JPS61270143A - Method and device for manufacturing single-side corrugated board paper - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

FIELD OF THE INVENTION The present invention relates to improvements in a method and apparatus for producing single-sided corrugated paperboard.

[Conventional technology]

Single-sided corrugated paper is produced by forming it into a corrugated shape using corrugated rolls.
This is done by laminating corrugated paper, called a core, and a piece of liner. A raw starch solution, in which starch particles are dispersed in water, is widely used as the bonding adhesive.The raw starch solution is applied to the peaks of the core and heated to gel to form a glue. The raw starch liquid is heated in the first half, when the core coated with the raw starch liquid is pressed against the liner and until it leaves the corrugating rolls, and in the second half, after pressing, it is heated in advance. This is done using heat from the liner and residual heat from the core. The liner is heated by contacting it with a heating roll, which is generally heated with high temperature steam (pressure 10-12 ffg/ai).
The line speed for manufacturing corrugated paperboard varies depending on the equipment, such as high speed, medium speed, and low speed, and the higher the speed, the larger the roll diameter. In either case,
Although it is desirable for the line speed to be constant from the standpoint of quality control, in reality it is unavoidable that it varies due to various reasons. Since the heat capacity of the roll is quite large, it is difficult to quickly adjust the temperature of the roll in response to variations in line speed. When the line speed is too high, the contact time between the liner and the heating roll becomes short, resulting in insufficient heating of the liner as a whole. Then, the raw starch liquid is not heated enough,
Since bonding is performed with insufficient gelation, the manufactured single-sided corrugated paperboard will have poor adhesion. If the line speed is slow, the liner will be in contact with the heated rolls for longer than necessary and will be heated too much, causing it to dry out too much. When the liner in this state is pressed against the core, it rapidly absorbs only water from the raw starch liquid, and the starch liquid, which has become highly concentrated, is heated and turns into a gel. This too thick glue has poor flexibility when it dries, causing the glue to peel off with a noise in later steps, a phenomenon known as ``stickiness.'' Furthermore, it is inevitable that the liner will have more or less uneven moisture content, and areas with high moisture content will partially stretch, impairing the flatness of the liner. Liners with poor flatness are
Since the contact with the heating roll is not uniform, there will be insufficient heating in some areas, resulting in insufficient gelation in some parts of the raw starch liquid, which will cause poor adhesion of the product corrugated paperboard. Instead of the fingers conventionally used to guide the corrugated core to the lower roll, this stage uses a number of small holes in the lower roll to suck air, attract and guide the core. Rolls have come into use. In this no-finger type, moisture is also lost when air passes through the core, so the core tends to warp.

[Problems to be solved by the invention]

An object of the present invention is to solve the above-mentioned problems and to provide a technique for manufacturing single-sided corrugated paperboard of good quality with sufficient adhesion and no warping. Another object of the present invention is to provide a single-sided corrugated paper manufacturing technology that changes the heating conditions in accordance with changes in line speed in the production of single-sided corrugated paperboard, thereby always producing a product of constant quality. be. [Means for solving the problem] The present inventor has previously invented and disclosed an apparatus for blowing steam onto a raw starch solution applied to a pile of core, in connection with the production of double-sided corrugated paperboard. (Unexamined Japanese Patent Publication No. 57-25940). This device has been widely recognized as useful in the art, and is becoming popular under the name "accelerated steamer" because of its remarkable effectiveness in increasing line speeds in corrugated paperboard production. The method for producing single-sided corrugated paperboard of the present invention utilizes this steam blowing device, and involves applying raw starch liquid to the peaks of the core obtained by shaping the core material into a corrugated shape.
In a method for producing single-sided corrugated paperboard, which consists of heating a raw starch liquid to gel it to form a paste, heating the liner with a heating roll and pressing it against the core to bond and integrate the liner, in addition to heating with the heating roll, the liner is It is characterized by heating and/or humidifying by blowing steam onto it. As shown in the drawings, the apparatus of the present invention for carrying out this manufacturing method includes a means for continuously feeding out the core material 2A, a pair of heating rolls 4 and 5 for forming the core material into a corrugated shape, and a core material 2A. Means 9 for applying the raw starch liquid to the mountain portions, means for continuously feeding out the liner 1, heating rolls 7.8 for heating the liner, press rolls 6 for pressing the core 2B and the liner, and the manufactured 11.12 in an apparatus for producing single-sided corrugated paper consisting essentially of means (not shown) for continuously drawing off the liner, the means for heating and/or humidifying the liner with steam; It is characterized by having the following. The heating of the liner with the heating roll is preferably carried out in two stages: preliminary heating and main heating. In that case, the steam blowing means 11.12 are preferably arranged between these two heating rolls 7.8. In order to achieve a good balance between heating and humidifying the liner,
It is preferable to prepare a plurality of steam blowing means and to select the number of them used and the temperature and humidity of the steam to be sprayed depending on the line speed. The figure shows an example in which five steam blowing means are used. Steam having a temperature of 80 to 90°C is useful for humidification, and 120 to 140°C for heating. In order to adjust the temperature or humidity of the steam, it is of course possible to mix an appropriate amount of air, and in the present invention, "steam" includes a mixture with such air in any proportion. . According to the present invention, the amount of steam used to heat the corrugating rolls and heating rolls can be reduced compared to the conventional method, so the apparatus may be configured to apply the steam to the steam blowing means. [Function] When the line speed for manufacturing single-sided corrugated paperboard is high, insufficient heating of the liner can be avoided by blowing high-temperature steam onto it. Therefore, according to the present invention, the manufacturing speed of single-sided corrugated paperboard can be increased. When the speed changes to the low speed side, even if the liner is overheated by the heating roll, blowing relatively low-temperature moist steam will prevent the liner from drying out too much.
In either case, the raw starch solution gels normally. - According to a preferred embodiment of the present invention, which is provided with means for blowing steam under such different conditions, the temperature and moisture content of the liner can be appropriately controlled in response to variations in line speed over a wide range. Even if the liner has poor flatness, where heating with heating rolls alone would result in partial heating, it is possible to uniformly heat the liner by spraying it with high-temperature steam. The liner thus hydrated also comes into contact with a heated roll to improve its flatness. On a corrugated roll using a no-finger type, the core, which has warped due to lack of moisture, is replenished with water from the liner during pressing, and the warpage is improved.

