JPS6226478A - Method of drying 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 "Field of Industrial Application" The present invention relates to a vertical multi-stage hot press in which a plurality of hot plates are arranged at equal intervals between vertically opposed frames;
Alternatively, in a horizontal multi-stage hot press in which multiple heating plates are arranged at equal intervals between left and right frames, the veneer is transported and inserted between the heating plates that can be opened and closed in the pressing direction. This method involves drying veneers while fixing them at arbitrary intervals.

``Conventional Technology'' Conventionally, when drying veneer veneers, a contact heating method using a hot plate was used, which has superior thermal efficiency compared to hot air convection type veneer dryers.

According to this contact heating method, the moisture contained in the veneer veneer can be vaporized in a short time.

``Problems to be Solved by the Invention'' However, according to this contact heating method, the veneer veneer is inserted between hot plates with smooth surfaces and heated and pressurized, so the moisture content is absorbed into the fibers. When the steam evaporates into the atmosphere through the conduit of the veneer, and when the steam generated between the fiber rows of the veneer veneer is released to the atmosphere by the breathing opening of the hot plate, the stress accumulated inside the veneer acts. , resulting in free contraction.

In addition, immediately after drying, the moisture content of the veneer veneer varies between the center and the edges, and over time, when the moisture content of each part of the veneer equilibrates, distortion, cracks, etc. occurs.

The amount of free shrinkage, the moisture content, the degree of looseness, the amount of distortion, the amount of cracking, etc. vary depending on the species of the log, the thickness of the veneer veneer, etc.

``Means for Solving the Problems'' In view of the above, the present invention provides a first aspect of the present invention in which a plurality of stages are arranged oppositely at equal intervals in the pressurizing direction of a vertical or horizontal multi-stage hot press. A plurality of discontinuous protrusions are carved on one side of the hot plate in parallel with one side of the hot plate, and a plurality of discontinuous protrusions are formed at arbitrary intervals to form protrusions. A veneer veneer is inserted between the hot plates and the press is closed so that the direction in which the veneer is discontinuously engraved matches the direction of its fibers, and the veneer veneer is fixed to the plurality of discontinuous protrusions. It is heated and pressurized at the same time.

Further, in the second invention, discontinuous protrusions are carved on the other surface of the hot plate, with the phase between each strip being shifted by half a pitch, and the veneer veneer is fixed from the front and back surfaces in a staggered manner. It is heated and pressurized at the same time.

"Embodiment" First, an embodiment of the first invention will be described below with reference to FIGS. 1 to 4.

After perforating a plurality of holes at regular intervals in the length and width of the interior of the hot plate 1 body, the perforated portions are appropriately closed with plug rods to form a passage 2, and a supply port 3 and a discharge port 4 are formed in this passage 2.
is installed to circulate heating media such as hot oil and steam.

The hot plates 1 are arranged horizontally in multiple stages at equal intervals between the frames arranged above and below in a vertical multi-stage hot press, or arranged oppositely on the left and right sides of a horizontal multi-stage hot press. A plurality of stages are arranged vertically in parallel between the frames at equal intervals, and can be opened and closed in the pressurizing direction by the operation of a ram.

One side of the hot plate 1, that is, the left side or the right side in a horizontal multi-stage hot press, or the top or bottom surface in a vertical multi-stage hot press, or the bottom surface 5 in the illustrated example. Parallel to the side 6, a plurality of narrow protrusions 7 of a constant length are discontinuously carved at regular intervals.

Furthermore, a plurality of these discontinuous protrusions 7 are arranged at arbitrary intervals in the orthogonal direction on one side 6 of the hot plate 1, and the protrusions 7 of each strip are arranged in an inclined manner, or as in the illustrated example. It is formed into a curved shape 8.

Then, the veneer veneer 9 is carried between each stage of the hot plates 1 in the open state of the press, with the direction in which these protrusions 7 are discontinuously engraved matched with the fiber direction of the veneer veneer 9, Interpose.

After insertion, when the press is closed, discontinuous protrusions 7 carved on the lower surface 5 of the hot plate 1 are inserted between the fiber rows on the surface of the veneer veneer 90.
When the veneer veneer 9 is heated and pressed while being fixed to the smooth upper surface of the hot plate 1, it becomes K. At this time,
The opposite surface of the back crack side that has occurred in the veneer veneer 9 is inserted opposite to the protrusion 7 to correct the warpage of the veneer veneer 9.

During heating and pressurization, the moisture contained in the veneer veneer 9 is released into the atmosphere through the conduit, and the steam generated between the fiber rows is transferred to the curved concave portion 8 and the veneer veneer 9 as shown in FIG. The gap between the surface and the surface of the material will lead to air leakage.

Also, as it dries, shrinkage stress acts on the veneer veneer 9,
The entire surface of the veneer veneer 9 is pressed and fixed to the protrusions 7 which are discontinuous in the direction of the fibers.
A tensile force acts on the contraction stress, and free contraction is prevented by forming fine grooves in the region where the protrusion 7 is present.

