Process for improving ring crush compression resistance of corrugated paper

Abstract

The invention discloses a process for improving ring crush compression resistance of corrugated paper, which is characterized in that a reinforcing agent is added into raw materials, and the reinforcing agent is a mixture of carboxymethyl starch, polyvinyl alcohol, polyacrylic acid and synthetic fibers, so that the ring crush compression resistance of the prepared corrugated paper is improved to a certain extent compared with that of an existing product, and the corrugated paper has higher stability in use; repeated utilization can be achieved, and the use cost is reduced. Meanwhile, according to the scheme, the water absorption performance of the corrugated paper is also obviously improved by selecting the coating.

Description

Technical Field

[0001] The invention relates to the technical field of corrugated paper processing, and more specifically to a process for improving the ring compression strength of corrugated paper. Background Art

[0002] Corrugated paper is a board-shaped material made of noodle paper and corrugated paper formed by corrugating rollers. It usually consists of two layers of flat paper and one layer of corrugated paper core. With its superior performance and good processing performance, corrugated boxes have gradually replaced wooden boxes and other transport packaging containers and become the main force of transport packaging. In addition to protecting goods and facilitating storage and transportation, it also plays a role in beautifying and promoting goods.

[0003] The ring crush strength (RCS) of corrugated paper is an important indicator to measure the pressure resistance of corrugated paper. It is usually used to evaluate the ability of corrugated paper to withstand vertical loads in a stacked state. The type and quality of raw materials will directly affect the ring crush strength. At present, in the process flow of the papermaking industry, the strength of the paper is usually improved by adding a ring crush enhancer. At present, the commonly used corrugated paper ring crush enhancer is made of starch and starch oxidant, but this implementation method still has the following problems: the effect of increasing the ring pressure is not very obvious, and the ring crush strength and stiffness of the finished paper are not high. At the same time, the moisture resistance of corrugated paper is also an important factor affecting the ring crush strength and stability of strong corrugated paper. Therefore, how to solve the problems of low ring crush strength and low stiffness of high-strength corrugated paper has become a problem that needs to be solved urgently. Summary of the invention

[0004] The purpose of the present invention is to provide a process for improving the ring compression strength of corrugated paper, so as to solve the technical problems existing in the above-mentioned background technology.

[0005] The technical solution of the present invention provides a process for improving the ring compression strength of corrugated paper, comprising the following steps:

[0006] S1: Select waste paper and put it into a pulper for crushing, and soak it in water for 2-5 hours. Use a pulper to stir the soaked paper pieces into slurry, then use a pulper to further refine the pulp, and then pass through a filter to remove impurities to obtain pure pulp;

[0007] S2: The prefabricated material is concentrated by a concentrator to remove excess water, so as to obtain a concentrated slurry with a water content of 20-35%;

[0008] S3: adding the following auxiliary materials in percentage by weight of the total raw materials to the pulp obtained in S2, specifically: 5-8% filler, 2-3% reinforcing agent, 0.2-0.5% adhesive, 0.2-0.5% moisture-proof agent, and then stirring and mixing by a mixer to obtain a prefabricated material;

[0009] S4: The preform is fed into a paper machine and further dehydrated by a press roller to form a wet paper sheet with a moisture content of 12-15%, and then dried by a dryer to a dry paper with a moisture content of 4-6%;

[0010] S5: heating the dried paper by a heating roller to obtain a flat paper, then pressing the heated paper by a corrugating roller to form a corrugated structure, and then cooling it to room temperature by a cooling roller to obtain a corrugated paper core structure;

[0011] S6: gluing a piece of flat paper on both sides of the corrugated paper core to obtain prefabricated corrugated paper;

[0012] S7: spraying a waterproof coating on the exterior of the prefabricated corrugated paper, and drying the coating to obtain the corrugated paper.

[0013] In a preferred embodiment, the stirring speed of the stirrer in S2 is 1000-1300 r / min, and the stirring time is 45-60 min.

[0014] In a preferred embodiment, the filler is a mixture of calcium carbonate and kaolin, and the mass ratio of calcium carbonate to kaolin is 1:(2-5).

