JP2007030171A - Method and apparatus for manufacturing corrugate cardboard - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus of corrugate cardboard constituted so as to omit the use of a hot plate indispensable heretofore to perform the heating due to the blowing overheated steam in place of the hot plate. <P>SOLUTION: The constituent part is composed of (1) a curing zone (X) composed of a large number of rolls and two canvases constituted so that uncompleted single-walled corrugated cardboard is formed by spraying overheated steam on the paste applied to the corrugation apexes of single-faced corrugated cardboard to paste the corrugated cardboard to a surface liner while (2) double-walled corrugated cardboard is formed by spraying overheated steam on the paste applied to the corrugation apexes of two double faced corrugated cardboards to paste the double faced corrugated cardboards to the surface liner and both corrugated cardboards allowed to run in the pasted state to penetrate the paste in the corrugated boards, a heating zone (Y) composed of a large number of overheated steam nozzles for spraying overheated steam to the surface liners of the corrugated boards to gel the paste to achieve complete adhesion and (3) a cooling zone (Z) composed of a large number of rolls and two canvases for cooling the completed corrugated cardboard to take over the same. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a method for producing corrugated paper and an apparatus used for the method. Corrugated paper manufactured according to the present invention is called “single-wall corrugated cardboard”. One-sided corrugated cardboard (also called “single facer”) obtained by bonding a corrugated core to one back liner is There can be both a configuration in which one front liner is applied and a configuration called “double wall corrugated cardboard” in which two single-sided cardboards are stacked and one front liner is applied. The improvement of the present invention relates to a process for completing a corrugated paper by laminating the last liner sheet, whether it is a single wall or a double wall. The significance of the present invention is exhibited particularly in the production of single-wall corrugated paper and double-wall corrugated paper made from thick base paper. “Thick base paper” is typically one having a front and back liner paper of about 280 g / m ² and a core paper of about 200 g / m ² .

The manufacturing method of the single wall corrugated paper currently performed consists of the following processes.
A) A core manufacturing process in which a core sheet is drawn out and continuously formed, and processed into a corrugated shape,
B) First paste application step of applying raw starch solution to the top of the corrugated core
C) A first gelatinization step in which the first paste applied to the top of the step is heated to gel a part thereof.
D) A single-sided corrugated board manufacturing process in which the core is continuously bonded to the back liner sheet, and the first glue is heated to promote gelation and complete adhesion and single-sided cardboard.
E) A second paste application step of applying raw starch solution to the top of the corrugated corrugated board on one side,
F) A second gelatinization step in which the second paste applied to the top of the single-sided cardboard is heated by a preheater comprising a heating roll, and a part thereof is gelled.
G) Single wall corrugated paper board forming process that continuously bonds the front liner sheet and single-sided cardboard, and H) The front liner side of the single wall corrugated paper is continuously brought into contact with the hot platen, and the second glue is applied. A single wall corrugated cardboard completion process that heats and promotes gelation to ensure complete adhesion.

Double wall corrugated paper is manufactured by stacking and bonding two single-sided corrugated paper and one front liner sheet. In this case, in order to satisfy the mechanical properties required for double-wall corrugated paper, the first single-sided corrugated cardboard uses a corrugated wave called “A flute”, and the second single-sided corrugated cardboard It is common to use what is called a “B flute” in which the corrugated wave is relatively small.

Corrugated paper produced as described above, whether single or double walled, is continuously taken up, usually cut into appropriate lengths, stacked and shipped, but in some cases further printed inline , Subjected to punching and box making.

One of the technical issues related to the production of corrugated paper is to improve production efficiency, and there is a demand for higher line speeds. This requirement is not limited. Today, the most manufactured A flute single wall products are being produced at high speeds of up to 400 m / min. The other is the quality requirement of the product, which requires less warping and a beautiful surface. In particular, it is indispensable that the surface of the surface liner, which is called “decorative corrugated cardboard”, is printed or laminated.

In order to realize high-speed production as described above, it is necessary to preheat the paper prior to pasting and to heat with a hot plate after pasting. However, the main problem of the current technology is that the single-sided cardboard obtained through the above-mentioned process D (single-sided cardboard manufacturing process) is directed to the stacking conveyor while being directed to the process E (second paste application process). When it is stored in the cardboard, it will be overdried or warped, and in the final process H (corrugated cardboard completion process), the hot platen and the front liner will rub against the surface of the product corrugated cardboard. It means that there are scratches.

The inventors have been involved in improving the manufacturing technology of corrugated paper for many years, and during that time, have developed and proposed several technologies for promoting line speed and improving the quality of product corrugated paper. One of them is that when an aqueous dispersion of starch (hereinafter referred to as “raw starch solution”) applied to the top of the core is gelled and used as a paste, the low-pressure steam is reheated as a heat source and heated to a high temperature. (Patent document 1, patent document 2), and the other is a technique of spraying steam on the core prior to application of the raw starch solution to humidify and heat (patent document 3). It is. A technique for humidifying and heating liner paper (Patent Document 4) is also disclosed.

