JPH09201805A - Manufacture of wooden composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for making the separation of a split wooden piece smooth, leaving any wooden fiber uncut with the help of a highly durable splitting blade, and consequently, securing a wooden composite material of uniform quality stably, in a method of manufacturing a wooden composite material consisting of split wooden pieces laminated and bonded together an adhesive. SOLUTION: A single splitting step is divided into two working steps, and in a first working step, a group of rotary blades consisting of pairs of mutually opposed pairs of both-edged blades 1 arranged in parallel and at a specified pitch are used, and a crevice is formed in both front and rear faces of a material to be split 3. In a second working step, the pairs of the mutually opposed blades 2 with the edges overlapping each other split and separate the material to be split along the crevide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention accumulates a large number of pieces in a state in which an adhesive is applied to split pieces obtained by splitting wood in the longitudinal direction.
The present invention relates to a method for producing a wood-based composite material, which is formed into a desired shape and is then cured by curing an adhesive to bond them to each other.

[0002]

2. Description of the Related Art A low yield of lumber products traditionally used as timber-based structural materials such as columns and beams, and elimination of variations in strength due to the presence of defects such as knots. In order to make effective use of wood resources,
In other words, the wood-based composite material in the form of a plate or rod having a relatively large cross-sectional area and the method for producing the same are split along the fiber direction of the eyes, and a large number of the split pieces are compressed and bonded to each other with an adhesive. Proposed (JP-A-7-195)
313).

According to this proposal, a small-diameter tree, a lumber back plate, a branch, or the like can be used as the raw material wood, and since no sawdust is produced, the yield is significantly improved as compared with the lumber product. In addition, since the individual split pieces are made of wood fibers and are bonded to each other substantially in parallel with each other by a thermosetting adhesive or the like, the strength is stable and high.

In this proposal, in order to obtain a split piece from a raw material, first, a plurality of pairs of raw materials, in which rotary blades of both blades are opposed to each other, are arranged in parallel with each other at a predetermined pitch in the longitudinal direction. By splitting it into small pieces (small splitting step), and passing the split pieces in the longitudinal direction between a group of blades in which rotary blades with single blades are opposed to each other and arranged in parallel at a fine pitch. By this, finer split pieces are obtained (fragmentation step).

[0005]

By the way, as a result of detailed examination of the manufacturing process of the split piece in the above proposal, the present inventor has found that the splitting step has the following problems.

That is, in this splitting process, a large number of pairs of rotary blades facing each other are used side by side, but due to subtle differences in the processing precision of the individual rotary blades, the blades facing each other are overlapped by a slight amount. In this case, a gap is likely to be generated between the cutting edges, but when a double-edged rotary blade is used, the tip shape of the blade is poor in the cuttability of the fiber. It's easy to get stuck.

When a single-edged rotary knife is used,
By stacking opposing blades on top of each other, a cutting action by shearing is added like scissors, so cutting performance is improved, but the pressure at the time of splitting acts from one direction on the cutting edge due to its tip shape. Therefore, the blade tips are pressed against each other, and the blade tips are easily damaged. In particular, it is hard to say that the edge of a single-edged tool is easily damaged when a hard portion such as a knot is split, and the durability of the tool is good.

The present invention has been made to solve the above problems, and has excellent durability of a splitting blade, and also makes the splitting piece extremely good without cutting the wood fiber. Therefore, it is an object of the present invention to provide a method capable of obtaining a split piece that is stable and has good separability over a long period of time, and that is a stable and homogeneous wood-based composite material.

[0009]

According to the method for producing a wood-based composite material of the present invention, wood is split once or plural times in the longitudinal direction to obtain split pieces, and the split pieces are uncured thermosetting materials. After the adhesive is applied, a plurality of the adhesives are accumulated on each other, shaped into a desired shape, and heated and pressed to cure the thermosetting adhesive. The splitting process is divided into two steps, and in the first step, a material to be split is passed between rotary blade groups in which a plurality of pairs of rotary blades having a pair of opposing blades are arranged in parallel at a predetermined pitch. By making a crack on both the front and back surfaces of the material to be split, in the second stage, by passing between the rotary blade groups in which a plurality of pairs of rotary blades facing each other and their blade edges overlap each other are arranged. , Along the crack formed in the first stage It characterized by Wari裂 to be split 裂材.

Here, in the present invention, one splitting step means that the raw material wood is once split into relatively coarse splitting pieces as described above (small splitting step), and then the splitting pieces are separated. In the case of further fine splitting (fragmentation step), each splitting step is referred to.