[0015] In a preferred embodiment, the reinforcing agent is a mixture of carboxymethyl starch, polyvinyl alcohol, polyacrylic acid and synthetic fiber, and the mass ratio of carboxymethyl starch, polyvinyl alcohol, polyacrylic acid and synthetic fiber is 2:(1-2):1:(6-8).

[0016] In a preferred embodiment, the preparation steps of the synthetic fiber are: crushing the dry wood, and then gradually pressurizing the crushed fibers to 20-30MPa, and then releasing the pressure instantly to obtain prefabricated fibers; spraying water glass curing agent and water glass solution that has been atomized on the prefabricated fibers under vacuum to obtain moist and loose treated fibers; gradually reducing the vacuum degree of the treated fibers, and when the treated fibers are under normal pressure, gradually pressurizing the treated fibers to 5-20MPa, stirring for 30-60 minutes, and then drying to a moisture content of 3% to obtain synthetic fibers.

[0017] In a preferred embodiment, the adhesive is polyurethane adhesive, and the moisture-proof agent is silicone.

[0018] In a preferred embodiment, the temperature of the heating roller in S5 is 120-140°C, the heating time is 10-20s, the pressure of the corrugated roller is 1-3 tons / meter, and the surface temperature of the cooling roller is 5-25°C.

[0019] In a preferred embodiment, the maximum distance between two adjacent corrugations of the corrugation roller in S5 is 0.5-1 cm, and the corrugation height is 0.5-1 cm.

[0020] In a preferred embodiment, the waterproof coating in S7 is one of polyethylene (PE), polyurethane, and acrylic acid.

[0021] The beneficial effects of the technical solution of the present invention are:

[0022] In the papermaking industry, the ring crush index is usually used for comparison in order to facilitate comparison. The ring crush index is the ring crush strength divided by the quantitative weight of the paper. When the quantitative weight of the paper is the same, the larger the ring crush index, the greater the ring crush strength. From the above results, it can be seen that by adding a reinforcing agent to the raw materials, and the reinforcing agent is a mixture of carboxymethyl starch, polyvinyl alcohol, polyacrylic acid and synthetic fibers, the ring crush strength of the corrugated paper obtained has a certain commission compared with the existing products, so that the corrugated paper has a higher stability in use, can be reused, and reduce the cost of use. At the same time, through the selection of coatings, this solution also significantly improves the water absorption performance of corrugated paper. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below. The embodiments of the present invention are provided for the purpose of illustration and description, and are not intended to be exhaustive or to limit the present invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described to better illustrate the principles and practical applications of the present invention, and to enable those of ordinary skill in the art to understand the present invention and design various embodiments with various modifications suitable for specific uses.

[0024] Example 1

[0025] The technical solution of the present invention provides a process for improving the ring compression strength of corrugated paper, comprising the following steps:

[0026] S1: Select waste paper and put it into a pulper for crushing, and soak it in water for 2 hours. Use a pulper to stir the soaked paper pieces into slurry, then use a pulper to further refine the pulp, and then pass through a filter to remove impurities to obtain pure pulp;

[0027] S2: The prefabricated material is concentrated by a concentrator to remove excess water, thereby obtaining a concentrated slurry with a water content of 20%;

[0028] S3: adding the following auxiliary materials in percentage by weight of the total raw materials to the pulp obtained in S2, specifically: 5% filler, 2% reinforcing agent, 0.2% adhesive, 0.2% moisture-proof agent, and then stirring and mixing by a mixer to obtain a prefabricated material;

[0029] S4: The preform is fed into a paper machine and further dehydrated by a press roller to form a wet paper sheet with a moisture content of 12%, and then dried by a dryer to form a dry paper with a moisture content of 4%;

[0030] S5: heating the dried paper by a heating roller to obtain a flat paper, then pressing the heated paper by a corrugating roller to form a corrugated structure, and then cooling it to room temperature by a cooling roller to obtain a corrugated paper core structure;

[0031] S6: gluing a piece of flat paper on both sides of the corrugated paper core to obtain prefabricated corrugated paper;

[0032] S7: spraying a waterproof coating on the exterior of the prefabricated corrugated paper, and drying the coating to obtain the corrugated paper.