Next, an embodiment of the second invention will be explained based on FIG. 5 to FIG. This is intended for materials with large variations in the amount of

Therefore, in the first invention, the protrusions 7 are carved only on one side of the hot plate 1, but in the second invention, the protrusions 7 are carved on both sides of the hot plate 1, that is, the horizontal multi-stage hot press. Projections 7 are carved on both the left and right sides of the hot press, and on both the top and bottom sides of a vertical multi-stage hot press.

That is, to explain its characteristic parts based on an embodiment, in the first invention, a plurality of discontinuous protrusions 7 carved on the lower surface 5 of the hot plate 1 are formed in a plurality of stripes at arbitrary intervals. However, similar protrusions 11 are provided on the upper surface 10 of the hot plate 1 so that the phase between each strip is at least half the pitch L between the strips on the lower surface 5.
It is engraved at a different angle.

In the illustrated example, the protrusions 7 on the lower surface 5 and the protrusions 11 on the upper surface 10 are also carved with a phase shift of half a pitch P with respect to the direction parallel to one side 6 of the hot plate 1. .

Therefore, similarly to the first invention, the direction in which these protrusions 7 and 11 are discontinuously carved between each stage of hot plates 1 when the press is opened matches the fiber direction of the veneer veneer 9. Then, the veneer veneer 9 is carried in and inserted. When the press is closed after insertion, the discontinuous protrusions carved on the lower surface 5 of the hot plate 1 are inserted between the fiber rows on the surface of the veneer veneer 9. At the same time, a body 7 is carved on the upper surface IO of the hot plate 1 between the fiber rows on the back side of the veneer veneer 9.

The discontinuous protrusions 11 bite into the entire front and back surfaces of the veneer veneer 9 in a staggered manner, and heat and pressurize the veneer veneer 9 while fixing it at a plurality of locations from the front and back surfaces.

During heating and pressurization, the moisture contained in the veneer veneer 9 is released into the atmosphere through the conduit, and the steam generated between the fiber rows is transferred to the lower surface 5 and upper surface 10 of the hot plate 1, as shown in FIG. It is led out to the atmosphere through the gaps created between the curved recesses 8 formed in a staggered manner and the front and back surfaces of the veneer veneer 9.

In addition, the shrinkage stress that occurs due to drying is suppressed by the fact that the veneer veneer 9 is pressed and fixed to the protrusions 7° 11 in a staggered manner over the entire front and back surfaces of the veneer veneer 9, so that fine grooves are formed on the front and back surfaces. formed and prevents free contraction.

``Effects'' As described above, according to the present invention, a plurality of narrow protrusions of a constant length and a narrow width are discontinuously provided on one side or both sides of the hot plate in a direction parallel to one side of the hot plate. Furthermore, since multiple stripes of discontinuous protrusions are formed at arbitrary intervals, the veneer veneer will not break or break along its fiber direction when heated and pressurized. Fine grooves are intermittently formed parallel to the fiber direction without causing any damage, and the shrinkage stress caused by drying can be absorbed.

However, it is possible to reduce the amount of distortion and the amount of cracking caused by changes over time after drying, and it is possible to dry a veneer veneer with excellent thermal efficiency.゛

[Brief explanation of drawings]

FIG. 1 is a partially cutaway plan view showing an embodiment of the first invention;
2 is a side view of the same, FIGS. 3 and 4 are explanatory diagrams of the same operating state, FIG. 5 is a partially cutaway plan view showing an embodiment of the second invention, and FIG. 6 is a side view of the same, FIG. 7 to FIG. 8 are explanatory diagrams of the same operating state. DESCRIPTION OF SYMBOLS 1...Hot plate, 5...Bottom surface, 6...-side, 7...Protrusion, 8...Curved shape, 9...Plywood veneer, 10...
Top surface, 11... Projection patent applicant: Taihei Seisakusho Co., Ltd. 8ヱ

Claims (1)

[Scope of Claims] 1. In the pressing direction of the multi-stage hot press, a protrusion is provided on one surface of each of the hot plates arranged in multiple stages at equal intervals in parallel with one side of the hot plate. A plurality of discontinuous protrusions are continuously carved, and a plurality of these discontinuous protrusions are formed at arbitrary intervals, and the direction between the hot plates is adjusted so that the direction in which the protrusions are discontinuously carved matches the fiber direction of the protrusions. A plywood veneer is inserted and the press is closed.
A method for drying a veneer veneer characterized by heating and pressurizing the veneer veneer while fixing the veneer veneer by a plurality of discontinuous protrusions. 2. On one side of each of the hot plates installed in multiple stages at equal intervals in the pressurizing direction of the multi-stage hot press, protrusions parallel to one side of the hot plate are discontinuously carved. In addition, a plurality of protrusions are formed at arbitrary intervals, and discontinuous protrusions are carved on the other surface of each hot plate, with the phase between each of the protrusions being shifted by half a pitch, so that the protrusions are discontinuous. A veneer veneer is inserted between the hot plates so that the fiber direction matches the direction in which the veneer is formed, and the press is closed. A method for drying veneer veneer, which is characterized by applying heat and pressure.