A super-tough, biodegradable, natural polymer composite environmentally friendly corrugated cardboard

Abstract

This invention relates to an ultra-tough, biodegradable, natural polymer composite environmentally friendly corrugated cardboard, belonging to the field of corrugated cardboard technology. The invention prepares this ultra-tough, biodegradable, natural polymer composite environmentally friendly corrugated cardboard through a process of paste preparation, single-layer corrugation, composite corrugation, and slitting. The invention involves mixing water, starch, alkali solution, amino starch, stabilizer, cashew phenol glycidyl ether, triallyl borate, epoxy succinic acid polymer, borax, and a bridging agent to prepare the paste. The ultra-tough, biodegradable, natural polymer composite environmentally friendly corrugated cardboard prepared by this invention exhibits high adhesive strength and burst strength.

Description

Technical Field

[0001] This invention relates to the field of corrugated cardboard technology, and in particular to an ultra-tough, biodegradable, natural polymer composite environmentally friendly corrugated cardboard. Background Technology

[0002] With the development of the food economy, the enhancement of people's economic capacity and aesthetic awareness, and the improvement of requirements for packaging quality, corrugated cardboard boxes are required not only to protect goods and facilitate transportation, but also to display goods, beautify goods, and promote sales. Therefore, people are no longer satisfied with the crude production, poor printing quality, and monotonous single-color cardboard box printing. Cardboard boxes are developing towards multi-color and halftone printing of images.

[0003] Chinese Patent CN118880666B relates to the field of paperboard product technology and discloses an environmentally friendly anti-mildew and antibacterial corrugated paperboard and its preparation method. The quaternary ammonium salt of the modified isocyanate-terminated polyurethane can attack the cell membrane or cell wall of microorganisms, causing the cell membrane function to be affected and resulting in irreversible damage to the structure of microbial organelles. Its structure contains the chemical element S, which has strong oxidizing and reducing properties, and can destroy the cell membrane of microorganisms, decompose organic matter, and destroy the metabolism and growth environment of mold. The epoxy and isocyanate groups of the modified isocyanate-terminated polyurethane can react with the hydroxyl and carboxyl groups on the surface of oxidized cassava starch. At the same time, the dihydroxymethylurea and oligomers in the urea-formaldehyde resin cross-link with the hydroxyl groups in the starch molecules to form a cross-linked network structure, which prevents water molecules from penetrating into the paper, thereby improving the bonding strength and water resistance of the corrugated paperboard.

[0004] Chinese Patent CN222251532U: This invention relates to a high-strength, deformation-resistant corrugated cardboard, belonging to the field of corrugated cardboard technology. It includes a substrate, an outer reinforcing plate, an inner reinforcing plate, a first corrugated paper, and a second corrugated paper. The outer reinforcing plate and the inner reinforcing plate are respectively disposed on the upper and lower sides of the substrate. The first corrugated paper and the second corrugated paper are respectively fixedly connected to the upper and lower sides of the substrate. First compression ribs are fixedly connected to both the upper and lower sides of the substrate.

[0005] Chinese Patent CN222251534U discloses a high-strength corrugated cardboard, including an outer cardboard layer and an inner cardboard layer, and further including reinforcing components for reinforcing the corrugated cardboard body. There are multiple reinforcing components. A first support plate and a second support plate are respectively bonded to both sides of the reinforcing components. A first UV-shaped corrugated paper core is bonded to the outer wall of the first support plate, and a second UV-shaped corrugated paper core is bonded to the outer wall of the second support plate. The outer cardboard layer and the inner cardboard layer are respectively bonded to the outer walls of the first UV-shaped corrugated paper core and the second UV-shaped corrugated paper core.

[0006] The corrugated cardboard prepared by the above patents and existing technologies has poor bonding strength and bursting strength, which need to be further improved. Summary of the Invention

[0007] To address the above problems, this invention provides an ultra-tough, biodegradable, natural polymer composite environmentally friendly corrugated cardboard, the operation steps of which are as follows:

[0008] S1 paste preparation: By weight, add 200-300 parts water and 30-40 parts starch, heat to 30-35℃ and stir for 3-5 minutes, then add 30-40 parts alkaline solution and stir for 15-30 minutes.