As the raw material wood used in the present invention, known wood can be used. For example, cedar,
Cypress, pine, toga, sawara, fir, if, mackerel, beech, oak,
Rawan, hiba, chestnut, keyaki, shii, willow, etc., or bamboo can also be used. Such timber does not have to be lumbered, and lumber mill ends, back boards, small-diameter trees, parts such as twigs, construction mill ends, waste wood, and thinned wood can also be used.

The cross section of the finally split cleaved piece is 0.1 to 10 mm in length and width and 20 to 3000 mm in length.
If it is smaller than this range, the strength as a thick product is difficult to obtain, and if it is larger than this range, it becomes difficult to obtain raw materials and handle the split pieces, which is not preferable.

In the present invention, as the double-edged rotary blade used in the first stage, those having the following specifications can be used.
As a material, a known material which is usually used as a blade can be used, and for example, steel, stainless steel, molybdenum steel, etc. can be preferably used. Moreover, the outer diameter of the blade can be appropriately determined according to the size of the material to be split. It is possible to use a blade having a tip angle in the range of 20 ° to 50 °. In the first stage of the present invention, since only a crack is made in the material to be split, the cutting property of wood fiber is not particularly required. Instead, focusing on the durability to withstand the pressure acting when making a crack in the material to be split,
It is more preferable that the angle is 25 ° to 35 °. The hardness of the blade is appropriately selected in the range of HRC (Rockwell C scale) 20 to 55 according to the splitting conditions including the hardness of the material to be split, etc. H
The range of RC35 to 45 is more preferable.

Further, in this first-stage cutting tool, it is sufficient to make a split on the front and back without separating the material to be split, so that even if there is a gap between the cutting edges of a pair of opposing rotary cutting tools. Alternatively, the cutting edges may be in a state of being butted against each other. However, in order to make the pressure applied to the cutting edge as small as possible when splitting with the subsequent second-stage cutting tool, it is necessary to make a deepest possible crack, so the gap between the cutting edges of the opposing first-stage cutting tools is , 0-1
It is 0 mm, more preferably 0 to 3 mm.

On the other hand, as the rotary blade used in the second stage,
The same material as that of the first stage can be used as the material, and the outer diameter can be appropriately determined as in the case of the first stage. Further, both the double-edged blade and the single-edged blade can be used as the second-stage rotary blade. The tip angle of the blade can be in the range of 15 ° to 45 °, but from the viewpoint of durability, it is more preferably in the range of 20 ° to 30 °. Further, the hardness of the blade is appropriately selected within the range of HRC25 to 55 depending on the conditions including the material of the material to be split, etc., but from the viewpoint of durability, it is more preferably within the range of HRC35 to 45.

<Operation> The present invention has been made based on the following results of analysis of various problems in the conventional wood splitting process.

That is, when splitting wood, usually,
In the step of splitting the raw material described above, a rotary blade of double-edged blades that are arranged opposite to each other is used because of the magnitude of the pressure that acts at the time of splitting, and further, in the segmentation step, the point of importance of cutting property Therefore, the single-edged rotary blades arranged facing each other are used. In the case of a double-edged blade, if the tips of the opposing rotary blades are exactly abutted against each other (gap 0), the cutting performance will be good, but from the viewpoint of the processing accuracy of the blades, all rotary blade pairs arranged in parallel will be It is virtually impossible to have a match, so usually
As schematically shown in FIG. 1, the tips of the rotary blades of the two blades facing each other are slightly overlapped. In this case, a gap G is inevitably formed between the opposite cutting edges D, D,
Further, the gap G varies depending on the machining accuracy of the cutting tool, so that the cutting property of the wood fiber is deteriorated and the split pieces are very difficult to separate.

On the other hand, when a single-edged rotary knife is used,
As schematically shown in FIG. 2, since it is possible to make the blade tips S of the opposing single-edged rotary blades contact each other like scissors, a shearing action is also added to improve the cutting property of the wood fiber, Due to the shape of the cutting edge, the pressure at the time of splitting acts from one direction, the opposing cutting tools rub against each other and press each other, and the tips of the cutting edges are easily damaged. In addition, depending on whether or not a hard portion such as a knot is split, or a grain of wood, a strong pressure is applied to the blade edge from a specific direction, and a single-edged blade is more easily damaged than a double-edged blade.

According to the present invention, one splitting step, that is, each of the above-described splitting step and fragmentation step is performed in two steps.
In the first stage, only the two-sided rotary blades facing each other are used to make cracks on both sides of the material to be split, and the second stage opposite rotary blades cut the material to be split along the cracks. By splitting and separating, both the durability of each rotary blade and the separability of split pieces are satisfied.

