JPS5851139A - Manufacture of one-surface corrugated cardboard sheet - 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]

The present invention relates to a method for manufacturing a single-sided corrugated board sheet, and more specifically, the present invention relates to a method for manufacturing a single-sided corrugated board sheet, and more specifically, the present invention relates to a method for manufacturing a single-sided corrugated board sheet, and more specifically, a glue is applied to the corrugated top part of the corrugated corrugated core in the process of forming the core into a continuous corrugated shape. The present invention relates to a method for producing a single-sided corrugated paperboard sheet in which the process of adhering it to a liner (hereinafter referred to as lamination) is carried out at a relatively low temperature.Generally, a corrugated paperboard sheet is made as follows. The core preheated with a hot roll is corrugated with two corrugated rolls heated in a single facer. Next, glue F is applied to the corrugated top part of the corrugated core, and this is crimped with a liner that is also preheated between a heated corrugating roll and a press roll.1. Lamination 1: Make one-sided cardboard. In the renitable facer, a glue is applied to the corrugated top part of the core of the single-sided corrugated board, and it is overlapped with another liner base paper, and then passed through a drying section and a cooling section to obtain a double-sided corrugated board. As mentioned above, the paste commonly used in the manufacturing method of corrugated board sheets is starch tea paste made by the stain hole method. This sizing material is made by gelatinizing starch with caustic soda [and adding viscosity to it]. In addition, the main part is a large amount of starch suspended in water, and the stone is used for mixing.The feature of this method is that due to the heating during bonding, ungelatinized starch particles rapidly absorb water, swell and dissolve. As a result, the entire size solution rapidly thickens [and develops adhesive strength], and the adhesive strength between the core and the liner when the size material is not dry (
(hereinafter referred to as initial adhesive strength), adhesive strength after the glue has dried (
Hereinafter referred to as permanent adhesive strength, 5) both are good, and the rigidity of the glue layer after drying is high, so that sufficient strength as a corrugated pole box can be obtained. However, this method requires a large amount of rapid heating in all steps of step forming, lamination, and drying. In addition, it requires various equipment, (2) it causes quality problems such as wrinkles in the sheet, washboard, etc. due to variations in the moisture content of the base paper and changes in drying, and (3) furthermore. There were various drawbacks such as loss due to waiting time at the beginning of operation. Research has been carried out on manufacturing methods for various corrugated cardboard sheets that do not require heating compared to conventional methods, but various problems in these manufacturing methods are ``problems of corrugated forming'' and ``problems of lamination''. It is broadly classified into two types. The present invention is concerned exclusively with the latter, particularly the problem of lamination in single facers. Various methods have been considered in the past, including the method of heating and laminating with trellis, and methods using synthetic resin emulsions such as poly-11 vinyl acetate and styrene-butadiene copolymer have been proposed. ing. . However, these adhesives are generally expensive, and when laminating at a low temperature, it is necessary to soften the resin by means such as internal plasticization or external plasticization in order to obtain the necessary initial adhesive strength. Therefore, when used together with a cardboard box, there is a drawback that the permanent adhesive force and the rigidity of the glue layer are insufficient. Furthermore, there are problems with wastewater treatment equipment, waste paper, and 1. There are also problems such as problems with gum when reusing it, and it has not yet been put into practical use. In addition, adhesives such as polyvinyl alcohol and starch, which are excellent in terms of permanent adhesive strength and rigidity of the adhesive layer, have poor initial adhesion (-they cannot be laminated without heating). The inventors of the present invention have conducted extensive research to improve these drawbacks, and have found that a polymeric substance that is soluble in cold water is present on the liner surface in advance, and this is applied to the top of the core corrugation to reduce the moisture content of the glue. It has been discovered that the above-mentioned problems can be solved by utilizing a so-called re-wetting adhesive force method in which adhesives are melted and bonded, and the present invention has been completed based on this knowledge. That is, in the present invention, the following aqueous solution (5
