JPS62160232A - 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 that can be used in paper processing machines, printing machines, paper making machines, etc.

(Prior Art) FIG. 6 shows a schematic diagram of a conventional double facer. In FIG. 6, 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 then similarly enters the double facer 5.

The single-sided corrugated paperboard 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 in a heating part 6, and further pressurized by a weight roll 10 and transferred.

When passing through this heating part 6, the starch paste is gelatinized by the heating of the heating box 9, which has high-temperature steam inside, and the corrugated tops of the corrugated 8 papers of the single-sided corrugated sheet 1 and the liner 2 are adhered to form a double-sided corrugated board. This will be sheet 3. This double-sided corrugated cardboard sheet 3 is held between belts 8, 11 and weight rolls 10 in the cooling bar 7, and is carried out and sent to the next process.

However, in the conventional double facer, the weight roll 10 is used to apply pressure to the double-sided corrugated cardboard sheet 3 and promote heating in the heating part 6, but it has the following drawbacks.

That is, since the weight roll 10 applies linear pressure due to its own weight to the double-sided corrugated sheet 3 via the belt 8, the weight roll 10 can This has the disadvantage that the line pressure is large (because of this), and step collapse 1a as shown in FIG. 7 occurs.

Also, the amount of heat required to gelatinize the starch paste depends on the heat conduction from the heating box 9 through the liner 2.
Because the thermal conductivity of the liner is low, it is necessary to keep the temperature of the liner itself above the gelatinization temperature. It was extremely wasteful as it was wasting time.

(Problems to be Solved by the Invention) The present invention attempts to solve problems such as occurrence of step collapse and uneconomical use of heat in conventional double facers.

(Means for Solving the Problems) Therefore, the present invention provides a method for applying glue to a strip-shaped corrugated pole sheet that runs continuously in a corrugated line, by applying the same material to one or both sides of the corrugated sheet. Several units of grid electrodes, which are inclined at a certain angle in the flow direction of the sheet on a horizontal plane, are arranged in the width direction of the corrugated sheet, with the electrodes parallel to each other and at a certain pitch, and between adjacent electrodes. The sheet is dielectrically heated by applying a high frequency voltage to the sheet, and this is used as a means to solve the problem.

(Operation) An electric field is generated in the grid electrode by applying a high frequency voltage between the (+) pole supported by the insulator and the grounded (-) pole.

Due to dielectric heating caused by this electric field, inside the cardboard sheet,
E"t tan δf (g: relative dielectric constant, tan δ:
Heat is generated in proportion to the dielectric loss coefficient (f: frequency, E: electric field strength).

(Example) An example of the present invention will be described below with reference to the drawings. FIGS. 1 to 5 show examples of the present invention, and FIG. 2 shows a layout to which the present invention is applied. The apparatus shown in FIG. 2 uses a grid electrode 1 in the heating bar 6 instead of the conventional heating box 9° and weight roll 10 shown in FIG.
5, and an insulating belt 16 is provided in place of the conventional belt 80 shown in FIG. However, the arrangement of the electrodes 15 is
As shown in the figure, it is installed so as to be inclined at a certain angle in the flow direction of the corrugated cardboard sheet 3.

The electrodes were each supported by an insulator 17 (+
) pole and a grounded (-) pole a high frequency:fX voltage is applied. Here, the grid with (+) pole and −) pole is
Several units of throat electrodes (the cross-sectional shape and length are not specified) are installed alternately in the width direction of the corrugated pole sheet 3. However, the distance between the +) and (-) electrodes is not specified), and the insulator. 17
By applying a high frequency voltage between the (+) pole supported by and the grounded (-) pole, an electric field as shown by arrow X in FIG. 3 is generated. Due to the dielectric heating caused by this electric field, heat proportional to E~janδr (ε: relative dielectric constant, tanδ: dielectric loss coefficient, f: frequency, E: electric field strength) is generated in the corrugated board sheet 3, but when ε tanδ Since the water content in the paper is 20 to 30 times higher than the water content in the glue, the generated electric field concentrates on the adhesive part 18 of the glue, making extremely efficient heating and drying possible. Become.

