CN115075041B

CN115075041B - High-air-permeability paper bag paper and preparation method and application thereof

Info

Publication number: CN115075041B
Application number: CN202210538092.3A
Authority: CN
Inventors: 杨仁党; 李海秋
Original assignee: South China University of Technology SCUT
Current assignee: South China University of Technology SCUT
Priority date: 2022-05-18
Filing date: 2022-05-18
Publication date: 2023-06-20
Anticipated expiration: 2042-05-18
Also published as: CN115075041A

Abstract

The invention relates to the technical field of stretchable paper bag paper processing, and discloses high-air-permeability paper bag paper, and a preparation method and application thereof. The method comprises the following steps: pretreating softwood pulp to obtain pretreated pulp, adding the pretreated pulp into water, pulping for multiple sections to obtain pulp, mixing the pulp with polyester fibers for papermaking, and carrying out pressurized drying to obtain the paper bag paper with high air permeability, wherein the polyester fibers account for 5% -20% of the absolute dry pulp of the paper bag paper. According to the invention, 5-20% of polyester fibers are added, so that the air permeability is greatly improved under the condition of ensuring good physical properties such as tensile index, and the air permeability can reach 28-47 mu m/Pa.s, and is improved by 320% compared with paper without polyester, so that a new thought is provided for paper bag paper production, and the paper bag paper has certain market value and good application prospect.

Description

High-air-permeability paper bag paper and preparation method and application thereof

Technical Field

The invention relates to the technical field of stretchable paper bag paper processing, in particular to high-air-permeability paper bag paper and a preparation method and application thereof.

Background

Paper bag paper is one of the most common packaging materials in life, and is widely applied in the fields of cement, chemical fertilizers and the like, and a cement packaging factory mostly adopts a rapid filling mode in the process of packaging cement, so that the cement bag is required to have good physical properties such as tensile index, tearing index and the like, and simultaneously has high air permeability. Higher air permeability is favorable to improving cement packaging manufacturer production efficiency, guarantees the balance of inside and outside atmospheric pressure of packing, prevents to break the package, and the condition that the package is expanded exists, and current cement wrapping bag is overlapped by two-layer paper and is formed, and the inlayer adopts high permeable paper, and the outer mode that adopts ordinary stretching paper to make the tiny hole on the paper surface through mechanical punching improves the air permeability, and mechanical punching can cause the loss to the structural strength of paper bag paper, and current high permeable paper is imported mostly, and is with high costs.

The polyester fiber has other excellent performances such as good affinity with plant fiber and extremely high cost performance, so that the polyester fiber is widely applied to the paper industry. However, the common polyester staple fibers have poor hydrophilicity due to lack of hydrophilic groups, have general dispersibility in water, are easy to flocculate and deposit in the process of mixing and fluffing with plant fibers, and finally lead to uneven dispersion of the fibers of the paper manufactured by the paper manufacturing process. Chinese patent CN109440533B discloses a method for producing high-permeability paper by utilizing bamboo pulp, which comprises the steps of mixing wood chips and needle-leaf wood, steaming, pulping, screening and forming to obtain the high-permeability paper, wherein the air permeability of the paper reaches 10.8-14.2 mu m/Pa.s, the process is complex, and the air permeability is low. Therefore, the novel process mode is provided, and the air permeability of the paper bag paper can be greatly improved.

Disclosure of Invention

Aiming at the defects and shortcomings of the prior art, the primary purpose of the invention is to provide a preparation method of paper bag paper with high air permeability.

Another object of the present invention is to provide a high air permeability paper bag sheet prepared by the above method.

It is a further object of the present invention to provide the use of the above-described high air permeability paper bag in packaging materials.

The aim of the invention is achieved by the following technical scheme:

a preparation method of high-air-permeability paper bag paper comprises the following steps:

(1) Pretreating softwood pulp to obtain pretreated pulp;

(2) Mixing the pretreated pulp with water, pulping for multiple segments to obtain pulp, mixing the pulp with polyester fiber for papermaking, and carrying out pressurized drying to obtain paper bag paper with high air permeability;

the polyester fiber in the step (2) accounts for 5% -20% of the mass of the paper bag paper absolute dry pulp.

