Heat insulating plate and double facer

Abstract

To provide a heat insulating plate that can reduce heat energy radiated from a hot platen heat, achieve energy saving, and be easily adopted in an existing double facer.SOLUTION: A double facer (1) is assembled with a plurality of hot platens (7) and a canvas belt (12); an adhesively bonded single-sided corrugated cardboard (K) and a surface liner paper (FL) are laminated together and sent to between the hot platen (7) and the canvas belt (12) and bonded together to form a corrugated cardboard (D). A heat insulating plate (22) according to the present invention is provided in this double facer (1). A plurality of heat insulating plates (22) are provided under the plurality of hot platens (7) with predetermined distances from the hot platen (7).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a double facer that bonds a single-faced corrugated cardboard, which has glue applied to the exposed ridges of the corrugating medium, to a liner paper. [Background technology]

[0002] Corrugated board manufacturing equipment consists of several devices, namely, a splicer that sends out the front and back liner paper and the core base paper from a roll stand, a single facer that forms the core into a corrugated shape and bonds it to the back liner paper to form single-faced corrugated board, and a double facer that bonds the single-faced corrugated board to the front liner paper to form corrugated board.

[0003] A double facer is composed of a so-called heating part and a cooling part, and the heating part is configured as described in Patent Document 1, for example. That is, the heating part of the double facer is provided with multiple heating plates, a canvas belt, a pressure device, etc. The heating plate is formed so that its width is wider than the width of the corrugated board, and its upper surface serves as a top plate against which the outer liner paper of the corrugated board slides. Heated steam is supplied inside to heat the inside to a high temperature such as 180°C. Multiple such heating plates are provided in the direction of flow of the corrugated board.

[0004] The canvas belt is also wider than the cardboard and is rotated and fed cyclically by multiple rollers. The canvas belt is fed parallel to multiple heated platens and is pressed toward the heated platens with a predetermined pressure by a pressure device. The pressure device may be, for example, a weight roll that is biased by an arm to press the canvas belt downward, or an air bag that is supplied with air and similarly presses the canvas belt. The pressure device presses the canvas belt against the heated platens so as not to crush the corrugated core and to ensure that the core and outer liner paper come into contact with each other with the appropriate pressure.

[0005] The single-faced corrugated board formed by the single facer is continuously heated by a preheater, and starch, or glue, is applied to the exposed crests of the corrugation medium before being sent out. Similarly, the face liner paper is continuously heated by a preheater and sent out. The glued single-faced corrugated board and the face liner paper are then stacked and fed into the double facer. The face liner paper is then sandwiched between the top plate of the heating platen and the single-faced corrugated board pressed against the canvas belt, and these are sent downstream by the canvas belt. The heat from the multiple heating platens causes the starch to swell, bonding the crests of the corrugated board to the face liner paper. In other words, the corrugated board is glued together to form the corrugated board. The corrugated board is then sent to the cooling section of the double facer to cool. It then undergoes cutting and other necessary processing. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-55778 [Patent Document 2] Japanese Utility Model Application Publication No. 2-10927 Summary of the Invention [Problem to be solved by the invention]

[0007] In a double facer, the multiple heating plates inevitably cool down when applying heat to the cardboard, so a large amount of heated steam must be supplied to maintain the high temperature. In other words, double facers consume a large amount of thermal energy. In light of recent demands for decarbonization and energy conservation, there is a challenge to reduce the thermal energy required for double facers.

[0008] Patent Document 2 describes a heating plate with a specific structure. The heating plate described in this document also includes a top plate (i.e., upper plate) that contacts the cardboard, side plates, and a bottom plate, and is designed to supply high-temperature steam to the interior. This heating plate is characterized by a lower bottom plate provided below the bottom plate, with heat insulating material inserted between the bottom plate and the lower bottom plate. Because of this configuration, the temperature rise of the lower bottom plate is relatively small compared to the bottom plate. This prevents the entire heating plate from bending and the central area from warping downward, even if the top plate is cooled by contacting the cardboard. In other words, the parallelism of the top plate can be maintained.

[0009] The heating platen described in Patent Document 2 has a heat insulating material between the bottom plate and the lower bottom plate, which is presumably effective in preventing heat dissipation downward from the bottom plate to some extent. In other words, it is thought to have some energy-saving effect. However, the lower bottom plate is connected to the bottom plate via multiple protrusions, i.e., ribs and side plates. This means that the lower bottom plate is also heated by thermal conduction. In other words, it cannot prevent the loss of thermal energy due to thermal conduction from the bottom plate. Furthermore, it is difficult to adopt this technology in conventional double facers that are currently in operation. If a heating platen with a lower bottom plate were to be adopted in a conventional double facer, the existing heating platen would have to be replaced, which would be wasteful. Furthermore, the lower bottom plate is heavier and thicker than conventional heating platen, which requires changes to the heating platen support structure in the double facer, and installation is difficult.

