JPS621501A - Manufacture of fiber board - Google Patents

Abstract

PURPOSE:To contrive space saving and time saving of both cooling and moisture/conditioning lines, by performing the moisture conditioning by spreading or applying water to one side or both the sides of a fiber board at a desired stage after completion of the final heating process. CONSTITUTION:While a post-molding fiber board is being kept at a high temperature water is spread or applied to one side or both the sides of the same. In case of spraying, though the smaller droplets are, the more cooling and moisture conditioning can be performed uniformly, cooling time becomes longer, therefore, a necessary space becomes larger and they are apt to be driven upward through generation of vapor. Therefore, as for the spraying, it is better to be performed by facing toward the upper part form the lower part. In case the droplets are large in size it is better to spray strongly to such an extent that the droplets are broken through colliding force and the uniform cooling and moisture conditioning are performed by making a spraying direction oscillate. As the water is vaporized instantly and the fiber board is deprived of evaporation heat at that instance, the cooling is performed rapidly and the fiber board to which the moisture conditioning has been adjusted at equilibrium moisture content with the air is produced efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION This invention relates generally to a method for manufacturing fiberboard, and more particularly to I! The present invention relates to a method for controlling or cooling fiber pine i- after heating and press-molding it using a hot press device, and controlling the humidity.

Conventional techniques Wet methods and dry methods are known as methods for producing root plates. In either method, b F) Tj or the formed fiber mat is generally heated and press-molded using a press machine.

In the dry method, the moisture content of the formed fiber pine 1 itself is relatively low, and it is further dried by heating in a hot press machine, and the temperature is high. Therefore, the fiberboard is removed immediately after heating and pressing. It cannot be deposited. Therefore, the heated and press-molded fiberboards are cooled by natural heat radiation or by blowing cold air with a cooling fan while being supported and transported separated from each other by a cooling device such as an elevator set or a wicket type.

In the wet method, the moisture content of the paper-made fiber mat itself is quite high, but it is dried by heating in a hot press machine, and is used to improve the water resistance of the fiberboard and mechanical strength such as 1 bending strength. heat treatment or oil impregnation treatment. Since the temperatures in these heat treatments and oil impregnation treatments are also high, the fiberboard is highly dry and at high temperatures, so that the fiberboard cannot be deposited immediately after these treatments. Therefore, cooling must be carried out in a manner similar to that described above.

Further, after cooling, the fiberboard obtained by either method is in a dry state far lower than its equilibrium moisture content with the atmosphere. When such a fiberboard is cut and cut as it is, the length and thickness increase due to subsequent moisture absorption, resulting in irregular dimensions, warping, misalignment, and distortion. Therefore, it is also common practice to condition the fiberboard after cooling.

Humidity conditioning needs to be carried out evenly, so it is carried out while the fiberboards are supported and transported at a distance from each other in a humid humidity conditioning chamber using a set of elevators, a wicket type conveyor, or the like.

Problems with the prior art Humidity control or cooling and humidity control in the prior art are ill
It requires a large amount of factory space due to the need to support the boards at a distance from each other, the low thermal conductivity of fiberboard, and the slow migration of moisture within the fiberboard.
It takes time, and requires equipment costs and power costs for blowing air with a cooling fan and preparing humid air.

In addition, when adhesives containing formalin are used to manufacture fiberboard, formalin odor remains in the product, which is not only unpleasant but also poses a hygiene problem.
is required to be lowered to the standard value. Removal of this formalin also required factory space and time, resulting in poor production efficiency.

In addition, by using an adhesive that does not contain formalin,
This problem is solved, but the cost is generally higher.

Technical Solution In the present invention, moisture is controlled by spraying or coating water on one or both sides of the IIN board at a desired stage after completion of the final heating step in the fiberboard manufacturing process. Spraying or application of water may be done after the RaH board has cooled down, or may be done while the fiberboard is still at a high temperature, and the :XA wetting may be done simultaneously with cooling. In the latter case, cooling may be performed by the first spraying or coating, and then humidity may be controlled by the second spraying or coating.

Formalin can be captured by adding a formalin catcher to the water used. Also,
Adding surfactants to water promotes humidity conditioning.

Lad boards sprayed or coated with water can be deposited immediately, saving factory space and humidity conditioning processing time. In addition, when water is sprayed or applied while the fiberboard is at high temperature, formalin can be efficiently captured by adding a formalin catcher agent, which simply reduces the amount of formalin remaining in the product. As well,
It is also effective in preventing air pollution within factories.

The present invention has been briefly outlined above, and the present invention will be explained in more detail below based on examples of the present invention.

Description of Examples Wood fibers made by defibrating wood chips using a rifling process and an adhesive.
A fiber mat is formed from a homogeneous mixture with a sizing agent using a forming device, and after being breathless, it is heated and press-molded using a hot press device. The temperature of the fiberboard after molding varies with the press schedule depending on the adhesive used, the thickness and specific gravity of the fiberboard being manufactured, but generally the surface temperature is around 150°C and the internal temperature is 100 to 140°C.
That's about it.

While the formed fiberboard is maintained at a high temperature, water is sprinkled or applied to one or both sides of the fiberboard. As for the spraying method,
Either spraying or roll application may be used, and the roll may be a sponge roll, cloth roll, cloth roll, or the like. In the case of spraying, the smaller the droplets, the more uniform the cooling and humidity control, but the cooling time is longer, the space required also tends to be larger, and there is a tendency for the droplets to be chased upward by the generation of steam. . Therefore, it is preferable to spray from the bottom to the top. If the droplets are large, it is best to spray them so strongly that the droplets break due to the collision force, and care should be taken to vibrate the jetting direction to achieve uniform cooling and humidity control.

By spraying or applying water while the plate temperature is high,
The water is instantaneously vaporized and takes away the heat of vaporization from the fiberboard, resulting in rapid cooling.

The steam generated during this process also helps control humidity.

The amount of water to be sprayed is determined depending on the plate temperature.

Although water may be sprayed or applied only to one side of the fiberboard, it is more preferable to spray or apply water to both sides.

However, if cooling proceeds relatively rapidly, -
By applying it only to the surface, and immediately applying it with the surface of the board horizontal, the result is essentially the same as spraying or applying water to both surfaces.

Cooling and humidity conditioning by spraying or applying water may be performed continuously, or may be performed intermittently in two or more times. For example, a first sprinkling or coating may be carried out while the mM plate is at a high temperature, then it is transferred to a conventional cooling device, and after cooling it is subjected to a second spraying or coating. In that case, the first sprinkling or coating may be done on one side of the $1Ift board and the second sprinkling or coating on the other side.

In addition, during heating and pressure forming, the fiber mat is generally heated from the surface at the same time as it is pressed, so the moisture in the layer near the surface evaporates, but some of it is reversed due to the vapor pressure bonding inside the fiberboard. Moving on to the core part.

Furthermore, when the pressure is released, water vapor on the surface side of the fiberboard is rapidly released. Therefore, in the fiberboard after heat and pressure molding, a difference in moisture content of 5% or more is likely to occur between the surface layer and the core. One like that! Cutting the skirting board tends to cause warping and misalignment. Therefore, it is not necessary to condition the humidity to show such a difference in moisture content immediately after the cooling and humidity conditioning process; In this case, by stacking multiple fiberboards in M1 piles without supporting them apart from each other, the required space in the factory and/or the residence time in the cooling system and humidity control system can be significantly reduced. .

As described above, according to the method of the present invention, fiberboard whose moisture content is adjusted to equilibrium with the atmosphere can be efficiently produced.

Urea resin and melamine resin as fiberboard materials.

When using a formalin-based adhesive such as urea-melamine resin, add urea, ammonium acetate, ammonium sulfite, sodium sulfite, thiosemicarbazide, ethylenediamine, natural protein, etc. as a formalin catcher agent to the above water. This makes it possible to collect 1 m of formalin remaining in the product. The formalin collection effect is
It is more efficient to spray or apply water to which a formalin catcher agent has been added while the fiberboard temperature is high, and it is also more effective in preventing pollution of the air within the factory.

