Oil-absorbing anti-seepage packing paper for fried food and preparation method thereof

Abstract

The invention belongs to the technical field of papermaking, and particularly relates to oil-absorbing seepage-proofing packing paper for fried food and a preparation method of the oil-absorbing seepage-proofing packing paper. The preparation method of the oil-absorbing anti-seepage packing paper for fried food comprises the following steps: dissolving stearic acid in distilled water, and adding sodium hydroxide to obtain a solution A; dissolving sodium alginate powder in distilled water, and heating in a water bath to obtain a solution B; adding the solution A into the paper pulp, then adding the solution B and aluminum sulfate to prepare a mixture, diluting, then adding AKD (Alkyl Ketene Dimer), performing sheet making and drying, and finally coating a polyvinyl alcohol solution on the back surface of a paper sheet and drying to obtain the oil-absorbing anti-seepage packing paper for the fried food. The oil-absorbing impermeable packing paper for fried food is prepared by taking plant fiber as a main raw material in a manner of in-pulp addition and surface sizing, and has excellent oil absorption capacity; meanwhile, the oil-proof agent is coated on the single surface, so that the permeation of oil is prevented, and the requirements of the oil-absorbing and anti-seepage packing paper for fried food are met; the invention also provides a preparation method, the preparation process is simple, and the product can be obtained through one-step molding.

Description

Technical Field

[0001] This invention belongs to the field of papermaking technology, specifically relating to an oil-absorbing and leak-proof pad for fried foods and its preparation method. Background Technology

[0002] In food processing and daily dining scenarios, fried foods are widely loved for their unique flavor. However, these foods often have a lot of oil residue on their surface, which not only affects the taste but may also cause the oil to seep through and contaminate the containers. Therefore, blotting paper has become an indispensable item in the kitchen.

[0003] Traditional greaseproof paper often uses fluorinated compounds as grease-repellent agents, achieving its grease-repellent effect through coating or sizing. However, fluorinated compounds have many drawbacks. Their main components, such as perfluorooctane sulfonyl compounds, are highly persistent and bioaccumulative in the environment, accumulating extensively in human and animal blood and seawater, causing harm to organisms. Furthermore, the large quantities of fluorinated compounds used are costly, and they can also lead to the non-biodegradability of greaseproof paper, posing risks to food safety and the environment. To address these issues, non-fluorinated greaseproof paper technology is constantly being developed.

[0004] CN117604820A discloses an oil-absorbing greaseproof paper and its preparation method. The technical solution is as follows: First, nanocellulose of different sizes and carboxyl content is prepared. Then, the fiber raw materials and nanocellulose are mixed and diluted in proportion to serve as raw materials for the permeation layer, oil storage layer, transition layer, and oil-proof layer, respectively. The paper is then sprayed out sequentially using a dynamic forming method to form a wet paper web. After vacuum dehydration and drying in a drying cylinder, an greaseproof paper with a four-layer structure and a basis weight of 20-100 g / m² is obtained. 2 Oil absorption capacity of the oil-absorbing surface: 20-500g / m² 2 The oil-proof paper prepared by the above scheme has excellent and controllable oil absorption and repellency properties, and the layers are firmly bonded, which can reduce the amount of oil ingested and is suitable for packaging high-oil foods. However, the realization of multi-layer dynamic forming in the forming process requires the use of a special four-layer wire paper machine, which results in high production costs.

[0005] CN108999024A proposes an oil-absorbing and oil-repellent paper, comprising a base paper and a hydrophobic oil-retaining layer. The hydrophobic oil-retaining layer is composed of a specific copolymer, two of cationic starch and polyvinyl alcohol, and hydrophobic oil-retaining particles. The hydrophobic oil-retaining particles are modified by coupling layered inorganic matter with stearic acid and its salts and esters. The hydrophobic long chains enhance the oil absorption capacity, while the hydrophilic resin blocks grease, thus exhibiting the characteristics of oil absorption and blocking grease diffusion. Although polyvinyl alcohol has oil-repellent properties and stearate has oil-retaining properties, mixing the two can easily affect the oil absorption and oil-repellent effect of the product.

