WO2003103911A1

WO2003103911A1 - Deep wooden container and production method therefor

Info

Publication number: WO2003103911A1
Application number: PCT/JP2002/008438
Authority: WO
Inventors: 啓次稲田; 嘉安藤元
Original assignee: 株式会社合電; 宮崎県
Priority date: 2002-06-11
Filing date: 2002-08-21
Publication date: 2003-12-18
Also published as: TW564212B; AU2002328643A1; AU2002328643A8; JP3972213B2; JPWO2003103911A1

Abstract

A method of producing a deep wooden container using natural wood only without using an adhesive. A 1.5 mm-thick plate formed by slicing a Japanese cedar raw material is dried to a moisture content of about 20% by natural or artificial drying, a veneer (B) not chamfered at the corners thereof is disposed so that its fiber direction is in the shorter-side direction of a mold (concave mold (2)), a veneer (A) chambered at the corners thereof is laid thereon so that its fiber direction is in the longer-side direction of the mold, the laminated veneers (A and B) are pressurized and compressed by a press device with their front and rear surfaces clamped by the mold (1), and the laminated veneers (A and B) are compacted to the thickness of one veneer and shaped.

Description

Description Wooden deep-bottom container and its manufacturing method

The present invention relates to a wooden container used as a substitute for a wooden container or a cardboard box used for food or other packaging, and a method for producing the same. It relates to a manufacturing method. Background art

In recent years, due to heightened awareness of garbage issues and environmental issues, unlike petroleum-based synthetic resins, there has been a great deal of interest in wooden containers that are easy to dispose of, such as being buried in the soil and rotting or incinerated. Various types of wooden containers of this kind have been proposed. Generally, wooden containers are manufactured by pressing a single veneer or laminated veneer.

However, wood is not a ductile or malleable material, unlike resins and metals. For this reason, when forming and pressing a laminated wooden board using a mold that causes deformation beyond a certain limit, there was a problem that cracks and cracks were generated in portions where the amount of deformation was large. For this reason, the depth of conventional wooden containers is about 3 cm at most, and containers with a deep bottom exceeding 6 cm have not yet been manufactured. In addition, since most conventional wooden containers use an adhesive during molding, it is not only difficult to dispose, but there is a sanitary problem in using them for food containers. Disclosure of the invention Thus, the present inventors have conducted intensive studies and have developed a deep-bottom wooden container using only natural wood without using an adhesive.

The present invention has a thickness of 1 ma! After stacking at least two pieces of wood with a thickness of ~ 2 mm so that their fiber directions intersect, they are compressed by a press using a mold heated to 180 ° C to 200 ° C. The first characteristic is that the molding is carried out. A second feature is that the mold is provided with a slant introduction surface having a slant angle of 10 ° to 60 ° with respect to the compression axis direction.

In the present invention, cracks and cracks during bending are suppressed by laminating at least two veneers such that their fiber directions intersect with each other and press forming. In other words, wood has the property of easily stretching in the fiber direction and easily tearing in the lateral direction. And cracks can be prevented. In addition, the mold is provided with an inclined introduction surface so that the laminated veneers can be smoothly introduced into the mold. The inclined introduction surface is set at an inclination angle of 10 ° to 60 ° with respect to the compression axis.

In addition, the bottom of the container is compressed, and the top is stretched, so a single veneer is easily cracked. It is possible to mold containers of various shapes such as round, triangular, square, flower, boat, etc. If the container is large and large, molding can be performed by increasing the number of layers and increasing the thickness to increase the strength.

The wooden deep-bottom container according to the present invention can be formed not only into a shallow bottom container but also into a deep bottom exceeding 6 cm in depth of the container, so that the shape of the contents that can be stored in the container, the purpose of use, etc. In addition to expanding the range of use, the use of adhesives is not required because containers are formed by compressing plate-shaped wood, especially for food Can be provided.

In addition, high temperature heating during molding sterilizes germs and the like in wood, so that sanitary safety as a food container can be obtained.