Preferably, in the step (2), the multi-stage pulping is that medium consistency pulping is carried out to 15-18 DEG SR, and then low consistency pulping is carried out to 20-25 DEG SR; the polyester fiber in the step (2) accounts for 5-10% of the mass of the paper bag paper absolute dry pulp.

Preferably, the concentration of the medium-concentration beating slurry in the step (2) is 10% -12%, and the concentration of the low-concentration beating slurry is 4% -6%.

Preferably, the medium consistency pulp concentration in step (2) is 10% and the low consistency pulp concentration is 6%.

Preferably, the titer of the polyester fiber in the step (2) is 1.5 d-5 d, and the length is 3 mm-6 mm.

Preferably, the pretreatment of step (1) comprises the steps of: fully soaking softwood pulp in water, dispersing into blocks, fluffing to disperse interwoven fiber bundles into single fibers, sieving, filtering, squeezing to remove water, and balancing water;

the length of the block is 20 mm-25 mm, the width is 20 mm-25 mm, the untwining revolution is 800 rpm-1200 rpm, and the balance moisture is placed in a freezer at the temperature of minus 4 ℃ to 4 ℃ for 24 h-48 h.

Preferably, the softwood pulp of step (1) is unbleached softwood pulp; and (3) drying under the pressure of 0.5-10 MPa for 5-10 min, wherein the drying temperature is 80-90 ℃.

Preferably, the full soaking time of the softwood pulp with water is 1-3 h, and the mass volume ratio g/L of the softwood pulp to the water is 1:25, wherein the papermaking is a Kaiser papermaking.

A paper bag paper with high air permeability is prepared by the method.

The paper bag paper with high air permeability is applied to packaging materials.

Compared with the prior art, the invention has the following advantages and beneficial effects:

(1) According to the invention, the polyester fiber and the plant fiber are added to mix to make paper, so that the good physical properties of the paper such as tensile index, burst index and the like are ensured, the air permeability of the paper can be improved, and the production requirement of high-permeability paper is met.

(2) The mode of mixing the polyester fiber and the plant fiber has the advantages of lower operation difficulty in actual production, simple process, lower energy consumption, better effect and certain production practice significance.

(3) By adding 5-10% of polyester fiber, the air permeability is greatly improved on the basis of ensuring good physical properties such as tensile index, elongation and the like. The air permeability of the paper can reach 28-47 mu m/Pa.s, which is improved by 320% compared with the paper without terylene.

Drawings

Fig. 1 is an SEM image of the polyester paper added in example 1.

Fig. 2 is an SEM image of comparative example 1 without polyester paper.

Detailed Description

The present invention will be described in further detail with reference to examples, but embodiments of the present invention are not limited thereto.

Example 1

(1) Taking 30g of unbleached softwood pulp, soaking the unbleached softwood pulp in 0.5L of water for 1h at room temperature, tearing the soaked paper pulp into 25 mm-25 mm small pieces, putting the pulp into a pulp fluffer for fluffing, starting a motor to enable a stirrer to start rotating, dispersing interwoven fibers or fiber bundles into single fibers through the dissociation, sieving, filtering, and squeezing out water. The mixture is placed in a freezer for 24 hours at the temperature of minus 4 ℃ to balance the water.

(2) Adding water to 300g of prepared pulp, pulping in a PFI (pulse frequency reactor) pulping machine, medium-consistency pulping (pulp consistency is 10%) to 18 DEG SR, low-consistency pulping (pulp consistency is 6%) to 20 DEG SR, mixing and defibering the absolute dry pulp corresponding to 95% and the polyester fiber of 5%, stirring the pulp by adding water through an automatic Kaiser papermaking system, sieving, filtering, and automatically forming. The radius of the paper sheet is 10cm, the paper sheet is dried for 8min under the pressure of 0.8MPa at 90 ℃ to obtain the base paper, and the polyester fiber accounts for 5% of the absolute dry pulp mass of the paper bag paper, and an SEM image is shown in figure 1.

Example 2

(2) Adding water to 300g of prepared pulp, pulping in a PFI (pulse frequency reactor) pulping machine, medium-consistency pulping (pulp consistency is 10%) to 18 DEG SR, low-consistency pulping (pulp consistency is 6%) to 20 DEG SR, mixing and defibering the absolute dry pulp which is 90% with 10% of polyester fibers, adding water to stir the pulp by an automatic Kaiser papermaking system, sieving, filtering, and automatically forming. The radius of the paper sheet is 10cm, and the paper sheet is dried for 8min under the pressure of 0.8MPa at 90 ℃ to obtain the base paper, wherein the polyester fiber accounts for 10% of the absolute dry pulp mass of the paper bag paper.

