperature and The difference from the end temperature is about 5 to 8°C, and the temperature difference is 20 when the plate-shaped dielectric 9 is not interposed.
Significantly better results were obtained compared to ~30°C.

In the present invention, instead of stacking and bonding prefabricated books, the books may be sequentially stacked and bonded to form a flitch while the books are being fabricated using the above-mentioned apparatus.

〔Effect of the invention〕

In order to manufacture a flitch as described above, this invention
A flitch without poor adhesion or deformation can be obtained without increasing the capacity of the high-frequency oscillator or lowering the cathode plate.

[Brief explanation of the drawing]

1 and 2 are explanatory diagrams of a conventional example, FIG. 3 is a configuration diagram of an embodiment of the present invention, and FIG. 4 is an explanatory diagram of its operation. 4.4'... Book 5... Lower mold 6.6'...
Adhesive layer 7... Upper mold 8... Cathode plate 9... Plate dielectric agent Patent attorney Takehiko Matsumoto Figure 1 Figure 2 Figure 4

Claims (1)

[Claims] (11) An upper mold that also serves as one electrode for high-frequency dielectric heating, a lower mold having a mold surface corresponding to the mold surface of the upper mold, and a vertically movable member between the upper mold and the lower mold. A flitch manufacturing device is prepared, which is a pair of left and right plate-shaped bodies to be arranged, and is equipped with an electrode plate that serves as the other electrode for high-frequency dielectric heating. An electrode plate is brought into contact with the opposing side surfaces of the material veneer laminate through a plate-like dielectric material having a lower dielectric constant than the material veneer of the material veneer laminate, and the upper mold and the upper mold are heated while applying high frequency dielectric heating. A method for manufacturing a flitch, which comprises pressing a laminate of material veneers with a lower mold to form a flitch. (2) A method for manufacturing a flitch according to claim 1, in which the plate-like dielectric is made of silicone resin. .