JP2020193396A5

JP2020193396A5 -

Info

Publication number: JP2020193396A5
Application number: JP2019097977A
Authority: JP
Filing date: 2019-05-24
Publication date: 2021-03-04
Anticipated expiration: 2039-05-24

Description

各層のサイズ剤の添加量の下限としては、固形分で０．５０ｋｇ／パルプｔが好ましく、１．５０ｋｇ／パルプｔがより好ましい。また、各層のサイズ剤の含有量の上限としては、固形分で５．００ｋｇ／パルプｔが好ましく、４．００ｋｇ／パルプｔがより好ましい。サイズ剤の添加量を上記範囲とすることで、当該段ボール用ライナに十分な耐水性を付与し、高温多湿の環境下において当該段ボール用ライナ中の湿度に対する耐久性を高めることができる。また、カチオン化澱粉を更に加えることにより、各層の紙質強度が増強され、高い耐衝撃性の段ボール用ライナを得ることができる。なお、「ｋｇ／パルプｔ」とは、段ボール用ライナ１トンに対する添加量（ｋｇ）を表す。
As the lower limit of the amount of the sizing agent added to each layer, the solid content is preferably 0.50 kg / pulp t, more preferably 1.50 kg / pulp t. The upper limit of the content of the sizing agent in each layer is preferably 5.00 kg / pulp t in terms of solid content, and more preferably 4.00 kg / pulp t. By setting the amount of the sizing agent added within the above range, it is possible to impart sufficient water resistance to the corrugated board liner and enhance the durability of the corrugated board liner in a high temperature and high humidity environment. Further, by further adding the cationized starch, the paper quality strength of each layer is enhanced, and a corrugated cardboard liner having high impact resistance can be obtained. In addition, "kg / pulp t" represents the addition amount (kg) with respect to 1 ton of corrugated cardboard liner.

表面層の紙力増強剤の添加量の下限としては、固形分で０．４０ｋｇ／パルプｔが好ましく、０．８ｋｇ／パルプｔがより好ましい。また、各層の紙力増強剤の添加量の上限としては、固形分で９．０ｋｇ／パルプｔが好ましく、８．０ｋｇ／パルプｔがより好ましい。表面層の紙力増強剤の添加割合が上記上限を超えると、濾水性が悪化し、抄紙機のプレスパートの圧搾及び脱水工程でパルプ原料が排出されやすい。また、上記プレスパートにおいて、ロールに貼り付いた湿紙を剥がすときに用いられるドクターブレードにパルプ原料の粕が付着し、表面層の品質が低下するおそれがある。一方、表下層及び裏面層の紙力増強剤の添加量の下限としては、固形分で６．０ｋｇ／パルプｔが好ましく、６．４ｋｇ／パルプｔがより好ましい。また、表下層及び裏面層の紙力増強剤の添加量の上限としては、固形分で８．０ｋｇ／パルプｔが好ましく、７．０ｋｇ／パルプｔがより好ましい。各層の紙力増強剤の添加量を上記範囲とすることで、当該段ボール用ライナの柔軟性を担保しつつ６０℃、８０％ＲＨの雰囲気下における比破裂強さを向上できる。
As the lower limit of the amount of the paper strength enhancer added to the surface layer, the solid content is preferably 0.40 kg / pulp t, more preferably 0.8 kg / pulp t. Further, as the upper limit of the amount of the paper strength enhancer added to each layer, the solid content is preferably 9.0 kg / pulp t, more preferably 8.0 kg / pulp t. When the addition ratio of the paper strength enhancer in the surface layer exceeds the above upper limit, the drainage is deteriorated, and the pulp raw material is likely to be discharged in the pressing and dehydration steps of the press part of the paper machine. Further, in the press part, the pulp raw material residue may adhere to the doctor blade used for peeling the wet paper attached to the roll, and the quality of the surface layer may be deteriorated. On the other hand, as the lower limit of the amount of the paper strength enhancer added to the lower surface layer and the back surface layer, the solid content is preferably 6.0 kg / pulp t, more preferably 6.4 kg / pulp t. The upper limit of the amount of the paper strength enhancer added to the lower surface layer and the back surface layer is preferably 8.0 kg / pulp t, more preferably 7.0 kg / pulp t in terms of solid content. By setting the amount of the paper strength enhancer added to each layer within the above range, it is possible to improve the relative burst strength in an atmosphere of 60 ° C. and 80% RH while ensuring the flexibility of the corrugated board liner.

Claims

It has at least a front surface layer, a front surface layer and a back surface layer
The surface layer contains softwood kraft pulp, and the content of the softwood kraft pulp in the surface layer is 80% by mass or more.
The lower surface layer contains softwood kraft pulp and corrugated cardboard waste paper pulp, and the content of the softwood kraft pulp in the lower surface layer is 25% by mass or more and 35% by mass or less.
The back surface layer contains corrugated cardboard waste paper pulp and magazine waste paper pulp,
The content of the corrugated cardboard waste paper pulp in the back surface layer is 30% by mass or more and 70% by mass or less.
The content of the magazine waste paper pulp in the back surface layer is 30% by mass or more and 70% by mass or less.
The ratio of the basis weight of the surface layer to the total basis weight is 20% or more and 35% or less.
^{A corrugated board liner having a specific burst strength of 3.45 kPa · m 2} / g or more in an atmosphere of 60 ° C. and 80% RH.

The front surface layer and the back surface layer contain a sizing agent,
The liner for corrugated cardboard according to claim 1, wherein the degree of bump size of the front surface layer and the back surface layer at a measurement time of 2 minutes is 10 g / m ² or more and 50 g / m ^{2 or less.}

The surface layer and the lower surface layer contain a paper strength enhancer,
The corrugated board liner according to claim 1 or 2, wherein the amount of the paper strength enhancer added to the lower surface layer is larger than the amount added to the surface layer.

The corrugated board liner according to claim 1, claim 2 or claim 3, wherein the density is 0.65 g / cm ³ or more and 0.85 g / cm ^{3 or less.}

The corrugated board liner according to any one of claims 1 to 4, wherein the freeness of the dissociated pulp dissociated in accordance with JIS-P8220 (1998) is 420 ml or more and 460 ml or less.

A method for manufacturing a corrugated board liner having at least a front surface layer, a front surface layer, and a back surface layer.
It is equipped with a process of making raw pulp using a paper machine that makes the pulp raw material ejected onto the traveling wire.
The raw material pulp contains softwood kraft pulp, corrugated cardboard waste paper pulp, magazine waste paper pulp or a combination thereof.
The ratio J / W ejection rate J of the pulp raw material with respect to the running speed W of the wire in the paper making process of the surface layer and the backing layer, much larger than the table below the J / W,
The surface layer contains softwood kraft pulp, and the content of the softwood kraft pulp in the surface layer is 80% by mass or more.
The lower surface layer contains softwood kraft pulp and corrugated cardboard waste paper pulp, and the content of the softwood kraft pulp in the lower surface layer is 25% by mass or more and 35% by mass or less.
The back surface layer contains corrugated cardboard waste paper pulp and magazine waste paper pulp,
The content of the corrugated cardboard waste paper pulp in the back surface layer is 30% by mass or more and 70% by mass or less.
The content of the magazine waste paper pulp in the back surface layer is 30% by mass or more and 70% by mass or less.
A method for producing a corrugated board liner, wherein the ratio of the basis weight of the surface layer to the total basis weight of the corrugated cardboard liner is 20% or more and 35% or less.