[0009] Continue adding 750-850 parts of water and stirring for 3-5 minutes, then add 260-320 parts of amino starch and 5-10 parts of alkaline solution, and stir for 3-5 minutes; add 2-7 parts of stabilizer SB-100 and stir for 20-50 minutes; wherein the amino starch is prepared according to the method described in the literature: Preparation of Amino Starch and Its Strengthening Effect on Paper, Section 1.3.2, Preparation of Cross-linked Amino Starch;

[0010] Continue adding 0.7-2.6 parts of cashew phenol glycidyl ether, 0.3-0.7 parts of triallyl borate, and 0.5-3.5 parts of epoxy succinic acid polymer, and stir at 50-65℃ for 20-60 minutes;

[0011] Continue adding 1-4.5 parts of borax and stirring for 3-6 minutes. Then add 10-16 parts of cable tray agent F-2921E and stir for 3-5 minutes to form a paste.

[0012] S2 Single Corrugated Paper: The base paper is fed forward by the paper splicer, preheating cylinder, single corrugator, and then conveyed forward by the overhead bridge to stack the single-sided corrugated paper;

[0013] S3 Composite Section: After the corrugated paper is aligned with its center by the overpass, paste is applied to the tips of the two corrugated papers by the gluing machine, and then it enters the laminating machine to bond with the face paper.

[0014] S4 Slitting Station: The cardboard is trimmed and crimped according to specifications by the trimming and crimping machine; then it is cut by the NC cross-cutting knife; and the cardboard is collected and sorted by the automatic stacking machine; thus, ultra-tough, biodegradable natural polymer composite environmentally friendly corrugated cardboard is obtained.

[0015] The starch mentioned is one of wheat starch, potato starch, corn starch, or cassava starch.

[0016] The preheating cylinder heats the base paper by passing steam through it, thereby removing moisture and increasing its strength; the preheating temperature is 120-150℃.

[0017] The single-wall corrugating machine presses the base paper into corrugations using upper and lower corrugating rollers, and then glues it onto the inner paper using a gluing machine to form corrugated paper; the preheating temperature is 120-180℃.

[0018] The laminating machine has 16 hot plates, each 600mm wide, with high-temperature steam circulating inside at a temperature of 120-180℃.

[0019] The NC cross-cutting blade uses a thin blade with a diameter of 270 mm and a minimum cutting distance of 135 mm.

[0020] Reaction mechanism

[0021] 1. Reaction of amino starch with cashew phenol glycidyl ether: Cashew phenol glycidyl ether (CGE) is an epoxy compound containing a benzene ring and a long unsaturated aliphatic chain; in the reaction, the amino group of amino starch undergoes a ring-opening addition reaction with the epoxy group of CGE to form a stable chemical bond.

[0022] 2. Reaction of amino starch with epoxy succinic acid polymer: Epoxy succinic acid polymer is a type of polymer material containing multiple epoxy groups; the amino groups of amino starch react with these epoxy groups to form stable chemical bonds.

[0023] 3. Reaction of amino starch with triallyl borate: Triallyl borate (BTE) is a compound containing multiple allyl groups, which can undergo an addition reaction with amino groups; this reaction introduces more flexible segments, further improving the toughness and impact resistance of the material.

[0024] Technical effect

[0025] The starch with grafted cashew phenol, succinic acid, and borate ester functional groups obtained through the above reaction is used to prepare ultra-tough, biodegradable, natural polymer composite environmentally friendly corrugated cardboard, which has the following technical effects:

[0026] 1. Improved Toughness: The introduced flexible segments and enhanced cross-linked network structure significantly improve the material's toughness, enabling it to maintain its integrity under significant external forces and resist fracture. By introducing flexible cashew nutshell chain and allyl structure, the material's molecular chains become more compliant, allowing them to deform under external forces and absorb a large amount of energy, reducing brittle fracture. The enhanced cross-linked network structure effectively disperses stress, prevents crack propagation, and significantly improves the material's mechanical properties and durability.

[0027] 2. Enhanced biodegradability: Using natural cashew nutmeg and starch as raw materials, the prepared materials have good biodegradability and can decompose in the natural environment, reducing environmental pollution.

[0028] 3. Improved processing performance: Due to the optimized molecular structure of the material, it exhibits better flowability and formability during processing, making it suitable for various processing techniques such as injection molding and extrusion.

[0029] 4. Broad application prospects: The obtained material has excellent mechanical properties. Detailed Implementation

[0030] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the following detailed description is provided in conjunction with embodiments and comparative examples:

[0031] 1. Adhesion strength test: The test shall be conducted in accordance with GB / T6548-2011 "Determination of Adhesion Strength of Corrugated Board".

[0032] 2. Bursting strength test: The test shall be conducted in accordance with GB / T6544-2008.