[0006] In summary, existing non-fluorinated oil-resistant paper technologies still have some shortcomings, such as low oil storage layer quality leading to limited oil absorption capacity, excessive reliance on coating for oil absorption and oil resistance while the base paper itself has insufficient performance, and complex or high production processes. Further improvements and refinements are still needed. Summary of the Invention

[0007] To overcome the aforementioned deficiencies in the existing technology, the oil-absorbing and leak-proof pad paper for fried foods provided by the present invention is prepared by adding plant fibers as the main raw material and applying sizing to the surface, resulting in excellent oil absorption capacity. At the same time, by coating an oil-resistant agent on one side, oil penetration is prevented, thus absorbing oil on one side and preventing oil on the other, meeting the needs of oil-absorbing and leak-proof pad paper for fried foods. The present invention also provides its preparation method, which is simple to prepare and the product can be obtained in one molding process.

[0008] The preparation method of the oil-absorbing and leak-proof liner for fried foods according to the present invention includes the following steps:

[0009] (1) Stearic acid was added to distilled water, heated and stirred to dissolve it to obtain stearic acid emulsion. Then, sodium hydroxide was added and stirred to obtain solution A.

[0010] (2) Dissolve sodium alginate powder in distilled water, heat in a water bath, stir and dissolve to obtain sodium alginate solution, i.e. solution B, and keep it warm for later use.

[0011] (3) Under stirring conditions, solution A is added to the pulp, and then solution B and aluminum sulfate are added slowly to obtain sodium alginate / coagulant / pulp mixture;

[0012] (4) Dilute the mixture in step (3) to a concentration of 0.4-0.8 wt.%, add AKD waterproofing agent and mix evenly, make paper sheets on a papermaking machine, and then transfer the paper sheets to a drum dryer to dry at 90-120°C. The amount of AKD used is 5 wt.% of the total amount of the diluted mixture.

[0013] (5) Add polyvinyl alcohol to distilled water, heat and stir to 90-95℃, gelatinize for 45-60 minutes to obtain polyvinyl alcohol solution, keep warm for later use;

[0014] (6) Coat the back of the paper after drying in step (4) with a layer of polyvinyl alcohol solution and dry at 90-120℃ to obtain oil-absorbing and leak-proof pad paper for fried food.

[0015] In step (1), the concentration of stearic acid emulsion is 40-47 g / L, and the amount of sodium hydroxide used is 1.3-1.5 times the molar amount of stearic acid.

[0016] In step (2), the concentration of the sodium alginate solution is 0.4-0.5 wt.%.

[0017] In step (3), the proportions of each raw material to the total mass of the sodium alginate / coagulant / pulp mixture are as follows: pulp: 92.3-99.1 wt.%, solution A: 0.5-4.4 wt.%, solution B: 0.1-0.7 wt.%, aluminum sulfate: 0.3-2.6 wt.%.

[0018] In step (3), the pulp ratio is 5-10% fluff pulp, 30-40% softwood pulp, and 50-65% hardwood pulp.

[0019] In step (3), the pulp needs to be pulped to 20-25°SR by a double-disc mill before use.

[0020] In step (5), the concentration of the polyvinyl alcohol solution is 8-12 wt.%.

[0021] In step (6), the coating amount of the polyvinyl alcohol solution is 18-22 g / m². 2 .

[0022] The oil-absorbing and leak-proof liner for fried foods is prepared according to the above-mentioned preparation method for oil-absorbing and leak-proof liner for fried foods.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] (1) The oil-absorbing and seepage-proof pad paper for fried food of the present invention uses plant fiber as the main raw material and is combined with environmentally friendly additives such as sodium alginate, sodium stearate, and polyvinyl alcohol. This avoids the use of chemically synthesized materials that are difficult to degrade. The oil-proofing uses additives that are free of fluorine and other harmful substances. The product is safe and environmentally friendly, can be naturally degraded, and reduces production costs.

