JP7281799B2 - How to exfoliate phloem from trees - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Law 1. 72nd Annual Meeting of the Kyushu Branch of the Society of Agricultural and Food Engineers of Japan and the 81st Kyushu Agricultural Research Presentation Meeting Agricultural Machinery Subcommittee Publication date August 31, 2018 2. 72nd Agricultural and Food Engineering Society Kyushu Branch Regular Meeting / 81st Kyushu Agricultural Research Presentation Meeting Agricultural Machinery Subcommittee Date September 1, 2018 Venue Tokai University Kumamoto Campus 3. The 81st (2018) Kyushu Agricultural Research Presentation Meeting Special Committee Presentation Abstracts (website) Publication date September 3, 2018 Address http://www. naro. affrc. go. jp/org/karc/qnoken/yoshi/no81/4. Agricultural machinery PDF/81-kikai12. pdf http://www. naro. affrc. go. jp/org/karc/qnoken/presentation/2018/04_nougyoukikai. pdf 4. Proceedings of the 28th Japan MRS Annual Conference (Website) Posting date December 5, 2018 Address https://www. mrs-j. org/meeting2018/abstract/jp/index_abst. php5. 6. Abstracts for the 28th Japan MRS Annual Conference (Abstract USB) Publication date: December 18, 2018 7. The 28th Japan MRS Annual Convention Date: December 18-20, 2018 Venue: Kitakyushu International Conference Center/West Japan General Exhibition Hall 2nd Shock Wave Applied Technology Study Group (Summary) Publication date March 1, 2019 8. 9. 2nd Shock Wave Applied Technology Study Group Date: March 1, 2019 Venue: Incubation, Faculty of Engineering, Kumamoto University 1F Liaison Conference Room Okinawa Institute of Technology Technical Office Technical Report Vol. 14 Publisher: National Institute of Technology, Okinawa College Technical Office Date of issue: March 12, 2019

The present invention is a method and apparatus for exfoliating phloem from trees using acoustic impedance differences.

The sap collected from trees such as lacquer, maple, rubber, birch, and pine is used as a natural resource for food and industrial products. In these methods, the phloem on the surface of the tree is scratched, and the sap that seeps out is collected.
For example, lacquer resin is conventionally collected from trees that are about 10 to 15 years old by a technique called lacquer tapping. Lacquer tapping is repeated for half a year from April to October, and the trees after collecting lacquer are cut down because they wither. A large amount of resin remains in trees after felling, but the recovery rate is low, so resin is not recovered from trees after felling.
By the way, lacquer tapping is a method in which the bark of the lacquer is stripped with a special plane, and only the phloem is scratched, and the resin that seeps out is collected with a spatula and collected in a bucket. It takes a lot of time to recover the resin that exudes from the tree, and it is said that about 200 g of lacquer can be collected from one 10- to 15-year-old tree by scraping the lacquer.
Since lacquer is mainly stored in the resin canals that pass through the phloem of trees, if only the resin canals can be squeezed, the recovery rate will be greatly improved, but it is difficult to recover only the resin canals.
For example, tree components such as essential oils are collected by volatilizing crushed wood chips with hot water or steam and cooling the volatilized steam, but resin collection cannot avoid deterioration of sap due to heating. There is a problem.
In addition, a method has been proposed in which shock wave treatment is used to destroy closed marginal pores of tree cells and collect bound water in trees (Patent Document 1). , and it is impossible to selectively collect only the resin.

JP 2005-262732

Therefore, the present invention focuses on the point that if the phloem having a resin canal can be peeled off from the tree, the resin recovery rate can be increased, and the present invention provides a method and apparatus for peeling the phloem from the tree. is the subject.

The phloem is separated from the tree by applying a shock wave to the tree and utilizing the difference in acoustic impedance inside the tree.

The propagation characteristics of shock waves in a medium depend on the acoustic impedance, which is the product of the sound velocity and density of the medium. A shock wave propagates in a straight line with constant attenuation in a medium with uniform acoustic impedance. However, when the acoustic impedance changes in the propagation medium of the shock wave as shown in FIG. 1, wave reflection and transmission occur at the interface with the acoustic impedance difference. The larger the acoustic impedance difference, the stronger the reflection of the shock wave at the interface, and the reflected stress acts on the interface.

A tree consists of xylem, phloem and bark, each of which has different acoustic impedance. When a shock wave is applied to a tree, the shock wave propagated inside the tree is partially reflected at the interface between the xylem and phloem and the interface between the phloem and bark, which have different internal tissues. The phloem and bark are separated from the xylem and phloem by the action of reflected stress at each interface.

The present invention focuses on the fact that the acoustic impedance differs depending on the tissue structure inside the tree. By applying a shock wave to the tree, reflected stress acts on the interface of the internal tissue with the difference in acoustic impedance, and the tissue with different acoustic impedance is created. It is to be peeled off.

