KR102562465B1 - Paper for manufacturing paper straw and method for preparing the same - Google Patents

Abstract

The paper manufacturing method according to an embodiment of the present invention includes the steps of beating linter cotton pulp, preparing a stock by adding a first added amount of a wet strength enhancer, preparing base paper using the prepared stock, It is characterized in that it comprises the step of surface treatment of the base paper using a surface treatment agent containing an added amount of a wet strength enhancer. The paper produced according to the embodiment of the present invention has a high bulk and excellent wet strength, and thus has an effect suitable for manufacturing paper straws.

Description

Paper suitable for making paper straws and its manufacturing method {PAPER FOR MANUFACTURING PAPER STRAW AND METHOD FOR PREPARING THE SAME}

The present invention relates to paper suitable for making paper straws and a method for manufacturing the same.

As environmental problems caused by plastic products become serious, interest in materials that can replace plastics is increasing. In accordance with this trend, efforts to make disposable straws used for beverage intake with paper have been steadily made.

However, in general, fibers that are raw materials of paper have a lot of hydrophilic functional groups (OH), and when immersed in liquids such as water and beverages, hydrogen bonds are easily broken, so they are released into individual fibers even with a small external force. Since the straw is used in a state in contact with liquid for a long time, paper having excellent wet strength that does not unravel into individual fibers even when immersed in liquid for a long time is required to manufacture paper straws.

In the case of paper that may come into contact with liquid, a chemical that imparts hydrophobicity is sometimes added in the paper manufacturing process to temporarily provide water resistance, but this method is not suitable for straws that are used in contact with liquid for a long time.

In addition, in order to impart permanent wet strength, a method of adding a certain amount of wet strength enhancer during the stock process can be considered, but if the amount of wet strength enhancer is small, the effect is not large, and if the amount is too large, the content of positive (+) ions It rises and the joint is not good.

In addition, paper straws are required to have shape stability, which maintains their shape for a long time even in a wet state. Paper straws may be manufactured by overlapping several layers of paper for shape stability, but in this case, the manufacturing process is complicated and disadvantageous in terms of cost.

Therefore, paper having excellent wet strength and shape stability suitable for manufacturing paper straws is required.

KR 10-2018-0089880 A

The present invention has been made to solve the problems of the prior art, and an object of the present invention is to provide paper having excellent wet strength suitable for manufacturing paper straws and a manufacturing method thereof.

Another object of the present invention is to provide a paper having excellent shape stability and a method for manufacturing the same, in which the shape is maintained even in a state of contact with liquid for a long time.

The paper manufacturing method according to an embodiment of the present invention includes the steps of beating linter cotton pulp, preparing a stock by adding a first added amount of a wet strength enhancer, preparing base paper using the prepared stock, It is characterized in that it comprises the step of surface treatment of the base paper using a surface treatment agent containing an added amount of a wet strength enhancer.

In the beating step, 100% linter cotton pulp may be used.

In addition, the first added amount may be 0.5 to 1.5 wt%, and the second added amount may be 2 wt% or less.

The wet strength enhancer added in the stock preparation step and the surface treatment step may be a polyamide-epichlorohydrin (PAE) resin.

In addition, in the beating step, it may be beaten to a degree of beating in the range of 45 to 50 ^SR .

Paper according to another aspect of the present invention is characterized in that it is manufactured by the above manufacturing method, and may have a bulk of 1.3 cm 3 / g or more and a wet strength of 6.0 kgf or more at a basis weight of 150 g / m 2 .

A paper straw according to another aspect of the present invention is characterized in that it is made of the above paper.

According to the present invention, by dividing and adding the wet strength enhancer to the stock preparation step and the surface treatment step during the paper manufacturing process, there is an effect of providing excellent wet strength suitable for making paper straws.

In addition, by manufacturing paper using linter cotton pulp, which can relatively increase bulk at the same basis weight, there is an effect of providing excellent shape stability in which the shape is maintained even in a state of contact with liquid for a long time.

However, the effects of the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

1 is a flowchart showing a paper manufacturing method according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited or limited by the embodiments. In describing the present invention, if it is determined that a detailed description of related known technologies may obscure the gist of the present invention, the detailed description will be omitted.

1 is a flowchart showing a paper manufacturing method according to an embodiment of the present invention.

Referring to FIG. 1, the paper manufacturing method according to an embodiment of the present invention includes a beating step (S10), a stock manufacturing step (S20), a papermaking step (S30), a surface treatment step (S40), a curing step (S50), and A drying step (S60) may be included.