[0033] The stirring speed of the stirrer in S2 is 1000 r / min, and the stirring time is 45 min.

[0034] The filler is a mixture of calcium carbonate and kaolin, and the mass ratio of the calcium carbonate to the kaolin is 1:2.

[0035] The reinforcing agent is a mixture of carboxymethyl starch, polyvinyl alcohol, polyacrylic acid and synthetic fiber, and the mass ratio of the carboxymethyl starch, polyvinyl alcohol, polyacrylic acid and synthetic fiber is 2:1:1:6.

[0036] The preparation steps of the synthetic fiber are as follows: crushing dry wood, then gradually pressurizing the crushed fibers to 20MPa, and then releasing the pressure instantly to obtain prefabricated fibers; spraying a water glass curing agent and a water glass solution that has been atomized on the prefabricated fibers under vacuum to obtain moist and loose treated fibers; gradually reducing the vacuum degree of the treated fibers, and when the treated fibers are under normal pressure, gradually pressurizing the treated fibers to 5MPa, stirring for 30 minutes, and then drying to a moisture content of 3% to obtain synthetic fibers.

[0037] The adhesive is polyurethane glue, and the moisture-proof agent is silica gel. The temperature of the heating roller in S5 is 120°C, the heating time is 10s, the pressure of the corrugated roller is 1 ton / m, and the surface temperature of the cooling roller is 5°C. The maximum spacing between two adjacent corrugations of the corrugated roller in S5 is 0.5-1cm, and the corrugation height is 0.5cm. The waterproof coating in S7 is polyethylene (PE).

[0038] Example 2

[0039] The technical solution of the present invention provides a process for improving the ring compression strength of corrugated paper, comprising the following steps:

[0040] S1: Select waste paper and put it into a pulper for crushing, and soak it in water for 5 hours. Use a pulper to stir the soaked paper pieces into slurry, then use a pulper to further refine the pulp, and then pass through a filter to remove impurities to obtain pure pulp;

[0041] S2: The prefabricated material is concentrated by a concentrator to remove excess water, thereby obtaining a concentrated slurry with a water content of 35%;

[0042] S3: adding the following auxiliary materials in percentage by weight of the total raw materials to the pulp obtained in S2, specifically: 8% filler, 3% reinforcing agent, 0.5% adhesive, 0.5% moisture-proof agent, and then stirring and mixing by a mixer to obtain a prefabricated material;

[0043] S4: The preform is sent to a paper machine for further dehydration through a press roller to form a wet paper sheet with a moisture content of 15%, and then dried through a dryer to form a dry paper with a moisture content of 6%;

[0044] S5: heating the dried paper by a heating roller to obtain a flat paper, then pressing the heated paper by a corrugating roller to form a corrugated structure, and then cooling it to room temperature by a cooling roller to obtain a corrugated paper core structure;

[0045] S6: gluing a piece of flat paper on both sides of the corrugated paper core to obtain prefabricated corrugated paper;

[0046] S7: spraying a waterproof coating on the exterior of the prefabricated corrugated paper, and drying the coating to obtain the corrugated paper.

[0047] The stirring speed of the stirrer in S2 is 1300 r / min, and the stirring time is 60 min.

[0048] The filler is a mixture of calcium carbonate and kaolin, and the mass ratio of the calcium carbonate to the kaolin is 1:5.

[0049] The reinforcing agent is a mixture of carboxymethyl starch, polyvinyl alcohol, polyacrylic acid and synthetic fiber, and the mass ratio of the carboxymethyl starch, polyvinyl alcohol, polyacrylic acid and synthetic fiber is 2:2:1:8.

