KR101210810B1 - Paperboard with increased bulk comprising fly ash powder and cationic starch, and process for preparing the same - Google Patents

Abstract

The present invention relates to a bulk increased cardboard containing fly ash powder and cationic starch and a method for producing the same. The cardboard according to the present invention can improve the bulk of the cardboard by minimizing the decrease in tensile strength by increasing the spacing between the fibers by adding fly ash powder or surface pretreated fly ash powder and cationic starch to the cardboard interlayer or filler layer. In addition, when the production of cardboard of the same thickness can reduce the amount of raw materials used to reduce the cost, the drying energy can also be reduced by reducing the amount of used paper.

Description

Paperboard with increased bulk comprising fly ash powder and cationic starch, and process for preparing the same}

The present invention relates to a bulk increased cardboard containing fly ash powder and cationic starch and a method for producing the same.

Cardboard is manufactured in the form of laminated paper of several layers due to the efficient use of raw materials and the dehydration of papermaking processes. In other words, after diluting natural and recycled pulp in water, natural pulp undergoes a mechanical grinding process such as a refining millstone to increase the strength of the paper, and recycled pulp does not undergo refining. In some cases refining and dispersing may be necessary. Mechanical and natural pulp and recycled pulp are added with additives such as retention agents and sizing agents, respectively, and put into paper-making processes called paper machines. At this time, natural pulp and recycled pulp are not mixed but are used as a raw material for each layer of cardboard. The paper machine for manufacturing paperboard, unlike the paper machine for printing printing paper, manufactures a plurality of layers of paper and stacks the paper on a couch roll. The wet paper pill is compressed and dried to make cardboard, and the base paper formed through this papermaking process is surface-treated or coated with a coating machine called a size press.

The raw materials used for paperboard are largely divided into natural pulp and recycled pulp, and various kinds of recycled pulp are composed of OCC (old corrugated container), DIP (deinking pulp), and OMG (old magazine). These recycled pulp has a finer content than natural pulp, which not only reduces dehydration but also swells, thereby reducing the bulk and strength of the paper. In particular, the drop in bulk increases the amount of pulp used in the manufacturing process of cardboard, thereby increasing the production cost. In addition, in the case of regenerated pulp, the number of reuse increases, the ability to contain water is increased, the drying energy is increased. Therefore, it is thought that increasing the bulk of the cardboard not only reduces the amount of recycled pulp, but also helps to reduce dry energy.

On the other hand, fly ash (fly ash) is a by-product of the oscillation tank generated after coal combustion in a coal-fired power plant is composed of fine powder-type particles that are shredded in the dust collector. Fly ash has pozzolanicity in the form of alumino silica-based spherical particles due to its chemical / physical properties, and thus the filler has properties of an insoluble compound when dried. In addition, fly ash is produced at three thermal power plants in Korea, so supply is smooth, and it is relatively cheaper than natural or recycled pulp, so it can be easily used as an auxiliary material in the manufacturing process of cardboard (natural pulp price). : About 1,000 ~ 1,200 won / kg, recycled pulp price: about 200 ~ 400 won / kg, fly ash price: about 30 ~ 50 won / kg). However, despite the advantages of fly ash as described above, fly ash is not utilized and is being discarded.

In general, fly ash is distributed in the form of spherical particles. Therefore, when fly ash is mixed with natural pulp or recycled pulp to be used as a raw material for cardboard, the thickness of the paper can be improved, and the adsorption between fly ash particle fibers As a result, it is believed that the bulk can be increased by maintaining the voids between fibers when dried. Therefore, if paper is manufactured using fly ash that is not being used and discarded, it is considered to be very useful in terms of cost reduction.

However, when the fly ash is simply added to the pulp slurry during paper manufacturing, the fly ash does not settle in the fibers and is pulled out with the water in the papermaking process so that the retention of the fly ash is reduced, and the fly ash is paper If it is distributed inside, there is a problem that the strength of the paper is lowered.

Therefore, it is required to develop a cardboard that can compensate for this to increase the bulk and minimize the decrease in strength.