[0025] (2) The preparation method of the oil-absorbing and leak-proof pad paper for fried food of the present invention is simple. By adding it into the pulp and combining it with a reasonable pulp ratio, it is formed in one step, so that the oil absorption capacity of the product reaches ≥4g / g, which can effectively absorb excess oil on the surface of fried food and meet the actual use needs. At the same time, by applying glue to one side, while ensuring the high oil absorption of the front side, it prevents oil from penetrating and contaminating the container, thus solving the problem that traditional oil-absorbing paper is prone to leakage and contamination of the container. Detailed Implementation

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

[0027] The preparation method of the oil-absorbing and leak-proof liner for fried foods includes the following steps:

[0028] (1) Stearic acid is added to distilled water, heated and stirred to dissolve it to obtain a stearic acid emulsion with a concentration of 40-47 g / L. Then, sodium hydroxide is added and stirred to obtain solution A. The amount of sodium hydroxide is 1.3-1.5 times the molar amount of stearic acid.

[0029] (2) Dissolve sodium alginate powder in distilled water, heat in a water bath at 75°C, stir and dissolve to obtain a sodium alginate solution with a concentration of 0.4-0.5 wt.%, i.e. solution B, and keep it at 70°C for later use.

[0030] (3) Under stirring conditions, solution A is added to the pulp, and then solution B and aluminum sulfate are slowly added to obtain a sodium alginate / coagulant / pulp mixture. The pulp ratio is 5-10% fluff pulp, 30-40% softwood pulp, and 50-65% hardwood pulp. The pulp needs to be beaten to 20-25°SR by a double-disc mill before use. The proportion of each raw material to the total mass of the sodium alginate / coagulant / pulp mixture is as follows: pulp: 92.3-99.1 wt.%, solution A: 0.5-4.4 wt.%, solution B: 0.1-0.7 wt.%, aluminum sulfate: 0.3-2.6 wt.%.

[0031] (4) Dilute the mixture in step (3) to a concentration of 0.4-0.8 wt.%, add 5 wt.% AKD waterproofing agent and mix evenly. Then, roll the paper into sheets on a paper roll making machine and then transfer the paper sheets to a drum dryer to dry at 90-120°C.

[0032] (5) Add polyvinyl alcohol to distilled water, heat and stir to 90-95℃, gelatinize for 45-60 min, and obtain a polyvinyl alcohol solution with a concentration of 8-12wt.% and keep it at 70℃ for later use.

[0033] (6) Coat the back of the paper sheet after drying in step (4) with a layer of polyvinyl alcohol solution. The coating amount of polyvinyl alcohol solution is 18-22 g / m². 2 The oil-absorbing and leak-proof padding paper for fried foods is obtained by drying at 90-120℃.

[0034] Example 1

[0035] The preparation method of the oil-absorbing and leak-proof liner for fried foods includes the following steps:

[0036] (1) Stearic acid was added to distilled water and heated and stirred to dissolve it to obtain a stearic acid emulsion with a concentration of 47 g / L. Then, sodium hydroxide was added and stirred to obtain solution A. The amount of sodium hydroxide used was 1.5 times the molar amount of stearic acid.

[0037] (2) Dissolve sodium alginate powder in distilled water, heat in a water bath at 75°C, stir and dissolve to obtain a sodium alginate solution with a concentration of 0.5 wt.%, i.e. solution B, and keep it at 70°C for later use.

[0038] (3) Under stirring conditions, solution A is added to the pulp, and then solution B and aluminum sulfate are added slowly to obtain a sodium alginate / coagulant / pulp mixture. The pulp ratio is 5 wt.% fluff pulp, 30 wt.% softwood pulp, and 65 wt.% hardwood pulp. The pulp needs to be beaten to 20-25°SR by a double disc mill before use. The proportion of each raw material to the total mass of the sodium alginate / coagulant / pulp mixture is as follows: pulp: 99.1 wt.%, solution A: 0.5 wt.%, solution B: 0.1 wt.%, aluminum sulfate: 0.3 wt.%.

