Physical micro-nano modified enhanced mixed paper pulp-based packaging paper, preparation method and application

Abstract

The invention provides physical micro-nano modified enhanced mixed paper pulp-based packaging paper, a preparation method and application, and relates to the field of packaging materials. The preparation method of the physical micro-nano modified enhanced mixed paper pulp-based packaging paper is characterized by comprising the following steps: pulp preparation, defibering treatment, pulp grinding treatment, papermaking treatment and calendering treatment. According to the preparation method of the physical micro-nano modified reinforced mixed paper pulp based packaging paper, no chemical medicine, no polyethylene, no coating film, no non-renewable fossil materials or toxic materials are added, the packaging paper is biodegradable, the preparation method is simple, the packaging paper can be in direct contact with food, and recycling and reusing are convenient and effective; the physical micro-nano modified enhanced mixed paper pulp-based packaging paper has good gas barrier, water resistance and oil resistance.

Description

Technical Field

[0001] The invention relates to the field of packaging materials, and in particular to a physically micro-nano modified and reinforced mixed pulp-based packaging paper, a preparation method and an application thereof. Background Art

[0002] Due to the low cost, light weight and wide range of uses of plastics, global plastic consumption has doubled in the past fifty years, but its unreasonable disposal has also caused serious environmental threats. It is estimated that by 2050, plastic waste will reach 1.3 billion tons. Most plastic waste cannot be composted and can only be disposed of by incineration and landfill, which will lead to the continuous deterioration of the climate. At the same time, plastic waste will harm the marine ecosystem when it is discarded, and eventually reach and deposit in the human body through the food chain. At present, about 70% of plastics worldwide are used to make disposable plastic products. Among them, with the increasing consumption of pre-prepared food and drinks, plastics are often made into disposable plastic packaging, which will directly affect human health and the ecological environment.

[0003] In recent years, people have begun to pay attention to renewable, human-friendly, and biodegradable paper-based packaging materials, and have tried to use various means to enhance the barrier properties of paper-based packaging materials against water vapor, gas, and grease, such as plastic coating, aluminum foil lamination, polymer coating, and atomic layer deposition. However, these methods still inevitably use non-biodegradable plastic materials, such as polypropylene and polyethylene. In addition, polymer coatings also contain highly toxic toluene diisocyanate, which poses a great potential risk to food safety. These laminates, multilayer materials, and coating materials pose many challenges in the recycling of paper-based composite materials, especially in terms of sustainability. A large part of these materials are eventually landfilled or incinerated, which aggravates environmental pollution and is not conducive to the effective management of waste. At present, people have begun to pay attention to these issues and have gradually begun to adopt sustainable, renewable, and biodegradable materials, but the current research focus is mostly on the improvement and efficacy of composite coatings, and has been looking for, designing, and combining composite coating materials with various additives. It has problems such as complex raw material synthesis and multi-layer coating, which not only consumes a large amount of additional additives and increases costs accordingly, but also brings greater difficulties and challenges to the subsequent recycling of paper-based packaging materials.

[0004] Thus, a paper-based packaging material is provided which has no added chemicals, no polyethylene, no coating, is biodegradable, has a simple preparation method, can be in direct contact with food, is convenient and effective to recycle and reuse, and has good air barrier, waterproof and oil resistance functions. This material has important significance and value for the further development of barrier paper-based packaging materials and renewable paper in the field of food packaging. Summary of the invention

[0005] In order to solve the technical problems existing in the prior art, the present invention aims at the problems that the existing paper-based packaging materials are not biodegradable, the coating contains toxic substances, and the coating preparation process is complicated. The present invention provides a physically micro-nano modified and enhanced mixed pulp-based packaging paper, a preparation method and an application. The paper does not contain added chemicals, polyethylene, or coatings, does not involve non-renewable fossil materials and toxic materials, is biodegradable, has a simple preparation method, can be in direct contact with food, and is convenient and effective to recycle and reuse. The physically micro-nano modified and enhanced mixed pulp-based packaging paper has good gas barrier, waterproof and oil resistance.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: A method for preparing physically micro-nano modified and reinforced mixed pulp-based packaging paper comprises the following steps: pulping, decomposition treatment, pulping treatment, papermaking treatment, and calendering treatment; The pulping method comprises soaking bleached hardwood pulp in water to obtain a first pulp; soaking bleached softwood pulp in water to obtain a second pulp; mixing the first pulp and the second pulp to obtain mixed paper pulp; The method of the deflaking treatment is to adjust the concentration of the mixed pulp and then perform the deflaking treatment to obtain the deflaked pulp; The pulping method comprises adjusting the concentration of the deflaked pulp and then performing fine grinding to obtain a finely ground mixed pulp; The papermaking method comprises adjusting the concentration of the refined mixed pulp and then performing papermaking to obtain base paper; The base paper is subjected to calendering treatment to prepare physically micro-nano modified and reinforced mixed pulp-based packaging paper.

[0007] Preferably, the bleached hardwood pulp is at least one of the following: bleached poplar pulp, bleached eucalyptus pulp; The bleached coniferous wood pulp is at least one of the following: bleached pine wood pulp and bleached fir wood pulp.

