JPS6316520B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention produces wood fiberboard using a circular net wet papermaking method.
This paper relates to improvements in the circular net wet papermaking method for manufacturing mineral fiberboards, etc.

BACKGROUND ART The circular wire wet papermaking method has been well known as a method for producing wood fiberboards, mineral fiberboards, and the like. This method uses, for example, the apparatus shown in FIGS. 1 to 3. This device includes a vessel 2 that stores a paper-making liquid 1, a cylinder 3 that is partially immersed in the paper-making liquid 1 in the vessel 2 and rotates, a pressing device 4 provided above the cylinder 3, and an object to be formed on the vessel 2. and a peeling plate 6 for peeling off the 5.

The surface of the cylinder 3 is partitioned into a number of small chambers 7, the outside of which is covered with a wire mesh 8'. The back side of the small chamber 7 is divided into a plurality of small chambers 7, each of which is connected to a pipe 9. The pipe 9 is connected to a pressure control device outside the machine via a rotary joint (not shown), and the connection to the pressure control device, etc. is switched during one rotation according to the rotation angle. .

For example, the surface portion of the cylinder 3 is configured such that the portion immersed in the papermaking liquid 1 becomes a suction portion 10, then switches to a blocking portion 11, a blowing portion 12, and a blocking portion 11.

In the above-mentioned apparatus, by rotating the cylinder 3, the components of the papermaking liquid are adhered to the wire mesh surface 8 in the immersed section, and then the material 5 is produced by suction and dewatering in the non-immersed section. In this case, if the small chamber 7 is kept in a reduced pressure state, the material to be made 5
is attracted to the wire mesh surface 8, making it difficult to separate. For this reason, a blocking part 11 and a blowing part 12 are provided near the separation part 13 of the material to be made 5 from the wire mesh surface 8 to release the reduced pressure state, and a peeling plate 6 is used to separate the material to be made 5 from the wire mesh surface 8. I'm letting you do it.

However, in the blowout section 12, the cylinder 3
At this time, as shown in FIG. 3, the moisture 14 remaining on the wire mesh surface 8 and inside the tube 9 flows into the material to be formed 5 at the same time as the air flows in. It blows up all the way. As a result, the papermaking material 5 that has been dehydrated once again becomes impregnated with such water, and moreover, becomes impregnated non-uniformly. For this reason, in the next drying process, the load on the dryer to evaporate the moisture in the material to be paper-sheeted is large.With today's strong demand for reducing energy consumption, one of the methods of wet paper-making using the circular mesh method is It was a big drawback.

The present invention has been made in view of such conventional problems, and its purpose is to provide a round-mesh wet papermaking method that eliminates uneven distribution of moisture content without increasing the moisture content of the papermaking material. There is a particular thing.

Next, the present invention will be explained with reference to the drawings which are one embodiment. Figures 4 and 5 show a circular mesh type wet papermaking apparatus to which the method according to the present invention is applied. This device is
In the apparatus shown in FIG. 1, an endless strip 15 is provided on the side edge of the outer wire mesh surface 8 of the cylinder 3, the blowing part 12 on the cylinder surface is eliminated, and the suction part 10
In this case, only the blocking section 11 is used. The other parts are substantially the same and are designated by the same numbers.

The belt-shaped body 15 is stretched between the cylinder 3 and a support roll 16 provided above the detachment portion 13 of the material to be formed 5 . The support roll 16 is configured to rotate in synchronization with the rotation of the cylinder 3.
The band 15 may be made of various materials, such as one made of rubber such as synthetic rubber, one made of synthetic resin such as soft polyethylene resin, or one made of cloth belt coated with rubber or synthetic resin such as soft PVC. It is desirable to have excellent durability and non-breathability or poor breathability.

Next, the operation of the apparatus having the above configuration will be explained.

Similarly to the previous period, in the area of the suction section 10, the material to be formed 5 is formed on the surface of the wire mesh surface 8 as the cylinder 3 rotates, and moves to the blocking section 11. Since the suction force is cut off to the part of the cylinder 3 where the belt-like body 15 is stretched, the papermaking liquid composition does not adhere to the part.

Even when the material to be formed 5 moves from the suction section 10 to the blocking section 11, the suction and dewatering effects from the wire mesh surface 8 are maintained in the portion where the strip 15 is in close contact with the wire mesh surface 8. As the material to be formed 5 approaches the separation section 13 through further rotation, the strip 15 gradually separates from the wire mesh surface 8, and air flows in from that part, causing the inside of the small chamber 7 to be at normal pressure (atmospheric pressure). ) state.
At the peeling plate 6, the paper material 5 is placed on the wire mesh surface 8.
The cylinder 3 separates from the cylinder 3 in a state where it is released from adsorption to the cylinder 3.

Note that the method according to the present invention is also applicable to a device in which the surface portion of the cylinder 3 is switched between a suction section, a cutoff section, a blowout section, and a cutoff section, or a device in which the surface section of the cylinder 3 is switched between a suction section, a blowout section, and a cutoff section, as described above. can.

Further, the band-shaped body 15 may be provided on both side edges of the cylinder 3, and does not necessarily need to rotate in synchronization with the cylinder 3.

Further, the means for releasing the strip 15 is not limited to the above-mentioned method, and various methods such as using a doctor plate instead of the support roll 16 can be adopted.

As is clear from the above description, the method according to the present invention involves installing a strip along the side edge of the wire mesh surface on the outer periphery of the cylinder in the circular mesh wet papermaking method, and removing this strip from the wire mesh surface at the detached portion. The paper is made using a simple method of releasing it. Therefore,
Unlike in the past, the moisture remaining in the piping or on the surface of the wire mesh does not blow up at the detachment section, and the moisture content of the papermaking material does not increase or become unevenly distributed at the detachment section.

Therefore, the amount of heat required to evaporate water in the drying process can be reduced, and the drying speed can be accelerated, which has a great practical effect of reducing fuel costs and improving productivity. It is something to play.

[Brief explanation of the drawing]

Fig. 1 is a partially sectional side view of the conventional device, Fig. 2 is a sectional view taken along the line of Fig. 1, Fig. 3 is an enlarged view of section A in Fig. 1, and Fig. 4 is a side view of a conventional device to which the method according to the present invention is applied. FIG. 5 is a sectional view taken along the line -- in FIG. 4. 3... Cylinder, 5... Paper-forming object, 8... Wire mesh surface, 15... Band-shaped body, 16... Support roll.

Claims (1)

[Scope of Claims] 1. In the circular mesh wet papermaking method, an endless strip made of a material that is non-breathable or has poor air permeability is brought into contact with the side edge of the wire mesh surface around the outer periphery of a rotating cylinder along the wire mesh surface. After dehydration and papermaking by suctioning the papermaking liquid under reduced pressure, the strip is released from the wire mesh surface at the papermaking material detachment section in the upper part of the cylinder, and air is allowed to flow into the cylinder from the exposed wire mesh surface, thereby forming the papermaking material. A circular net wet papermaking method characterized by the removal of objects. 2. The circular mesh type according to claim 1, characterized in that the endless strip is supported by rotatable rolls provided outside the cylinder at the sheet-forming material separation section and removed from the wire mesh surface. Wet papermaking method.