) is coated and dried - the liner and core base paper are fed to a single facer, and after one-stage forming, the following adhesive is applied to the top of the core corrugation, and the liner and the core corrugation top are laminated at a relatively low temperature. The present invention relates to a method for manufacturing a single-sided corrugated pole sheet. (5) An aqueous solution consisting of boric acid and a polymeric substance that can undergo a gelation reaction with a metal salt of boric acid in water and is soluble in cold water. (B) A glue comprising at least one substance selected from the group consisting of volvinyl alcohol, starch, and starch derivatives, and a hydroxide of an alkali-11 earth metal. The present invention uses a liner in which a polymeric substance soluble in cold water is present, and supplies water necessary for dissolving a portion of the polymeric substance on the surface of the liner to the top of the corrugated core. The top of the step and the liner are bonded together by pressure. Therefore, lamination is possible even if only water is supplied to the top of the corrugated core, but in reality, water is not supplied to the top of the corrugated core, and the water flows inside the core before being crimped with the liner. It is necessary that the aqueous solution has a certain degree of viscosity because it is easily absorbed. Therefore, Bo 11 Vinyl Ryukoru. By using an aqueous solution of TC polymeric substances such as starch or starch derivatives as a sizing agent, the viscosity of the sizing agent is increased, preventing moisture from penetrating into the core, and supplying the necessary moisture to the liner surface. . In addition, by using such a glue, it is possible to sufficiently increase the permanent adhesive strength and the rigidity of the glue layer required when using the box and I. In addition, since such rewet adhesion alone does not provide sufficient initial adhesive strength, in the present invention, boric acid is added to the cold water-soluble polymer material applied to the liner, and boric acid is added to the sizing agent supplied to the core. The 11 alkali substances rapidly gel the glue and the polymeric substances on the surface of the liner dissolved in the glue, increasing the initial adhesive strength. In the present invention, a cold water-soluble polymeric substance that can undergo a gelation reaction with a metal salt of boric acid in water is a substance that is soluble in water at room temperature of about 0 to 40°C, and whose aqueous solution is boric acid. Substances that gel with metal salts such as partially hydrogenated vinyl alcohol, carvone MK,
1 Vinyl alcohol, cyan ethyl etherified starch, etc. In the present invention, the partially saponified polyvinyl alcohol used in the aqueous solution applied to the liner base paper is
~95% and a polymerization degree of 500 to 2,600. Further, the carboxylic acid-modified vinyl alcohol has a carboxylic acid mole fraction of 2 to 6, and may be a completely saponified product or a partially saponified product. Cyanethyl etherified starch is made from corn

[Starch, wheat starch, potato starch, etc. are converted into cyan ethyl ether to a degree of etherification of 0.5 to 2.0. In addition to these polymeric substances, the amount of boric acid added to the aqueous solution applied to the liner is 3 to 12 parts by weight based on the solid content of the polymeric substance. The amount of aqueous solution applied to the liner base paper needs to be 0.51/rd or more based on the solid content after drying, preferably 1.5 to 3
r/Tr? It is. If the coating amount is less than 0.52 mm, the required initial adhesive strength and sufficient permanent adhesive strength cannot be obtained. The aqueous solution can be applied to the liner base paper by any method that can apply the coating solution to the base paper, such as a roll coater, gravure coater, or spray method.In the present invention, the aqueous solution is applied to the top of the core corrugation. The polyvinyl alcohol used in the glue has a polymerization degree of 50, which is usually commercially available.
0 to 2,600 completely saponified youth (partially saponified products can be used, but are not limited to these, and include so-called modified boils)
You can also use vinyl lacquer. There are no particular restrictions on the starch used for the thickening agent, as long as it is a natural starch such as corn L starch, wheat starch, potato starch, etc., and starch derivatives [such as hydroxyethyl etherified starch, cyan ethyl ether] Etherified starch such as esterified starch-II acid, esterified starch such as esterified starch-acetate esterified starch, other oxidized starch, pregelatinized starch-dex) 117, etc. can be used. It is necessary to add the alkaline earth metal hydroxide to the paste in an amount of at least 1.0.5% by weight relative to the water in the paste. The solid content concentration of the glue applied to the top of the core corrugation is %.
There is no limit to the viscosity, but its viscosity is 300 to 2000Cp (
It is preferable to adjust the temperature using a Type 3 viscometer at 12 rpm). The amount of adhesive to be applied to the top of the corrugated core is 18 to 20 f/n on one side of the corrugated pole sheet, depending on the amount of water in the adhesive. Well, no matter how little or how much you use, you won't be able to obtain the necessary initial adhesion force. In the method of the present invention, the temperature of the base paper and each roll during lamination is maintained at room temperature to 90°C. In conventional methods of manufacturing corrugated board sheets, bonding is performed because no heat is applied to either the core or the liner base paper. However, in the present invention, there is no need to heat each roll to a high temperature (approximately 150 DEG -190 DEG C.) in order to apply heat to the core and liner base paper. Lamination is possible even at substantially room temperature. However, if necessary, the temperature of the base paper may be adjusted to approximately 90°C.