In these techniques, a device that performs humidification is called a “moisner”, and a device that performs heating (and some humidification) is called a “steamer”. Moisner is a paste that makes it easy to process corrugated core paper by applying normal pressure, not too hot water vapor, to the corrugated paper material in the manufacturing process. It has a function of preventing rapid and large amount of moisture from being absorbed into the core.

At this time, if the core is dry and easily absorbs water, the raw starch liquid that is the applied paste is in the portion in contact with the core, and only the water is the core paper. Is absorbed into the water, and the moisture around the starch is insufficient, making it impossible to produce an appropriate paste. On the other hand, if a solution having a low starch concentration is used, even if the paste located in the part away from the center core is heated and gelled, the adhesive does not have sufficient adhesive strength. The moistness that the Moisner imparts to the core eliminates these problems and allows it to turn into a glue with sufficient adhesion when an appropriate starch concentration glue is applied.

On the other hand, the steamer is mainly intended to cause the heated paste to be heated and gelled by the action of heated slightly high-temperature steam. In the case of gelation, if only heat is applied, the surface of the paste applied to the top of the core may dry rapidly to form a film and may not exhibit adhesive strength. Heating by means of an increase in the humidity of the atmosphere due to water vapor and generation of moisture on the surface of the paste due to condensation makes it possible to avoid such problems in principle.

However, Moisner is a good steamer, both of which spray water vapor toward the surface of the paper, so by selecting the temperature and pressure of the water vapor, the temperature rise and humidity on the corrugated paper production paper One or both of the increases in the range can be brought about in a concentrated manner. Therefore, it should be understood that a Moisner and a steamer are devices that are named according to the intended effect, with respect to the subject used. By using these auxiliary devices, the production efficiency can be improved.

As mentioned above, in the manufacture of cosmetic corrugated cardboard, it is necessary that the surface of the product be kept well. To achieve this reliably, contact with the hot platen that causes scratches is eliminated. But this is a radical solution. From this point of view, one of the inventors invented a corrugated board manufacturing apparatus in which the use of a hot platen was abolished by completely preheating, heating and humidifying the material, and also proposed this (Patent Document 5).
JP-B 59-15066 Japanese Patent Publication 3-65365 JP 4-74181 JP 6-11521 Japanese Patent Application No. 2005-36983

To abolish the use of a hot platen, the above-mentioned step H is not carried out, and after bonding the single-sided cardboard and the front liner, heat for promoting the gelation of the second glue is no longer given. Means that. Therefore, in order to achieve good adhesion between the single-sided corrugated cardboard and the front liner, at the time when the two are bonded, sufficient heat is applied to the second glue to cause subsequent gelation. After that, it is necessary to hold the unfinished cardboard in a bonded state for a considerable period of time while bonding with the progress of gelation is performed. For this reason, the corrugated paper manufacturing apparatus without a hot platen is composed of a set of canvases that are driven by a large number of rolls that run the corrugated cardboard completion process and run across the rolls. However, it had to be quite long and the production speed could not be so high.

The general object of the present invention is to produce a high production rate and good product without the use of a hot plate in the manufacture of both single wall and double wall type corrugated paper, thus avoiding the problems associated with the use of the hot plate. An object of the present invention is to provide an improved corrugated paper board manufacturing method that can be enjoyed in combination with quality, and a manufacturing apparatus used for carrying out the method. One of the specific objects of the present invention is to effectively perform the gelatinization of raw starch liquor, which is not easy in the production of single wall corrugated paper made from thick base paper, and to provide a single material having good mechanical properties. The purpose is to provide an improved corrugated paper manufacturing method that enables the production of wall corrugated paper at a high line speed, and a manufacturing apparatus used to implement the method. An improved method for producing corrugated paper, which makes it possible to produce a double wall corrugated paper having good mechanical properties by effectively gelling the raw starch solution at a line speed comparable to that of a single wall. And a manufacturing apparatus used for carrying out the method.

The method for producing single-wall corrugated paper of the present invention is a method for producing corrugated paper using the production apparatus shown in FIG. 1 and FIG. The process consists of the following steps.
-A core paper supply process in which the core paper (21) is fed out and brought into contact with a heating roll to preheat.
A core manufacturing process in which preheated core paper is continuously formed and processed into a corrugated core (2),
-A first paste (8) application step for applying raw starch liquid to the top of the corrugate of the core (2),
・ Back liner paper supply process for feeding back liner paper (3) and preheating,
-The core (2) preheated and coated with paste and the back liner paper (3) preheated are continuously bonded together to form a single-sided cardboard (4) with the first gelatinized paste. , Single-sided cardboard manufacturing process,
-A second paste (9) application step of applying a raw starch solution to the top of the corrugated corrugated cardboard (4),
-A gelatinization process in which superheated steam is blown onto the second paste (9) applied to the top of the single-sided cardboard to heat it to a half gel.
・ The front liner paper supply process that feeds out the front liner paper (1) and preheats it if necessary.
A corrugated cardboard (4) and a front liner paper (1) that are continuously pasted together to form an unfinished single-wall corrugated cardboard (5) with a second half-gelled glue. Paper formation process and ・ Glue penetration that allows unfinished single-wall corrugated paper to run while being held in a bonded state, and in the meantime, the second gel that has been semi-gelled penetrates into the core (2) and the front liner Process,
・ A final heating process that blows superheated steam to the side of the front liner and fully gels and dries the infiltrated second paste with that heat, and completes the adhesion. A process for completing corrugated cardboard (5C) to cool and take it out.