The phloem contains structures that store a large amount of resin, such as resin canals, and its hardness is also low. .

FIG. 4 is an explanatory diagram of the propagation of shock waves in a propagation medium having two or more acoustic impedances and the action of reflected stress at the interface of acoustic impedance difference; FIG. 4 is an explanatory diagram of an embodiment of a device that applies shock waves to trees cut mainly near the phloem (Example 1). It is an embodiment of a wood processing apparatus using a shock wave generation method by high-voltage electric discharge (Example 2). It is a photograph of the tree before shock wave treatment, the tree after shock wave treatment, and the peeled phloem used in the experiment. FIG. 11 is an explanatory diagram of an embodiment when shock waves are applied mainly to log-shaped trees (Example 3). It is explanatory drawing which shows the cross section of a tree.

<Example 1>
FIG. 2 shows an embodiment of a wood processing apparatus used in this embodiment. 1 is a tree sample to be treated, which is a longitudinal cut of a tree and includes xylem, phloem, and bark. 2 is a shock wave generating portion, 3 is a generated shock wave, 4 is a shock wave propagating medium, 5 is a partition wall between the shock wave propagating medium and the tree or the outside of the apparatus, and 6 is a reflection acting on each tissue structure inside the tree. Stress, 7 is the pressure vessel.

The shock wave generating unit 2 is installed inside the processing pressure vessel 7, and the shock wave generating source may be a high-voltage electric discharge, an explosive, a high-pressure gas gun, laser ablation, or the like. The pressure vessel 7 is filled with a shock wave propagation medium 4, and the propagation medium may be a liquid such as water or oil, or a gas such as air.

When a liquid such as water or oil is used as the propagation medium 4, a boundary wall 5 may be used to prevent the outflow of the medium and transmit the shock wave. However, the boundary wall 5 may be omitted when the shock wave propagation medium is not expected to flow out. The boundary wall 5 is desirably made of the propagation medium 4, the tree 1, or a material having an acoustic impedance between them.

It is assumed that the pressure vessel 7 not only prevents the propagation medium of the shock wave from flowing out, but also functions to collect the shock wave to the processing section by reflecting the shock wave.

<Example 2>
FIG. 3 shows an embodiment of a wood processing apparatus using a method of generating shock waves by high-voltage electrical discharge, and a wood processing method according to this embodiment will be described. A 7-year-old lacquer tree from Daito, Iwate Prefecture (about 70 mm in diameter and 100 mm in length) was prepared. The vicinity of the bark of this lacquer tree was cut to a thickness of 10 mm in the length direction (tree growth direction) (see the cutting plane indicated by the chain double-dashed line in FIG. 6). That is, the arc length of the lacquer wood piece obtained by cutting was shorter than the length of the lacquer tree. A lacquered wood piece (tree sample 1) obtained by cutting was placed on the upper surface of a boundary wall 5 (a silicon sheet in this example) placed on the top of a pressure vessel 7 of the wood processing apparatus shown in FIG. At this time, the cut surface (wood part) of the tree sample 1 was placed in contact with the upper surface of the boundary wall 5, and the shock wave generated inside the pressure vessel 7 was applied from the wood part through the boundary wall 5. placed. A metal sample holder 9 was placed above the piece of lacquer wood to be treated. At this time, a space was secured as an air layer as a low acoustic impedance layer 8 above the piece of lacquer.
Next, a shock wave was applied by the wood processing apparatus shown in FIG. 3 (shock wave treatment). After that, the tree sample 1 was separated (exfoliated) into xylem, phloem, and bark by shock wave treatment. Lacquer resin was extracted by squeezing the exfoliated phloem using a squeezing machine described later.

Metal wire explosion by high-voltage electrical discharge was used as a shock wave generation method. A discharge electrode 2a for a high-voltage electric discharge as a shock wave generator was placed in a pressure vessel 7 filled with a propagation medium 4 (water in this example).
A thin metal wire 2b was attached to the discharge electrode 2a. When the high-voltage electrical energy stored in the capacitor is suddenly applied to the discharge electrode, the fine metal wire evaporates explosively, and the rapid expansion generates shock waves in the water.
An underwater shock wave is a compression wave accompanied by a rapid pressure rise immediately after the leading wave, and attenuates during the process of propagating in water. In this experimental device, the impact pressure ranges from several 100 MPa to several MPa depending on the propagation distance. Shock wave treatment was performed three times by metal wire explosion by electric discharge with charging voltage of 3.5kV and charging energy of 4.9kJ. Aluminum (A1015) thin wires with a diameter of 1.2 mm and a length of 8 mm were used as the thin metal wires.
A shock wave generated in water propagates through the water of the propagation medium 4 and propagates through the silicon sheet of the parting wall 5 to the piece of lacquer wood placed above. At this time, the silicon sheet (thickness 5 mm, hardness 60) of the boundary wall 5 was arranged at a position 125 mm from the discharge electrode.