While the present inventors have been researching a method for increasing the bulk of the paperboard and minimizing the strength degradation, the paperboard was prepared by adding the flyash powder or the surface pretreated flyash powder together with the positive starch to the paperboard intermediate layer or the filler layer. When the bulk of the paperboard is confirmed that the increase in strength is minimized, to complete the present invention.

The present invention relates to a bulk increased cardboard containing fly ash powder and cationic starch and a method for producing the same.

1 is a view showing a schematic manufacturing process of the cardboard according to the present invention.
2 is a view showing the bulk change of the cardboard according to the dosage of the fly ash powder.
Figure 3 is a view showing the change in tensile strength of the cardboard according to the amount of fly ash powder.

The present invention provides a bulk increased paperboard containing 0.1 to 15% by weight of fly ash powder or surface pretreated fly ash powder, and 0.01 to 2% by weight of positive starch, relative to dry paper weight.

In addition,

1) precipitating the pulp in water and then dissociating it,

2) preparing a wetland by adding fly ash powder or surface pretreated fly ash powder, cationic starch and retention agent to the dissociated stock, and

3) provides a method for producing a bulk paperboard, including the step of manufacturing the paperboard by pressing, dewatering and drying the wetlands prepared above.

Hereinafter, the present invention will be described in detail.

The bulk paper of the present invention is characterized by containing the fly ash powder or surface pre-treated fly ash powder 0.1 to 15% by weight based on the weight of the dry stock, and the starch containing 0.01 to 2% by weight relative to the weight of the dry stock do.

The bulk paperboard of the present invention is produced by the following method. First, the pulp is precipitated in water for 15-20 hours and then dissociated. For the manufacture of paperboard, the dissociated stock is diluted to 0.1 ~ 1.0% concentration. The pulp is HW-BKP (hard wood bleached kraft pulp), SW-BKP (soft wood bleached kraft pulp), BCTMP (bleached chemi thermo mechanical pulp), OCC (old corrugated container), DIP (deinking pulp), OMG (old) magazine) and the like, but are not limited thereto.

The fly ash powder is added in an amount of 0.1 to 15% by weight, preferably 1 to 10% by weight, and 0.01 to 2% by weight of the dry starch, preferably 0.1 to 1% of the fly ash powder. After adding 1% by weight, the retention agent is added in an amount of 0.01 to 0.5% by weight based on the weight of the dry stock to prepare the wetland using a weeding machine. The wetlands are compressed, dehydrated and dried to produce cardboard.

The fly ash powder may be used by pretreating the fly ash surface using amphoteric starch. Specifically, the cationic starch gelatinized in a fly ash slurry diluted to 20 to 50% is charged at 0.1 to 1% by weight based on the dry fly ash weight to pretreat the fly ash surface.

As said retention agent, polyacrylamide or starch is preferable.

The manufactured fly ash powder or surface pretreated fly ash powder and the cardboard containing the positive starch increases the bulk of the fly ash powder, the bulk increases and minimizes the decrease in tensile strength.

As described above, the cardboard according to the present invention can improve the bulk of the cardboard by increasing the spacing between the fibers by adding fly ash powder or surface pretreated fly ash powder and cationic starch to the cardboard interlayer or filler layer and the tensile strength of The reduction can be minimized, and the cost of raw materials can be reduced by producing cardboard of the same thickness, and the drying energy can be saved as the amount of used paper is reduced.

Hereinafter, preferred embodiments of the present invention will be described in order to facilitate understanding of the present invention. However, the following examples are provided only for the purpose of easier understanding of the present invention, and the present invention is not limited by the examples.

Example 1  : Preparation of cardboard containing 3% by weight of fly ash powder and cationic starch

The fillers used in this study were fly ash from thermal power plants in Hadong, Boryeong, and Seosan.

1. Manufacture of stock

The Korean Old Corrugated Container (KOCC) was precipitated in water for 18 hours and then dissociated at 2 kg (total weight of KOCC and water) and 10% concentration in a disintegrator for about 30 minutes. After confirming that the fibers were completely dispersed without clumping, it was used as a stock. In the manufacture of paperboard, the dissociated stock was diluted to a concentration of 0.65%.