[0050] The preparation steps of the synthetic fiber are as follows: crushing dry wood, gradually pressurizing the crushed fibers to 30MPa, and then releasing the pressure instantly to obtain prefabricated fibers; spraying a water glass curing agent and a water glass solution that has been atomized on the prefabricated fibers under vacuum to obtain moist and loose treated fibers; gradually reducing the vacuum degree of the treated fibers, and when the treated fibers are under normal pressure, gradually pressurizing the treated fibers to 20MPa, stirring for 60 minutes, and then drying to a moisture content of 3% to obtain synthetic fibers.

[0051] The adhesive is polyurethane glue, and the moisture-proof agent is silica gel. The temperature of the heating roller in S5 is 140°C, the heating time is 20s, the pressure of the corrugated roller is 3 tons / meter, and the surface temperature of the cooling roller is 25°C. The maximum spacing between two adjacent corrugations of the corrugated roller in S5 is 1cm, and the corrugation height is 1cm. The waterproof coating in S7 is polyurethane.

[0052] Example 3

[0053] The technical solution of the present invention provides a process for improving the ring compression strength of corrugated paper, comprising the following steps:

[0054] S1: Select waste paper and put it into a pulper for crushing, and soak it in water for 3 hours. Use a pulper to stir the soaked paper pieces into slurry, then use a pulper to further refine the pulp, and then pass through a filter to remove impurities to obtain pure pulp;

[0055] S2: The prefabricated material is concentrated by a concentrator to remove excess water, thereby obtaining a concentrated slurry with a water content of 30%;

[0056] S3: adding the following auxiliary materials in percentage by weight of the total raw materials to the pulp obtained in S2, specifically: 6% filler, 3% reinforcing agent, 0.4% adhesive, 0.3% moisture-proof agent, and then stirring and mixing by a mixer to obtain a prefabricated material;

[0057] S4: The preform is fed into a paper machine and further dehydrated by a press roller to form a wet paper sheet with a moisture content of 13%, and then dried by a dryer to form a dry paper with a moisture content of 5%;

[0058] S5: heating the dried paper by a heating roller to obtain a flat paper, then pressing the heated paper by a corrugating roller to form a corrugated structure, and then cooling it to room temperature by a cooling roller to obtain a corrugated paper core structure;

[0059] S6: gluing a piece of flat paper on both sides of the corrugated paper core to obtain prefabricated corrugated paper;

[0060] S7: spraying a waterproof coating on the exterior of the prefabricated corrugated paper, and drying the coating to obtain the corrugated paper.

[0061] The stirring speed of the stirrer in S2 is 1200 r / min, and the stirring time is 50 min.

[0062] The filler is a mixture of calcium carbonate and kaolin, and the mass ratio of the calcium carbonate to the kaolin is 1:3.

[0063] The reinforcing agent is a mixture of carboxymethyl starch, polyvinyl alcohol, polyacrylic acid and synthetic fiber, and the mass ratio of the carboxymethyl starch, polyvinyl alcohol, polyacrylic acid and synthetic fiber is 2:2:1:7.

[0064] The preparation steps of the synthetic fiber are as follows: crushing dry wood, gradually pressurizing the crushed fibers to 25MPa, and then releasing the pressure instantly to obtain prefabricated fibers; spraying a water glass curing agent and a water glass solution that has been atomized on the prefabricated fibers under vacuum to obtain moist and loose treated fibers; gradually reducing the vacuum degree of the treated fibers, and when the treated fibers are under normal pressure, gradually pressurizing the treated fibers to 15MPa, stirring for 45 minutes, and then drying to a moisture content of 3% to obtain synthetic fibers.

[0065] The adhesive is polyurethane glue, and the moisture-proof agent is silica gel. The temperature of the heating roller in S5 is 130°C, the heating time is 15s, the pressure of the corrugated roller is 2 tons / meter, and the surface temperature of the cooling roller is 15°C. The maximum spacing between two adjacent corrugations of the corrugated roller in S5 is 0.5cm, and the corrugation height is 1cm. The waterproof coating in S7 is acrylic acid.