The beating step (S10) is a mechanical treatment process of finely cutting the fibers of the pulp, and may be performed using a beater. Beaters generally have metal or stone rotating rolls with many teeth inside the barrel. When the pulp to be beaten is mixed with water and allowed to flow inside the barrel, the pulp is beaten as it passes between the rotating roll and the teeth of the bottom of the barrel provided below it. In the beating process, the fibers are cut into uniform sizes and softened at the same time, and fibrils are formed on the surface.

In the embodiment of the present invention, linter cotton pulp is used as the pulp introduced into the beating step. Linter cotton fiber has a thick cell wall compared to softwood fibers or broadleaf fibers, so it is easy to obtain high bulk at the same basis weight when manufactured as paper. That is, since the volume of the paper can be relatively large at the same basis weight, the paper straw can be relatively hard and the shape can be maintained for a long time. In the embodiment of the present invention, only 100% linter cotton pulp can be used to maximize bulk.

The degree of beating is expressed as Freeness, and the pulp used for papermaking is usually treated at a level of 16 to ²⁰ SR (Schopper Riegler). However, in the embodiment of the present invention, the beating step may be performed so that the degree of beating is 40 to 55 ^° SR, preferably 45 to 50 ^° SR.

If the degree of beating is less than 40 ^o SR, the bulk can be increased, but ^there is a disadvantage that the wet strength does not come out much.

After the beating step (S10), the stock preparation step (S20) is performed. The stock preparation step (S20) is a step of dissolving and diluting the beaten pulp in water, and the pulp concentration in the stock may be dissolved to be about 0.1 to 0.5 wt%.

In the embodiment of the present invention, a wet strength enhancer is added in the stock preparation step (S20). A polyamide-epichlorhydrin (PAE) resin may be used as a wet strength enhancer. Since PAE resin is harmless to the human body, it is a suitable material to improve the wet strength of paper for making paper straws.

On the other hand, when an excessive amount of the wet strength enhancer is added in the stock preparation step to increase the wet strength, the effect of increasing the wet strength is not great, but the content of positive (+) ions increases, resulting in poor formation. Therefore, in the embodiment of the present invention, the wet strength enhancer is divided and added to the stock preparation step (S20) and the surface treatment step (S40) to be described later. The amount of the wet strength enhancer added in the stock preparation step may be in the range of 0.5 to 1.5 wt%.

The papermaking step (S30) is a step of manufacturing base paper from stock, and may be a step of manufacturing hand-made paper using a hand-sheet machine, and the same method as a conventional paper manufacturing step may be used. Preferably, the pulp having the fiber size evenly selected is sent to a handing machine to be sucked and/or filtered to produce wet base paper.

The papermaking step may include a compression dewatering step. The compression dewatering step is a step of squeezing the base paper to remove moisture contained in the base paper, and the base paper may be compressed by mechanical force while passing between successive press rolls.

Next, a surface treatment step (S40) is performed. The surface treatment step (S40) is a step of treating the base paper with a surface treatment agent containing a material capable of realizing high strength such as polyvinyl alcohol (PVA). The surface treatment step (S40) may be a step of impregnating the base paper with a surface treatment agent so that the surface treatment agent can sufficiently penetrate into the base paper. For this impregnation treatment, a netting system may be used.

The surface treatment step (S40) may be a step of sizing treatment in a two roll size or gate roll method. The sizing treatment may be to coat both sides of the base paper with a surface treatment agent as the base paper passes between two rolls. A long netting system may be used for the sizing process.

As a surface treatment agent, a solution containing phenolic resin, gelatin, etc. may be used instead of PVA.

In an embodiment of the present invention, a predetermined amount of a wet strength enhancer is added to the surface treatment agent. As the wet strength enhancer, the same material as that added in the stock preparation step may be added. For example, polyamide-epichlorhydrin (PAE) resin may be added.

On the other hand, if an excessive amount of the wet strength enhancer is added in the surface treatment step in order to increase wet strength, the viscosity and adhesive strength of the surface treatment agent increase, resulting in reduced production efficiency and severe process contamination, which may cause adverse effects. Therefore, the amount of the wet strength enhancer added in the surface treatment step may be 2.0 wt% or less, preferably in the range of 1.0 to 2.0 wt% in the surface treatment agent.

In addition, the surface treatment step may include a compression dewatering step. The compression dehydration step may be a step of removing moisture contained in the handsheet by pressing the handsheet that has been surface-treated.