Furthermore, since the wooden deep-bottom container according to the present invention uses only natural wood as a raw material, it is not only easy to dispose after use, but also to collect and crush the used container to obtain high-quality wood. Chips can be obtained and have excellent recyclability. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an exploded perspective view showing an example of a mold used in the present invention, FIG. 2 is a plan view of a laminated veneer, FIG. 3 is a perspective view showing a laminated veneer in a laminated state, and FIG. FIG. 5 (a) is a longitudinal side view of a mold, (b) is a plan view, FIG. 6 is a lateral side view of a mold, and FIG. Fig. 7 is a graph showing the test results verifying the effects of hot-press temperature and hot-press time on veneer bonding strength.Fig. 8 shows the test results verifying the effects of veneer moisture content on veneer bonding strength. Fig. 9 is a graph showing the test results verifying the effect of the heat pressure time on the veneer bonding strength at a heat pressure temperature of 200 ° C. Fig. 10 shows the veneer crossed (orthogonal). Fig. 11 is a graph showing the test results for verifying the bonding force in the case, Fig. 11 is a graph showing the test results for verifying the bonding force in the thickness direction of the single plate, and Figs. 12 to 14 are Fig. 15 and Fig. 16 are illustrations showing another embodiment of the method for manufacturing a deep-bottom wooden container, and Fig. 17 (a) is a plane rectangle. Fig. 18 (a) is a longitudinal side view of a flat circular mold, and Fig. 18 (b) is a plan view. BEST MODE FOR CARRYING OUT THE INVENTION

Tree species that can be used as a material for the wood tray according to the present invention include, but are not limited to, conifers, hardwoods, bamboo bark, etc. Suitable in point. In addition, the cedar wood contains an extractant that has an antibacterial action, and in addition to the high moisture absorption of wood, it can provide antibacterial and humidity control functions inside the tray sealed with wrap etc. Optimum as a container material for food.

The thickness of the veneer usable in the present invention is preferably a plate or sheet having a thickness of 1 mm to 2 mm. That is, if the plate thickness is less than l mm, the immersion effect of the laminated veneers cannot be obtained. If the plate thickness exceeds 2 mm, the bending rigidity of the veneer is so high that bending becomes difficult, and the softening due to heating becomes uneven, and cracks and cracks may occur due to molding distortion during molding.

If the veneer has a moisture content of 10% or less, bending rigidity increases and machining becomes difficult, but machining is possible with other moisture contents. However, if the raw material has a water content of 30% or more, puncture will occur unless the steam generated at the time of heat and pressure is properly released. In addition, high moisture content materials not only require extra energy to evaporate water, but also may cause the product color to become darker ^ :. In addition, there is a risk that various germs may proliferate during storage in a saturated state. Therefore, it is preferable to be in an air-dried state or a state having a slightly higher moisture content, that is, a moisture content of 20 to 30%.

The heating temperature of the veneer, that is, the heating temperature of the mold, may be at least 130 ° C., which is the lignin softening point.However, in the production method of the present invention, in order to obtain bonding by only veneers. A temperature of 180 ° C to 200 ° C is required. In particular, when heated to around 200 ° C, most of the germs can be killed, which is beneficial in terms of hygiene when used as a food container. The hot-pressing time of veneer is about 15 seconds if only veneer bending is performed, but it takes 30 to 300 seconds to join veneers. is there. It is considered that the longer the heat and pressure time, the higher the bonding degree, but it takes at least 120 seconds or more to obtain a certain level of firm bonding strength. Hereinafter, embodiments of the present invention will be described with reference to the drawings. Example 1

In the present invention, first, a plate obtained by slicing a cedar log is dried to a water content of about 20% by natural or artificial drying. Next, this veneer is cut into two types of veneer A and veneer B as shown in FIG. In the present embodiment, two cedar boards having a thickness of 1.5 mm were formed into a rectangular shape having a length L 1: 25 O mm and a width W 1: 22 O mm, and the corners were R == 4 O Two types of plate materials were prepared: a veneer A chamfered in mm and a veneer B cut into a rectangular shape having a length L 2: 20 O mm and a width W 2: 18 O mm.

Next, as shown in FIG. 3, first, the fiber direction of the veneer B without the chamfered corners is arranged so that the fiber direction is the short direction of the mold (concave mold 2), and the corners are placed thereon. Laminated so that the fiber direction of the chamfered veneer A is the longitudinal direction of the mold, and the fiber directions cross each other (here, orthogonal), and the veneer A and veneer B are laminated. Both surfaces were sandwiched between a mold 1 composed of a concave mold 2 and a convex mold 3 shown in FIG. 1 and pressed and compressed by a press device (not shown).