Since a hot platen is not used for the production of corrugated paper according to the present invention, various problems associated with the use of the hot platen are solved in principle. In other words, there is no risk of scratches on the surface liner, it is possible to use a surface liner that has been subjected to surface treatment such as printing or embossing, and it is also possible to use a surface liner that has been laminated. Become. This is particularly advantageous for the production of cosmetic cardboard. Contact with the hot plate inevitably causes shrinkage of the front liner, resulting in warping of the product corrugated board, but if the present invention is carried out, the concern is eliminated.

As a heating means in place of the hot platen, in the present invention, superheated steam is blown from the front liner side to the unfinished cardboard in the final heating step. This superheated steam gels the second glue between the core of the unfinished corrugated cardboard and the front liner to ensure an adhesive action, and at the same time realizes the drying process. By cooling in the paper completion process, a finished corrugated paper without warping can be obtained immediately. In order to achieve the purpose of heating by the contact with the hot platen, the line speed is inevitably restricted, but there is no restriction unless the hot platen is used. In this way, the production speed of corrugated paper can be remarkably improved, and the line speed can be realized at 400 m / min or more for single wall corrugated board and 300 to 350 m / min for double wall corrugated board.

When heating with a conventional hot platen, the water content of the product cardboard is lowered to a low level of 4 to 5% unless a countermeasure is taken. This amount of moisture is unfavorable in handling because the corrugated cardboard has a large amount of paper dust. According to JIS, the appropriate amount of water is set to 7-8%, and in order to achieve this level, in actual operations, measures are taken to increase the amount of raw starch paste applied to provide moisture, Needless to say, this leads to the disadvantage of using extra adhesive. The present invention also eliminates this disadvantage.

As shown in FIGS. 1 and 2, the apparatus for producing the corrugated paper of the present invention for carrying out the above-described method for producing single wall corrugated paper comprises the following components.
A means (A2) for feeding out the core sheet, and a core sheet preheating roll (B2) for preheating the fed-out core sheet
A pair of tooth profile rolls (C) for continuously forming pre-heated core paper to produce a corrugated core
・ First glue supply means (D1) for applying raw starch solution as glue to the top of the corrugated core
A means for feeding back liner paper (A3) and a back liner paper preheating roll (B3) for preheating the fed back liner paper
-Crimping roll (E) for continuous bonding of preheated back liner paper and core coated with glue to form single-sided cardboard (4)
・ Second glue supply means (D2) for applying raw starch liquid to the top of corrugated corrugated cardboard
・ Second glue heating means (L1) for spraying superheated steam on the second glue applied to the top of the single-sided cardboard to heat it to make it half-gel
A means for feeding out the front liner paper (A1) and a front liner paper preheating roll (B1) for preheating the fed out front liner paper
・ A set of crimping rolls (I) that continuously laminates single-sided cardboard and front liner paper to produce unfinished single-wall corrugated paper
A set of a number of rolls for running an unfinished single-wall corrugated paper (5) while being held in a bonded state, and allowing the second gel, which is semi-gelled in the meantime, to penetrate the core and the front liner Curing zone (X) consisting of two canvases running opposite each other
・ Running to spray the superheated steam on the front liner side of the unfinished single-wall corrugated paper (5), to fully gel the second glue material that has penetrated by the heat and to achieve complete adhesion The heating zone (Y) where the superheated steam jet pipe (P) with a number of nozzles (N) provided below the unfinished corrugated paper is arranged, and the completed single wall corrugated paper (5C) are cooled. Cooling zone (Z) consisting of a large number of rolls and two canvases running in opposition to each other.

The corrugated board manufacturing technique of the present invention is characterized by processes or components after forming an incomplete corrugated paper, that is, a paste penetration process (a curing zone corresponding to the apparatus in the manufacturing method) in the manufacturing method, and a final heating process. (A corresponding heating zone) and a cooling step (a corresponding cooling zone). In the final heating step, the superheated steam sprayed on the front liner of the unfinished cardboard paper is heated at 100 ° C. steam generated at normal pressure to increase the temperature. On the other hand, both sensible heat and latent heat (condensation heat) of superheated steam serve as heating energy. 120-150 degreeC is suitable for the temperature of the superheated steam used for the final heating process of this invention. In recent years, a superheated steam generator that uses electromagnetic induction heating and that is small in size, has a high temperature rise rate, and can accurately control temperature can be used.