After the surface treatment step, a curing step (S50) may optionally be performed. The curing step (S50) may be a step of curing the surface treatment agent including polyvinyl alcohol by impregnating for 3 to 7 seconds in 3 to 6 wt% borax solution. That is, it may be carried out by impregnating the surface-treated base paper in the borax solution and then pressing and dehydrating to remove excess borax solution.

Next, a drying step (S60) may be performed to produce paper suitable for manufacturing paper straws. The drying step (S60) may be a step of drying the dehydrated base paper in a temperature range of 50 to 120 ° C. At temperatures below 50 ° C, drying takes a long time, and when it exceeds 120 ° C, paper may be warped due to rapid vaporization. Specifically, it may be a step of stress drying using a dryer so that the surface temperature becomes 100 ° C.

The paper according to the embodiment of the present invention manufactured by the method described above can have a relatively high bulk at the same basis weight by using linter cotton pulp. Specifically, the paper according to the embodiment of the present invention may have a bulk of 1.3 cm 3 /g or more. Due to such a high bulk, the paper according to the embodiment of the present invention can maintain its shape for a long time even when wet with liquid.

In addition, the paper according to the embodiment of the present invention can obtain excellent wet strength characteristics of 6.0 kgf or more at a basis weight of 150 g / m 2 by dividing the paper into a stock preparation step and a surface treatment step and adding a wet strength enhancer.

Paper according to an embodiment of the present invention has properties suitable for manufacturing paper straws due to such excellent shape stability and wet strength. And these excellent properties of the paper according to the embodiment of the present invention are the effects of the manufacturing method according to the embodiment of the present invention in which linter cotton pulp is used and a wet strength enhancer is added to both the stock preparation step and the surface treatment step.

Hereinafter, examples of the present invention will be described in detail along with comparative examples.

1. Examples and Comparative Examples

(Example 1)

100wt% of linter cotton fiber was used and beaten to a degree of beating of 45 ^o SR. After diluting with water, base paper was prepared using stock stock to which 0.5 wt% of PAE resin was added. In the surface treatment step, the surface was treated by being impregnated with a surface treatment agent to which polyvinyl alcohol and 1.2 wt% of PAE resin were added, and paper having a basis weight of 150 g/m 2 was prepared through pressing and dehydration and drying steps.

(Example 2)

It was prepared under the same conditions as in Example 1, but the degree of beating was adjusted to 50 ^° SR.

(Example 3)

It was prepared under the same conditions as in Example 1, but the basis weight was changed to 200 g/m 2 .

(Example 4)

It was manufactured under the same conditions as in Example 1, but the degree of beating was changed to 50 ^° SR and the basis weight was changed to 200 g / m 2 .

(Example 5)

It was prepared under the same conditions as in Example 1, but the amount of PAE resin added in the stock preparation step was changed to 1.0 wt%.

(Example 6)

It was prepared under the same conditions as in Example 1, but the amount of PAE resin added in the stock preparation step was changed to 1.5 wt%.

(Example 7)

It was prepared under the same conditions as in Example 1, but the amount of PAE resin added in the stock preparation step was changed to 1.5 wt% and the amount of PAE resin added in the surface treatment step was changed to 2.0 wt%.

(Comparative Example 1)

It was prepared under the same conditions as in Example 1, but the PAE resin was added only in the stock preparation step and the PAE resin was not added in the surface treatment step.

(Comparative Example 2)

It was prepared under the same conditions as in Example 1, but PAE resin was added only in the surface treatment step without adding PAE resin in the stock preparation step.

(Comparative Example 3)

It was prepared under the same conditions as Comparative Example 1, but softwood fibers were used instead of linter cotton fibers.

(Comparative Example 4)

It was prepared under the same conditions as in Comparative Example 2, but softwood fibers were used instead of linter cotton fibers.

(Comparative Example 5)

It was prepared under the same conditions as in Example 1, but softwood fibers were used instead of linter cotton fibers.

(Comparative Example 6)

It was prepared under the same conditions as Comparative Example 1, but hardwood fibers were used instead of linter cotton fibers.

(Comparative Example 7)

It was prepared under the same conditions as Comparative Example 2, but hardwood fibers were used instead of linter cotton fibers.

(Comparative Example 8)

It was prepared under the same conditions as in Example 1, but hardwood fibers were used instead of linter cotton fibers.

2. Comparison of Paper Characteristics

Bulk properties and wet strength of the papers prepared in Examples and Comparative Examples were measured. The results are shown in Table 1 below.