[0039] (4) Dilute the mixture in step (3) to a concentration of 0.4 wt.%, add 5 wt.% AKD waterproofing agent and mix evenly. Then, roll the paper on a paper roll making machine and transfer the paper to a drum dryer to dry at 90°C.

[0040] (5) Add polyvinyl alcohol to distilled water, heat and stir to 90°C, gelatinize for 60 min to obtain a polyvinyl alcohol solution with a concentration of 8 wt.%, and keep it at 70°C for later use.

[0041] (6) A layer of polyvinyl alcohol solution is coated on the back of the paper sheet after drying in step (4). The coating amount of polyvinyl alcohol solution is 20 g / m². 2 Oil-absorbing and leak-proof padding paper for fried foods is obtained by drying at 90℃.

[0042] Example 2

[0043] The preparation method of the oil-absorbing and leak-proof liner for fried foods includes the following steps:

[0044] (1) Stearic acid was added to distilled water and heated and stirred to dissolve it to obtain a stearic acid emulsion with a concentration of 45 g / L. Then, sodium hydroxide was added and stirred to obtain solution A. The amount of sodium hydroxide used was 1.4 times the molar amount of stearic acid.

[0045] (2) Dissolve sodium alginate powder in distilled water, heat in a water bath at 75°C, stir and dissolve to obtain a sodium alginate solution with a concentration of 0.45 wt.%, i.e. solution B, and keep it at 70°C for later use.

[0046] (3) Under stirring conditions, solution A is added to the pulp, and then solution B and aluminum sulfate are added slowly to obtain a sodium alginate / coagulant / pulp mixture. The pulp composition is 8 wt.% fluff pulp, 32 wt.% softwood pulp, and 60 wt.% hardwood pulp. The pulp needs to be beaten to 20-25°SR by a double-disc mill before use. The proportion of each raw material to the total mass of the sodium alginate / coagulant / pulp mixture is as follows: pulp: 92.3 wt.%, solution A: 4.4 wt.%, solution B: 0.7 wt.%, aluminum sulfate: 2.6 wt.%.

[0047] (4) Dilute the mixture in step (3) to a concentration of 0.6 wt.%, add 5 wt.% AKD waterproofing agent and mix evenly. Then, roll the paper on a paper roll making machine and transfer the paper to a drum dryer to dry at 100°C.

[0048] (5) Add polyvinyl alcohol to distilled water, heat and stir to 95°C, gelatinize for 45 min to obtain a polyvinyl alcohol solution with a concentration of 10 wt.%, and keep it at 70°C for later use.

[0049] (6) A layer of polyvinyl alcohol solution is coated on the back of the paper sheet after drying in step (4). The coating amount of polyvinyl alcohol solution is 22 g / m². 2 Oil-absorbing and leak-proof padding paper for fried foods is prepared by drying at 120℃.

[0050] Example 3

[0051] The preparation method of the oil-absorbing and leak-proof liner for fried foods includes the following steps:

[0052] (1) Stearic acid was added to distilled water and heated and stirred to dissolve it to obtain a stearic acid emulsion with a concentration of 40 g / L. Then, sodium hydroxide was added and stirred to obtain solution A. The amount of sodium hydroxide used was 1.3 times the molar amount of stearic acid.

[0053] (2) Dissolve sodium alginate powder in distilled water, heat in a water bath at 75°C, stir and dissolve to obtain a sodium alginate solution with a concentration of 0.4 wt.%, i.e. solution B, and keep it at 70°C for later use.

