JPH0446202B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is a method for manufacturing dry-processed fiberboard, in which a plurality of layers of wood fiber mats laminated with a release layer interposed therebetween are simultaneously pressed between a pair of hot plates of a hot press machine. The present invention relates to a method for efficiently manufacturing wood fiberboard by hot-pressing and then peeling from the release layer.

Prior Art In a typical example of a dry manufacturing method for wood fiberboard, dry wood fibers containing adhesives, sizing agents, etc. are formed into a wood fiber mat using a forming device, and this is temporarily pressed using a prepress device. After that, it is cut to a certain size, placed on a coal plate, inserted into a hot press machine, and hot-pressed. Typical hot press equipment has multiple heating plates that slide along multiple guide columns, and formed mats placed on coal plates are inserted one by one between the heating plates to heat them. Pressure molded. The relationship between the thickness of the formed pine after pre-pressing and the thickness of the fiberboard after heat-pressing varies depending on the desired thickness of the fiberboard, specific gravity, type of wood fiber used, moisture content, etc. Generally, the thickness of molded mat is about 10 times that of fiberboard. For example, when trying to obtain a fiberboard with a specific gravity of around 0.7 and a board thickness of 10 mm, a molded mat of about 100 mm is used.

Problems with the prior art A certain clearance α is required in order to insert the formed mat between the hot platens. The maximum distance between the panels is set to 500mm+α. Hot press equipment is expensive, and it is not possible to easily change or adjust the maximum distance between the hot platens mentioned above, so it is preferable to use the same hot press to heat press fiberboards of various thicknesses. It is common. On the other hand, the supply of molded mats to hot press equipment is
It is efficient to use a multistage loader, the distance between the stages being fixed in correspondence with the above-mentioned maximum separation dimension in the hot press device. Therefore, when hot pressing a thin fiberboard with a thickness of, for example, 5 mm using a hot press machine whose maximum separation dimension is set to 500 mm + α, the wasted operating time of the hot platen cannot be ignored. Become. For example, if the number of stages of the hot press plate is 20, even if the clearance is considered to be the same,
This is because the operating time of the heating plate (450 x 20 = 9000 mm) is wasted. However, hot press equipment is expensive and large in size, so it cannot be easily expanded, and it is not easy to change the set distance between hot platens. Therefore, the actual situation is that the production line is designed and operated by taking into account the balance between the above-mentioned loss of operating time of the heating plate and expansion cost.

Means for Solving the Problems In the present invention, one or more release layers are laminated within the fiber mat layer inserted between a pair of heating plates,
The above-mentioned problem has been solved by hot-pressing the mat and then peeling it off.

Release layer materials include fibers that do not contain adhesives,
A powder or a sheet-like material that does not have an adhesive effect upon hot pressing may be used.

The outline of the present invention has been described above, and the present invention will be explained in further detail below based on examples of the present invention.

DESCRIPTION OF THE EMBODIMENTS The wood fibers used in the present invention may be those conventionally used as materials for wood fiberboards. For example, wood chips such as softwood or hardwood are fed into a refiner and defibrated to obtain wood fibers. Wood fibers, thermosetting adhesive, and sizing agents such as wax and paraffin are added and mixed in the air duct. These materials are dried while being air blown in the air duct, resulting in a fiberboard material with the desired degree of dryness.

However, adding a heat -curing adhesive and a size agent such as watcus and paraphras can be performed when the wood titsup is solution in the riff -eye device, or a dried wood fiber has been obtained in advance. This may be carried out later using a blender device, or may be carried out in an appropriate combination. Wood fibers other than wood fibers, such as natural fibers such as hemp, hemp, palm, etc., may be mixed into the above-mentioned fiber material.

As the release layer material used in the present invention, fibers, powders, and sheet materials that do not contain adhesive can be used. As the fibers, organic or inorganic fibers such as wood fibers, hemp, waste wool, glass fibers, and rock wool may be used, or synthetic resin fibers that do not melt during hot pressing in a hot press device may be used. As the powder, organic and inorganic powders such as sander powder, ceramic powder, charcoal, clay, and talc obtained in the siding process when finishing the surface of fiberboard, plywood, etc. are used, or hot press. A synthetic resin powder that does not melt during hot pressing in an apparatus may also be used. In particular, sander powder is advantageous in terms of cost because it does not require any special additional costs since it has conventionally been incinerated.
As the sheet-like material, paper, cloth, nonwoven fabric, metal foil, etc. may be used, or a synthetic resin sheet that does not melt during hot pressing in a hot press device may be used. A single sheet or a plurality of these sheets may be used, and when a plurality of sheets are used, different materials may be used in combination. Furthermore, when a plurality of sheet-like materials are used, a net-like material may be interposed between them. In order to avoid the so-called puncture phenomenon during hot pressing in a hot press device, it is desirable to use a sheet-like material with good air permeability. In short, the release layer material may be any material that inhibits adhesion between the plurality of laminated fiber mat layers during hot pressing in a hot press device.

There are various ways to form a release layer between a plurality of fiber mat layers using the above materials, as described below.