Raw material basis weight
(g/㎡) treatment conditions Surface treatment bulk
(cm3/g) wet strength
(kgf) Confession
( ^oSR ) PAE resin
(wt%) PAE resin
(wt%) Example 1 linter cotton fiber 150 45 0.5 1.2 1.35 6.2 Example 2 linter cotton fiber 150 50 0.5 1.2 1.32 6.4 Example 3 linter cotton fiber 200 45 0.5 1.2 1.35 6.8 Example 4 linter cotton fiber 200 50 0.5 1.2 1.32 7.0 Example 5 linter cotton fiber 150 45 1.0 1.2 1.35 6.4 Example 6 linter cotton fiber 150 45 1.5 1.2 1.35 6.6 Example 7 linter cotton fiber 150 45 1.5 2.0 1.35 6.6 Comparative Example 1 linter cotton fiber 150 45 0.5 - 1.35 5.8 Comparative Example 2 linter cotton fiber 150 45 - 1.2 1.35 5.4 Comparative Example 3 softwood fiber 150 45 0.5 - 1.10 5.1 Comparative Example 4 softwood fiber 150 45 - 1.2 1.10 4.8 Comparative Example 5 softwood fiber 150 45 0.5 1.2 1.10 5.5 Comparative Example 6 hardwood fiber 150 45 0.5 - 1.20 4.5 Comparative Example 7 hardwood fiber 150 45 - 1.2 1.20 4.0 Comparative Example 8 hardwood fiber 150 45 0.5 1.2 1.20 5.1

According to Table 1, in the case of Examples 1 to 7 in which linter cotton fiber was used and a wet strength enhancer was added in both the stock preparation step and the surface treatment step, an excellent Wet strength was shown.

Comparing Examples 1 and 3 and Examples 2 and 4, the wet strength increased by about 10% when the basis weight increased from 150 g/m 2 to 200 g/m 2 .

In addition, comparing Examples 1 and 2 and Examples 3 and 4, when the beating degree was increased from 45 ^° SR to 50 ^° SR, the bulk slightly decreased and the wet strength slightly increased. Even at 50 ^o SR, the bulk still showed a high value of 1.32 cm 3 /g.

According to Examples 5 and 6, when the amount of the wet strength enhancer added in the stock preparation step was increased to 1.5 wt%, the wet strength also increased. However, when comparing Example 6 and Example 7, the wet strength was not changed even though the addition amount of the wet strength enhancer added in the surface treatment step increased from 1.2 wt% to 2.0 wt%.

When comparing Comparative Examples 1 and 2, in which the wet strength enhancer was added to only one of the stock preparation step and the surface treatment step, with Example 1, the wet strength was found to be significantly lower than 6.0 kgf.

In addition, according to the results of Comparative Examples 3 to 5 using softwood fibers instead of linter cotton fibers and Comparative Examples 6 to 8 using hardwood fibers, both bulk and wet strength properties were found to be poor.

Although described above with reference to the limited embodiments and drawings, these are only examples, and it will be apparent to those skilled in the art that various modifications and implementations are possible within the scope of the technical idea of the present invention. Therefore, the protection scope of the present invention should be determined by the description of the claims and their equivalents.

Claims (10)

As a method for manufacturing paper for making paper straws,
Beating linter cotton pulp;
preparing a stock by adding a first amount of a wet strength enhancer;
Preparing base paper using the prepared stock;
Surface treating the base paper using a surface treatment agent containing a second added amount of a wet strength enhancer;
including,
The second addition amount is a paper manufacturing method for manufacturing paper straws, characterized in that 1.2 ~ 2wt%. According to claim 1,
In the step of beating, 100% linter cotton pulp is used. According to claim 1,
The first addition amount is 0.5 ~ 1.5wt% Paper manufacturing method for manufacturing paper straws, characterized in that. delete According to claim 1,
Paper for manufacturing paper straws, characterized in that the wet strength enhancer added in the stock preparation step and the surface treatment step is a PAE resin. According to claim 1,
Paper manufacturing method for making paper straws, characterized in that in the beating step, beating to a beating degree in the range of 40 to 55 ^o SR. Claims 1 to 3, 5 and 6, wherein the paper for manufacturing a paper straw manufactured according to any one of claims. According to claim 7,
Paper for making paper straws, characterized in that the bulk is 1.3 cm 3 / g or more. According to claim 7,
Paper for making paper straws, characterized in that the wet strength is 6.0 kgf or more at a basis weight of 150 g / m 2. Paper straws made of the paper of claim 7.

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