[0033] Example 1

[0034] An ultra-tough, biodegradable, natural polymer composite environmentally friendly corrugated cardboard, the operation steps of which are as follows:

[0035] S1 Paste Preparation: Heat 200kg of water and 30kg of starch to 30℃ and stir for 3 minutes. Then add 30kg of alkaline solution and stir for 15 minutes.

[0036] Continue adding 750 kg of water and stirring for 3 minutes, then add 260 kg of amino starch and 5 kg of alkaline solution, and stir for 3 minutes; add 2 kg of stabilizer SB-100 and stir for 20 minutes; the amino starch was prepared according to the method described in the literature: Preparation of Amino Starch and Its Strengthening Effect on Paper, Section 1.3.2, Preparation of Cross-linked Amino Starch;

[0037] Continue adding 0.7 kg of cashew phenol glycidyl ether, 0.3 kg of triallyl borate, and 0.5 kg of epoxy succinic acid polymer, and stir at 50°C for 20 min;

[0038] Continue adding 1kg of borax and stirring for 3 minutes. Then add 10kg of cable tray agent F-2921E and stir for 3 minutes to form a paste.

[0039] S2 Single Corrugated Paper: The base paper is fed forward by the paper splicer, preheating cylinder, single corrugator, and then conveyed forward by the overhead bridge to stack the single-sided corrugated paper;

[0040] S3 Composite Section: After the corrugated paper is aligned with its center by the overpass, paste is applied to the tips of the two corrugated papers by the gluing machine, and then it enters the laminating machine to bond with the face paper.

[0041] S4 Slitting Station: The cardboard is trimmed and crimped according to specifications by the trimming and crimping machine; then it is cut by the NC cross-cutting knife; and the cardboard is collected and sorted by the automatic stacking machine; thus, ultra-tough, biodegradable natural polymer composite environmentally friendly corrugated cardboard is obtained.

[0042] The starch mentioned is wheat starch.

[0043] The preheating cylinder heats the base paper by passing steam through it, thereby removing moisture and increasing the strength of the base paper; the preheating temperature is 120℃.

[0044] The single-wall corrugating machine presses the base paper into corrugations using upper and lower corrugating rollers, and then glues it onto the inner paper using a gluing machine to form corrugated paper; the preheating temperature is 120℃.

[0045] The laminating machine has 16 hot plates, each 600mm wide, with high-temperature steam circulating inside at a temperature of 120°C.

[0046] The NC cross-cutting blade uses a thin blade with a diameter of 270 mm and a minimum cutting distance of 135 mm.

[0047] Example 2

[0048] An ultra-tough, biodegradable, natural polymer composite environmentally friendly corrugated cardboard, the operation steps of which are as follows:

[0049] S1 Paste Preparation: Heat 240kg of water and 33kg of starch to 32℃ and stir for 4 minutes. Then add 33kg of alkaline solution and stir for 20 minutes.

[0050] Continue adding 780 kg of water and stirring for 4 min, then add 280 kg of amino starch and 6 kg of alkali solution, and stir for 4 min; add 4 kg of stabilizer SB-100 and stir for 30 min; the amino starch was prepared according to the method described in the literature: Preparation of Amino Starch and Its Strengthening Effect on Paper, Section 1.3.2, Preparation of Cross-linked Amino Starch;

[0051] Continue adding 1.3 kg of cashew phenol glycidyl ether, 0.4 kg of triallyl borate, and 1.5 kg of epoxy succinic acid polymer, and stir at 55°C for 30 min;

[0052] Continue adding 2kg of borax and stirring for 4 minutes. Then add 12kg of cable tray agent F-2921E and stir for 4 minutes to form a paste.

[0053] S2 Single Corrugated Paper: The base paper is fed forward by the paper splicer, preheating cylinder, single corrugator, and then conveyed forward by the overhead bridge to stack the single-sided corrugated paper;

[0054] S3 Composite Section: After the corrugated paper is aligned with its center by the overpass, paste is applied to the tips of the two corrugated papers by the gluing machine, and then it enters the laminating machine to bond with the face paper.

[0055] S4 Slitting Station: The cardboard is trimmed and crimped according to specifications by the trimming and crimping machine; then it is cut by the NC cross-cutting knife; and the cardboard is collected and sorted by the automatic stacking machine; thus, ultra-tough, biodegradable natural polymer composite environmentally friendly corrugated cardboard is obtained.

[0056] The starch mentioned is one of wheat starch, potato starch, corn starch, or cassava starch.

[0057] The preheating cylinder heats the base paper by passing steam through it, thereby removing moisture and increasing the strength of the base paper; the preheating temperature is 130℃.

[0058] The single-wall corrugating machine presses the base paper into corrugations using upper and lower corrugating rollers, and then glues it onto the inner paper using a gluing machine to form corrugated paper; the preheating temperature is 140℃.

[0059] The laminating machine has 16 hot plates, each 600mm wide, with high-temperature steam circulating inside at a temperature of 140°C.

[0060] The NC cross-cutting blade uses a thin blade with a diameter of 270 mm and a minimum cutting distance of 135 mm.

[0061] Example 3

[0062] An ultra-tough, biodegradable, natural polymer composite environmentally friendly corrugated cardboard, the operation steps of which are as follows:

[0063] S1 Paste Preparation: Heat 280kg of water and 38kg of starch to 34℃ and stir for 4 minutes. Then add 38kg of alkaline solution and stir for 25 minutes.

[0064] Continue adding 830 kg of water and stirring for 4 min, then add 300 kg of amino starch and 8 kg of alkaline solution, and stir for 4 min; add 6 kg of stabilizer SB-100 and stir for 40 min; the amino starch was prepared according to the method described in the literature: Preparation of Amino Starch and Its Strengthening Effect on Paper, Section 1.3.2, Preparation of Cross-linked Amino Starch;

[0065] Continue adding 2.1 kg of cashew phenol glycidyl ether, 0.6 kg of triallyl borate, and 2.5 kg of epoxy succinic acid polymer, and stir at 60°C for 50 min;

[0066] Continue adding 3kg of borax and stirring for 5 minutes. Then add 14kg of cable tray agent F-2921E and stir for 4 minutes to form a paste.

[0067] S2 Single Corrugated Paper: The base paper is fed forward by the paper splicer, preheating cylinder, single corrugator, and then conveyed forward by the overhead bridge to stack the single-sided corrugated paper;

[0068] S3 Composite Section: After the corrugated paper is aligned with its center by the overpass, paste is applied to the tips of the two corrugated papers by the gluing machine, and then it enters the laminating machine to bond with the face paper.

[0069] S4 Slitting Station: The cardboard is trimmed and crimped according to specifications by the trimming and crimping machine; then it is cut by the NC cross-cutting knife; and the cardboard is collected and sorted by the automatic stacking machine; thus, ultra-tough, biodegradable natural polymer composite environmentally friendly corrugated cardboard is obtained.

[0070] The starch mentioned is from potatoes.

[0071] The preheating cylinder heats the base paper by passing steam through it, thereby removing moisture and increasing its strength; the preheating temperature is 140℃.

[0072] The single-wall corrugating machine presses the base paper into corrugations using upper and lower corrugating rollers, and then glues it onto the inner paper using a gluing machine to form corrugated paper; the preheating temperature is 160℃.

[0073] The laminating machine has 16 hot plates, each 600mm wide, with high-temperature steam circulating inside at a temperature of 160°C.

[0074] The NC cross-cutting blade uses a thin blade with a diameter of 270 mm and a minimum cutting distance of 135 mm.

[0075] Example 4

[0076] An ultra-tough, biodegradable, natural polymer composite environmentally friendly corrugated cardboard, the operation steps of which are as follows:

[0077] S1 Paste Preparation: Heat 300 kg of water and 40 kg of starch to 35°C and stir for 5 minutes. Then add 40 kg of alkaline solution and stir for 30 minutes.

[0078] Continue adding 850 kg of water and stirring for 5 minutes, then add 320 kg of amino starch and 10 kg of alkali solution, and stir for 5 minutes; add 7 kg of stabilizer SB-100 and stir for 50 minutes; the amino starch was prepared according to the method described in the literature: Preparation of Amino Starch and Its Strengthening Effect on Paper, Section 1.3.2, Preparation of Cross-linked Amino Starch;

[0079] Continue adding 2.6 kg of cashew phenol glycidyl ether, 0.7 kg of triallyl borate, and 3.5 kg of epoxy succinic acid polymer, and stir at 65°C for 60 min;

[0080] Continue adding 4.5 kg of borax and stirring for 6 minutes. Then add 16 kg of cable tray agent F-2921E and stir for 5 minutes to form a paste.

[0081] S2 Single Corrugated Paper: The base paper is fed forward by the paper splicer, preheating cylinder, single corrugator, and then conveyed forward by the overhead bridge to stack the single-sided corrugated paper;

[0082] S3 Composite Section: After the corrugated paper is aligned with its center by the overpass, paste is applied to the tips of the two corrugated papers by the gluing machine, and then it enters the laminating machine to bond with the face paper.