That is, in the first stage where only a split is made in the material to be split, the durability is improved by using a double-edged rotary blade, and in the second stage the split material is split along the split. Thus, splitting is facilitated, and at the same time, the pressure acting on the blade is reduced, and even if the blade is securely split using a blade that is sharper than in the first stage, the durability is good.

[0021]

EXAMPLES Examples in which the method of the present invention is applied to actually split wood will be specifically described below together with comparative examples.

(Embodiment) Each of the step of splitting the raw material wood and the step of fragmenting the raw wood is divided into two stages, each of which is shown in FIG.
Fig. 4 shows a schematic perspective view, and Fig. 4 shows a schematic plan view.
As the first-stage blade group, a plurality of pairs of the rotary blades 1 of both blades facing each other vertically are arranged in parallel to each other, and immediately after that, as the second-stage blade group, the rotary blades 1 of the first stage are At the same pitch as the pitch, a plurality of pairs of rotary blades 2 of double blades, which are vertically opposed to each other, are arranged in parallel with each other. It should be noted that FIG. 3 and FIG. 4 are illustrated by taking the subdivision process as an example.

Each first stage (for crack formation) and each second stage (for splitting / separation) in the step of splitting and the step of segmenting.
All blades are double-edged and the material is SUS42
0, outer diameter 140 mm, and rotation speed 60 rpm were all common.

In the slicing process, the rotary blade 1 of the first-stage double-edged blade has a blade thickness of 5 mm, a blade tip angle of 35 °, a vertical gap between opposing blade tips of 3 mm, and a pitch between the blades of 10 mm. 20 sheets each were arranged.

In the slicing step, the blade thickness of both blades of the rotary blade 2 of the second stage is 3 mm, the blade tip angle is 30 °, the vertical overlap between the opposing blade tips is 1 mm, and the pitch between the blades is 10 mm. Twenty sheets were arranged on each side.

In the fragmentation step, the blade thickness of the rotary blade of the first-stage double-edged blade is 3 mm, the blade tip angle is 35 °, the vertical gap between the opposing blade edges is 3 mm, and the pitch between the blades is 4 mm. 20 sheets each were arranged.

In the fragmentation step, the blade thickness of the rotary blade of the second-stage double-edged blade is 2 mm, the blade tip angle is 30 °, the vertical overlap between the opposing blade tips is 1 mm, and the pitch between the blades is 4 mm. Similarly, 20 sheets were arranged above and below.

Now, as shown in FIGS. 3 and 4, as a raw material wood 3, a lumber back board of cedar (about 30 × 150 × 2000 m)
m) of the raw material wood 3 shown in the schematic longitudinal sectional view of FIG. Similarly, as shown in the schematic longitudinal sectional view, cracks 4 were formed on both the front and back sides at a pitch of 10 mm, which was equal to the pitch between the blades. Next, it is split along the cracks 4 by passing between the second-stage blade groups, and as shown in the schematic sectional view of FIG. Piece 5 was obtained.

Next, the small split pieces 5 are passed between the first group of cutting tools in the segmentation step to form cracks at a pitch of 4 mm on both front and back surfaces of the small split pieces 5,
By passing between the subsequent second-stage blade groups,
Splitting was performed along the cracks to obtain split pieces having a cross section of 4 × 10 mm and a length of 2000 mm.

When the above splitting work was continued for 500 hours, almost all the split pieces obtained were separated, and no damage or the like was found on any of the blades.

(Comparative Example 1) As a subdivision process, a plurality of pairs of cutting tools in which the rotary cutting tools of both blades are vertically opposed to each other are used in only one step, and as a fragmentation step, the rotary cutting tools of both cutting blades are also opposed to each other. A plurality of pairs of cut blades were used in only one step.

As a double-edged rotary blade in the slicing step, the material is SKS-5, the blade thickness is 4 mm, and the blade tip angle is 20.
With an outer diameter of 140 mm, a blade edge overlapping amount of 2 mm in the vertical direction and a pitch between the blades of 10 mm, 20 sheets were arranged in each of the upper and lower sides, and each was rotated at 60 rpm.

As a double-edged rotary blade in the fragmentation step, the material is SKS-5, the blade thickness is 2 mm, and the blade tip angle is 20.
Using an outer diameter of 140 mm and an outer diameter of 140 mm, a vertical overlapping amount of the blade edges of 2 mm and a pitch between the blades of 4 mm were arranged in each of the upper and lower blades and rotated at 60 rpm.

