Paper-based strapping tape and preparation method thereof

Abstract

The present invention relates to a paper-based strapping tape and a preparation method thereof, the method comprising the following steps: tearing unbleached coniferous wood pulp into pieces for dilution and debonding, and then performing pulping treatment, the pulping process must be carried out under certain conditions; diluting the prepared pulp, and then adding relevant papermaking additives thereto, and stirring evenly; molding the stirred pulp in a paper sheet former, and drying the wet paper sheets at 80°C and 100°C, respectively, to obtain a paper-based strapping tape base paper; cutting the paper-based strapping tape base paper into paper tapes of certain specifications, heat-sealing and bonding the paper tapes, moistening the areas to be heat-sealed with a small amount of clean water, and using a buckle-free hot-melt baler for hot-pressing and hot-melt bonding, and finally obtaining a paper-based strapping tape. The paper-based strapping tape involved in the present invention can be used for packaging lightweight packaging in the logistics industry, the food industry, the textile industry, and lightweight items in daily life, replacing plastic strapping tape, and is non-toxic and harmless, degradable and recyclable, and meets the requirements of low-carbon development.

Description

Technical Field

[0001] The invention belongs to the field of new materials, in particular to a paper-based packing tape and a preparation method thereof. Background Art

[0002] Paper strapping is made of natural plant fibers and is renewable, recyclable and biodegradable. However, in daily life, the handling, transportation and storage of large goods usually require plastic or metal strapping for strapping. Although plastic and metal strapping can be recycled in theory, there are certain difficulties and risks, and the cost is also high. In most cases, these plastic or metal strapping tapes will become garbage in landfills, and some will enter rivers, lakes and oceans, thereby causing harm to the ecological environment and wildlife. This harm is long-lasting and increasingly serious. Pulp mills that produce pulp products usually wrap commercial pulp boards with pulp sheets, and then wrap and tie the pulp boards with metal strapping tapes for transportation. The pulp sheets wrapped with pulp boards can be used directly in paper mills with pulp boards, while metal strapping tapes become garbage in paper mills. In the production process, removing metal strapping tapes and handling them safely is a dangerous, time-consuming and labor-intensive task, with many safety hazards, and will also incur unnecessary expenses and increase costs.

[0003] Paper-based strapping tape can solve the above problems. Paper-based strapping tape is made of natural plant fibers, so it is recyclable, renewable and degradable. In the preparation process, paper reinforcement, sizing and other additives are added, and it can also be mixed with other wood fibers and non-wood fibers to make paper-based strapping tape that can tie heavy cartons and commodity pulp bags. Importantly, the paper tape can be recycled non-toxic and harmless at the end of the work, and there is almost no danger.

[0004] After checking, the existing strapping tape has a high weight or needs to be filled with homemade glue to play a bonding role. This application has a low weight, that is, 120 g / m 2 , and there is no need to make your own glue, just use clean water to make the paper tape stick together. Summary of the invention

[0005] In view of various problems and shortcomings of existing technologies, a paper-based strapping tape and a preparation method thereof are provided, which can develop a new material paper-based strapping tape that is degradable and recyclable, non-toxic and harmless, has excellent strength properties and can be heat-sealed.

[0006] The present invention adopts the following specific scheme:

[0007] A method for preparing a paper-based strapping tape comprises the following steps:

[0008] S1. The pulp fibers are shredded to be diluted and debonded, and then the pulp is refined, with a pulping degree ranging from 22°SR to 34°SR; a pulping concentration of 8% to 12%; and a pulping gap of 0.01mm to 0.2mm;

[0009] S2, dilute the slurry prepared in S1, then add the additive into the barrel containing the slurry and stir it thoroughly;

[0010] S3, placing the stirred slurry in a paper sheet former to form a wet paper sheet, and drying the wet paper sheet at 80° C. and 100° C. respectively to obtain a paper-based strapping base paper;

[0011] S4. Cut the paper-based strapping tape into paper tapes of certain specifications for heat sealing. When heat sealing and bonding the paper tapes, use a small amount of clean water to evenly moisten the area to be heat sealed. Use a buckle-free hot melt strapping machine to heat seal and hot melt bond the area at a temperature of 155℃~165℃ and a time of 4s~6s.

[0012] Preferably, in S1, the pulp fiber is unbleached coniferous wood pulp. Unbleached coniferous wood pulp is used as the raw material, which is widely available and renewable.

[0013] Preferably, in S2, the auxiliary agents are 70°C PVA (water-soluble polyvinyl alcohol) fiber, PAE (polyamide epichlorohydrin), AKD (sizing agent alkyl ketene dimer) and cationic starch.

[0014] Among them, the addition amount of 70℃ water-soluble PVA fiber is 13.5%~15%, the addition amount of PAE is 1.5%~2%, the addition amount of AKD is 0.3%~0.4%, and the addition amount of cationic starch is 0.9%~1.2%. The addition amount of each additive is calculated as a percentage of the absolute dry weight of unbleached softwood pulp.

[0015] In the paper-based strapping tape composed of the above ingredients, 70℃ water-soluble PVA fiber and clean water are used to achieve heat-sealing and bonding effects, 70℃ water-soluble PVA fiber, PAE, AKD and cationic starch improve the strength of the paper sheet, and the strength of the heat seal can usually reach 200N, meeting the packaging requirements.

[0016] In step S3, wet paper sheets with 70°C water-soluble PVA fibers are added. In order to make the 70°C water-soluble PVA fibers fully exert their performance, the wet paper sheets are dried at 80°C to obtain paper-based strapping paper.

[0017] Preferably, in S4, the specification of the paper tape is 15 mm in width and 0.18 mm in thickness. When heat-sealing the paper tape, a small amount of clean water is used to evenly moisten the area to be heat-sealed, and a buckle-free hot-melt baler is used for heat-pressing and heat-sealing to achieve heat-sealing between the paper tapes.

[0018] The present invention also relates to a paper-based packing tape, which is prepared by the above-mentioned preparation method.

[0019] The unbleached coniferous wood pulp used in the present invention is a common papermaking fiber raw material, and its fiber can make the paper have stronger physical properties.

[0020] The 70°C water-soluble polyvinyl alcohol (PVA) fiber used in the present invention is a non-toxic, harmless, degradable, recyclable, sustainable, pollution-free, green and environmentally friendly material. By adding it into the pulp, high-strength paper can be produced. Moreover, by utilizing its property of being soluble in hot water, the heat-sealing property of the paper-based strapping tape can be achieved through a soaking, heat-sealing and hot-pressing process.

[0021] The PAE (polyamide epichlorohydrin) used in the present invention is a papermaking auxiliary wet strength agent, which is added into the pulp and combined with 70°C water-soluble PVA fiber to significantly improve the wet strength of paper.

[0022] The AKD (alkyl ketene dimer) used in the present invention is a papermaking auxiliary sizing agent, which is added into the pulp to improve the water resistance of paper.

[0023] The present invention adopts cationic starch and implements in-slurry addition to improve the retention rate of sizing agent AKD.

[0024] Compared with the prior art methods, the beneficial effects of the present invention are as follows:

[0025] The paper-based packing tape of the present invention can still maintain good strength performance when in contact with water.

[0026] The paper-based packing tape of the present invention does not need to use various adhesive substances, and can be hot-pressed and bonded using only clean water. The heat-sealing operation is simple, fast and efficient.

[0027] The paper-based packing tape of the present invention has a low basis weight of 120 g / m 2 , saving raw materials, reducing energy consumption, lowering costs, and still maintaining good strength properties.

[0028] Since paper additives and sizing agents are added to paper, the paper tends to become hard and brittle after drying, causing large fluctuations in various strength properties. After improvement, the drying temperature is reduced to 80°C and the drying time is increased to 30 minutes, which can significantly improve the flexibility of the finished paper and make various strength properties tend to be stable. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with embodiment.It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.If specific techniques or conditions are not indicated in the embodiments, they are carried out according to the techniques or conditions described in the literature in this area or according to the product specification.If the manufacturer is not indicated in the reagents or instruments used, they are all conventional products that can be purchased. Example 1

[0030] The method for preparing the paper-based strapping tape of the present embodiment comprises the following steps:

[0031] Step (1) determining the moisture content of the unbleached coniferous wood pulp board, and then tearing off a certain amount of absolute dry pulp weight of the unbleached coniferous wood pulp according to the moisture content determination result and soaking it in clean water.

[0032] Step (2) The diluted and deflocculant pulp is subjected to pulping treatment. The pulping concentration is 10%, and the refining gap of the PFI pulping machine is 0.2 mm. When the beating degree reaches 30°SR, the pulping is stopped and the pulp is collected.

[0033] Step (3) dilute the unbleached softwood pulp with a beating degree of 30°SR with water to a pulp concentration of 0.2%, then add 15.0% of 70°C water-soluble PVA fiber, 1.8% of PAE, 0.4% of AKD and 1.2% of cationic starch (the added amounts are all relative to the mass of the absolute dry pulp) into the pulp, then stir evenly and put it on the screen to form a wet paper sheet.

[0034] Step (4) drying the wet paper sheet obtained above at 80°C so that the 70°C water-soluble PVA fibers are in a semi-molten state, which is convenient for heat sealing and maximally enhancing the physical properties of the paper.

[0035] Step (5) The paper sheets obtained above are cut into paper strips with a width of 15.0 mm and a thickness of 0.18 mm. The area to be heat-sealed is uniformly moistened with clean water. Then, a buckle-free hot-melt baler is used to heat-seal the strips at 165° C. for 4 seconds, and a tensile strength test is performed.

[0036] Step (6) According to GB / T1040, the heat-sealed portion of the paper tape is tested by a universal tensile testing machine. Example 2

[0037] The method for preparing the paper-based strapping tape of the present embodiment comprises the following steps:

[0038] Step (1) determining the moisture content of the unbleached coniferous wood pulp board, and then tearing off a certain amount of absolute dry pulp weight of the unbleached coniferous wood pulp according to the moisture content determination result and soaking it in clean water.

[0039] Step (2) The diluted and deflocculable pulp is subjected to pulping treatment. The pulping concentration is 10%, and the refining gap of the PFI pulping machine is 0.2 mm. When the beating degree reaches 30°SR, the refining is stopped and the pulp is collected.

[0040] Step (3) dilute the unbleached softwood pulp with a beating degree of 30° SR with water to a pulp concentration of 0.2%, then add 14.8% of 70°C water-soluble PVA fiber, 2.0% of PAE, 0.39% of AKD and 1.17% of cationic starch (the added amounts are all relative to the mass of the absolute dry pulp) into the pulp, then stir evenly and put it on the net to form a wet paper sheet.

[0041] Step (4) drying the wet paper sheet obtained above at 80°C so that the 70°C water-soluble PVA fibers are in a semi-molten state, which is convenient for heat sealing and maximally enhancing the physical properties of the paper.

[0042] Step (5) The paper sheets obtained above are cut into paper strips with a width of 15.0 mm and a thickness of 0.18 mm, and the area to be heat-sealed is evenly moistened with clean water, and then heat-sealed at 155° C. for 6 seconds using a buttonless hot-melt baler, and a tensile strength test is performed.

[0043] Step (6) According to GB / T1040, the heat-sealed portion of the paper tape is tested by a universal tensile testing machine. Example 3

[0044] The method for preparing the paper-based strapping tape of the present embodiment comprises the following steps:

[0045] Step (1) determining the moisture content of the unbleached coniferous wood pulp board, and then tearing off a certain amount of absolute dry pulp weight of the unbleached coniferous wood pulp according to the moisture content determination result and soaking it in clean water.

[0046] Step (2) The diluted and deflocculable pulp is subjected to pulping treatment. The pulping concentration is 10%, and the refining gap of the PFI pulping machine is 0.2 mm. When the beating degree reaches 30°SR, the refining is stopped and the pulp is collected.

[0047] Step (3) dilute the unbleached softwood pulp with a beating degree of 30°SR with water to a pulp concentration of 0.2%, then add 14.0% of 70°C water-soluble PVA fiber, 1.95% of PAE, 0.38% of AKD and 1.14% of cationic starch (the added amounts are all relative to the mass of the absolute dry pulp) into the pulp, then stir evenly and put it on the screen to form a wet paper sheet.

[0048] Step (4) drying the wet paper sheet obtained above at 80°C so that the 70°C water-soluble PVA fibers are in a semi-molten state, which is convenient for heat sealing and maximally enhancing the physical properties of the paper.

[0049] Step (5) The paper sheets obtained above are cut into paper strips with a width of 15.0 mm and a thickness of 0.18 mm, and the area to be heat-sealed is evenly moistened with clean water, and then heat-sealed at 160° C. for 6 seconds using a buttonless hot-melt baler, and a tensile strength test is performed.

[0050] Step (6) According to GB / T1040, the heat-sealed portion of the paper tape is tested by a universal tensile testing machine. Example 4

[0051] The method for preparing the paper-based strapping tape of the present embodiment comprises the following steps:

[0052] Step (1) determining the moisture content of the unbleached coniferous wood pulp board, and then tearing off a certain amount of absolute dry pulp weight of the unbleached coniferous wood pulp according to the moisture content determination result and soaking it in clean water.

[0053] Step (2) The diluted and deflocculable pulp is subjected to pulping treatment. The pulping concentration is 10%, and the refining gap of the PFI pulping machine is 0.2 mm. When the beating degree reaches 30°SR, the refining is stopped and the pulp is collected.

[0054] Step (3) dilute the unbleached softwood pulp with a beating degree of 30°SR with water to a pulp concentration of 0.2%, then add 15.0% of 70°C water-soluble PVA fiber, 2.0% of PAE, 0.4% of AKD and 1.2% of cationic starch (the added amounts are all relative to the mass of the absolute dry pulp) into the pulp, then stir evenly and put it on the screen to form a wet paper sheet.

[0055] Step (4) drying the wet paper sheet obtained above at 80°C so that the 70°C water-soluble PVA fibers are in a semi-molten state, which is convenient for heat sealing and maximally enhancing the physical properties of the paper.

[0056] Step (5) The paper sheets obtained above are cut into paper strips with a width of 15.0 mm and a thickness of 0.18 mm. The area to be heat-sealed is uniformly moistened with clean water. Then, a buttonless hot-melt baler is used to heat-seal the strips at 165° C. for 6 seconds, and a tensile strength test is performed.

[0057] Step (6) According to GB / T1040, the heat-sealed portion of the paper tape is tested by a universal tensile testing machine.

[0058] Comparative test of different heat sealing temperatures and heat sealing times:

[0059] Comparative Example 1

[0060] In this embodiment, the conditions of step (5) are: heat sealing at 155° C. for 5 seconds using a buttonless hot melt packaging machine, and the remaining steps are the same as those in Example 4.

[0061] Comparative Example 2

[0062] In this embodiment, the conditions of step (5) are: heat sealing at 160° C. for 4 seconds using a buttonless hot melt packaging machine, and the remaining steps are the same as those in Example 4.

[0063] Comparative test of different papermaking additive addition amounts:

[0064] Comparative Example 3

[0065] In this embodiment, the conditions of step (3) are as follows: 10.0% of 70°C water-soluble PVA fiber, 1.0% of PAE, 0.1% of AKD and 0.3% of cationic starch are added to the slurry (the added amounts are all relative to the mass of the absolute dry slurry), and the remaining steps are the same as in Example 4.

[0066] Comparative Example 4

[0067] In this embodiment, the conditions of step (3) are as follows: 13.0% of 70°C water-soluble PVA fiber, 1.5% of PAE, 0.2% of AKD and 0.6% of cationic starch are added to the slurry (the added amounts are all relative to the mass of the absolute dry slurry), and the remaining steps are the same as in Example 4.

[0068] Comparative test of different types of additives:

[0069] Comparative Example 5

[0070] In this embodiment, the condition of step (3) is: no papermaking additives are added to the slurry, and the remaining steps are the same as those in embodiment 4.

[0071] Comparative Example 6

[0072] In this embodiment, the conditions of step (3) are: adding an appropriate amount of 70°C water-soluble PVA fiber into the slurry, and the remaining steps are the same as those in Example 4.

[0073] Comparative Example 7

[0074] In this embodiment, the conditions of step (3) are: adding appropriate amounts of wet strength agent PAE, sizing agent AKD and cationic starch into the slurry, and the remaining steps are the same as those in embodiment 4.

[0075] Comparative Example 8

[0076] In this embodiment, the conditions of step (3) are as follows: adding appropriate amounts of 70°C water-soluble PVA fiber, wet strength agent PAE, sizing agent AKD and cationic starch into the slurry, and the remaining steps are the same as those in embodiment 4.

[0077] Comparative test of different drying temperatures:

[0078] Comparative Example 9

[0079] In this embodiment, the conditions of step (4) are: drying the wet paper sheet at 90° C. for 20 minutes, and the remaining steps are the same as those of embodiment 4.

[0080] Comparative Example 10

[0081] In this embodiment, the conditions of step (4) are: drying the wet paper sheet at 100° C. for 10 minutes, and the remaining steps are the same as those of embodiment 4.

[0082] After testing different heat sealing temperatures and heat sealing times, the experimental results are shown in Table 1 below:

[0083] Table 1

[0084]

[0085] We found that different heat-sealing temperatures and heat-sealing times will have a great influence on the tensile strength of the heat-sealed portion of the paper tape. As shown in Table 2, specific embodiments 1-4 have excellent effects, and the tensile force at the heat-sealed portion exceeds 200N, reaching the expected strength standard, and can meet the actual application requirements in certain scenarios. However, the effects of comparative examples 1 and 2 are poor, the appearance of the paper tapes is uneven and flat, and the expected strength standard is not reached, so the heat-sealing temperature of 155°C and the heat-sealing time is 5s; the heat-sealing temperature of 160°C and the heat-sealing time is 4s, these two heat-sealing conditions are eliminated. The heat-sealing conditions of specific embodiments 1-4 are usable heat-sealing conditions. It can be seen that adjusting the heat-sealing temperature and time can solve the above problems.