Comparative example 1

This comparative example is based on the preparation of example 1, with the difference that: polyester is not added.

Comparative example 2

This comparative example is based on the preparation of example 1, with the difference that: the adding amount of the terylene reaches 20 percent.

Comparative example 3

This comparative example is based on the preparation of example 1, with the difference that: no polyester was added and only low consistency beating was performed to 20 ° SR.

Comparative example 4

This comparative example is based on the preparation of example 1, with the difference that: polyester is not added and only high consistency beating is carried out to 20 DEG SR.

Examples 1 to 2 and comparative examples 1 to 4 were tested, and the test results obtained are shown in table 1:

the test result shows that compared with the method for pulping only by low-consistency and medium-consistency, the method for combining the low-consistency and medium-consistency has better overall performance of the finished paper. With the increase of the adding amount of the polyester fiber, the air permeability of the paper is obviously improved, and when the adding amount of the polyester fiber is 10%, the air permeability of the paper is improved by 320% compared with the paper without the polyester fiber (comparative example 1). When the addition amount of terylene exceeds 10%, the tensile index, the elongation and other physical properties of the finished paper are greatly reduced, and the requirements of national superior products are not met.

From fig. 1 and 2, it can be seen that the fibers on the surface of the base paper are adhered to each other and are tightly combined. After the polyester fibers are added, the plant fibers are adhered to the polyester fibers, and the adhesion between the plant fibers and the polyester fibers is less. After terylene is added, the size and the number of pores on the surface of the paper are greatly improved, so that the gaps in the plant fiber reticular framework are more, and the improvement of air permeability is finally promoted.

TABLE 1 Performance test results

The above examples are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above examples, and any other changes, modifications, substitutions, combinations, and simplifications that do not depart from the spirit and principle of the present invention should be made in the equivalent manner, and the embodiments are included in the protection scope of the present invention.

Claims

1. The preparation method of the paper bag paper with high air permeability is characterized by comprising the following steps:

(1) Pretreating softwood pulp to obtain pretreated pulp;

(2) Adding the pretreated pulp into water, pulping for multiple segments to obtain pulp, mixing the pulp with polyester fibers for papermaking, and carrying out pressurized drying to obtain paper bag paper with high air permeability;

the multi-stage pulping in the step (2) is to perform medium consistency pulping to 15-18 DEG SR, and then perform low consistency pulping to 20-25 DEG SR;

the adding amount of the polyester fiber in the step (2) accounts for 5% -10% of the mass of the absolute dry pulp of the paper bag paper;

the concentration of the medium-concentration pulping slurry in the step (2) is 10% -12%, and the concentration of the low-concentration pulping slurry is 4% -6%.

2. The method for producing high air permeability paper bag according to claim 1, wherein the medium consistency pulp in step (2) is 10% and the low consistency pulp is 6%.

3. The method for preparing the high-air-permeability paper bag paper according to claim 1 or 2, wherein the fineness of the polyester fiber in the step (2) is 1.5 d-5 d, and the length is 3 mm-6 mm.

4. The method for producing high air permeability paper bag according to claim 1, wherein the pretreatment in step (1) comprises the steps of:

fully soaking softwood pulp, dispersing into blocks, fluffing to disperse the interweaved fiber bundles into single fibers, sieving, filtering, squeezing to remove water, and balancing the water; the fluffing revolution is 800-1200 rpm, the blocks are 20-25 mm 20-25 mm, and the balance moisture is placed in a freezer at-4 ℃ for 24-48 hours.

5. The method for producing high air permeability paper bag according to claim 1, wherein:

the softwood pulp in the step (1) is unbleached softwood pulp;

and (2) drying under the pressure of 0.5-1.0 MPa for 5-10 min, wherein the drying temperature is 80-90 ℃.

6. A high air permeability paper bag, characterized in that it is produced by the method according to any one of claims 1 to 5.

7. Use of the high air permeability paper bag according to claim 6 in packaging materials.