2. Manufacture of cardboard

Fly ash powder was added to 927 g of 0.65% of the feed stock at 3% by weight (0.1875 g) relative to the weight of the dry stock and stirred for 150 seconds. Then, 0.5% by weight (6 g) of the positive starch was added to the dry stock, followed by 60 seconds. Was stirred. Next, TAPPI Test Method was prepared by using a laboratory waterweed machine (Kumagai) having an area of 25 × 25 cm2 and adding C-PAM (cationic polyacrylamide), which is a retention agent, at 0.1% by weight (6.25g) based on the weight of the dry paper. Wetlands were prepared according to T205 sp-02. The wetland was compressed and dehydrated at 3.5 kg / cm 2 for 5 minutes and then dried in a laboratory cylinder dryer to prepare a cardboard having a basis weight of 100 ± 5 g / m 2. At this time, the moisture content of the cardboard was about 8%. Stirring was carried out at 600 rpm for mixing the raw materials in all the process of manufacturing the cardboard.

A schematic manufacturing process of the cardboard according to the present invention is shown in FIG.

Example 2  : Preparation of cardboard containing 6% by weight of fly ash powder and cationic starch

In the same manner as in Example 1 except that fly ash powder was used in 6% by weight (0.375 g) instead of 3% by weight (0.1875 g), and 5.8 g of positive starch was used instead of 6 g. A cardboard of 100 ± 5 g / m 2 was prepared.

Example 3  : Manufacturing cardboard containing 9% by weight of fly ash powder and cationic starch

In the same manner as in Example 1 except that fly ash powder was used in 9% by weight (0.5625g) instead of 3% by weight (0.1875g), and 5.6g of positive starch was used instead of 6g. A cardboard of 100 ± 5 g / m 2 was prepared.

Example 4  : Preparation of cardboard containing 3% by weight of fly ash powder surface-treated with cationic starch and cationic starch

1. Manufacture of stock

The Korean Old Corrugated Container (KOCC) was precipitated in water for 18 hours and then dissociated at 2 kg (total weight of KOCC and water) and 10% concentration in a disintegrator for about 30 minutes. After confirming that the fibers were completely dispersed without clumping, it was used as a stock. In the manufacture of paperboard, the dissociated stock was diluted to a concentration of 0.65%.

2. Pretreatment of Fly Ash Surface Using Cationic Starch

The cationic starch, pregelatinized in a fly ash slurry diluted to 30%, was added at 0.5% by weight (6 g) relative to the dry fly ash weight and stirred at 600 rpm. The fly ash surface was pretreated.

3. Manufacture of cardboard

The surface pretreated fly ash powder was added to 927 g of 0.65% of the feed stock at 3% by weight (0.625 g) based on the weight of the dry paper, stirred for 150 seconds, and 0.5 wt% (5.99 g) of the positive starch was added to the dry paper. Charged and stirred for 60 seconds. Next, TAPPI Test Method was prepared by using a laboratory waterweed machine (Kumagai) having an area of 25 × 25 cm2 and adding C-PAM (cationic polyacrylamide), which is a retention agent, at 0.1% by weight (6.25g) based on the weight of the dry paper. Wetlands were prepared according to T205 sp-02. The wetland was compressed and dehydrated at 3.5 kg / cm 2 for 5 minutes and then dried in a laboratory cylinder dryer to prepare cardboard having a basis weight of 100 ± 5 g / m 2. At this time, the moisture content of the cardboard was about 8%. Stirring was carried out at 600 rpm for mixing the raw materials in all the process of manufacturing the cardboard.

Example 5  : Preparation of cardboard containing 6% by weight of fly ash powder surface-treated with cationic starch and cationic starch

In the same manner as in Example 4 except that fly ash powder was used in 6 wt% (1.25 g) instead of 3 wt% (0.625 g) and 5.79 g of positive starch was added instead of 5.99 g in Example 4. Cardboard having a basis weight of 100 ± 5 g / m 2 was prepared.

Example 6  : Preparation of cardboard containing 9% by weight of fly ash powder surface-treated with cationic starch and cationic starch

In the same manner as in Example 4 except that fly ash powder was used in 9 wt% (1.875 g) instead of 3 wt% (0.625 g) and 5.5 g of positive starch was added instead of 5.99 g in Example 4. Cardboard having a basis weight of 100 ± 5 g / m 2 was prepared.

Comparative Example 1  : Preparation of cardboard containing only 3% by weight of fly ash powder without cationic starch

Except that the positive starch was not used in Example 1, a cardboard having a basis weight of 100 ± 5 g / ㎡ was prepared in the same manner as in Example 1.

Comparative Example 2  : Preparation of cardboard containing only 6% by weight of fly ash powder without amphoteric starch

Except that no positive starch was used in Example 2, a cardboard having a basis weight of 100 ± 5 g / ㎡ was prepared in the same manner as in Example 2.

Comparative Example 3  : Preparation of cardboard containing no starch and only 9% by weight of fly ash powder

Except that the positive starch was not used in Example 3, a cardboard having a basis weight of 100 ± 5 g / ㎡ was prepared in the same manner as in Example 3.

Experimental Example 1  : Measurement of physical properties of cardboard

The cardboard prepared in Examples 1 to 6 and Comparative Examples 1 to 3 was subjected to a humidity treatment (T 402 sp-98) at 23 ° C. and 50% RH, and then soft rolled on a super calendar, 0.15 × 100 (weight of roll ) and passed twice with kN pressure. Bulk was calculated by measuring the basis weight (T 410 om-98) and the thickness (T 411 om-97) of the cardboard according to the TAPPI Test Methods (bulk = thickness / base weight). In addition, the tensile strength (T 494 om-01) was measured.

The bulk change and tensile strength change of the paperboard according to the amount of fly ash powder is shown in FIGS. 2 and 3, respectively.

As shown in Figures 2 and 3, the cardboard containing the fly ash powder and cationic starch of Examples 1 to 6 and the cardboard containing only the fly ash powder of Comparative Examples 1 to 3 is bulk as the dosage of the fly ash powder increases Increased. In addition, the cardboard containing only the fly ash powder of Comparative Examples 1 to 3 significantly decreased the tensile strength, but the cardboard containing the fly ash powder and the positive starch of Examples 1 to 6 minimized the decrease in tensile strength.

The cardboard according to the present invention can improve the bulk of the cardboard by increasing the spacing between the fibers by adding fly ash powder or surface pretreated fly ash powder and cationic starch to the cardboard interlayer or filler layer can minimize the decrease in tensile strength In addition, when the production of cardboard of the same thickness can reduce the amount of raw materials used to reduce the cost, the drying energy can also be reduced by reducing the amount of used paper.

Claims (7)

A paperboard containing 0.1-15% by weight of the surface pretreated fly ash powder, and 0.01-2% by weight of the amphoteric starch, based on the weight of the dry stock, wherein the surface pretreated flyash powder is coated in a fly ash slurry. A bulk increased paperboard, characterized in that pretreated by adding the prepared positive starch at 0.1 to 1% by weight based on the weight of the dry fly ash.
delete 1) precipitating the pulp in water and then dissociating it,
2) to prepare the wetland by adding the pre-treated fly ash powder, the positive starch and the retention agent by adding 0.1 ~ 1% by weight of the cationic starch gelatinized to the fly ash slurry to the dissociated material. Steps, and
3) A method of manufacturing a cardboard with an increased bulk according to claim 1, comprising the step of pressing, dewatering and drying the manufactured wetland to produce a cardboard.
delete The method of claim 3, wherein the surface of the fly ash powder pre-treated in the step 2) is contained in 0.1 to 15% by weight based on the weight of the dry paper. 4. The method of claim 3, wherein the positive starch in step 2) is contained in an amount of 0.01 to 2% by weight based on the weight of the dry paper. 4. The method of claim 3, wherein the retention agent in step 2) is contained in an amount of 0.01 to 0.5% by weight based on the weight of the dry paper.

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