As shown in FIG. 3 and FIG. 4, the actual apparatus has an arrangement of superheated steam jet pipes (P) equipped with a number of nozzles (N), and the unfinished single wall corrugated paper (5) that runs. In order to be able to eject superheated steam having a uniform temperature in the width direction, a required number of stages are provided so as to be supplied from the center of the pipe. In the illustrated example, superheated steam generated by one superheated steam generator (Q) is supplied to three supply pipes via respective solenoid valves and ejected from the nozzles of the ejection pipes ahead of them. Such units are usually arranged, for example, 3 to 5 units, and if necessary, all or some of the units and all or some of the ejection pipes are used.

One of the factors that determine the degree of necessity to use the above-mentioned unit is the type of cardboard to be manufactured, and the other is the operating speed of the apparatus. For example, in order to produce B flute single wall corrugated cardboard, it is often sufficient to use one of the three jets, and two flute single wall is suitable. , A flute or B flute double wall is better to hit all three. However, all three are cases where the production apparatus is operated at a high speed (exceeds a line speed of 200 m / min), and even a double wall is a medium speed (150 to 180 m / min) or a low speed ( In the case of less than 150 m / min), two or one ejection pipe is sufficient. The number of units used increases with the operating speed of the manufacturing equipment. 5 units are appropriate for high speed, 3 to 4 units for medium speed, and 2 to 3 units for low speed.

A preferred embodiment of the process for producing corrugated paper according to the present invention will be described below with reference to the drawings. As shown in FIG. 1, the core paper is preheated by turning around a core paper preheating roll (B2) which is fed from the feeding means (A2) and brought to a predetermined temperature by passing a heat medium through the inside. To a predetermined surface temperature. Next, it is bitten by a pair of tooth profile rolls (C) to give a corrugated shape. While the formed core (2) is on the tooth profile roll, the glue is applied to the top of one of the steps by the first glue supply means (D1).

The back liner paper is fed out from the feeding means (A3) and comes into contact with the back liner paper preheating roll (B3), and after this also reaches a predetermined surface temperature, it is applied to the core (2) to which the above paste is applied. On the other hand, it is crimped by a large crimping roll (E). The single-sided cardboard (4) formed in this way is taken up by a pair of single-sided cardboard conveyors (F) that are picked up and run. During this time, the glue that bonds the core to the back liner is removed a substantial part of its moisture by the heat that the paper retains.

The single-sided corrugated cardboard (4) discharged from the single-sided cardboard paper conveyor (F) is applied with a paste on the other top of the corrugated mountain by the second paste supply means (D2), followed by single-sided cardboard heating and humidification Heat and moisture are given by the steamer (L1), and the paste is partially gelled. The dancer roll (M) provided in front of the second glue supply means (D2) is usually used to adjust the running speed between the single-sided cardboard stored on the stacking conveyor and the front liner paper (1) to be bonded to it. Performs a buffering action necessary for synchronization.

On the other hand, the front liner paper (1) fed out from the front liner paper feeding means (A1) is bonded to the single-sided cardboard (4) at the entrance of the curing zone (X). As the front liner paper, it is possible to use one that has already been printed or embossed offline, or one that has been printed or processed by a device not shown, as desired. it can. The curing zone (X) consists of a large number of small pressure rolls (I) and a set of canvases (K) that are driven by a drive roll and run between a large number of thin pressure rolls. The unfinished corrugated paper (5) obtained by the above is sandwiched between the canvases and run while being held in a bonded state. During the run, the second paste that had been semi-gelled penetrates into the core (2) and the front liner.

In the subsequent heating zone (Y), the above-described superheated steam blowing, which is the final heating step, is performed on the front liner side. Therefore, due to the sensible heat and latent heat of the superheated steam, the second paste that has penetrated into the core (2) and the front liner is sufficiently gelled and acts as an adhesive, and further drying is performed. Corrugated paper is completed. Since the product corrugated paper exiting the heating zone has a high temperature, it finally travels in the cooling zone (Z) between a large number of thin crimping rolls (I) as in the curing zone (X). Run between a pair of canvases (K) to lower the temperature of the cardboard. In the heating zone, not only heat but also moisture is given, but since this moisture is almost evaporated, a product having an appropriate moisture content can be obtained. As a result of being kept in a warp-free state while traveling in the cooling zone, the product corrugated paper has no warp. This is different from the warp that occurs in a hot platen that only gives heat.

In this corrugated paper manufacturing apparatus, a cutter for cutting the double-sided corrugated paper into a regular size, if desired, or a stacker for stacking the cut double-sided corrugated paper before the means (J) for picking up the formed double-faced corrugated paper (Both not shown) may be provided. When manufacturing the same cardboard box in a large quantity, as described above, a facility for punching the manufactured double-sided cardboard paper in-line into a blank having a predetermined size and shape may be provided.

