JPS62179934A - Double facer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a double facer for paper processing machinery.

(Prior Art) FIG. 13 shows a schematic side cross-sectional view of a conventional double facer. In the figure, a single-sided corrugated board sheet 1 made with a single facer (not shown) in the previous step is coated with starch glue 13 on the corrugated tops of the eight corrugated papers by a glue machine 14, and then enters the double facer 5. On the other hand, the liner 2 is preheated by the preheater 4 and similarly enters the double facer 5. In the heating part 6, the single-sided corrugated sheet 1 and liner 2 that have entered the double facer 5 are held between a belt 8 driven by a roll 12 and a heating box 9, and a weight roll arranged in a row on the back side of the belt 8. 1
It is pressurized at 0 and transferred. When the single-sided corrugated cardboard sheet 1 and the liner 2 pass through this heating par 16, the adhering starch paste is gelatinized by the heating of the heating box 9, which has high-temperature steam inside, and the single-sided corrugated cardboard sheet 1
The corrugated tops of the 8 corrugated papers and the liner 2 are adhered to form 11 double-sided corrugated pole sheets 3. In the subsequent cooling part 7, this double-sided corrugated cardboard sheet 3 is pressed between the belt 8 and the lower belt 11 by the weight roll 10, and is then carried out and sent to the next process.

Here, the weight roll 10 in the conventional double facer applies pressure to the double-sided corrugated sheet 3, and
Although this is intended to promote heating in the heating part 6, it also has the following problems.

That is, since the pressure by the weight roll 10 acts on the double-sided corrugated sheet 3 through the belt 8 as linear pressure due to its own weight, the weight roll 1
The linear pressure due to zero becomes too large, and a step collapse as shown in FIG. 14 occurs.

The main reason for this is that the heating of the adhesive part by the heating box 9 depends mainly on conduction heat through the container wall of the box 9 and the liner 2 that is in contact with it. It is necessary to increase thermal conductivity,
This is because it is therefore necessary to apply a fairly strong pressing force to both of the above from the back side of the single-sided corrugated sheet 1 using the weight rolls 10. Furthermore, since such an indirect heating method is used, the heating efficiency is low, and the heating part inevitably has to be long.

(Problems to be Solved by the Invention) As described above, according to the heating and pressurizing means in the conventional double facer, most of the thermal energy is wasted because the heating depends on thermal conduction, and the pressurizing method also uses linear pressure. Therefore, there is a problem in that the corrugated sheet surface cannot be pressurized uniformly, causing corrugation collapse, which results in energy consumption, generation of defective products, and impediment to miniaturization of equipment. It had become.

The present invention was developed in view of these points, and aims to provide a double facer that eliminates all of the above problems by increasing heating efficiency and simultaneously using a uniform pressurizing means. .

(Means for Solving the Problems) For this reason, the present invention has a dielectric heating device on one side of the corrugated cardboard sheet for a strip-shaped corrugated sheet to be pasted that runs continuously on a corrugated line, and on the other side. A gas blowing device for pressurizing the sheet surface with air pressure is disposed on the side, and this is used as a means for solving the above problem.

(Function) One side of the corrugated cardboard sheet is dielectrically heated using a dielectric heating device, taking advantage of the fact that the glue part absorbs more power than the paper part.
Performs efficient adhesion and drying.

At the same time, gas pressure from a gas blowing device is applied to the other side of the corrugated cardboard sheet to further strengthen the adhesion without causing collapsing.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side sectional view showing the entire double facer which is an embodiment of the present invention. This device is heating bart 6
In this case, instead of the conventional heating box 9 and weight roll 10 disposed on the back side of the belt 8 shown in FIG.
A dielectric heating device having a grid electrode 15 is installed on one side, and a gas blowing device 16 is installed on the other side.

As shown in FIGS. 2 to 4, the grid electrodes 15 can be arranged in three ways: parallel to, perpendicular to, or oblique to the flow direction of the corrugated cardboard sheet.
As shown in the figure, the dimensions and shape are determined under the condition that L sin θ≧P.

Here, L is the width of the corrugated cardboard sheet, P is the pitch interval of the electrodes, and θ is the inclination angle of the electrodes in the width direction of the corrugated cardboard sheet.

Next, dielectric heating using the grid electrode will be explained.

When a high frequency alternating voltage is applied to the grid electrode 15, an electric field is generated between each electrode as shown in FIG. 6, and acts on the glued portion 17. Note that FIG. 6 shows a cross section taken along the line AA shown in FIG. 2, and the generation of electric fields is the same in FIGS. 3 and 4.

By the way, the power absorbed internally by dielectric heating is [・
It is proportional to E2・ε・tanδ. Here, f is the frequency,
E is the strength of the electric field, ε is the dielectric constant of the object to be heated, and tan δ is the dielectric loss coefficient of the object to be heated. By the way, since the value of E2·ε·tan δ is 20 to 30 times higher in the adhesive part than in the paper part, the absorbed power is concentrated in the peripheral part and drying is accelerated. In the case of conventional heating using a heating box, heat is conducted through the paper, and approximately 70% of the heat is used to raise the temperature of the paper.Compared to this, this dielectric heating is a more efficient heating method. be.

Next, regarding the pressurizing means, in the present invention, the gas blowing device 16
This can be roughly divided into two types: one based on static pressure and one based on dynamic pressure. In FIG. 1, the dynamic pressure is shown.

