Low-attenuation high-strength corrugated base paper and production method thereof

Abstract

The invention belongs to the technical field of papermaking, and particularly relates to low-attenuation high-strength corrugated base paper and a production method thereof. Comprising the following technological processes. Raw materials, chain plate conveying, D-type hydrapulper, high-concentration sand remover, coarse screen, low-concentration sand remover, fine screen, multi-disc thickener, pulp storage tank, double-disc pulping machine, pulp forming tank, machine front tank, machine external white water tank, pulp fan pump, screen front screen, headbox, screen part, pressing part, front drying part, sizing machine, rear drying part and coiling part are sequentially subjected to chain plate conveying, D-type hydrapulper, high-concentration sand remover, coarse screen, low-concentration sand remover, fine screen, multi-disc thickener, pulp storage tank, double-disc pulping machine, pulp forming tank, machine front white water tank, pulp fan pump, screen front screen, headbox, screen part, pressing part, front drying part, sizing machine, rear drying part and coiling part. And rewinding, packaging and warehousing. The paper machine is a fourdrinier multi-cylinder corrugated paper machine; the proportions of the raw materials are as follows: 85-90 wt.% of the waste cartons and 15-10 wt.% of the mineral fibers; surface glue is added into the glue applicator and comprises edible corn starch and acrylic ester; and glyoxal. The mineral fibers are added to replace part of fibers, the mineral fibers are not prone to moisture absorption, moisture can be prevented from invading the fibers, and meanwhile the mineral fibers can improve the ring crush compression resistance of finished paper; meanwhile, sodium silicate also has the effect of improving the ring crush compression resistance of finished paper.

Description

Technical Field

[0001] The invention belongs to the technical field of papermaking, and in particular relates to low-attenuation high-strength corrugated base paper and a production method thereof. Background Art

[0002] As the core material of packaging cartons, the performance of high-strength corrugated paper directly determines the compressive strength and overall stability of cartons. In the packaging industry, the compressive strength of cartons is an important indicator to measure their quality, especially in the process of logistics transportation and warehousing, cartons need to withstand a variety of external forces such as stacking, extrusion, vibration, etc. Therefore, the ring crush strength (CCT, Concora Crush Test) of high-strength corrugated paper is one of the key factors affecting the compressive strength of cartons.

[0003] However, high-strength corrugated paper faces a significant technical difficulty in practical application, that is, in a high temperature and high humidity environment, especially in the rainy season in summer, the ambient air humidity is usually as high as 70-90%, and the paper is easy to absorb moisture. After absorbing moisture, the fiber structure inside the paper will expand, resulting in a weakening of the bonding force between the fibers, which in turn causes a significant attenuation of the ring compression strength. Studies have shown that in a high humidity environment, the ring compression strength of high-strength corrugated paper may decay by 30-40%, seriously affecting the compression performance of the carton. This attenuation will not only cause the carton to collapse during transportation and stacking, but may also cause damage to the internal goods, causing huge economic losses to the company.

[0004] The ring compression strength attenuation problem of existing high-strength corrugated paper in high humidity environment has become a technical bottleneck restricting the improvement of packaging carton performance. Therefore, the development of a low-attenuation high-strength corrugated paper has important practical significance and application value. Summary of the invention

[0005] In view of the deficiencies of the prior art, the object of the present invention is to provide a low-attenuation high-strength corrugated paper having good ring crush strength.

[0006] The invention also provides a preparation method thereof, which is simple and feasible and suitable for large-scale production.

[0007] The method for producing low-attenuation high-strength corrugated paper of the present invention comprises the following process flow:

[0008] Raw materials → chain conveyor → D-type hydraulic pulper → high-concentration desander → coarse screen → low-concentration desander → fine screen → multi-disc thickener → pulp storage tank → double-disc refiner → pulping tank → pre-slurry tank → external white water tank → pulp pump → pre-net screen → headbox → net section → press section → front drying section → sizing machine → post-drying section → winding section → rewinding → packaging and storage;

[0009] The paper machine used is a fourdrinier multi-cylinder corrugated paper machine;

[0010] The ratio of the raw materials: 85-90wt.% waste paper boxes, 15-10wt.% mineral fibers;

[0011] The surface glue is added into the sizing machine: 45-55kg / ton of paper of edible corn starch, 2.25-2.75kg / ton of paper of acrylate, and 1.5-2.5kg / ton of paper of glyoxal.