Example 1 Single-sided corrugated paperboard was manufactured using the apparatus of the present invention at various line speeds. The following conditions were selected depending on the line speed. Line speed Steam temperature Blowing means (m/ll)
1in >Kotanjo-J'? [Number O~50
85 2 50-70 85 1 70-100 130 1100-130
゛ 130 2130 or more 130
The single-sided corrugated paperboard produced in No. 3 had good lamination and no warping at any line speed, and was of good quality. The steam pressure required to heat the corrugating rolls and heating rolls could be reduced from the conventional 12 KI/crA to 8 Ky/d. [Example 2] Applying the present invention to an existing corrugator, sheet width 240
0 rrm corrugated paperboard was produced. The base paper composition is (a) K280xSCP160xK280 (b)
K280xMM200 (reinforced core) K280. Two means for blowing steam at 85° C. and three means for blowing steam at 130° C. were arranged in this order and used. The line speed increased exponentially. (A) 140-+1857FL/m1n (B)
135-+150 m/min Previously, there was a tendency for products to warp downward, which was thought to be due to lack of moisture in the core due to the no-finger one-way system, but this has been resolved. If single-sided corrugated paperboard is manufactured according to the present invention, the liner can be sufficiently heated even at high line speeds, increasing productivity. The liner can be moderately humidified even at slow line speeds without affecting quality, and can quickly respond to large fluctuations in line speed. Therefore, high-quality single-sided corrugated paperboard can be produced over a wide line speed range.

BRIEF DESCRIPTION OF THE DRAWINGS The drawing is a conceptual side view showing the configuration of the single-sided corrugated paperboard manufacturing apparatus of the present invention. 1... Liner 2A... Core material 2B... Core 4.5...
・Heating corrugated roll 6...Press roll 7...Heating roll 8...Preheating roll 9...
・Raw starch liquid application means

Claims (6)

[Claims] (1) Apply a raw starch solution to the peaks of the core obtained by forming the core material into a corrugated shape, heat the raw starch solution to gel it into a paste, and heat the liner with a heating roll to form the core. A manufacturing method for single-sided corrugated paperboard comprising pressing and bonding together the liner, which comprises heating and/or humidifying the liner by blowing steam onto it in addition to heating with a heating roll. (2) The manufacturing method according to claim 1, wherein steam is blown onto the liner heated by the first heating roll and then further heated by the second heating roll. (3) The manufacturing method according to claim 1, in which steam at a temperature of 80 to 90°C and/or steam at a temperature of 120 to 140°C is blown onto the liner. (4) The method according to claim 1, wherein a plurality of steam blowing means are provided, and the number of the steam blowing means used and the temperature and humidity of the blowing steam are selected depending on the line speed for producing single-sided corrugated paperboard. (5) a means for continuously feeding out the core material, a pair of heated rolls for forming the core material into a corrugated shape, a means for applying raw starch liquid to the peaks of the core, a means for continuously feeding out the liner; Single-sided corrugated paperboard basically consists of a heating roll to heat the liner, a press roll to press and bond the core and liner together to form single-sided corrugated paperboard, and a means for continuously taking out the produced single-sided corrugated paperboard. An apparatus for producing corrugated paperboard, characterized in that the apparatus is provided with means for heating and/or humidifying the liner by blowing steam onto it. (6) A first heating roll on the line where the liner runs;
6. An apparatus according to claim 5, comprising means for blowing steam and a second heating roll in this order.