Also, adding a surfactant to the water that is being sprayed or applied will help the water penetrate into the interior of the fiberboard. It is desirable to spray or apply the surfactant-added water after the board temperature has decreased. This is because, regardless of the number of sheets, when sprayed or applied to a high-temperature fiberboard, more marks will evaporate than permeate.

Effects for production The functions and effects of the present invention can be summarized as follows.

1. After cooling, water can be sprayed or applied on one or both sides of the fiberboard and then deposited immediately, saving space and time in the humidity control line, improving production efficiency.

2. When water is sprayed or applied on one or both sides of the 11M plate while the $Ii, llt plate is at high temperature, it can save space and time in the cooling line.

3. When performing cooling W and humidity control by spraying or applying water, it is possible to save space and time on both lines.

4. Production efficiency can be improved simply by adding a spraying device and a coating device to existing equipment.

5. Fiberboard with uniform moisture content can be efficiently produced.

6. When a formalin-based adhesive is used, free formalin can be efficiently captured simply by adding a formalin catcher agent to water.

7. Moisture control is efficiently achieved by using surfactants.

8. By using a formalin catcher agent and a surfactant in combination, free formalin in the inner layer of the fiberboard can be easily collected.

9. The deposition curing time for humidity control and formalin collection is shortened or unnecessary.

Claims (13)

[Claims] (1) In a fiberboard manufacturing method in which a fiber mat is heated and pressure-molded using a hot press device, and then humidity control is performed,
A method for manufacturing a fiberboard, characterized in that the humidity of the fiberboard is controlled by spraying or coating water on one or both sides of the fiberboard. (2) A method for producing a fiberboard according to claim 1, characterized in that the sprinkling or application of water is carried out after the fiberboard has been cooled. (3) Production of a fiberboard in the method according to claim 1, characterized in that the sprinkling or application of water is carried out while the fiberboard is at a high temperature after the fiber mat is heated and press-molded. Method. (4) In the method according to claim 1, the fiberboard is characterized in that the sprinkling or application of water is carried out twice: once when the fiberboard is at a high temperature and once after the fiberboard has been cooled. Method of manufacturing the board. (5) The method according to any one of claims 1 to 3, characterized in that a surfactant and/or a formalin catcher agent is added to the water to be sprayed or applied. Method of manufacturing fiberboard. (6) A method for manufacturing a fiberboard according to claim 4, characterized in that a surfactant and/or a formalin catcher agent is added to the water to be sprayed or applied. (7) In the method according to claim 6, there is an interface between the water that is sprayed or applied when the fiberboard is at a high temperature, and the water that is sprayed or applied after the fiberboard has cooled. A method for producing a fiberboard, comprising adding an activator and a formalin catcher agent to the other. (8) In the method described in any one of claims 1 to 7, water is sprayed only on one side of the fiberboard when the fiberboard is at high temperature and when it is cooled. A method for manufacturing a fiberboard, characterized in that a plurality of fiberboards that have been sprayed with water are stacked horizontally with the side that has been sprayed with water facing upward or downward. (9) Production of a fiberboard in the method according to claim 9, characterized in that water is sprayed or applied only to the same side of the fiberboard when the fiberboard is at high temperature and when it is cooled. Method. (10) In the method according to claim 9, the water that is sprayed or applied to the fiberboard when the fiberboard is at a high temperature and the water that is sprayed or applied after the fiberboard has cooled are sprayed or applied only to different surfaces. A method for manufacturing fiberboard, characterized by: (11) In the method according to any one of claims 1 to 7, water is sprayed on one side of the fiberboard, and a plurality of fiberboards that have been sprayed with water are A method for manufacturing fiberboard, characterized in that it is deposited horizontally. (12) In the method according to claim 4 or 7, water is sprayed or applied to both sides of the fiberboard only when the fiberboard is at a high temperature, and after the fiberboard has been cooled, water is applied to both sides of the fiberboard. A method for manufacturing fiberboard characterized by spraying or applying water only on one side. (13) In the method according to claim 10,
A method for producing a fiberboard, characterized in that at least a formalin catcher agent is added to the water that is sprayed or applied when the fiberboard is at a high temperature.