The raw wood material is exactly the same as that of the embodiment, and after passing between the blade groups in the slicing step, and subsequently passing between the blade groups in the slicing step, the cross section is 4 × 10 m.
A split piece having a length of m and a length of 2000 mm was obtained. Splitting work 50
When it was continued for 0 hours, many of the obtained split pieces were connected to each other by the uncut wood fibers, and about 50 pieces had to be manually separated after splitting.
It was over%.

(Comparative Example 2) As a subdivision process, only one stage of a plurality of pairs of single-edged rotary blades opposed to each other was used, and as a fragmentation step, the same single-edged rotary blades were opposed to each other. A plurality of pairs of cut blades were used in only one step.

As the single-edged rotary blade in the step of splitting, a material SKS-5, a blade thickness of 4 mm, and a blade tip angle of 20.
Using an outer diameter of 140 mm and an outer diameter of 140 mm, 20 blades were arrayed in the vertical direction with an overlapping amount of the blade edges in the vertical direction of 2 mm and a pitch between the blades of 10 mm, and these were rotated at 60 rpm.

As the single-edged rotary blade in the fragmentation step, the material SKS-5, the blade thickness 2 mm, and the blade tip angle 20.
Using an outer diameter of 140 mm and an overlapping amount of the blade edges in the up-down direction of 2 mm and a pitch between the blades of 4 mm, 20 sheets each were arranged vertically and rotated at 60 rpm.

The raw wood material is exactly the same as that of the embodiment, and after passing between the blade groups in the slicing step, it is subsequently passed between the blade groups in the slicing step to obtain a cross section of 4 × 10 m.
A split piece having a length of m and a length of 2000 mm was obtained. Splitting work 50
When it was continued for 0 hours, the blade edge of each blade was damaged over about 70% of the entire circumference, and the wood that passed through the damaged portion was not split at all and could not be separated. About 80 items require manual separation after work
It reached over%.

[0039]

As described above, according to the present invention, one splitting process is divided into two stages, and in the first stage, the two-sided rotary blades facing each other are used to form cracks on both front and back surfaces of the material to be split. In the second stage, the rotating blades are arranged so that the cutting edges are opposed to each other and overlap each other, so that the material to be split is split and separated along the crack formed in the first stage. It is possible to select a highly durable tool without regard to the cuttability of the wood fiber as the first-stage blade, and the second-stage blade only splits along the already formed cracks. Therefore, even if durability is emphasized, it is easy to split the material to be split.
Since separation is possible and the pressure at the time of splitting is low, sufficient durability can be obtained even if a sharp one is selected. As a result, according to the present invention, it is possible to obtain a split piece that is stable for a long time and has good separability, and thus it is possible to manufacture a wood-based composite material with stable quality.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the types and arrangements of blades used in the step of splitting raw wood in the conventional wood-based composite material manufacturing process.

FIG. 2 is a schematic diagram showing the types and arrangements of blades used in the fragmentation process in the conventional wood-based composite material manufacturing process.

FIG. 3 is a schematic perspective view showing one splitting step in the embodiment of the present invention by taking a splitting step as an example.

FIG. 4 is a schematic plan view of FIG.

FIG. 5 is an explanatory view of the splitting process of the material to be split in one splitting process of the embodiment of the present invention, showing a schematic longitudinal section of the material taking the splitting process as an example.

[Explanation of symbols]

 1 1st-stage double-edged rotary knife (for forming cracks) 2 2nd-stage double-edged rotary knife (for splitting / separation) 3 Raw wood (material to be split) 4 Cracks 5 Split pieces

Claims (1)

[Claims] 1. A piece of wood is split once or a plurality of times in the longitudinal direction thereof to obtain split pieces, and an uncured thermosetting adhesive is applied to the split pieces, and the plurality of pieces are accumulated on each other to obtain a desired piece. In the method of manufacturing a wood-based composite material by shaping into a shape and heating and pressing to cure the thermosetting adhesive, one splitting step is divided into two steps, and in the first step, By passing a material to be split between a group of rotary blades having a pair of opposing double-edged rotary blades arranged in parallel at a predetermined pitch, a crack is formed on both front and back surfaces of the material to be split, In the step, the material to be split is cut along the crack formed in the first step by passing between a pair of rotary blades in which a plurality of pairs of rotary blades, which face each other and overlap each other, are arranged. Of wood-based composite material characterized by splitting Production method.