[0083] S4 Slitting Station: The cardboard is trimmed and crimped according to specifications by the trimming and crimping machine; then it is cut by the NC cross-cutting knife; and the cardboard is collected and sorted by the automatic stacking machine; thus, ultra-tough, biodegradable natural polymer composite environmentally friendly corrugated cardboard is obtained.

[0084] The starch mentioned is tapioca starch.

[0085] The preheating cylinder heats the base paper by passing steam through it, thereby removing moisture and increasing the strength of the base paper; the preheating temperature is 150℃.

[0086] The single-wall corrugating machine presses the base paper into corrugations using upper and lower corrugating rollers, and then glues it onto the inner paper using a gluing machine to form corrugated paper; the preheating temperature is 180℃.

[0087] The laminating machine has 16 hot plates, each 600mm wide, with high-temperature steam circulating inside at a temperature of 180°C.

[0088] The NC cross-cutting blade uses a thin blade with a diameter of 270 mm and a minimum cutting distance of 135 mm.

[0089] Comparative Example 1

[0090] Cashew phenol glycidyl ether, triallyl borate, and epoxy succinic acid polymer were not added; otherwise, the same as in Example 1 was used.

[0091] Comparative Example 2

[0092] Cashew phenol glycidyl ether was not added; otherwise, it was the same as in Example 1.

[0093] Comparative Example 3

[0094] Without adding epoxy succinic acid polymer, otherwise the same as in Example 1.

[0095] The test results are shown in Table 1:

[0096] Table 1

[0097]

[0098] Based on the data analysis of the above embodiments and comparative examples, the ultra-tough biodegradable natural polymer composite environmentally friendly corrugated cardboard prepared by the present invention has high bonding strength and bursting strength.

[0099] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A super-tough biodegradable natural polymer composite environment-friendly corrugated paperboard, the operation steps of which are as follows: S1: paste preparation: 200-300 parts of water, 30-40 parts of starch, 30-40 parts of lye, 750-850 parts of water, 260-320 parts of amino starch, 5-10 parts of lye, 2-7 parts of stabilizer, 0.7-2.6 parts of cardanol glycidyl ether, 0.3-0.7 parts of triallyl borate, 0.5-3.5 parts of epoxy succinic acid polymer, 1-4.5 parts of borax, and 10-16 parts of bridging agent are added in sequence and stirred for 3-5 min, 3-5 min, 3-5 min, 20-60 min, 3-6 min, 3-5 min, and 20-50 min, respectively, and then heated to 30-35℃ and stirred for 3-5 min; S2: single corrugation: the raw paper is conveyed forward by a single corrugator through a preheating cylinder and a single corrugator; S3: compounding: the corrugated paper is aligned at the center and then enters a paste applicator to coat the corrugated paper with paste, and then enters a laminating machine to be bonded with the face paper; S4: slitting: the paperboard is trimmed and ruled according to the specifications, and then cut by an NC cross cutter and collected and arranged by an automatic stacking machine; a super-tough biodegradable natural polymer composite environment-friendly corrugated paperboard is obtained. The starch is one of wheat starch, potato starch, corn starch, and cassava starch. The preheating cylinder heats the raw paper by internal steam to remove the water content of the raw paper and improve the strength; the preheating temperature is 120-150℃. The single corrugator presses the raw paper into corrugations by upper and lower corrugating rollers, and then applies paste on the corrugations to bond with the inner paper to form corrugated paper; the preheating temperature is 120-180℃.

2. The super-tough biodegradable natural polymer composite environment-friendly corrugated paperboard according to claim 1, characterized in that: The laminating machine has 16 hot plates with a width of 600 mm, and the inside is connected with high-temperature steam with a temperature of 120-180℃.

3. The ultra-tough biodegradable natural polymer composite environment-friendly corrugated paperboard according to claim 1, characterized in that: The NC cross cutter adopts a thin blade with a diameter of 270 mm and a minimum cutting distance of 135 mm.

4. The super-tough biodegradable natural polymer composite environment-friendly corrugated paperboard according to claim 1, characterized in that: ​ 5. The super-tough biodegradable natural polymer composite environment-friendly corrugated paperboard according to claim 1, characterized in that: ​ 6. The super-tough biodegradable natural polymer composite environment-friendly corrugated paperboard according to claim 1, characterized in that: ​

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