A shock wave generated in water was applied to the lacquer wood piece through a silicon sheet. The xylem, phloem, and bark of the lacquer wood piece have different acoustic impedances, and the shock wave propagated through the lacquer wood piece repeats reflection and transmission at each tissue interface. For this reason, the reflected stress acts only on the tissue interface, which is considered to be effective for detachment between the respective tissues. By such shock wave treatment, lacquer wood pieces were exfoliated into xylem, phloem and bark.

The phloem contains tissues such as resin canals where a large amount of resin is stored, and the hardness is also low.

The peeled phloem was squeezed with a roller-type juice squeezer, and the amount of extracted lacquer resin was evaluated.
When the phloem of the same lacquer wood part was peeled off manually and squeezed with a roller-type juicer, the weight ratio of the lacquer wood piece was 1.55%, so the extraction amount of lacquer resin in this example was 3.1%. showed a two-fold increase.

As described above, by using the wood processing method and apparatus according to the present invention, it is possible to effectively extract the resin by peeling off only the phloem containing sap and extracting only the phloem by pressing.

In the case of squeezing the resin, the direction of the resin canal in the peeled phloem is not particularly limited, but it is more preferable that it coincides with the longitudinal direction of the peeled phloem.

<Example 3>
FIG. 5 shows an embodiment when shock waves are applied to a log-shaped tree. 1 is a cross-sectional cut of the tree to be treated, which includes xylem, phloem, and bark. 2 is a shock wave generating portion, 3 is a generated shock wave, 4 is a medium in which the shock wave propagates, and 6 is a reflected stress acting on each tissue structure inside the tree.

The generated shock wave 3 propagates radially to the xylem and phloem of the tree. The tree phloem and bark 1 are around the tree, and reflected stress 6 acts outward due to the difference in acoustic impedance.

Next, the wood processing method will be explained. Prepare a lacquer tree. A hole is made in the wood part of this lacquer tree. This forms an internal space in the lacquer tree. The drilling position is located in the center of the tree. At this time, the hole may be made into a bag-like shape having an opening at only one end without penetrating the hole, or the through hole may be closed at one end to prevent the propagation medium from flowing out. A shock wave generating part and a propagation medium are inserted and filled into the hole.
The generated shock wave propagates through the medium to the wood of the lacquer tree. The shock wave propagated to the xylem of the lacquer tree passes through the phloem and bark, and propagates to the outer air layer. Since the air layer is a low acoustic impedance layer, it is effective for exfoliating lacquer and bark. In addition, since the shock wave propagates radially from the inside of the tree and the reflected stress at the reflection interface also acts radially on the tree, the sample holder is not required if the method according to this embodiment is used.
After inserting and filling the generator and propagation medium, a shock wave is applied (shock wave treatment) in the embodiment shown in FIG. After that, the lacquer tree is separated (exfoliated) into xylem, phloem and bark by shock wave treatment. Lacquer resin can be extracted from the exfoliated phloem by squeezing it using a squeezing machine, which will be described later. In addition, since it is the same as that of Example 2 about juicing, description is abbreviate|omitted.

The method and apparatus according to the invention are not limited to the embodiments. Modified methods and devices that do not depart from the spirit of the invention are included in the scope of the invention.

For example, trees processed by shock wave treatment are not limited to lacquer trees. It is also expected to be applied to trees that use resins and sap inherent in the phloem of maple and natural rubber. The same means can also be used for trees that use phloem such as cork as lumber, and trees that mainly use xylem such as Japanese cypress.

The acoustic impedance of each part of the tree varies depending on the species of the tree and the state (for example, degree of dryness after cutting). For example, when the xylem and the phloem are compared, there are cases where the acoustic impedance of the xylem is high and that of the phloem is high.

The shock wave generator 2 may use an explosive, a high pressure gas gun, laser ablation, or the like, as well as a high-voltage electric discharge as a shock wave generation source. A propagation medium 4 may be used around the shock wave generator for the purpose of increasing the propagation efficiency of the shock wave.

INDUSTRIAL APPLICABILITY The present invention is utilized as a technique for effectively collecting resin in general industries where sap such as resin is collected from trees and used industrially. In addition, by peeling off the phloem, it is possible to effectively extract the xylem.

1 Cut tree, including xylem, phloem and bark 2 Shock wave generator 2a Discharge electrode 2b Fine metal wire 3 Shock wave 4 Propagation medium 5 Boundary wall 6 Reflected stress 7 Pressure vessel 8 Low acoustic impedance layer 9 Sample holder

Claims (2)

A phloem exfoliation method characterized by exfoliating a phloem from a tree using an acoustic impedance difference by applying a shock wave to the tree including the phloem. Phloem detachment is characterized by detaching the phloem from the tree using the acoustic impedance difference by applying a shock wave from the xylem side to the phloem of the tree having the phloem and the xylem. Method.

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