Wood fibers containing adhesive and sizing agent are spread onto the screen belt using a forming device to form a continuous fiber mat of desired thickness. Fibers or powder containing no adhesive are spread onto the fiber mat using a forming device to form a thin release layer. Next, the wood fibers containing the adhesive and sizing agent are again formed into a fiber mat having a desired thickness using a forming device. A continuous laminate in which a release layer is interposed between a plurality of fiber mat layers is formed by performing the above-described process of forming a release layer and forming a further fiber mat layer one or more times. After prepressing this, it is cut to a fixed length according to a conventional method, placed on a coal plate, and hot pressed. The fiberboard taken out from the hot press is separated into multiple fiberboards along the release layer,
If necessary, one or both surfaces thereof are sanded to finish the surface.

By the above-mentioned method, for example, using a hot press device in which the maximum distance between the hot plates is set to 500 mm + α, the fiber mat layers after pre-pressing between each hot plate are 50 mm each, and there is no separation between the fiber mat layers. The 10-layer laminate is heat-pressed, and the resulting fiberboard can be peeled and divided into 10 fiberboards.

The number of layers can be changed arbitrarily, and the thickness of each layer in a single laminate does not have to be the same.

However, during hot pressing, the hardening state of the layer that was close to the hot plate and the layer that was far away differs to some extent, resulting in differences in the structure and properties of the fiberboard. Therefore, they should be sorted and provided for appropriate use.

Fibers and powder containing no adhesive were used to form the above-mentioned release layer. Instead of these materials,
A sheet-like material can be used. These sheet-like materials may be continuously supplied, or sheets of fixed length may be placed. If it is continuously supplied, it is cut together with the fiber mat layer during cutting to a fixed length after pre-pressing. Therefore, when recycling the wood fibers produced during cutting, it is necessary to separate the fragments of the sheet-like material. In the latter case, by making the sheet slightly shorter than the fiber mat layer,
There is no need to separate the pieces of the sheet-like material.

For example, two or more sheet-like materials may be stacked one on top of the other, and in this case, peeling can be facilitated by a combination of different materials. For example, a metal foil or a net-like sheet may be interposed between two sheets of paper. At this time, by using a paper with good air permeability as the outer paper, the so-called puncture phenomenon can be prevented.

In the second aspect, similar to the conventional method, wood fibers containing adhesive and sizing agent are formed into a continuous mat of desired thickness using a forming device, temporarily pressed using a prepress device, and then The formed pine was cut to a specified length and placed on a coal plate, and wood fibers containing no adhesive were spread on it using a forming device in the same manner as above to form a release layer. Molded mats formed in the same manner (mats that have been temporarily pressed and cut to a specified length) are laminated. When forming three or more fiber mat layers, the above-described process of forming a peeling layer and laminating a formed mat are repeated a desired number of times. The thus obtained laminate is hot pressed according to a conventional method. Prior to hot pressing, it is desirable to remove release layer material deposited on the coal plate during formation of the release layer. As a removal method, suction or a rotating brush can be used. The laminated fiberboard thus obtained can be easily separated into a plurality of fiberboards using a peeling layer.

As described in connection with the first embodiment, also in the second embodiment, sheet-like materials can be laminated instead of using fibers or powder that do not contain an adhesive as the release layer material.

As a third embodiment, a release layer is formed before or after forming each fiber mat layer, and then prepressing and cutting to a fixed length are performed in the same manner as in the second embodiment,
A desired number of molded mats thus obtained may be stacked. In this case, the formation of a release layer can be omitted during the initial or final forming of the molded mat. According to this method, since fibers or powder as release layer material are not deposited on the coal plate, the step of removing them can be omitted.

The fourth aspect is a modification of the first aspect, in which the first layer of fiber mat is pre-pressed to form a continuous pre-pressed mat, a release layer is continuously formed thereon, and the pre-pressed The successive pre-pressed mats are stacked, and the latter two steps are performed one or more times to form a desired number of consecutive pre-pressed laminated mats, which are then cut to a fixed length and placed on a coal plate. Place,
Thereafter, heat compaction is performed according to the conventional method. This method is particularly suitable when using fibrous materials as release layer material. This is because the fibers in the release layer have a somewhat lower density, making it easier to peel off after hot pressing.

Although some embodiments of the present invention have been described in detail above, the present invention is not limited to the above-mentioned embodiments. The present invention can be modified in various ways without departing from its technical concept.

Effects By using a laminated molded mat that is laminated in multiple layers with a release layer in between, it is possible to make full use of the maximum distance between hot press plates, and it is possible to process thin materials without installing a hot press machine specifically for thin materials. wood fiberboard can be efficiently produced.

In addition, hot press equipment can be efficiently used to manufacture wood fiberboards of various thicknesses.

Claims (1)

[Claims] 1 A laminated pine with a release layer formed between multiple layers of wood fiber pine is inserted between the hot plates of a hot press machine having multiple hot platens set to a predetermined maximum separation dimension, and then hot-press-formed. A method for manufacturing wood fiberboard, which comprises dividing the wood fiberboard into a plurality of wood fiberboards by peeling along a peeling layer.