[0010] The present invention aims to solve the above-mentioned problems, specifically to provide a heat shield plate that can sufficiently reduce the thermal energy radiated from the hot platen to achieve significant energy savings, can be easily adopted in existing double facers, and is easy to install.Another aim of the present invention is to provide a double facer equipped with such a heat shield plate. [Means for solving the problem]

[0011] The invention described in claim 1 targets a double facer that is provided with multiple heating plates and a canvas belt that is guided by multiple rollers, and in which single-faced corrugated cardboard glued to the exposed ridges of the corrugated medium and liner paper are superimposed and fed between the multiple heating plates and the canvas belt, and are bonded together by the heat of the heating plates to form corrugated cardboard, and is configured as a heat shield plate to be installed therein. Multiple heat shield plates are configured to be installed below the multiple heating plates at a specified interval from the heating plates. In the invention described in claim 2, the heat shield plate is formed from an iron plate into a hollow plate shape, and the hollow portion is filled with grit wool.

[0012] The invention described in claim 3 is configured as a double facer comprising a plurality of heating plates, a canvas belt guided by a plurality of rollers, and a plurality of heat shield plates. In the double facer, single-faced corrugated cardboard with glue attached to the exposed ridges of the corrugated board and liner paper are stacked and fed between the plurality of heating plates and the canvas belt, and are bonded together by the heat of the heating plates to form corrugated cardboard. The plurality of heat shield plates are configured to be installed below the plurality of heating plates at a predetermined distance from the heating plates. According to the invention of claim 4, the heat shield plate is formed from an iron plate into a hollow plate shape, and the hollow portion is filled with glass wool. The invention described in claim 5 is configured as follows: Adjacent heating plates are arranged with a predetermined gap therebetween, and a plurality of heat shield plates are arranged at predetermined intervals in positions aligned vertically with the gaps. [Effects of the Invention]

[0013] According to the present invention, a heat shield for a double facer is configured, with multiple heat shields installed below multiple hot plates at a predetermined distance from the hot plates. This allows the heat shield to appropriately reduce the thermal energy dissipated below the hot plates. Furthermore, because the heat shield is spaced a predetermined distance from the hot plates, it does not absorb heat from the hot plates through thermal conduction. This provides an excellent energy-saving effect. Furthermore, in conventional double facers, a predetermined space is provided below multiple hot plates, and this space can be used to install a heat shield. In this case, there is no need to replace the existing hot plates. Furthermore, because the heat shield is independent of the hot plates, it is lightweight. Therefore, it can be easily adopted in existing double facers and is easy to install.

[0014] In the invention described in claim 2, the heat shield is formed from a steel plate into a hollow plate shape, and the hollow space is filled with grit wool, so that despite its simple structure, it can withstand relatively high heat and has the excellent effect of having a high insulating effect. The invention described in claim 5 is an invention relating to a double facer, in which adjacent heating plates are arranged with a predetermined gap between them, and multiple heat shield plates are arranged at predetermined intervals in positions that are aligned vertically with the gaps. When corrugated cardboard is produced, glue residue and the like falls through the gaps between adjacent heating plates. If such residue accumulates, it needs to be cleaned, but according to the invention described in claim 5, the heat shield plates are arranged at a predetermined interval. In other words, the residue falls downward through this gap, preventing the residue from accumulating on the heat shield plates. This means that it is only necessary to clean the floor surface below the heating platens, and the installation of heat shield plates does not affect the maintainability of the double facer. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 2 is a front view of the double facer according to the present embodiment. [Figure 2] 1 is a perspective view showing a heat shield plate according to an embodiment of the present invention, partially in cross section. [Figure 3]FIG. 2 is a side view of the double facer according to the present embodiment. [Figure 4] FIG. 2 is a front view showing a part of the double facer according to the present embodiment. [Figure 5] FIG. 10 is a front view showing a portion of a double facer according to a modified example of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] An embodiment of the present invention will be described below. As shown in FIG. 1, a double facer 1 according to this embodiment is a device that constitutes a so-called corrugating machine. A single facer (not shown) is provided upstream of the double facer 1, i.e., on the left side in FIG. 1, and produces single-faced corrugated cardboard K consisting of a corrugated corrugating medium and a back liner paper. The single-faced corrugated cardboard K is heated by a preheater 40, glued to the exposed ridges of the corrugating medium by a gluing device 41, and then supplied to the double facer 1. Also, a splicer (not shown) is provided on the left side in FIG. 1, and supplies a front liner paper FL. The front liner paper FL is heated by a preheater 43 and supplied to the double facer 1 together with the single-faced corrugated cardboard K.