The technique for manufacturing the single wall corrugated cardboard described above can be applied to a method and an apparatus for manufacturing a double wall corrugated cardboard by making necessary modifications thereto. The method for producing the double wall corrugated board of the present invention thus provided comprises the following steps:
・ First single-sided cardboard (6A) is fed out and the corrugated core is brought into contact with the heating roll to preheat the first single-sided cardboard supply process. A first paste (8) application step for applying raw starch liquid,
-A gelatinization process in which superheated steam is sprayed on the first glue applied to the top of the first single-sided cardboard to make it a half-gel.
A second single-sided cardboard supply step of pre-heating the second single-sided cardboard (6B) by bringing the liner side into contact with a heating roll;
A second paste (9) application step of applying a raw starch solution to the top of the corrugated corrugated second-side corrugated cardboard;
-Gelatinization process in which superheated water vapor is sprayed onto the second glue applied to the top of the second single-sided cardboard to make it half-gel.-Front liner paper supply process for feeding out and preheating the front liner paper (1) ,
The first single-sided cardboard (6A), the second single-sided cardboard (6B), and the front liner are successively stacked in this order, and the unfinished double-wall cardboard ( 7) Double wall corrugated paper forming process,
-While the unfinished double-wall corrugated paper is run while being held in a bonded state, the first paste that is semi-gelled in the meantime penetrates into the middle liner that was the second single-sided cardboard liner, A paste-penetrating step for allowing the second gelled gel to penetrate the surface liner;
・ A final heating step that blows superheated steam to the side of the front liner and sufficiently gels and dries the permeated first and second sizing agents with that heat to dry them completely. A process for completing a double wall corrugated cardboard (7C) to cool and take it out.

The apparatus of the present invention used to carry out the method for producing the double wall corrugated paper described above comprises the following components:
A means for feeding out the first single-sided cardboard (6A), a first single-sided cardboard preheating roll (B4) for preheating the fed-out first single-sided cardboard,
A first glue supply means (D1) for applying the raw starch solution to the top of the corrugated corrugated first-side corrugated cardboard,
-A first steamer (L2) for spraying superheated steam on the first glue applied to the top of the first single-sided cardboard to make it half-gelled,
A means for feeding out the second single-sided cardboard (6B), a second single-sided cardboard preheating roll (B5) for preheating the fed-out second single-sided cardboard,
A second paste supply means (D2) for applying the raw starch solution to the top of the corrugated corrugated second-side corrugated cardboard,
-A second steamer (L3) for spraying superheated steam on the second paste applied to the top of the second single-sided cardboard to make it half gelled,
A means for feeding out the front liner paper (1) and a front liner paper preheating roll (B1) for preheating the fed out front liner paper;
The first single-sided corrugated cardboard (6A), the second single-sided cardboard (6B), and the front liner paper (1) are successively stacked and bonded in this order to form an unfinished double wall corrugated cardboard (7). Pair (I),
-The unfinished double-wall corrugated paper (7) is run while being held in the laminated state, and during that time, the first gel that has been semi-gelled penetrates the middle liner that was the liner for the second single-sided cardboard. At the same time, a curing zone (X) consisting of a set of a number of rolls and two canvases running opposite each other to infiltrate the surface liner with the second gelled paste.
・ Blowing superheated steam to the front liner side of unfinished double wall corrugated paper (7) to fully gel the first and second glues penetrated by the heat to achieve perfect adhesion A heating zone (Y) provided with a superheated steam jet pipe (P) provided with a number of nozzles (N) provided under the running unfinished double wall corrugated paper, and a completed double wall corrugated paper A cooling zone (Z) consisting of a set of a large number of rolls and two canvases running in opposition to each other for cooling (7C) and taking it out.

As described above, the corrugated cardboard manufacturing technique of the present invention is particularly effective in the manufacture of single-wall corrugated paper made of thick base paper and in the manufacture of double-wall corrugated paper. The manufacturing process in the case of manufacturing the latter double-wall corrugated paper will be described below. First, as shown in FIG. 5, a first single-sided corrugated board having an A flute previously manufactured and wound around a coil is used. (6A, hereinafter referred to as “AF single-sided cardboard”) and a second single-sided cardboard having B flute (6B, hereinafter referred to as “BF single-sided cardboard”) are fed out while being tensioned using a suction brake. At the same time, the front liner paper (1) is fed out, and these three kinds of materials are preheated by the respective preheating rolls (B4, B5, B1). With this preheating, both the AF single-sided cardboard and the BF single-sided cardboard are heated to about 80 ° C., and the front liner sheet is heated to about 70 ° C.

The preheated AF single-sided cardboard (6A) and BF single-sided cardboard (6B) are then processed into raw starch by a glue machine, that is, a first paste supply means (D1) and a second paste supply means (D2). The liquid is applied to the top of the corrugate, and further, superheated steam is blown by a steamer (L2, L3) from the side where the paste is applied, and heated and humidified. The temperature of the superheated steam to be sprayed is suitably 110 ° C. inside or outside. By this treatment, the temperature of the AF single-sided cardboard and the BF single-sided cardboard once decreased due to adhesion of the raw starch solution, but recovered to 90 to 100 ° C. on the top side and 60 to 70 ° C. on the liner side. On the other hand, the front liner sheet is further overlapped by a pair of the two single-sided cardboards and the pressure-bonding rolls in a state where the temperature is increased to about 90 ° C. via a heating roll.