[0012] The preparation method of the surface glue is:

[0013] Add 500±10kg of clean water into the starch dissolving tank, start the agitator, slowly add 100±5kg of edible corn starch and 5±0.5kg of acrylate, stir evenly, move to the starch cooking tank, start stirring, heat to 95-98℃ through steam, close the steam valve, keep warm for 25-30min, then move to the starch dilution tank, add 55-60℃ warm water, dilute to a concentration of 9.5-10%, a viscosity of 30-80mPa·s, and a temperature of 65-70℃ to obtain the surface glue, which is then moved to the surface glue storage tank for standby use.

[0014] The sizing process of the sizing machine is as follows: the surface glue is lifted from the surface glue storage tank to the sizing machine feeding tank, 1.5-2.5 kg / ton of paper of glyoxal is added to the feeding tank by a metering pump, and the surface glue is lifted to the surface sizing machine for surface sizing of the corrugated base paper.

[0015] Glyoxal can improve the waterproof and moisture-proof properties and tensile strength of the finished paper, and increase the wrinkle resistance of the paper; acrylate can improve the wrinkle resistance and waterproof properties of the finished paper;

[0016] In the double-disc refiner process, three DD1200mm double-disc refiners are used in series for refining, with deflaking type refiners. The power of the three double-disc refiners is 600kW, 500kW, and 500kW respectively, the valve opening is 70-75%, the refining concentration is 4.5-5.0%, the pulping degree is 33-36°SR, and the wet weight is 3-4g.

[0017] 7-10 kg / ton of paper of sodium silicate with a solid content of 34-36%, 5-10 kg / ton of paper of PAE wet strength agent with a solid content of 37-39%, and 200-300 g / ton of paper of organic bromine fungicide with a solid content of 9-11% are added into the pulping tank.

[0018] ASA 5-8 kg / ton of paper with a solid content of 39-41% is added into the pre-papermaking pool.

[0019] 300-500 g / ton of paper of polyethyleneimine with a solid content of 19-21% is added to the inlet of the front screen.

[0020] 100-300g / ton of paper of defoamer with a solid content of 9-11% is added into the white water tank outside the paper machine.

[0021] The paper machine is a 4400-type fourdrinier multi-cylinder corrugated paper machine, and the operating parameters of the paper machine are: basis weight 135-145g, web concentration 1.0-1.2%, headbox lip opening 12-14mm, pulp-web speed ratio 0.94-0.96, dryness of the exiting roller 21-23%; dryness of the exiting press section 48-52%, and line pressure of the large roller of the press section 280-300KN / m. The line pressure of the glue roller of the sizing machine is 100-120KN / m, the dryness of the entry into the sizing machine is 93-95%, the dryness of the exiting sizing machine is 65-68%, and the dryness of the finished paper is 93-95%.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The present invention adds mineral fiber to replace part of the fiber. The mineral fiber is not easy to absorb moisture and can prevent moisture from invading the interior of the fiber. At the same time, the mineral fiber can improve the ring compressive strength of the paper. At the same time, sodium silicate also has the effect of improving the ring compressive strength of the paper.

[0024] 2. Adding ASA sizing agent into the pulp can speed up the aging process after leaving the machine and reduce the decay rate of the ring compression strength of the finished paper.

[0025] 3. Adding glyoxal and acrylate to the surface sizing can enhance the internal water resistance of the paper, improve the film-forming performance of the paper surface, reduce the intrusion of external moisture, and ensure the stability of the ring crush strength of the paper. DETAILED DESCRIPTION

[0026] The present invention will be further described below with reference to the embodiments.

[0027] Unless otherwise specified, all raw materials used in the examples are commercially available.