Each roll may be heated to such an extent that Heating the rolls accelerates the reaction--therefore, the higher the temperature, the better the result. However, heating the base paper to a temperature of about 90 DEG C. or higher does not result in a significant improvement in the effect. In the present invention, lamination of single-sided corrugated cardboard sheets is carried out at a low temperature of room temperature to 90°C, but when lamination is carried out at such a low temperature, corrugation of the core is also carried out prior to lamination. It is desirable that the process be carried out at a low temperature (not room temperature, but close to this). At this time, if an untreated core is used, the core may be damaged or the step forming will not be carried out properly, so treatments such as applying a lubricant are often applied to the core, but there are no restrictions on these treatments. Furthermore, when manufacturing double-faced corrugated poles, double facer
There are no limitations on the method of manufacturing a double-sided corrugated cardboard sheet, which is carried out by laminating a liner to a single-sided corrugated cardboard sheet and then forming the single-sided corrugated cardboard sheet of the present invention in an H-shape. That is, lamination may be carried out by applying stainhole glue and heating as in the past, or by lamination in the single facer of the present invention or by other methods in which lamination is carried out at low temperature without heating. You can do it. Further, regarding the drying process, the drying temperature of the corrugated cardboard sheet is not particularly limited. Natural 1. However, in order to maximize the effects of the present invention, it is desirable that the process of laminating the double-sided corrugated cardboard in the double facer and the drying process be performed at a relatively low temperature of room temperature to 90°C. According to the method described above, the initial adhesion is excellent even if the core and liner base paper are laminated at a relatively low temperature from room temperature to about 90° C. without being heated to high temperatures. Therefore, it is possible to use a Steinhall force type adhesive to achieve lamination at a speed equal to or faster than the conventional method of laminating by heating.Furthermore, it is possible to use a starch tea adhesive. Since I can do it, Bo 11
The room-temperature lamination method using vinyl acetate, styrene-butadiene copolymer, etc. is inexpensive, and it is possible to produce corrugated board sheets with strong permanent adhesive strength and adhesive layer stiffness. The effects of the present invention will be explained in more detail below using Examples. Example: To a 12% aqueous solution of ethyl etherified starch (manufactured by Ryopebe, Netherlands: Har7 Ektamil K 250) was added boric acid with a solid content of 6.2% based on the starch solid content, and the mixture was applied to a liner base paper. Apply 1 coat of aqueous solution and dry. Another 77 parts by weight of esterified starch, 1 part by weight of caustic soda, 75 parts by weight of water were mixed together, and the glue to be applied to the top of the corrugated core was mixed. The viscosity of this glue is 875c at room temperature.
prB viscometer at 12 rpm). Semi-core 125t/lr? And above also liner 22
．． Supply 011/WI to the test corrugator 1. JIS
Z15161F stipulation 4. A single-sided corrugated board with tier A was produced through all steps at room temperature. ．． 16 fi × application, that is, the starch solid content is 4
fi taka, applied moisture content 12279, lamination speed 1
There was no problem at all for 00v minutes. In order to facilitate step forming at room temperature, step forming W '0
In No. 11, a lubricant was supplied to both the front and back sides of the core using a solid bar of paraffin wax and zinc ester II phosphate. Example 2 In Example I, carboxylic acid-modified starch was used instead of ethyl etherified starch in the aqueous solution applied to the liner base paper.
1 vinyl alcohol (manufactured by Nippon Gohsei; Gosenal T-
1) Vinyl alcohol (manufactured by Nippon Gosei Co., Ltd.; Gohsenol N-300"
A single-sided corrugated board was laminated in exactly the same manner as in Example 1, except that the aqueous solution of Example 1-9 was used. In this case as well, the lamination speed was 100 rnA+ and there was no problem at all Comparative Example 1 In Example 1, completely saponified polyvinyl alcohol (manufactured by Nippon Gosei Co., Ltd. Gohsenol N-30 (
Same as in Example 1 except that a 10% aqueous solution of 1 was used to bond single-sided corrugated poles.The bonding speed was 2
There was one below 0IrL10. Comparative Example 2 In Example 111, the aqueous solution of cyanoethyl etherified star and powder to be applied to the liner base paper was replaced with IK Completely Hydrogenated Bottle 11 Vinyl Alcohol (Nippon Gosei Co., Ltd. Gohsenol N-
A single-sided corrugated board was laminated using the same Vr as in Example 1, except that a 10% aqueous solution of No. 300) was used and boric acid was not added. Even at a lamination speed of 10 m/% or less, the liner and core did not adhere to each other and could not be laminated. Comparative Example 3 In Example IV, the aqueous solution of cyanoethyl etherified starch applied to the liner base paper substituted for 11-ruic acid C.
A single-sided corrugated board was laminated in exactly the same manner as in Example 1 except that an aqueous solution of Aron A-10H (manufactured by Takuyasei Co., Ltd.) was used and boric acid was not added. When the lamination speed was 40m7% or higher, lamination was poor. Patent applicant Honshu Paper Co., Ltd.

Claims (1)

[Claims] The following aqueous solution (5) is applied to the liner base paper in advance and dried.The liner and core base paper are fed to a single facer. After forming in 5 stages, the following glue (B) is applied to the top of the core step. 1. A method for producing a single-sided corrugated cardboard sheet, which comprises coating the liner and laminating the corrugated top portion of the core at a relatively low temperature. An aqueous solution consisting of boric acid and a polymeric substance that can undergo a gelation reaction with metal salts of boric acid in water and is soluble in cold water. 03) at least one substance selected from the group consisting of vinyl alcohol, starch-starch derivatives,
A glue consisting of an alkali metal lid or an alkaline earth metal hydroxide.