While the superposed AF single-sided corrugated cardboard, BF single-sided cardboard and front liner sheet pass through the curing zone (X), the raw starch solution, which is a half-gelled first paste, is used as the corrugated step of the AF single-sided cardboard. Similarly, the raw starch solution, which is the second paste, penetrates the corrugated top of the BF single-sided cardboard and the front liner sheet, and gelation proceeds there. In order to allow sufficient penetration and gelation of raw starch solution and to enable high line speed from the spraying of superheated steam in the previous process to the end of curing in this process It is preferable to secure the longest possible travel distance. In particular, if the environment in which the corrugated paper manufacturing apparatus is installed is allowed from the time when the superheated steam is blown to the stacking, the second paste is run for a longer distance than the conventional apparatus, preferably about 2 to 3 times. It is desirable to allow sufficient time for the agent to gel.

The unfinished double wall corrugated paper (7) is then subjected to the above-mentioned superheated steam blowing from the front liner side in the heating zone (Y). As a result, although gelation proceeds in the previous curing zone, heat is applied to the unfinished double-wall corrugated paper (7) whose temperature has been slightly lowered to promote gelation. On the other hand, drying also proceeds by the applied heat. Double wall corrugated paper (7C) is completed by the promotion and substantial completion of gelation and the progress of drying. Since the product double wall corrugated paper exiting the heating zone has a high temperature, it is finally cooled and taken up in the cooling zone (Z). In the heating zone, not only heat but also moisture is given, but since this moisture is almost evaporated, a product with a moderate moisture content is obtained, and the result is that there is no warp while running in the cooling zone The product has no warping. This is a benefit that can be obtained only by the present invention, unlike the case where warping occurs only in a heating plate that only gives heat.

In the double wall corrugated paper manufacturing apparatus using a conventional hot platen, the unfinished corrugated paper and the finished corrugated paper which are progressing through the apparatus after superimposing three materials are shown in the upper part of FIG. The data obtained by the inventors regarding the heat conduction performance of the corrugated paper material based on the measured values of the points a, b and c, measured with a non-contact thermometer. 6 is shown in the lower part of FIG. On the other hand, according to the present invention, in the double wall corrugated paper board manufacturing apparatus using superheated steam without a hot platen, each point corresponding to the above “a”, “b”, and “c” from the curing zone Similar temperature courses are shown in FIG. 7 at various points including the “a ′” point to be transferred to the heating zone.

FIG. 8 is a graph in which the data regarding the transition of the temperature shown in FIGS. 6 and 7 is made to be easily compared. This graph lists the following five types of data for comparison. 1) The temperature of the adhesive between the top of the corrugation and the front liner when the manufacture of single wall corrugated board (AF) is carried out with an apparatus only equipped with a conventional hot platen. The temperature of the paste at the above position when the steamer proposed by the person is added. 3) When the manufacture of the double wall (AF + BF) corrugated cardboard is carried out with an apparatus only having a conventional hot platen, The temperature of the glue between the middle liner (BF liner) 4) The temperature of the glue at the above position when the steamer proposed by the inventor is added to the above 3) 5) Manufacture of double wall (AF + BF) cardboard In accordance with the present invention, when the use of a hot plate is abolished and superheated steam is blown

As shown by the hatched portion in the graph of FIG. 8, the temperature at which the gelatinization of the raw starch solution is approximately in the range of 58 to 63 ° C. Even if this temperature is reached or exceeded, the progress of gelation is naturally faster at higher temperatures and slower at lower temperatures. Therefore, in order to efficiently produce corrugated paper, the raw starch solution applied to the top of the corrugate reaches the gelation temperature range as quickly as possible, and further reaches a higher temperature as soon as possible. There is a need. However, in addition to the problem that the drying due to the rapid heating only on the surface of the raw starch solution described above causes a coating on the surface of the gelatinized paste, which hinders adhesion. In relation to the speed and degree of penetration, there are the following restrictions.

That is, if the core (corrugated material) has high water absorption, only water in the applied raw starch solution is absorbed by the paper, and there is insufficient moisture as a paste, so that gelatinization is appropriate. It is not performed, and a desired adhesive force cannot be obtained (ungelatinized adhesion). On the other hand, if the water absorption is low, the raw starch solution does not readily penetrate, so that the gelation proceeds first and the bonding is performed in a state where there is a paste only on the surface (surface bonding). The latter adhesion tends to occur when a high-sizing paper called “reinforced core” is selected as the AF core in an attempt to improve the strength of the double-wall cardboard. When this happens, the trouble is often experienced that the corrugated cardboard, which appears to be completely bonded, peels off after a few hours from the finish. The desired adhesion (osmotic adhesion) is only achieved when proper penetration of the raw starch liquid has occurred and it has gelled.