[0086] After determination, the comparison test of different papermaking additive addition amounts was carried out, and the experimental results were shown in Table 2 below:

[0087] Table 2

[0088]

[0089] We found that different amounts of papermaking additives added have a significant impact on the strength of the paper tape. As shown in Table 2, the paper tape prepared under the conditions of Specific Example 4 has a tensile strength of up to 99.20 N·m / g at the heat seal, and has excellent strength performance, which can meet the actual application standards; while in Comparative Examples 3 and 4, due to the low amounts of papermaking additives added, the paper tape strength is low, which is insufficient to meet the actual application requirements, so the conditions of Comparative Examples 3 and 4 are not desirable. It can be seen that the optimization of the amount of additives added can solve the above problems.

[0090] After determination, the comparative test of different types of additives, the experimental results are shown in Table 3 below:

[0091] Table 3

[0092]

[0093] We found that different types of additives have a great impact on the various performances of paper tapes. As shown in Table 3, in the paper tape of Comparative Example 5, no papermaking additives were added, and the paper tape was not heat-sealable, water-resistant, and had poor tensile strength; in Comparative Example 6, an appropriate amount of 70°C water-soluble PVA fiber was added, and no other additives were added, and the paper tape only had good heat-sealability, but poor water resistance and ordinary tensile strength; in Comparative Example 7, an appropriate amount of wet strength agent PAE, sizing agent AKD and cationic starch were added, so that the paper tape had good water resistance but no heat sealability; in Comparative Example 8, an appropriate amount of 70°C water-soluble PVA fiber, wet strength agent PAE, sizing agent AKD and cationic starch were added, and the paper tape had good heat sealability, water resistance and tensile strength.

[0094] After testing, the drying temperature and drying time of different papers were compared, and the experimental results were shown in Table 4 below:

[0095] Table 4

[0096]

[0097] We also found that different drying temperatures and drying times have a great influence on the appearance and various physical strength properties of paper. As shown in Table 4, the drying temperatures of specific embodiment 4, comparative examples 9 and 10 are 80°C, 90°C and 100°C respectively; the drying times are 30min, 20min and 10min respectively, and the strength properties of the paper decrease successively. This is because 70°C water-soluble PVA fibers are added, so if the drying temperature is too high, the PVA fibers will be destroyed, the strength of the paper tape will be reduced, and the paper will become hard and brittle. When the drying temperature is 80°C, the strength properties of the paper are excellent, and the paper is uniform, soft and flat.

[0098] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a paper-based strapping tape, characterized in that: The steps include: S1. Shredding pulp fibers for dilution and debonding, and then refining the pulp, with a beating degree of 30°SR; a refining gap of 0.01 mm to 0.2 mm; a refining concentration of 8% to 12%; and the pulp fibers are unbleached coniferous wood pulp; S2, diluting the slurry prepared in S1, then adding the additive into the container containing the slurry, and stirring thoroughly; The additives include 70°C water-soluble PVA fiber, PAE, AKD and cationic starch; wherein the addition amount of 70°C water-soluble PVA fiber is 15.0%, the addition amount of PAE is 2%, the addition amount of AKD is 0.4%, and the addition amount of cationic starch is 1.2%, and the addition amount is calculated as a percentage of the absolute dry weight of unbleached coniferous pulp; S3, placing the stirred slurry in a paper sheet former to form a wet paper sheet, and drying the wet paper sheet at 80° C. to obtain a paper-based strapping tape base paper; S4. Cut the prepared paper-based strapping tape, and heat-seal the paper tape cut into a certain specification. First, use a small amount of clean water to moisten the part that needs to be heat-sealed, and then use a buckle-free hot-melt strapping machine to hot-press and hot-melt the part that needs to be heat-sealed at 165°C for 6 seconds; the paper-based strapping tape has a paper weight of 120 g / m 2 .

2. The preparation method according to claim 1, characterized in that: In S4, the paper tape specifications are 15 mm in width and 0.18 mm in thickness.

3. A paper-based strapping tape, characterized in that: Prepared by the preparation method according to any one of claims 1 to 2.

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