In addition, here, the electrode 15 is installed at a certain angle in the sheet flow direction. If installed parallel to the direction, temperature distribution will occur in the width direction of the sheet, which may cause uneven adhesion of the sheet, and this is taken as part of the measures to prevent this. Further, the electrodes can be arranged so as to sandwich corrugated pole sheets as shown in FIGS. 4 and 5. That is, the present invention can also be applied to a double-sided corrugated cardboard sheet 19. The flow of the electric field at this time is as shown in FIGS. 4 and 5.

Furthermore, the most efficient arrangement of the electrodes 15 is under the following conditions. That is, in FIG. 8, the inclination angle of the electrode 15 is θ, the electrode pitch is P, and the paper width that can be manufactured by the apparatus is L.
-L+win w Lmax, the configuration is such that P≦L min sin θ is satisfied. In this way, the adhesive portion is included between the electrodes, thereby increasing the heating efficiency.

Note that the present invention is applicable not only to double facers but also to single facers, which are units that perform heat bonding in corrugated lines.

(Effects of the Invention) As described in detail above, in the present invention, only the amount of heat necessary for gelatinization can be supplied by installing the grid electrode at a certain angle in the flow direction. Therefore, it is not necessary to supply the power conventionally used to raise the temperature of the paper, and considerable energy savings can be achieved. In addition, there is no need to use a pressure roll, so there is no step collapse.
Quality can be improved. Furthermore, by installing the electrode at a certain angle with respect to the paper flow, uniform drying in the width direction is possible, which improves quality. In addition, it is possible to selectively heat only the sugar part, which can be expected to increase the speed of the machine (on the contrary, if the machine speed is the same as before, the length of the double facer itself can be shortened).

[Brief explanation of drawings]

FIG. 1 is an overall plan view of a heating device showing an embodiment of the present invention;
Fig. 2 is a side sectional view of a double facer showing an embodiment of the present invention, Figs. 3, 4 and 5 are front sectional views of the heating device portion showing different embodiments, and Fig. 6 is a conventional double facer. FIG. 7 is a side sectional view of the weight roll section, and FIG. 8 is an explanatory diagram schematically showing the arrangement of electrodes. Explanation of the main parts of the figure 3 - Corrugated cardboard sheet 5 - Double facer 15 - Grid electrode 18 - Sugar section Patent Applicant Mitsubishi Heavy Industries, Ltd. Figure 3 June 30th, Commissioner of the Japan Patent Office, Kuro 1) Mr. Akio 1, Indication of the case, Patent Application No. 61-2367 2, Name of the invention, Double Facer 3, Person making the amendment Relationship to the case Patent applicant address: Marunouchi, Chiyoda-ku, Tokyo 2-5-1 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 correction 1, "An electric field is generated in grid snow shoveling" on page 4, lines 17 to 19 of the specification is corrected as follows. "When a high-frequency voltage is applied between adjacent electrodes, an electric field is generated between the two electrodes." 2. "(+) pole and the grounded "(-) pole" is corrected to "A pole and B pole". 3. Correct the "(+) pole" on page 5, line 18 and page 6, lines 1-2 to "A pole". 4. Correct the "(-) pole" in the 19th line of page 5 and the 2nd line of the 6th column to "B pole". 5. Correct Figure 1 of the drawings as shown in the attached sheet. that's all

Claims (1)

[Claims] For a strip-shaped corrugated sheet to be glued that runs continuously in a corrugated line, a grid is installed on one or both sides of the corrugated sheet on the same horizontal plane as the sheet and inclined at a certain angle in the flow direction of the sheet. Several units of electrodes are arranged in parallel to each other at a certain pitch in the width direction of the corrugated cardboard sheet, and a high frequency voltage is applied between adjacent electrodes to dielectrically heat the sheet. A double facer featuring