In the graph of FIG. 8, when the double wall corrugated board is manufactured according to the present invention, the temperature of the glue increases gradually in the curing zone up to the “a” point or the “a ′” point. It can be seen that in the heating zone from the point “a ′” to the point “b”, the temperature rises rapidly due to the spraying of superheated steam. According to the present invention, gelation proceeds rapidly in this heating zone, and complete adhesion is obtained.

The corrugated paper manufacturing apparatus of the present invention includes a cutter for cutting the formed corrugated paper, whether it is a single wall or a double wall, at a point, if necessary, or a cut corrugated cardboard. It is preferable to provide a stacker (not shown) for stacking paper. When a large number of the same cardboard boxes are manufactured, as described above, a facility for punching the manufactured cardboard paper in-line into a blank having a predetermined size and shape can be provided.

The side view which showed the part which implements the process of the middle from the first half of a manufacturing method in the preferable aspect of the single wall corrugated paper manufacturing apparatus of this invention. The side view which showed the part which is integrated with the apparatus of FIG. 1 and implements the latter half process of a manufacturing method. The top view which shows the principal part of the apparatus of FIG. FIG. 4 is a side view showing a main part of the apparatus of FIG. 2, the same part as FIG. 3, with a part cut away. The side view corresponding to FIG. 1 and 2 which shows an example of the manufacturing apparatus of the double wall corrugated paper of this invention. The figure which shows the transition of the temperature of each point in the second half part of the double wall corrugated paper manufacturing apparatus using the conventional hot platen. The figure corresponding to FIG. 6 which shows transition of the temperature of each point in the latter half part of the double wall corrugated paper manufacturing apparatus which abolished the heat board by this invention. The graph which made it possible to list the temperature in each point of FIG. 6 and FIG.

Explanation of symbols

1 Front liner paper 2 Medium core 21 Medium core paper 3 Back liner paper 4 Single-sided cardboard 5 Unfinished cardboard paper (single wall)
5C Completed corrugated paper (single wall)
6A First single-sided cardboard 6B Second single-sided cardboard 7 Unfinished cardboard paper (double wall)
7C Completed corrugated paper (double wall)
8 First glue 9 Second glue A1 Front liner paper feeding means A2 Core paper feeding means A3 Back liner paper feeding means B1 Front liner paper preheating roll B2 Core paper preheating roll B3 Back liner paper preheating roll B4 One single-sided corrugated cardboard preheating roll B5 Second single-sided cardboard preheating roll C Tooth-shaped roll pair D1 First glue supply means D2 Second glue supply means E Large set of crimping rolls F Single-sided cardboard paper conveyor I Small crimping roll No. J Double-sided corrugated paper take-up means K Canvas L1 Heating means for second glue (single-sided cardboard heating and humidifying steamer)
L2 1st steamer L3 2nd steamer M Dancer roll N Nozzle P Superheated steam jet pipe Q Superheated steam generator X Curing zone Y Heating zone Z Cooling zone

Claims (4)