As shown in FIGS. 5 and 6, the mold 1 used is composed of a concave mold 2 and a convex mold 3, and has a longitudinal width D: 21 O mm, a lateral width d: 150 mm, and a deep width. H: 9 O mm The angle of the inclined introduction surface 4 with the compression axis is 0: 30 °. At this time, mold 1 is heated to 200 ° C. by a heater (not shown), and the press working pressure is initially 70 to 150 kgf / cm ² , and then 10 to 20 kgf / cm ² for 20 to 30 seconds. 220 kgf / cm \ Press-compression at a mold closing speed of 1.5 mm / "sec for 180 seconds to form. Forming was performed and cooled to obtain a wooden deep bottom container 5. The laminated veneer A and veneer B having a thickness of 3 mm were consolidated to a thickness of 1.5 mm, which is the thickness of one veneer. Heating at a temperature exceeding 130, which is the softening point of the rig Yun, facilitates the plastic deformation of the wood, and the veneer A and veneer B are similar to each other due to the indentation of each other. In addition, the long sides of the wooden deep-bottomed container 5 after molding are compressed to the thickness of one veneer in a state where the veneer is partially folded into two or three layers. This part is compacted In the method for manufacturing a wooden container according to the present invention, in order to verify the joining strength of a joint portion where two veneers are overlapped, and to obtain appropriate manufacturing conditions for the wooden container according to the present invention. The following shows the test results: First, a hot-press bonding test was performed between veneers under various bonding conditions (heat-pressure conditions). The joint was subjected to a tensile shear test and a thickness direction tensile test of the joint.

Test Example 1: Hot-press bonding test

Bonding tests were performed by changing the veneer moisture content, veneer thickness, hot pressing temperature and hot pressing time. In addition, a test was performed when the veneers were overlapped with the fiber directions crossing (orthogonal) each other. The dimensions and shape of the veneer were a square of 18 Omm X 18 Omm, and 5 Omm was overlapped from the end. The moisture content of the veneer was set at almost 30% (wet state). The setting conditions for various tests are shown below.

(1) Heat pressure temperature and heat pressure time

Heat pressure temperature: 160, 180, 200 (° C)

Heat pressure time: 60, 120, 180 (seconds)

Veneer thickness: 1.0, 1.5, 2.0 (mm)

Veneer moisture content: saturated (about 200%), wet (about 30%), air-dried (about 15%), dry (less than 10%)

(2) Test results: The hot-press bonding of veneers using a flat press varied from completely non-bonded due to differences in heat-pressure conditions to those that were firmly bonded. The dried veneer and the 2.Omm thick veneered veneer were not joined when the heat pressure time was 60 seconds or 120 seconds. Also, 2. Omm thick and wet veneers were not joined if the hot pressure temperature (160 ° C) and time (60 seconds) were not sufficient. In addition, even when the heat pressure temperature was high (200 ° C), if the heat pressure time (15 seconds) was extremely short, a good bonding state could not be obtained, and a partial gap was observed between the veneers. . Test example 2

A tensile load was applied to the joined specimen in the fiber direction, and the maximum load was divided by the area of the joint to determine the tensile shear strength, which was evaluated as the joining force. The test was performed using a universal testing machine (Shimadzu Autograph AG 100 KNG) at a loading speed of lmm / min. The joint area of the veneer was 30 × 50 mm. The test results are shown in the graph of FIG. From the graph in Fig. 7, As is evident, the thickness increased in proportion to the hot pressing time at any thickness and hot pressing temperature. In addition, it was found that as the veneer thickness increases, the effect of the heat and pressure temperature is remarkable, and the tensile shear strength increases. This is thought to be because the greater the veneer thickness, the greater the degree of penetration between veneers.

Test example 3

In order to verify the effect of the moisture content of the veneer on the joining, the veneer thickness was 1.0 mm and 2.0 mm, and the moisture content of the veneer was saturated (about 200%) and wet ( The tensile shear test was performed using four types, adjusted to four types: a dry state (about 15%), a dry state (about 15%), and a dry state (less than 10%). The test results are shown in the graph of FIG. As is evident from the graph in Fig. 8, for any veneer of any thickness, in the range from the dry state to the water content of 30%, the tensile shear strength increases as the water content increases. There was found. No difference due to the heat and pressure time was observed in the case of a single plate thickness of 1.0 mm, but in the case of a single plate thickness of 2.0 mm, the tensile shear strength increased as the heat pressure time increased. There was found. However, in the case of a saturated condition, the tensile shear strength was reduced and the joint was not well formed under conditions where the heat pressure was short and sufficient heat could not be obtained. In the case of a single veneer with a thickness of 1.0 mm, it was observed that a puncture was caused due to the lack of an escape route for water vapor at the time of heat and pressure. Therefore, it was found that the water content of the veneer is preferably about 15% to 30%. Test example 4

If the pressing time required for veneer bonding is several minutes, it is expected that mass production of containers will be hindered. Therefore, in order to verify the possibility of shortening the heating time, the upper limit of the heating of the hot press apparatus used in this example was used. At a certain heat pressure temperature of 200 ° C, the tensile shear strength was examined by changing the heat pressure time to three stages of 15 seconds, 30 seconds and 45 seconds. The veneer thickness was 1.0 mm and 1.5 mm. Under the same conditions, the results are shown in the graph of FIG. 9 including the cases where the heat pressure time is 60 seconds, 120 seconds and 180 seconds. As is evident from the graph in Fig. 9, when the heat pressure time is less than 60 seconds, the tensile shear strength is strongly affected by the heat pressure time. In addition, it can be seen that the heat pressure time is required to be at least about 60 seconds for any single plate thickness. Therefore, it was found that the heat pressure temperature needs to exceed 200 in order to shorten the heat pressure time required for the heat pressure bonding.

Test example 5

Since the wooden deep-bottom container of the present invention is hot-pressed in such a manner that the fiber directions of the veneers cross each other, it is necessary to verify the bonding strength when the fiber directions of the veneers cross. Therefore, the tensile shear test was performed by bonding the veneers with the fiber direction orthogonal to each other by hot-press bonding. The heat pressure time was changed to three stages of 120 seconds, 150 seconds and 180 seconds, and the thickness of the single plate was set to 1.0 mm and 1.5 mm. The results are shown in the graph of FIG. As is clear from the graph of FIG. 10, the value is lower than that in the case where the fiber directions are aligned in parallel under the same conditions.

Test example 6: Tensile test in thickness direction

A peeling test was conducted in which the veneers of the joined specimens were peeled off in the direction of the plate pressure. A pair of L-shaped jigs were bonded to the surfaces of both veneers, and the L-shaped jig was sandwiched between chucks of a test machine to apply a tensile load. The test was performed using a universal testing machine (Shimadzu Autograph AG 100 KNG) with a loading speed of I mmZ. The bonding area of the L-shaped jig was 15 × 3 O mm, and the maximum load was divided by this area to obtain the peel strength. The test results are shown in the graph of Fig. 11. You. As is evident from the graph in Fig. 11, the tensile strength in the plate pressure direction is about 1/10 of the tensile shear strength at the maximum load, regardless of the thickness of the veneer and the hot pressure temperature. there were. Since the degree of joining of the veneer joints by hot pressure is significantly different between the fiber direction and the plate thickness direction, the direction of external force is taken into consideration, so that the container is strong when used, and easily after use with weak force. It is considered that a container that can be disassembled is obtained. It should be noted that almost no difference in strength due to the heat pressure time was observed except for a single plate pressure of 2.0 mm. When the veneer thickness was 2.0 mm, the strength increased in proportion to the heat pressure time. In addition, it was found that as the thickness of the veneer increases, the effect of the heat and pressure temperature increases, and the tensile strength in the thickness direction increases. This is probably because the greater the veneer thickness, the greater the degree of penetration between veneers. It should be noted that the present invention is not limited to the above embodiment, and various applications are possible without departing from the spirit of the present invention. For example, in the above embodiment, the container is formed from two veneers, but it may be formed by laminating three or more veneers. In addition, although veneers cut into wide plates are used, even narrow plates can be stacked or cut (rectangular or triangular) as shown in Fig. It is also possible to join planks, and by using this technique to obtain wide veneers, small diameter trees such as thinned wood can be used effectively.