FIGS. 7 and 8 show examples in which static pressure is used, and show an example in which static pressure pads 18 are arranged in a row and an example in which the entire box is made into one static pressure container 19.

Furthermore, FIG. 9 shows an example of a blow-off device using dynamic pressure, and FIG. 10 shows an example of the configuration of the slit hole 20 as the shape of the blow-off portion shown in FIG. FIG. 11 shows a staggered arrangement, and FIG. 12 shows a staggered arrangement. In addition, Figures 7 to 9
The arrows in the figure indicate the flow of gas. Here, it is also possible to use high-temperature gas for both static pressure and dynamic pressure, and in that case, it will have the effect of not only pressurization but also heating for drying the surrounding area.

As described above, in the present invention, the desired purpose can be achieved by any combination of the grid electrode arrangement shown in FIGS. 2 to 4 and the dynamic pressure or static pressure pressurization device shown in FIGS. 7 to 9. It is achievable.

Next, a process for manufacturing double-sided corrugated board using the apparatus of this embodiment will be explained based on FIG.

The single-sided corrugated pole sheet 1 and the liner 2 to which the adhesive has adhered are conveyed by the conveying rolls 22, merging at the entrance of the heating par 1-6'. In the heating part 6', the dielectric heating device having the grid electrode 15 installed on the bottom side of the sheet concentrates the electric field particularly on the glued part of the corrugated sheet as described above, while Uniform pressure is applied by air from the gas blowing device 16 using a static pressure method or a dynamic pressure method, and the temperature of the glued portion increases while it is in a crimped state, and the glue gels and dries to bond.

Here, the air blown out from the gas blowing device 16 has a wind speed of 50~
If the speed is about 60 m/s, pressurizing conditions equivalent to those of the conventional method can be obtained. Further, as described above, by using high-temperature gas with an air temperature of 150 to 180°C, the effect of heating from the upper surface side can be expected.

The double-sided corrugated paperboard sheet 3, on which the adhesion has been completed, then enters a cooling part 7 whose upper and lower surfaces are guided between a pair of endless belts, and is sent out to the next process.

(Effects of the Invention) As explained in detail below, according to the present invention, localized pressure is applied by a non-contact type of pressurization that uses gas static or dynamic pressure instead of weight rolls. This eliminates the occurrence of collapsing and can be expected to improve the quality of the sheet.

At the same time, in the present invention, by utilizing dielectric heating using grid electrodes, not only can significant thermal energy savings be achieved compared to indirect heating by heat conduction using a conventional heating box, but also It also makes it possible to shorten the line length of the heating part.

[Brief explanation of drawings]

FIG. 1 is an overall side sectional view of a double facer showing one embodiment to which the present invention is applied, FIGS. 2 to 4 are layout diagrams of different grid electrodes showing embodiments of the present invention, and FIG. A condition diagram for determining the dimensions in the example shown in the figure, FIG. 6 is a diagram showing the electric field generation situation in the A-A cross section of FIG. 2,
Figure 7 is a side sectional view when a static pressure pad is used as an example of a static pressure type pressurizing device, and Figure 8 is a side sectional view when a static pressure container is used as an example of a static pressure type pressurizing device. Figures 9 and 9 are side sectional views when a nozzle is used as an example of a dynamic pressure type pressurizing device, and Figures 10 to 1N! /I is a diagram showing the shape of the nozzle in FIG. 9, respectively, where FIG. 10 shows a slit shape, FIG. 11 shows a base hole shape, and FIG. 12 shows a zigzag shape. FIG. 13 is an overall side sectional view of a conventional double facer, and FIG. 14 is a partial side view showing the state in which collapsing occurs in a corrugated board sheet. Explanation of the main parts of the figure 3 - Double-sided corrugated pole sheet 15 - Grid electrode 16 - Gas blowing device 18 - Static pressure panel 19 - Static pressure vessel 20 - Slit hole 21 - Round hole hole Patent Applicant: Mitsubishi Heavy Industries, Ltd. No. Figure 2 Figure 3 Figure 5 Figure 6 Figure 7 Figure 9 Procedural amendment September 30, 1985 Commissioner of the Patent Office Black 1) Mr. Ming Jji 1, Indication of case Patent application No. 1988-21771 2, Name of the invention Double Facer 3, Relationship to the case of the person making the amendment Patent applicant address 2-5-1 Marunouchi, Chiyoda-ku, Tokyo Name
(620) Mitsubishi Heavy Industries, Ltd. 4, Agent Address: Mitsubishi Heavy Industries, Ltd., 2-5-1 Marunouchi, Chiyoda-ku, Tokyo Name (6124) Patent Attorney Akatsuki Sakama, 2 others 5
, Contents of Subagent Amendment 1, the description of ``rA-A cross section'' on page 6, line 14 and line 11 of page 10 of the specification cylinder (two locations) is amended to ``rx-x cross section.'' 2. Figures 2, 3, and 4 of the drawings will be corrected as shown in the attached sheet. that's all

Claims (1)

[Claims] A dielectric heating device is provided on one side of the corrugated cardboard sheet to be glued, which runs continuously on a corrugated line, and a gas blowing device that pressurizes the sheet surface with air pressure is placed on the other side. A double facer that is characterized by: