JPH078546B2 - Double facer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a double facer which is one unit in a corrugator which is an equipment for manufacturing corrugated board.

(Prior Art) FIG. 5 is a side sectional view schematically showing a conventional double facer. In the figure, the single-faced corrugated board sheet 1 made of a single facer (not shown) in the previous step is coated with starch paste 13 by the glue machine 14 on the corrugated core paper and 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-faced cardboard sheet 1 and the liner 2 that have entered the double facer 5 are sandwiched between a belt 8 driven by a roll 12 and a heating plate 9 and, at the same time, the belt 8
Is transferred by being pressurized by the weight rolls 10 arranged on the back side of the.

When the single-sided corrugated board sheet 1 and the liner 2 pass through the heating part 6, the hot plate 9 having high temperature steam therein
By heating, the attached starch paste is gelatinized and the corrugated top of the corrugated core paper of the single-sided corrugated sheet 1 and the liner 2 are bonded to each other to form the double-sided corrugated sheet 3. This double-sided corrugated sheet 3
Continue to the cooling part 7 and the belt 8 and lower belt
The space between 11 is pressurized by the weight roll 10 and carried out, and sent to the next step.

Here, the weight roll 10 in the double facer is
Although the pressure is applied to the double-faced corrugated board sheet 3 and the heating is promoted in the heating part 6, the conventional structure has the following problems at the same time.

FIG. 4 shows the II cross section of FIG. As shown in the figure, the conventional weight roll 10 has its end portion rotatably supported by a pair of bearings 15. The bearing for adjusting the pressure applied to the double-faced corrugated cardboard sheet 3
A rod 16 is joined to 15 via a rotary joint 17, and further the rod 16 is connected to a motor and is a weight roll.
It is possible to move 10 vertically. Although the pressure applied to the corrugated cardboard sheet 3 can be adjusted to some extent by this device, there are actually the following problems.

Here, the corrugated cardboard sheet 3 receives heat while sliding on the heating plate 9 to proceed with adhesion. In the continuous operation state, the corrugated board sheet 3 continuously takes heat from the upper surface of the hot plate 9 so that the hot plate 9
The amount of heat supplied to the heating plate 9 is not in time, and a temperature difference is generated between the upper surface and the lower surface of the heating plate 9, which results in a concave curved surface in the cross section in the width direction. The amount of deformation of the heating plate 9 at this time is large on the entrance side of the double facer because the amount of heat taken by the corrugated cardboard sheet 3 is large, and the temperature of the heating plate itself rises as the corrugated cardboard sheet 3 runs, so that the heating plate 9 approaches the exit side of the double facer. The amount of deformation becomes small.

FIG. 3 shows the result of measuring the deformation amount δ of each heating plate 9. From this figure, it can be seen that the hot plate 9 is most deformed on the entrance side of the double facer, and the deformation amount is decreased toward the exit side of the double facer.

In the conventional device, the weight roll 10 is a roll having a uniform diameter over the entire length in the longitudinal direction, or a roll having a uniform diameter portion having a length at the center and gradually reducing the diameter from the same portion to both ends. However, the design concept considering the deformation characteristics of each heating plate 9 of the double facer as described above is not adopted.

When each hot plate 9 is deformed into a concave curved surface with different deformation amount at its arranged position, the conventional weight roll 10 is deformed along the deformation of each hot plate 9 by the action of its own weight or the pressing means. Therefore, it is not possible to apply a uniform weight in the width direction of the seat 3. When the corrugated board is manufactured in such a state, defective adhesion of the corrugated board may occur, resulting in waste paper, and it becomes impossible to maintain uniform corrugated board quality due to uneven pressure in the width direction.

(Problems to be Solved by the Invention) As described above, in the double facer, each hot plate is deformed into a concave curved surface with a different deformation amount depending on the position where the double facer is continuously operated. Does not adopt a weight roll structure and configuration that conforms to the deformation of each hot plate, so uniform pressure is not applied to the corrugated board sheets to be bonded in the width direction, causing damage to the paper. Or, there remains a problem that it is difficult to homogenize the quality of corrugated board.

Therefore, the present invention is intended to solve the above problems, along with the deformation of the hot plate in the continuous operation of the double facer, the double facer so that the weight roll can apply a uniform load in the width direction of the sheet. Is to provide.

(Means for Solving the Problems) Therefore, the present invention provides a plurality of hot plates that heat a traveling corrugated cardboard sheet from its lower surface, and a conveyor belt that conveys the sheets while sandwiching the sheets between the hot plates. In a double facer which is arranged on the upper surface of the conveyor belt and comprises a plurality of weight rolls for pressing the sheet against the hot plate via the conveyor belt, the same weight roll group is placed on the unit hot plate. With the amount of crown, it is configured to gradually reduce the amount of crown to be applied to each weight roll group corresponding to the unit hot plate from the double facer inlet side to the outlet side, which is a means for solving the above problems. To do.

(Operation) When the double facer is continuously operated, a temperature difference occurs between the upper surface and the lower surface of the hot plate, which causes the hot plate to deform into a concave curved surface in the paper width direction. The amount of deformation of this hot plate is large on the entrance side of the double facer because the amount of heat absorbed by the corrugated cardboard sheet is large, and the amount of deformation of the hot plate becomes smaller as it approaches the exit side of the double facer. The amount of deformation in each of the arranged hot plates is shown by the measured value in FIG.

When the means according to the present invention is adopted, weight rolls having a structure in which the crown according to the amount of deformation or profile of the hot plate, that is, the roll diameter is gradually decreased toward the end, the roll diameter is largest in the center, are arranged in a row, and Since the size of the crown of the roll group is configured to gradually decrease from the double facer entrance side to the exit side, uniform pressure is applied in the width direction of the corrugated cardboard sheet to any position of the hot plate. As a result, it is possible to prevent adhesion failure and to make the quality of corrugated board uniform.

(Example) Hereinafter, the present invention will be described in detail based on an example with reference to the drawings.

FIG. 1 shows an upper half view of the double facer according to this embodiment. Here, the basic configuration as a double facer is the fifth
Since it is the same as the conventional device shown in the figure, its description is omitted.

In the illustrated embodiment, the arrayed heating plates 9 (~, 9j _-1 , 9j, 9
j ₊₁ , ~) each has one or more weight rolls 10
(-, 10j- ₁ , 10j, 10j _{+ 1} , ...) are grouped and mounted via a belt and a corrugated cardboard sheet (not shown). The weight roll group mounted on one (unit) hot plate 10 is provided with the same amount of crowns. The term "one unit of hot plate" as used herein does not necessarily mean one hot plate and may be composed of two or more sheets. Further, the crown means a structure in which the roll diameter is the largest at the central portion of the roll, and the roll diameter gradually decreases toward the end portion. Ideally, the profile of the crown should be the same as the average deformation pattern (dotted line) of the hot plate 9 as shown in FIG.

Further, the amount of crown of each group of weight rolls 10 on each hot plate is gradually reduced from the double facer entrance side to the exit side.
In other words, the crown amount Cj of each group of weight rolls 10j (= maximum diameter Dj at the central portion-minimum diameter D ₀ at the end portion) is ...> Cj _-1 >
The relationship of Cj> Cj ₊₁ > ... is satisfied.

In the above description, the amount of crown of the corresponding roll group is gradually reduced with one hot plate as a unit, but it may be gradually reduced with two hot plates (or three) as a unit in some cases. . That is, ……> [Cj _-1 = Cj]> [Cj ₊₁ =
In some cases, the relationship of Cj ₊₂ ]> [Cj ₊₃ = Cj ₊₄ ]> …… is satisfied.

Now, the operation of this embodiment will be described.

Since the manufacturing process of the double-faced corrugated board sheet in the double facer is the same as that of the conventional apparatus, its description is omitted here.

In the double facer, as described above, in the continuous operation state, the heat of the upper surface of the hot plate 9 is removed as the corrugated board sheet travels, so that the double facer is deformed into a concave curved surface that is recessed downward. As described above, the amount of deformation of the hot plate 9 is large because the amount of heat absorbed by the corrugated cardboard sheet is larger on the entrance side of the double facer, and the amount of deformation of the hot plate decreases as it approaches the exit side of the double facer.
With the weight roll structure and configuration according to this embodiment, since the weight rolls 10 on any of the hot plates 9 follow the deformation of the hot plates, a uniform pressure is applied in the width direction of the corrugated board sheet.

(Effects of the Invention) As described above in detail, in the double facer according to the present invention, the hot plate at any array position has a different deformation amount at each array position as the corrugated board sheet travels. Since the weight roll acts so as to follow its deformation, it is possible to apply a uniform load in the width direction of the corrugated board sheet, and it is possible to expect the prevention of damaged paper such as adhesion failure and the assurance of corrugated board quality. Is played.

[Brief description of drawings]

FIG. 1 is an upper half view of a double facer according to the present invention, FIG. 2 is a front view of the same weight roll, FIG. 3 is a characteristic diagram with respect to a hot plate position of a deformation amount of a hot plate, and FIG. 4 is a partial front cross-sectional view of a conventional double facer. FIG. 5 is a schematic side sectional view showing the entire conventional double facer. Explanation of main parts of figure 9 …… Hot plate 10 …… Weight roll

Claims (1)

[Claims] 1. A plurality of hot plates that heat a traveling corrugated cardboard sheet from the lower surface thereof, a conveyor belt that conveys the sheets while sandwiching the sheets between the heat plates, and a conveyor belt that is arranged in line on the upper surface of the conveyor belt. In a double facer composed of a plurality of weight rolls for pressing the sheet against a hot plate via a conveyor belt, the same amount of crown is given to the weight roll group placed on the unit hot plate, and the unit is The double facer is characterized in that the amount of crown given to each weight roll group corresponding to the hot plate is gradually reduced from the double facer input side to the output side.