[0028] Mineral fiber, basalt mineral fiber, Xiamen Sulu Mineral Fiber Material Co., Ltd.;

[0029] Basalt mineral fiber indicators:

[0030] (1) Length, the typical maximum fiber length is 6 mm;

[0031] (2) diameter, average diameter 5 μm;

[0032] (3) Sieving: 95% passing through a 250 μm sieve and 65% passing through a 63 μm sieve;

[0033] (4) Melting point, 1500°C;

[0034] (5) Tensile strength, ≥2500MPa;

[0035] (6) Elastic modulus, ≥90 Gpa.

[0036] Sodium silicate, solid content 35±1%, Zibo Guanxin New Material Factory;

[0037] Organic bromine fungicide, solid content 10±1%, model WL-20, Zhejiang Chuanhua Chemical Co., Ltd.;

[0038] PAE wet strength agent, solid content 38±1%, Tianfang Shenghong Chemical Co., Ltd.;

[0039] ASA, solid content 40 ± 1%, Kemira Chemical Co., Ltd.;

[0040] Polyethyleneimine, solid content 20±1%, Zhejiang Chuanhua Chemical Co., Ltd.;

[0041] Defoamer DF9500, solid content 10±1%, Nantian Agrochemical Co., Ltd.;

[0042] Glyoxal, solid content 30±1%, Hubei Guangao Biotechnology Co., Ltd.;

[0043] Acrylate, model TK1109, Shanghai Kaiyin Chemical Co., Ltd.

[0044] Example 1

[0045] The method for producing low-attenuation high-strength corrugated paper comprises the following process flow:

[0046] Raw materials → chain conveyor → D-type hydraulic pulper → high-concentration desander → coarse screen → low-concentration desander → fine screen → multi-disc thickener → pulp storage tank → double-disc refiner → pulping tank → pre-slurry tank → external white water tank → pulp pump → pre-net screen → headbox → net section → press section → front drying section → sizing machine → post-drying section → winding section → rewinding → packaging and storage;

[0047] The paper machine used is a fourdrinier multi-cylinder corrugated paper machine;

[0048] The ratio of the raw materials: 85wt.% waste paper boxes, 15wt.% mineral fibers;

[0049] The surface glue is added into the sizing machine: 45 kg / ton of paper of edible corn starch, 2.25 kg / ton of paper of acrylate, and 1.5 kg / ton of paper of glyoxal.

[0050] The preparation method of the surface glue is:

[0051] Add 490 kg of clean water into the starch dissolving tank, start the agitator, slowly add 95 kg of edible corn starch and 4.5 kg of acrylate, stir evenly, move to the starch cooking tank, start stirring, pass steam to raise the temperature to 95°C, close the steam valve, keep warm for 25 minutes, then move to the starch dilution tank, add 55°C warm water, dilute to a concentration of 9.5%, a viscosity of 30 mPa·s, and a temperature of 65°C to obtain the surface glue, which is moved to the surface glue storage tank for standby use.

[0052] The sizing process of the sizing machine is as follows: the surface glue is lifted from the surface glue storage tank to the sizing machine feeding tank, 1.5 kg / ton of paper of glyoxal is added to the feeding tank by a metering pump, and the surface glue is lifted to the surface sizing machine for surface sizing of the corrugated base paper.

[0053] In the concentrated multi-disc refiner process, three DD1200mm disc refiners are used in series for refining, with debonding type refiners. The power of the three refiners is 600kW, 500kW, and 500kW respectively, the valve opening is 70%, the refining concentration is 4.5%, the pulping degree is 33°SR, and the wet weight is 3g.

[0054] 7kg / ton of paper of sodium silicate, 5kg / ton of paper of PAE wet strength agent and 200g / ton of paper of organic bromine fungicide were added into the pulping tank.

[0055] ASA 5kg / ton of paper was added into the pre-papermaking pool.

[0056] 300 g / ton of polyethyleneimine is added to the inlet of the front screen.

[0057] 100g / ton of paper of defoaming agent is added into the white water tank outside the paper machine.

[0058] The paper machine is a 4400-type fourdrinier multi-cylinder corrugated paper machine, and the operating parameters of the paper machine are: web concentration 1.0%, lip opening 12mm, pulp-web speed ratio 0.94, dryness of exiting the couching roll 21%, dryness of exiting the press section 48%, and line pressure of the large roll of the press section 280KN / m. The line pressure of the glue roller of the sizing machine is 100KN / m, dryness of the entry into the sizing machine 93%, dryness of the exit from the sizing machine 65%, and dryness of the finished paper 93%.

[0059] Example 2

[0060] The method for producing low-attenuation high-strength corrugated paper comprises the following process flow:

[0061] Raw materials → chain conveyor → D-type hydraulic pulper → high-concentration desander → coarse screen → low-concentration desander → fine screen → multi-disc thickener → pulp storage tank → double-disc refiner → pulping tank → pre-slurry tank → external white water tank → pulp pump → pre-net screen → headbox → net section → press section → front drying section → sizing machine → post-drying section → winding section → rewinding → packaging and storage;

[0062] The paper machine used is a fourdrinier multi-cylinder corrugated paper machine;

[0063] The ratio of the raw materials: 90wt.% waste paper boxes, 10wt.% mineral fibers;

[0064] The surface glue is added into the sizing machine: 55 kg / ton of paper of edible corn starch, 2.75 kg / ton of paper of acrylate, and 2.5 kg / ton of paper of glyoxal.

[0065] The preparation method of the surface glue is:

[0066] Add 510kg of clean water into the starch dissolving tank, start the agitator, slowly add 105kg of edible corn starch and 5.5kg of acrylate, stir evenly, move to the starch cooking tank, start stirring, pass steam to raise the temperature to 98℃, close the steam valve, keep warm for 30min, then move to the starch dilution tank, add 60℃ warm water, dilute to a concentration of 10%, a viscosity of 80mPa·s, and a temperature of 70℃ to obtain the surface glue, which is moved to the surface glue storage tank for standby use.

[0067] The sizing process of the sizing machine is as follows: the surface glue is lifted from the surface glue storage tank to the sizing machine feeding tank, 2.5 kg / ton of paper of glyoxal is added to the feeding tank by a metering pump, and the surface glue is lifted to the surface sizing machine for surface sizing of the corrugated base paper.

[0068] In the double-disc refiner process, three DD1200mm double-disc refiners are used in series for refining, with deflaking type refiners. The power of the three double-disc refiners is 600kW, 500kW, and 500kW respectively, the valve opening is 75%, the refining concentration is 5.0%, the pulping degree is 36°SR, and the wet weight is 4g.

[0069] 10 kg / ton of paper of sodium silicate, 10 kg / ton of paper of PAE wet strength agent and 300 g / ton of paper of organic bromine fungicide were added into the pulping tank.

[0070] ASA 8kg / ton of paper was added into the pre-papermaking pool.

[0071] 500 g / ton of polyethyleneimine is added to the inlet of the front screen.

[0072] 300 g / ton of paper of defoaming agent is added into the white water tank outside the paper machine.

[0073] The paper machine is a 4400-type fourdrinier multi-cylinder corrugated paper machine, and the operating parameters of the paper machine are: web concentration 1.2%, lip opening 14mm, pulp-web speed ratio 0.96, dryness of exiting the couching roll 23%, dryness of exiting the press section 52%, and line pressure of the large roll of the press section 300KN / m. The line pressure of the glue roll of the sizing machine is 120KN / m, dryness of the entry into the sizing machine 95%, dryness of the exit from the sizing machine 68%, and dryness of the finished paper 95%.

[0074] Example 3

[0075] The method for producing low-attenuation high-strength corrugated paper comprises the following process flow:

[0076] Raw materials → chain conveyor → D-type hydraulic pulper → high-concentration desander → coarse screen → low-concentration desander → fine screen → multi-disc thickener → pulp storage tank → double-disc refiner → pulping tank → pre-slurry tank → external white water tank → pulp pump → pre-net screen → headbox → net section → press section → front drying section → sizing machine → post-drying section → winding section → rewinding → packaging and storage;

[0077] The paper machine used is a fourdrinier multi-cylinder corrugated paper machine;

[0078] The ratio of the raw materials is: 87wt.% waste paper boxes, 13wt.% mineral fibers;

[0079] The surface glue is added into the sizing machine: 50 kg / ton of paper of edible corn starch, 2.5 kg / ton of paper of acrylate, and 2 kg / ton of paper of glyoxal.

[0080] The preparation method of the surface glue is:

[0081] Add 500 kg of clean water into the starch dissolving tank, start the agitator, slowly add 100 kg of edible corn starch and 5 kg of acrylate, stir evenly, move to the starch cooking tank, start stirring, pass steam to raise the temperature to 96 ° C, close the steam valve, keep warm for 28 minutes, then move to the starch dilution tank, add 58 ° C warm water, dilute to a concentration of 9.8%, a viscosity of 50 mPa·s, and a temperature of 68 ° C to obtain the surface glue, which is moved to the surface glue storage tank for standby use.

[0082] The sizing process of the sizing machine is as follows: the surface glue is lifted from the surface glue storage tank to the sizing machine feeding tank, 2 kg / ton of paper of glyoxal is added to the feeding tank by a metering pump, and the surface glue is lifted to the surface sizing machine for surface sizing of the corrugated base paper.

[0083] In the double-disc refiner process, three DD1200mm double-disc refiners are used in series for refining, with deflaking type refiners. The power of the three double-disc refiners is 600kW, 500kW, and 500kW respectively, the valve opening is 72%, the refining concentration is 4.8%, the pulping degree is 34°SR, and the wet weight is 3.5g.

[0084] 8kg / ton of paper of sodium silicate, 8kg / ton of paper of PAE wet strength agent and 250g / ton of paper of organic bromine fungicide were added into the pulping tank.

[0085] ASA 7kg / ton of paper was added into the pre-papermaking pool.

[0086] 400 g / ton of polyethyleneimine is added to the inlet of the front screen.

[0087] 200g / ton of paper of defoaming agent is added into the white water tank outside the paper machine.

[0088] The paper machine is a 4400-type fourdrinier multi-cylinder corrugated paper machine, and the operating parameters of the paper machine are: web concentration 1.1%, lip opening 13mm, pulp-web speed ratio 0.95, dryness of exiting the couching roll 22%, dryness of exiting the press section 50%, and line pressure of the large roll of the press section 290KN / m. The line pressure of the glue roll of the sizing machine is 110KN / m, dryness of the entry into the sizing machine 94%, dryness of the exit from the sizing machine 67%, and dryness of the finished paper 94%.

[0089] Comparative Example 1: 87% waste carton + 13% mineral fiber was changed to 100% waste paper pulp, and other production process conditions were the same as those in Example 3;

[0090] Comparative Example 2: Sodium silicate was removed, and other production process conditions were the same as those in Example 3;

[0091] Comparative Example 3: Glyoxal was removed, and other production process conditions were the same as those in Example 3;

[0092] Comparative Example 4: The acrylate was removed, and other production process conditions were the same as those in Example 3;

[0093] Comparative Example 5: ASA was replaced with alkyl ketene dimer (AKD), and other production process conditions were the same as those in Example 3.

[0094] The obtained paper was tested: quantitative: GB / T 451.2, water absorption: GB / T 1540, ring crush strength: GB / T2679.8, moisture: GB / T 462.

[0095] The following data are the test results of the paper sheets when they are off the machine:

[0096] Table 1 Paper sheet off-machine test results

[0097]

[0098] The following data is the result of the paper being left in the laboratory for 48 hours:

[0099] Table 2 Test results of paper sheets after 48 hours of standing

[0100]

[0101]

[0102] The above comparison data shows that:

[0103] (1) When mineral fiber, sodium silicate, acrylate, glyoxal, and ASA are replaced by AKD, the ring crush strength cannot meet the requirements of papermaking; when glyoxal is not used and ASA is replaced by AKD, the water absorption and dripping time of the paper cannot meet the requirements.

[0104] (2) By comparing the data of paper sheets placed at different times, it can be seen that when mineral fiber, sodium silicate, acrylate, glyoxal, and ASA are not used and replaced with AKD, the ring pressure strength is reduced. However, when the time is long enough, the ring pressure reduction tends to balance.

Claims

1. A method for producing low-attenuation and high-strength corrugated paper, characterized in that: Including the following process: Raw materials → chain conveyor → D-type hydraulic pulper → high-concentration desander → coarse screen → low-concentration desander → fine screen → multi-disc thickener → pulp storage tank → double-disc refiner → pulping tank → pre-slurry tank → external white water tank → pulp pump → pre-net screen → headbox → net section → press section → front drying section → sizing machine → post-drying section → winding section → rewinding → packaging and storage; The paper machine used is a fourdrinier multi-cylinder corrugated paper machine; The ratio of the raw materials: 85-90wt.% waste paper boxes, 15-10wt.% mineral fibers; The surface glue is added into the sizing machine: 45-55kg / ton of paper of edible corn starch, 2.25-2.75kg / ton of paper of acrylate, and 1.5-2.5kg / ton of paper of glyoxal.

2. The method for producing low-attenuation and high-strength corrugated paper according to claim 1, characterized in that: The preparation method of the surface glue is: Add water to the starch dissolving tank, start the agitator, add edible corn starch and acrylate, stir evenly, lift to the starch cooking tank, start stirring, pass steam to raise the temperature to 95-98℃, close the steam valve, keep warm for 25-30min, then lift to the starch dilution tank, add 55-60℃ warm water, dilute to a concentration of 9.5-10%, a viscosity of 30-80mPa·s, and a temperature of 65-70℃ to obtain the surface glue, which is then lifted to the surface glue storage tank for standby use.

3. The method for producing low-attenuation and high-strength corrugated paper according to claim 2, characterized in that: The sizing process of the sizing machine is as follows: the surface glue is lifted from the surface glue storage tank to the sizing machine feeding tank, 1.5-2.5 kg / ton of paper of glyoxal is added to the feeding tank by a metering pump, and the surface glue is lifted to the surface sizing machine for surface sizing of the corrugated base paper.

4. The method for producing low-attenuation high-strength corrugated paper according to claim 1, characterized in that: In the double-disc refiner process, three DD1200mm double-disc refiners are used in series for refining, with deflaking type refiners. The power of the three double-disc refiners is 600kW, 500kW, and 500kW respectively, the valve opening is 70-75%, the refining concentration is 4.5-5.0%, the pulping degree is 33-36°SR, and the wet weight is 3-4g.

5. The method for producing low-attenuation and high-strength corrugated paper according to claim 1, characterized in that: 7-10 kg / ton of paper of sodium silicate, 5-10 kg / ton of paper of PAE wet strength agent and 200-300 g / ton of paper of organic bromine fungicide are added into the pulping tank.

6. The method for producing low-attenuation and high-strength corrugated paper according to claim 1, characterized in that: ASA 5-8 kg / ton of paper is added into the pre-papermaking pool.

7. The method for producing low-attenuation and high-strength corrugated paper according to claim 1, characterized in that: 300-500 g / ton of paper of polyethyleneimine is added to the inlet of the front screen.

8. The method for producing low-attenuation and high-strength corrugated paper according to claim 1, characterized in that: 100-300g / ton of paper of defoaming agent is added into the white water tank outside the machine.

9. The method for producing low-attenuation and high-strength corrugated paper according to claim 1, characterized in that: The paper machine is a 4400-type fourdrinier multi-cylinder corrugated paper machine, and the operating parameters of the paper machine are: basis weight 135-145g, web concentration 1.0-1.2%, headbox lip opening 12-14mm, pulp-web speed ratio 0.94-0.96, dryness of the exiting roller 21-23%; dryness of the exiting press section 48-52%, line pressure of the large roller of the press section 280-300KN / m, line pressure of the glue roller of the sizing machine 100-120KN / m, dryness of the entry into the sizing machine 93-95%, dryness of the exiting sizing machine 65-68%, and dryness of the finished paper 93-95%.

10. A low-attenuation and high-strength corrugated paper, characterized in that: The method is prepared by any one of claims 1 to 9.

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