[0066] Example 4

[0067] The technical solution of the present invention provides a process for improving the ring compression strength of corrugated paper, comprising the following steps:

[0068] S1: Select waste paper and put it into a pulper for crushing, and soak it in water for 2-5 hours. Use a pulper to stir the soaked paper pieces into slurry, then use a pulper to further refine the pulp, and then pass through a filter to remove impurities to obtain pure pulp;

[0069] S2: The prefabricated material is concentrated by a concentrator to remove excess water, so as to obtain a concentrated slurry with a water content of 20-35%;

[0070] S3: adding the following auxiliary materials in percentage by weight of the total raw materials to the pulp obtained in S2, specifically: 8% filler, 2% reinforcing agent, 0.4% adhesive, 0.4% moisture-proof agent, and then stirring and mixing by a mixer to obtain a prefabricated material;

[0071] S4: The preform is fed into a paper machine and further dehydrated by a press roller to form a wet paper sheet with a moisture content of 14%, and then dried by a dryer to form a dry paper with a moisture content of 5%;

[0072] S5: heating the dried paper by a heating roller to obtain a flat paper, then pressing the heated paper by a corrugating roller to form a corrugated structure, and then cooling it to room temperature by a cooling roller to obtain a corrugated paper core structure;

[0073] S6: gluing a piece of flat paper on both sides of the corrugated paper core to obtain prefabricated corrugated paper;

[0074] S7: spraying a waterproof coating on the exterior of the prefabricated corrugated paper, and drying the coating to obtain the corrugated paper.

[0075] The stirring speed of the stirrer in S2 is 1100 r / min, and the stirring time is 55 min.

[0076] The filler is a mixture of calcium carbonate and kaolin, and the mass ratio of the calcium carbonate to the kaolin is 1:4.

[0077] The reinforcing agent is a mixture of carboxymethyl starch, polyvinyl alcohol, polyacrylic acid and synthetic fiber, and the mass ratio of the carboxymethyl starch, polyvinyl alcohol, polyacrylic acid and synthetic fiber is 2:1:1:8.

[0078] The preparation steps of the synthetic fiber are as follows: crushing dry wood, gradually pressurizing the crushed fibers to 22MPa, and then releasing the pressure instantly to obtain prefabricated fibers; spraying a water glass curing agent and a water glass solution that has been atomized on the prefabricated fibers under vacuum to obtain moist and loose treated fibers; gradually reducing the vacuum degree of the treated fibers, and when the treated fibers are under normal pressure, gradually pressurizing the treated fibers to 10MPa, stirring for 40 minutes, and then drying to a moisture content of 3% to obtain synthetic fibers.

[0079] The adhesive is polyurethane glue, and the moisture-proof agent is silica gel. The temperature of the heating roller in S5 is 125°C, the heating time is 12s, the pressure of the corrugated roller is 3 tons / meter, and the surface temperature of the cooling roller is 20°C. The maximum spacing between two adjacent corrugations of the corrugated roller in S5 is 0.6cm, and the corrugation height is 0.6cm. The waterproof coating in S7 is acrylic acid.

[0080] Comparative Example 1

[0081] The preparation method is the same as that of Example 1, except that no reinforcing agent is added.

[0082] Comparative Example 2,

[0083] Choose corrugated paper produced by a company currently on the market.

[0084] According to GB / T2679.3-1996, GB / T 12914-2008, GB / T2679.8-2016 and other standards, the corrugated paper prepared in Examples 1-4 was tested for performance such as ring crush index and water absorption. The results are shown in Table 1 below:

[0085] Table 1

[0086]

[0087]

[0088] In the papermaking industry, the ring crush index is usually used for comparison in order to facilitate comparison. The ring crush index is the ring crush strength divided by the quantitative weight of the paper. When the quantitative weight of the paper is the same, the larger the ring crush index, the greater the ring crush strength. From the above results, it can be seen that by adding a reinforcing agent to the raw materials, and the reinforcing agent is a mixture of carboxymethyl starch, polyvinyl alcohol, polyacrylic acid and synthetic fibers, the ring crush strength of the corrugated paper obtained has a certain commission compared with the existing products, so that the corrugated paper has a higher stability in use, can be reused, and reduce the cost of use. At the same time, through the selection of coatings, this solution also significantly improves the water absorption performance of corrugated paper.