That is, as shown in Fig. 13, plank wood A and B, for example, two narrow veneers A1 and A2, B1 and B2 are parallel to each other in fiber direction. In this case, the ends may be superposed to form an area necessary for forming the container. In this case, as shown in Fig. 14, a notch 6 that switches up and down alternately is formed at the butting boundary of the veneer and assembled. By doing so, it is possible to prevent displacement during pressing.

In addition, as shown in Fig. 15, a plurality of narrow veneers are woven vertically and horizontally using a small-diameter tree so that their fiber directions intersect with each other to form the required area for container formation. Plates A and B may be used.

The woven veneer may be formed by stacking a plurality of plywoods to form a container.However, as shown in Fig. 16, the woven plywood C is used as the lowermost layer. The two veneers A and B may be further laminated and compression-molded such that the fiber directions of the two veneers A and B intersect. In this case, for example, if the mold is a flat rectangular shape as shown in Fig. 17, if the two veneers A and B are arranged so that the fiber direction is parallel to the diagonal line of the mold, the heat pressure In this case, cracks of veneers A and B can be suppressed. In addition, the strength of the container corner after molding is increased by folding the veneer. In addition, according to this method, containers of various shapes such as a deep-bottom container using a plane circular mold as shown in FIG. 18 can be manufactured. According to the present invention, the depth of the container can be adjusted as required, so that a shallow container can be formed, of course, and a shallow container can be prepared as a container lid. In addition, a height difference can be provided in the height of the side surface of the container, so that a cut can be partially made in the edge of the container, or the edge can be formed into a corrugated shape.

Further, irregularities can be provided on the bottom of the container, and a container having a raised part at the bottom or a container having a step at the height of the bottom can be formed. It is also possible to draw characters and figures by branding. Since the present invention is configured as described above, the following excellent effects are obtained.

(1) Since only wood is used without using an adhesive as a raw material, it can be easily buried in the soil for decay or incineration. Wood chips obtained by crushing the collected containers can be used for recycling.

(2) Cracking during bending is suppressed by laminating at least two veneers so that their fiber directions intersect each other and press forming. In addition, since the mold is provided with an inclined introduction surface so that the laminated veneers can be smoothly introduced into the mold, various shapes of deep-bottom wooden trays can be manufactured.

(3) High temperature heating during molding sterilizes various bacteria in wood, and when used as containers for food, extremely high sanitary safety is obtained. Industrial applicability

As described above, the wooden deep-bottom container according to the present invention has a wide range of types, shapes, and intended purposes of the stored items that can be stored in the container, and is excellent in not only disposal processing after use but also easy. It is also recyclable and may be used in a wide variety of fields as containers to store various items, including food.

Claims

The scope of the claims

1. Sheet thickness l mn! A wooden deep-bottom container comprising at least two plate-shaped pieces of wood having a thickness of up to 2 mm, which are stacked so that the directions of the respective fibers intersect with each other and pressure-formed.

2. A slab of wood is formed to have the area required for container formation by polymerizing or snagging the ends of a plurality of narrow veneers so that their fiber directions are parallel to each other. The woody deep-bottomed container according to claim 1, wherein:

'3. The plate-shaped wood is formed by knitting a plurality of narrow veneers vertically and horizontally so that their fiber directions intersect with each other to form an area necessary for forming a container. The wooden deep bottom container described.

4. At least two sheets of wood with a board thickness of 1 mm to 2 mm and a moisture content of 10% to 30% are stacked so that their fiber directions cross each other, and without using an adhesive The deep wooden bottom container according to any one of claims 1 to 3, characterized in that the container is formed by compressing with a press machine using a mold heated to 180 ° (: up to 200 ° C). Manufacturing method.

5. A plurality of narrow veneers with a thickness of 1 mm to 2 mm are woven vertically and horizontally so that their fiber directions intersect each other, and the thickness of the plank wood is adjusted to the area required for container formation. At least two veneers with a moisture content of 1% to 2mm and a moisture content of 10% to 30% are stacked so that the fiber directions of these two veneers cross each other, and then the adhesive is used. A method for producing a deep wooden container, wherein the molding is performed by using a mold heated to 180 ° C. to 200 ° C. without using a press machine.

6. The deep wood volume according to claim 4 or 5, wherein the mold is provided with an inclined introduction surface having an inclination angle of 10 ° to 60 ° with respect to the compression axis direction. Container manufacturing method _c