JPH0542341B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a double facer with an improved heating device.

[Conventional technology]

The conventional technique will be explained with reference to FIG. Fourth
The figure is a sectional view showing the overall structure of the double facer. Reference numeral 1 in the figure indicates a single-sided corrugated board, and this single-sided corrugated board 1 is made in a single facer as a pre-process (not shown) and transferred to a double facer 2 . At this time, starch glue 4 is applied by the glue machine 3 to the corrugated top 1A of the corrugated core paper of the single-sided corrugated board 1. On the other hand, reference numeral 5 in the figure is a liner, and this liner 5 is preheated by a preheater 6 and transferred into the double facer 2 . That is, inside the double facer 2 , the single-sided corrugated board 1 and the liner 5 are bonded and integrated via the starch glue 4.

In the heating part 7, the single-sided corrugated cardboard 1 and the liner 5 that have entered the double facer 2 are held between a belt 9 driven by a roll 8 and a heating box 10, and are held by a weight roll 11.
is pressurized and transported. When passing through the heating part 7, the starch glue 4 is heated by the heating box 10 having high temperature steam inside.
becomes gelatinized. As a result, one-sided cardboard 1 and liner 5
are glued together to form a double-sided corrugated board 12. Then, this double-sided corrugated board 12 is held in the cooling part 13 by the belts 9, 15 and the weight roll 11, and is transferred to the next step (not shown).

[Problem that the invention seeks to solve]

In the above configuration, the weight roll 11 is intended to apply pressure to the double-sided corrugated board 12 and at the same time promote heating in the heating part 7, but it has the following problems. In other words, the amount of heat required to gelatinize the starch paste 4 depends on heat conduction from the heating box 10 through the liner 5, but since the thermal conductivity of the liner 5 is low, the temperature of the liner 5 itself must be kept above the gelatinization temperature. It is necessary to keep it. Approximately 70% of the steam power supplied to the heating box 10 is used to heat the liner 5, and there has been a demand for improvement.

The present invention has been made based on the above points, and its purpose is to provide a double facer that can improve the heating mechanism, eliminate uneconomical heat consumption, and reduce costs. It is in.

[Means for solving problems]

That is, the double facer according to the present invention is a double facer in which a single-sided corrugated board coated with glue on one side and a liner are introduced and bonded together under pressure and heat to form a double-sided corrugated board. An electrode roll and a grid electrode are arranged in the liner, a voltage is applied between the electrode roll and the grid electrode to generate an electric field, and the single-sided corrugated board and the liner are bonded to each other by dielectric heating caused by the electric field. It is something.

〔effect〕

Therefore, only the amount of heat required for gelatinization can be supplied, and the amount of heat conventionally consumed for heating the liner is no longer necessary, making it possible to effectively reduce energy consumption. In addition, since the electrode roll maintains its conventional pressing function, the adhesive strength is not impaired, and the effect is great.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. It should be noted that the same parts as in the prior art are denoted by the same reference numerals and the explanation thereof will be omitted. That is, in this embodiment, in the heating part 107, a grid electrode 121 is provided in place of the conventional heating box, and an electrode roll 122, which is a conventional weight roll with an additional electrode function, is provided. Further, the belt 123 is an insulating belt.

The electrode roll 122 has the same size as a conventional weight roll, and as shown in FIG. 3, rotates in the direction indicated by the arrow in the figure while contacting the electric brush 124. It should be noted that there are various types of electricity supply materials other than the electric brush mentioned above. Further, the grid electrode 121 is connected to the ground base 1 as shown in FIG.
The electrode roll 122 is embedded in an insulator 126 fixed to the electrode roll 125, and the portion where the electrode 121 is not embedded forms a back-up of the electrode roll 122 and is in contact with the corrugated paper.

The operation will be explained based on the above configuration. By applying high frequency heating between the electrode roll 122 and the grid electrode 121, electrolysis occurs in the direction indicated by the arrow in FIG. Due to the dielectric heating caused by the electrolysis, heat proportional to εtanδ is generated within the corrugated board sheet.

However, ε: relative dielectric constant tan δ: dielectric loss coefficient. At this time, the value of ε tan δ is about 20 to 30 times higher for the water in the starch glue 4 than in the corrugated paper, and as a result, the electrolysis generated will concentrate on the water in the bonded part of the starch glue 4. Highly efficient heating drying becomes possible.

According to this embodiment, the following effects can be achieved.

(1) First, by using a heating mechanism using a grid electrode 121 and an electrode roll 122 instead of the conventional steam heating using a heating box, it becomes possible to supply only the amount of heat necessary for gelatinization. Therefore, the heat conventionally consumed in heating the liner is no longer necessary, and energy consumption can be reduced.

(2) Next, the electrode roll 122 performs the pressurizing action as before, and the quality of the starch paste 4 permeating into the paper is maintained as before. Therefore, there are no problems with adhesive strength, etc.

(3) Furthermore, it is possible to selectively heat only the adhesive portion, and it is possible to effectively increase the manufacturing speed (the feeding speed of the cardboard). Furthermore, it goes without saying that the length of the apparatus can be shortened if the feeding speed of the cardboard remains the same.

It should be noted that the present invention is not limited to the above embodiments, and various arrangements and shapes of the grid electrode, insulator, and grounding base can be considered, for example.

[Brief explanation of drawings]

Figures 1 to 3 are views showing an embodiment of the present invention, in which Figure 1 is a sectional view of a double facer, Figure 2 is an enlarged view of a part of Figure 1, and Figure 3 is a heating A perspective view showing the mechanism, and FIG. 4 is a sectional view of a conventional double facer. 1...Single-sided cardboard, 2 ...Double facer,
4... Starch glue, 5... Liner, 107... Heating part, 121... Grit electrode, 122
...Electrode roll.

Claims (1)

[Claims] 1. In a double facer in which a single-sided corrugated board coated with glue on one side and a liner are introduced and bonded together by applying pressure and heat to form a double-sided corrugated board, an electrode roll and a grid electrode are placed so as to sandwich the single-sided corrugated board and liner. A double facer is characterized in that a voltage is applied between these electrode rolls and grid electrodes to generate an electric field, and the single-sided corrugated board and liner are bonded to each other by dielectric heating caused by the electric field.