[0017] <Double Facer> The double facer 1 according to this embodiment is also divided into an upstream heating part 2 and a downstream cooling part 3, with multiple devices mounted on a frame 5 composed of multiple components. First, in the heating part 2, multiple heating plates 7 are installed at a predetermined height. Each heating plate 7 includes a top plate 8, whose width (i.e., its length in the depth direction of the paper in FIG. 1 ) is wider than the width of the front liner paper FL. The heating plates 7 may be of a type with a relatively large steam chamber formed inside, or may be of a Gundry type with multiple steam holes formed inside through which steam passes. In either type, heated steam is supplied by a steam supply device (not shown) and heated to a high temperature, such as 180°C. The front liner paper FL flows downstream while in contact with the top plates 8 of the heating plates 7.

[0018] Above the double facer 1, a canvas belt 12 is provided, guided by multiple rollers 10, 10, ... and circulated. The canvas belt 12 is also formed to a width roughly equal to the width of the heating platens 7, 7, but wider than the width of the single-faced corrugated cardboard K. The canvas belt 12 is pressed downward, i.e., toward the heating platens 7, 7, ..., by a pressure device 14 in the heating part 2. In this embodiment, the pressure device 14 is composed of upstream weight rolls 15, 15, ... and downstream air bags 16, 16, .... The weight rolls 15, 15, ... are attached to predetermined arms (not shown) and are biased downward, and air is supplied to the air bags 16, 16, .... Therefore, these pressure devices 14 press the single-faced corrugated cardboard K against the front liner paper FL with appropriate pressure. The heating part 2 of the double facer 1 is provided with multiple heat shield plates 22, 22, ... according to this embodiment. The heat shields 22 will be described later.

[0019] The cooling part 3 of the double facer 1 has the canvas belt 12 above it and a cooling belt 18 below it. The cooling belt 18 is also guided by rolls 19, 19, ... and is sent out in a cyclical manner.

[0020] The operation of the double facer 1 will now be explained. After being heated and glued, single-faced corrugated cardboard K and outer liner paper FL are stacked and supplied to the double facer 1. The single-faced corrugated cardboard K and outer liner paper FL are then sent downstream by the circulating canvas belt 12. While being sent out, the heat from the heating platens 7, 7, ... causes the glue, or starch, to swell, bonding the crest of the core of the single-faced corrugated cardboard K to the outer liner paper FL. In other words, a corrugated cardboard D is formed. The corrugated cardboard D is eventually sent to the cooling part 3 where it is cooled. After that, it is cut and other processing is performed by a specified device, not shown in Figure 1.

[0021] <Heat shield> The heat shield 22 according to this embodiment will now be described. The heat shield 22 according to this embodiment is formed in a flat plate shape as shown in FIG. 2. The heat shield 22 has a main body 23 formed from a metal plate, preferably an iron plate. The main body 23 has a width H that is approximately equal to the width of the heating plates 7, 7, ... (see FIG. 1), is hollow, and is reinforced with ribs or the like as needed. An insulating material 24 is placed in the hollow portion. The insulating material 24 may be any material that can withstand high-temperature environments such as 180°C for a long period of time, but is preferably made of glass wool. While the main body 23 is shown in FIG. 2 as being integrally formed from an iron plate, it is preferable that the top surface 25 be removable so that the insulating material 24 can be replaced.

[0022] <How to install the heat shield> A method for attaching heat shield plates 22, 22, ... to a double facer 1 will be described with reference to Figures 1 and 3. The frame 5 of the double facer 1 is composed of multiple components. As shown in Figure 3, the heating plate 7 is fixed to mounting portions 27, 27, which are components constituting the frame 5. As shown in Figures 1 and 3, multiple beam members 29, 29, ... are provided in the width direction of the frame 5 below the heating platens 7, 7, .... A pair of rails 31, 31 is provided on these beam members 29, 29. As shown in Figure 1, the rails 31, 31 are provided in the heating part 2 of the double facer 1 so as to have a predetermined length from the upstream side to the downstream side. Multiple heat shield plates 22, 22, ... are placed on this pair of rails 31, 31. The heat shield plates 22, 22, ... do not necessarily need to be fixed to the rails 31, 31, but may be fixed using fasteners such as bolts.

[0023] Since the heat shield plates 22, 22, ... are attached in this manner, the heat shield plates 22, 22, ... are installed below the heating plates 7, 7, ... with a predetermined distance between them. Therefore, the heat radiated from below the heating plates 7, 7, ... is insulated by the heat shield plates 22, 22, ..., saving thermal energy, and since the heat shield plates 22, 22, ... are not in contact with the heating plates 7, 7, ..., there is no loss of thermal energy due to heat conduction. In other words, significant energy savings can be achieved in the double facer 1. Furthermore, the heat shield plates 22, 22, ... can be easily installed on existing double facers 1.