A method for producing single-wall corrugated paper comprising the following steps:
-A core paper supply process in which the core paper (21) is fed out and brought into contact with a heating roll to preheat.
A core manufacturing process in which preheated core paper is continuously formed and processed into a corrugated core (2),
-A first paste (8) application step for applying raw starch liquid to the top of the corrugate of the core (2),
・ Back liner paper supply process for feeding back liner paper (3) and preheating,
-The core (2) preheated and coated with paste and the back liner paper (3) preheated are continuously bonded together to form a single-sided cardboard (4) with the first gelatinized paste. Single-sided cardboard manufacturing process,
-A second paste (9) application step for applying raw starch liquid to the top of the corrugated corrugated cardboard (4),
-A gelatinization process in which superheated steam is blown onto the second paste applied to the top of the single-sided cardboard to heat it to make it a half-gel.
・ The front liner paper supply process that feeds out the front liner paper (1) and preheats it if necessary.
Single-sided corrugated cardboard (4) coated with the second paste and the front liner paper (1) are continuously bonded together, and the unfinished single wall corrugated cardboard (5 ) And the corrugated paper forming process,
・ Glue infiltration process in which unfinished single-wall corrugated paper is run while being held in a bonded state, and the second gelatin that has been gelled in the meantime penetrates into the core (2) and the front liner.
・ A final heating process that blows superheated steam to the side of the front liner and fully gels and dries the infiltrated second paste with that heat, and completes the adhesion. A process for completing corrugated cardboard (5C) to cool and take it out. A device for producing single-wall corrugated paper comprising the following components:
A means (A2) for feeding out the core paper, and a core paper preheating roll (B2) for preheating the fed core paper,
A pair of tooth profile rolls (C) for continuously forming pre-heated core paper to produce a corrugated core;
A first paste supply means (D1) for applying a raw starch solution as a paste to the top of the corrugated core;
A means for feeding back liner paper (A3) and a back liner paper preheating roll (B3) for preheating the fed back liner paper;
A pressure roll (E) for continuously bonding the preheated back liner paper and the core coated with the first paste to form a single-sided cardboard (4);
-A second paste supply means (D2) for applying the raw starch solution to the top of the corrugated corrugated board on one side;
-Heating means (L1) of the second glue material for heating by spraying superheated steam onto the second glue applied to the top of the single-sided cardboard, and making it half gelled,
A means (A1) for feeding the front liner paper, a front liner paper preheating roll (B1) for preheating the fed front liner paper,
-A set of small crimping rolls (I), in which single-sided corrugated cardboard and front liner paper are continuously bonded to form unfinished single-wall corrugated paper.
・ Move the unfinished single wall corrugated paper (5) while holding it in a bonded state, and in the meantime, use a number of rolls to infiltrate the semi-gelled second paste material into the core and the front liner. A curing zone (X) consisting of a pair and two canvases running in opposition between them,
・ Running to spray the superheated steam on the front liner side of the unfinished single-wall corrugated paper (5), to fully gel the second glue material that has penetrated by the heat and to achieve complete adhesion A heating zone (Y) provided with a superheated steam jet pipe (P) with a number of nozzles (N) provided below the unfinished single wall corrugated paper, and a completed single wall corrugated paper (5C) A cooling zone (Z) consisting of a set of a large number of rolls and two canvases running opposite each other in between. A method for producing a double-wall corrugated paper comprising the following steps:
A first single-sided cardboard supply step of pre-heating the first single-sided cardboard (6A) by bringing the corrugated core into contact with a heating roll;
A first paste (8) application step of applying a raw starch solution to the top of the corrugated corrugated first-side corrugated cardboard;
-A gelatinization process in which superheated steam is sprayed on the first glue applied to the top of the first single-sided cardboard to make it a half-gel.
A second single-sided cardboard supply step of pre-heating the second single-sided cardboard (6B) by bringing the liner side into contact with a heating roll;
A second paste (9) application step of applying a raw starch solution to the top of the corrugated corrugated second-side corrugated cardboard;
-A gelatinization step in which superheated steam is sprayed on the second paste applied to the top of the second single-sided cardboard to make it a half-gel.
-Front liner paper supply process for feeding out and preheating the front liner paper (1),
The first single-sided cardboard (6A), the second single-sided cardboard (6B), and the front liner paper (1) are successively stacked in this order, and the unfinished double is formed by the first and second pastes that are semi-gelled. Double wall corrugated cardboard forming process to make corrugated cardboard paper (7),
・ The unfinished double-wall corrugated paper is run while being held in a bonded state, and during that time, the first gel paste that has been semi-gelled penetrates the middle liner that was the liner for the second single-sided cardboard (6B). And a paste-penetrating step for allowing the semi-gelled second paste to penetrate the surface liner,
・ A final heating step that blows superheated steam to the side of the front liner and sufficiently gels and dries the permeated first and second sizing agents with that heat to dry them completely. A process for completing a double wall corrugated cardboard (7C) to cool and take it out. An apparatus for producing double-wall corrugated paper comprising the following components:
A means for feeding out the first single-sided cardboard (6A), a first single-sided cardboard preheating roll (B4) for preheating the fed-out first single-sided cardboard,
A first glue supply means (D1) for applying the raw starch solution to the top of the corrugated corrugated first-side corrugated cardboard,
-A first steamer (L2) for spraying superheated steam on the first glue applied to the top of the first single-sided cardboard to make it half-gelled,
A means for feeding out the second single-sided cardboard (6B), a second single-sided cardboard preheating roll (B5) for preheating the fed-out second single-sided cardboard,
A second paste supply means (D2) for applying the raw starch solution to the top of the corrugated corrugated second-side corrugated cardboard,
-A second steamer (L3) for spraying superheated steam on the second paste applied to the top of the second single-sided cardboard to make it half gelled,
A means for feeding out the front liner paper (1) and a front liner paper preheating roll (B1) for preheating the fed out front liner paper;
A large pressure-bonding roll in which the first single-sided cardboard (6A), the second single-sided cardboard (6B), and the front liner paper (1) are successively stacked and bonded in this order to form an unfinished double wall cardboard (7). Pair (E),
-The unfinished double-wall corrugated paper (7) is run while being held in the laminated state, and during that time, the first gel that has been semi-gelled penetrates the middle liner that was the liner for the second single-sided cardboard. At the same time, a curing zone (X) consisting of a set of a number of rolls and two canvases running opposite each other to infiltrate the surface liner with the second gelled paste.
・ Blowing superheated steam on the side of the front liner of unfinished double wall corrugated paper (7) to fully gel the first and second glue materials that have penetrated by the heat, and to achieve complete adhesion , A heating zone (Y) provided with a superheated steam jet pipe (P) with a number of nozzles (N) provided under the running unfinished double wall corrugated paper, and cooling the finished corrugated paper A cooling zone (Z) consisting of a large number of rolls and two canvases running in opposition to each other.

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