[0089] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field and related fields without creative work should fall within the scope of protection of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention are implemented according to the conventional means in the field unless otherwise specified and limited.

Claims

1. A process for improving the ring compression strength of corrugated paper, characterized in that: The steps include: S1: Select waste paper and put it into a pulper for crushing, and soak it in water for 2-5 hours. Use a pulper to stir the soaked paper pieces into slurry, then use a pulper to further refine the pulp, and then pass through a filter to remove impurities to obtain pure pulp; S2: The prefabricated material is concentrated by a concentrator to remove excess water, so as to obtain a concentrated slurry with a water content of 20-35%; S3: adding the following auxiliary materials in percentage by weight of the total raw materials to the pulp obtained in S2, specifically: 5-8% filler, 2-3% reinforcing agent, 0.2-0.5% adhesive, 0.2-0.5% moisture-proof agent, and then stirring and mixing by a mixer to obtain a prefabricated material; S4: The preform is fed into a paper machine and further dehydrated by a press roller to form a wet paper sheet with a moisture content of 12-15%, and then dried by a dryer to a dry paper with a moisture content of 4-6%; S5: heating the dried paper by a heating roller to obtain a flat paper, then pressing the heated paper by a corrugating roller to form a corrugated structure, and then cooling it to room temperature by a cooling roller to obtain a corrugated paper core structure; S6: gluing a piece of flat paper on both sides of the corrugated paper core to obtain prefabricated corrugated paper; S7: spraying a waterproof coating on the exterior of the prefabricated corrugated paper, and drying the coating to obtain the corrugated paper.

2. A process for improving the ring compression strength of corrugated paper according to claim 1, characterized in that: The stirring speed of the stirrer in S2 is 1000-1300 r / min, and the stirring time is 45-60 min.

3. A process for improving the ring compression strength of corrugated paper according to claim 1, characterized in that: The filler is a mixture of calcium carbonate and kaolin, and the mass ratio of the calcium carbonate to the kaolin is 1:(2-5).

4. A process for improving the ring compression strength of corrugated paper according to claim 1, characterized in that: The reinforcing agent is a mixture of carboxymethyl starch, polyvinyl alcohol, polyacrylic acid and synthetic fiber, and the mass ratio of the carboxymethyl starch, polyvinyl alcohol, polyacrylic acid and synthetic fiber is 2:(1-2):1:(6-8).

5. A process for improving the ring compression strength of corrugated paper according to claim 4, characterized in that: The preparation steps of the synthetic fiber are as follows: crushing the dry wood, gradually pressurizing the crushed fibers to 20-30 MPa, and then releasing the pressure instantly to obtain prefabricated fibers; spraying a water glass curing agent and a water glass solution that has been atomized on the prefabricated fibers under vacuum to obtain moist and loose treated fibers; The vacuum degree of the treated fiber is gradually reduced. When the treated fiber is under normal pressure, the treated fiber is gradually pressurized to 5-20 MPa, stirred for 30-60 minutes, and then dried to a moisture content of 3% to obtain synthetic fiber.

6. A process for improving the ring compression strength of corrugated paper according to claim 1, characterized in that: The adhesive is polyurethane glue, and the moisture-proof agent is silica gel.

7. A process for improving the ring compression strength of corrugated paper according to claim 1, characterized in that: In S5, the temperature of the heating roller is 120-140°C, the heating time is 10-20s, the pressure of the corrugated roller is 1-3 tons / meter, and the surface temperature of the cooling roller is 5-25°C.

8. A process for improving the ring compression strength of corrugated paper according to claim 1, characterized in that: The maximum distance between two adjacent corrugations of the corrugation roller in S5 is 0.5-1 cm, and the corrugation height is 0.5-1 cm.

9. A process for improving the ring compression strength of corrugated paper according to claim 1, characterized in that: The waterproof coating described in S7 is one of polyethylene (PE), polyurethane, and acrylic acid.

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