[0024] In this embodiment, adjacent heating plates 7, 7, ... have predetermined gaps 32, 32, ... as shown in Figure 4. When manufacturing corrugated cardboard D, glue residue is generated, and the gaps 32, 32 are opened to allow this glue residue to fall downward. The heat shield plates 22, 22, ... according to this embodiment are preferably arranged so that predetermined intervals 33, 33, ... are opened in positions that are aligned vertically with the gaps 32, 32, ... as shown in Figure 4. In this way, glue residue 35, 35 falling from the gaps 32, 32 does not accumulate on the heat shield plates 22, 22, but falls from the intervals 33, 33 and accumulates on the floor surface 36. An operator can remove the glue residue 35, 35 accumulated on the floor surface 36 as needed.

[0025] <Modification of this embodiment> FIG. 5 shows a modified example of this embodiment. While it has been explained that it is preferable to arrange the heat shield plates 22, 22, ... at predetermined intervals 33, 33, ... (see FIG. 4 ), they may also be laid out without any gaps, as shown in FIG. 5 . In this case, the heat energy radiated from the heating plates 7, 7, ... can be further insulated, resulting in high thermal efficiency. However, glue residues 35, 35 that fall from the gaps 32, 32 between the heating plates 7, 7, ... accumulate on the heat shield plates 22, 22, .... The heat shield plates 22, 22, ... are simply placed on rails 31, 31 and can be removed as needed. In other words, when the amount of glue residues 35, 35 accumulated becomes too large, the heat shield plates 22, 22, ... can be removed and cleaned. [Example]

[0026] To investigate the energy-saving effect of the heat shield plates 22, 22, ... according to this embodiment, a demonstration experiment was conducted at a corrugated cardboard manufacturing factory. The heat shield plates 22, 22, ... according to this embodiment were installed in an existing double facer 1 and operated for three months. When the total amount of thermal energy, such as fuel, consumed by the entire corrugating machine was investigated, the thermal energy per unit length of corrugated cardboard D, i.e., the basic unit, was reduced by approximately 5% when the heat shield plates 22, 22, ... were installed compared to when they were not installed. The corrugating machine includes not only the double facer 1 but also single facers, etc. Therefore, it is estimated that the thermal energy reduction effect of the double facer 1 alone is even greater. It was demonstrated that the heat shield plates 22, 22, ... according to this embodiment have a high energy-saving effect. [Explanation of symbols]

[0027] 1 Double facer 2 Heating part 3 Cooling Part 5 Frame 7 Heating plate 8 Top plate 10 Roller 12 Canvas Belt 14 Pressure device 15 Weight roll 16 Airbag 18 Cooling belt 19 rolls 22 Heat shield 23 Main body 24 Insulation 25 Top 27 Mounting portion 29 Beam member 31 Rail 32 Gap 33 Spacing 35 Glue residue 36 Floor surface 40 Preheater 41 Gluing device 43 Preheater K Single-faced corrugated cardboard FL Outer liner paper D Cardboard H Width

Claims

1. In a double facer, a plurality of heating plates and a canvas belt are provided, which is guided by a plurality of rollers and fed, and single-faced corrugated cardboard with glue attached to the exposed ridges of the corrugated medium and liner paper are superimposed and fed between the plurality of heating plates and the canvas belt, and are bonded together by the heat of the heating plates to form corrugated cardboard. A plurality of heat shield plates are provided below the plurality of heating plates at predetermined intervals from the heating plates.

2. 2. The heat shield plate according to claim 1, wherein the heat shield plate is formed from an iron plate into a hollow plate shape, and the hollow portion is filled with glass wool.

3. A plurality of heating plates; a canvas belt that is guided and fed by a plurality of rollers; A plurality of heat shield plates, The single-faced corrugated cardboard with glue attached to the exposed ridges of the corrugation medium and the liner paper are stacked together and fed between the multiple heating plates and the canvas belt, and are bonded together by the heat of the heating plates to form the corrugated cardboard. A double facer, wherein the plurality of heat shield plates are provided below the plurality of heating plates at a predetermined interval from the heating plates.

4. 4. The double facer according to claim 3, wherein the heat shield plate is formed from an iron plate into a hollow plate shape, and the hollow portion is filled with glass wool.

5. A double facer as described in claim 3 or 4, wherein adjacent heating plates are arranged with a predetermined gap between them, and multiple heat shield plates are arranged at predetermined intervals in positions that are aligned vertically with the gaps.

Images