[0054] (3) Under stirring conditions, solution A is added to the pulp, and then solution B and aluminum sulfate are added slowly to obtain a sodium alginate / coagulant / pulp mixture. The pulp ratio is 10 wt.% fluff pulp, 40 wt.% softwood pulp, and 50 wt.% hardwood pulp. The pulp needs to be beaten to 20-25°SR by a double disc mill before use. The proportion of each raw material to the total mass of the sodium alginate / coagulant / pulp mixture is as follows: pulp: 95 wt.%, solution A: 2.4 wt.%, solution B: 0.5 wt.%, aluminum sulfate: 2.1 wt.%.

[0055] (4) Dilute the mixture in step (3) to a concentration of 0.8 wt.%, add 5 wt.% AKD waterproofing agent and mix evenly. Then, roll the paper on a paper roll making machine and transfer the paper to a drum dryer to dry at 120°C.

[0056] (5) Add polyvinyl alcohol to distilled water, heat and stir to 95°C, gelatinize for 45 min to obtain a polyvinyl alcohol solution with a concentration of 12 wt.%, and keep it at 70°C for later use.

[0057] (6) A layer of polyvinyl alcohol solution is coated on the back of the paper sheet after drying in step (4). The coating amount of polyvinyl alcohol solution is 18 g / m². 2 The oil-absorbing and leak-proof pad paper for fried foods is obtained by drying at 100℃.

[0058] Comparative Example 1

[0059] The preparation method of the oil-absorbing and leak-proof liner for fried foods includes the following steps:

[0060] (1) Stearic acid was added to distilled water and heated and stirred to dissolve it to obtain a stearic acid emulsion with a concentration of 47 g / L. Then, sodium hydroxide was added and stirred to obtain solution A. The amount of sodium hydroxide used was 1.5 times the molar amount of stearic acid.

[0061] (2) Add aluminum sulfate to solution A in 0.5 times the mass of stearic acid to prepare sodium stearate-aluminum sulfate gelling agent;

[0062] (3) Dissolve sodium alginate powder in distilled water, heat in a water bath at 75°C, stir and dissolve to obtain a sodium alginate solution with a concentration of 0.5 wt.%, i.e. solution B, and keep it at 70°C for later use.

[0063] (4) Under stirring conditions, the sodium stearate-aluminum sulfate coagulant prepared in (2) is added to solution B, and the volume ratio of the two solutions is 5:5.

[0064] (5) Add polyvinyl alcohol to distilled water, heat and stir to 95°C, gelatinize for 45 min to obtain a polyvinyl alcohol solution with a concentration of 20 wt.%, and keep it at 70°C for later use.

[0065] (6) Under stirring conditions, add the solution obtained in (4) to the polyvinyl alcohol solution obtained in (5), with a volume ratio of 5:5 between the two solutions; keep warm at 70℃ for later use.

[0066] (7) The pulp ratio is 5wt.% fluff pulp, 40wt.% softwood pulp, and 55wt.% hardwood pulp. The pulp is beaten to 20-25°SR by double disc mill before use.

[0067] (8) Dilute the slurry in step (7) to a concentration of 0.4 wt.%, add 5 wt.% AKD waterproofing agent and mix evenly. Make the paper on the papermaking machine, and then transfer the paper to the drum dryer to dry at 90°C.

[0068] (9) Coat the back of the paper sheet dried in step (8) with a layer of the polyvinyl alcohol mixed solution prepared in step (6), with a coating amount of 20 g / m². 2 The oil-absorbing and leak-proof pad paper for fried foods is obtained by drying at 100℃.

[0069] The oil-absorbing and leak-proof liner paper for fried foods prepared in the above embodiments and comparative examples was subjected to performance testing. The test results are shown in Table 1 below. Determination of paper oil absorption capacity: The sample was immersed in soybean oil in a free-fall state for 60 seconds, drained for 120 seconds, weighed, and the oil absorption capacity was calculated; Oil absorption capacity (g / g) = mass of oil absorbed by the sample / mass of the sample; Determination of oil resistance level: The oil resistance of the paper was tested according to the test method of GB / T22805.2-2008 standard.

[0070] Table 1. Performance test results of oil-absorbing and leak-proof padding paper for fried foods

[0071] Sample Name <![CDATA[Quantitative g / m 2 > Oil absorption capacity (g / g) Kit oil resistance rating Example 1 59.0 4.6 5 Example 2 60.0 3.8 5 Example 3 59.5 4.0 5 Comparative Example 1 60.5 2.0 4

[0072] As shown in Table 1, a comparison between Example 1 and Comparative Example 1 reveals that the coagulant and the oil-resistant agent interact with each other, resulting in a decrease in both the oil absorption and oil resistance of the paper sheets. In contrast, this application achieves both oil resistance and oil absorption in the product by adding a coagulant to the pulp and applying an oil-resistant agent to the surface, without any oil seepage.

Claims

1. A method for preparing an oil-absorbing and leak-proof liner for fried foods, characterized in that, Includes the following steps: (1) Stearic acid was added to distilled water, heated and stirred to dissolve it to obtain stearic acid emulsion. Then, sodium hydroxide was added and stirred to obtain solution A. (2) Dissolve sodium alginate powder in distilled water, heat in a water bath, stir and dissolve to obtain sodium alginate solution, i.e. solution B, and keep it warm for later use. (3) Under stirring conditions, solution A was added to the pulp, and then solution B and aluminum sulfate were added to obtain sodium alginate / coagulant / pulp mixture; (4) Dilute the mixture in step (3) to a concentration of 0.4-0.8 wt.%, add AKD waterproofing agent and mix evenly, then roll the paper on a paper roll making machine, and then transfer the paper to a drum dryer to dry at 90-120°C. (5) Add polyvinyl alcohol to distilled water, heat and stir to 90-95℃, gelatinize for 45-60 minutes to obtain polyvinyl alcohol solution, keep warm for later use; (6) Coat the back of the paper after drying in step (4) with a layer of polyvinyl alcohol solution and dry at 90-120℃ to obtain oil-absorbing and leak-proof pad paper for fried food.

2. The method for preparing the oil-absorbing and leak-proof liner for fried foods according to claim 1, characterized in that, In step (1), the concentration of stearic acid emulsion is 40-47 g / L, and the amount of sodium hydroxide used is 1.3-1.5 times the molar amount of stearic acid.

3. The method for preparing the oil-absorbing and leak-proof liner for fried foods according to claim 1, characterized in that, In step (2), the concentration of the sodium alginate solution is 0.4-0.5 wt.%.

4. The method for preparing the oil-absorbing and leak-proof liner for fried foods according to claim 1, characterized in that, In step (3), the proportions of each raw material to the total mass of the sodium alginate / coagulant / pulp mixture are as follows: pulp: 92.3-99.1 wt.%, solution A: 0.5-4.4 wt.%, solution B: 0.1-0.7 wt.%, aluminum sulfate: 0.3-2.6 wt.%.

5. The method for preparing the oil-absorbing and leak-proof liner for fried foods according to claim 1, characterized in that, In step (3), the pulp ratio is 5-10% fluff pulp, 30-40% softwood pulp, and 50-65% hardwood pulp.

6. The method for preparing the oil-absorbing and leak-proof liner for fried foods according to claim 1, characterized in that, In step (3), the pulp needs to be pulped to 20-25°SR by double-disc milling before use.

7. The method for preparing the oil-absorbing and leak-proof liner for fried foods according to claim 1, characterized in that, In step (5), the concentration of the polyvinyl alcohol solution is 8-12 wt.%.

8. The method for preparing the oil-absorbing and leak-proof liner for fried foods according to claim 1, characterized in that, In step (6), the coating amount of the polyvinyl alcohol solution is 18-22 g / m². 2 .

9. An oil-absorbing and leak-proof liner for fried foods, characterized in that, It is prepared by the method of preparing the oil-absorbing and leak-proof liner for fried foods according to any one of claims 1-8.