[0008] Preferably, the ISO brightness of the bleached hardwood pulp is 83-87%, the average fiber length is 0.7-1.5 mm, the average fiber width is 12-20 μm, and the fiber thickness is 100-200 mg / km; The ISO brightness of the bleached coniferous wood pulp is 84-87%, the average fiber length is 2.0-2.5 mm, the average fiber width is 25-30 μm, and the fiber thickness is 250-300 mg / km.

[0009] Preferably, in the mixed pulp, the absolute dry mass ratio of bleached hardwood pulp to bleached softwood pulp is 1-10:1-10.

[0010] Preferably, in the deflaking treatment, the deflaking speed is controlled to be 13000-16000 r / min, and the deflaking concentration is 0.8-1.6wt%.

[0011] Preferably, in the refining treatment, the refining concentration is controlled to be 7-14wt%, and the refining speed is controlled to be 8000-17000r / min.

[0012] Preferably, in the papermaking process, the concentration of the refined mixed pulp is adjusted to 0.2-0.5wt%, and the papermaking process is performed to obtain a basis weight of 60g / m 2 The original paper.

[0013] Preferably, in the calendering treatment, the calendering temperature is 80-130° C., the calendering pressure is 700-1400 PSI, and the calendering times are 2-7 times.

[0014] A physically micro-nano modified and reinforced mixed pulp-based packaging paper, prepared by the aforementioned preparation method; the physically micro-nano modified and reinforced mixed pulp-based packaging paper has a tensile strength of 2.4-3.5 KN / m, an air resistance of 5507-9030s, and a water vapor permeability of 287-384 g / m 2 ·sky.

[0015] The above-mentioned physically micro-nano modified and reinforced mixed pulp-based packaging paper is used as packaging for oil-containing foods.

[0016] Compared with the prior art, the present invention has the following beneficial effects: (1) The preparation method of the physical micro-nano modified and enhanced mixed pulp-based packaging paper of the present invention adopts two physical micro-nano modification means in combination: fine grinding and pulping treatment in combination with calendering treatment. Among them, the fine grinding and pulping treatment can effectively disperse the pulp after decomposition, create more complex and tortuous channels for gas molecules, reduce the permeability of gas molecules, and form a more effective barrier to block air penetration; at the same time, during the fine grinding and pulping process, promoting the formation of fibrils and microfibrils can increase the surface area of ​​the fibers and enhance the barrier-forming ability of the fibers. Calendering treatment can effectively enhance the flatness of the surface of the lightweight paper base and further improve the oil resistance of the lightweight paper. Furthermore, the preparation method of the physical micro-nano modified and enhanced mixed pulp-based packaging paper can further optimize the barrier properties of the packaging paper by adjusting the proportion of specific raw materials (bleached hardwood pulp and bleached coniferous pulp).

[0017] (2) The physical micro-nano modified and reinforced mixed pulp-based packaging paper of the present invention has a tensile strength of 2.4-3.5 KN / m, an air resistance of 5507-9030s, and a water vapor permeability of 287-384 g / m 2 · Kit oil resistance can reach level 10.

[0018] (3) The physically micro-nano modified and reinforced mixed pulp-based packaging paper of the present invention has good oil resistance, gas barrier, waterproof and other properties, and the material used is only pulp material, no additional chemicals are required, no polyethylene, no coating, no non-renewable fossil materials and toxic materials are involved, it is biodegradable, can directly contact food, and the pulp is recyclable and the recycling operation is simple, and recycling and reuse are convenient and effective.

[0019] (4) The preparation method of the physically micro-nano modified reinforced mixed pulp-based packaging paper of the present invention is simple, the process is easy to control, and does not require the coating process and coating equipment used in the preparation of traditional air-barrier, waterproof and oil-proof paper. It is easy to promote and apply, and is conducive to large-scale industrial production. It can effectively replace existing plastic coating materials, aluminum-plastic materials and coated paper-based packaging materials, and has good practical application value. DETAILED DESCRIPTION

[0020] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific embodiments of the present invention are now described. It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those generally understood by those of ordinary skill in the art to which the present application belongs.

[0021] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0022] Specifically, in a typical embodiment of the present invention, the preparation method of the physically micro-nano modified reinforced mixed pulp-based packaging paper comprises the following steps: pulping, decomposition treatment, pulping treatment, papermaking treatment, and calendering treatment; The pulping method comprises soaking bleached hardwood pulp in water to obtain a first pulp; soaking bleached softwood pulp in water to obtain a second pulp; mixing the first pulp and the second pulp to obtain mixed paper pulp; The method of the deflaking treatment is to adjust the concentration of the mixed pulp and then perform the deflaking treatment to obtain the deflaked pulp; The pulping method comprises adjusting the concentration of the deflaked pulp and then performing fine grinding to obtain a finely ground mixed pulp; The papermaking method comprises adjusting the concentration of the refined mixed pulp and then performing papermaking to obtain base paper; The base paper is subjected to calendering treatment to prepare physically micro-nano modified and reinforced mixed pulp-based packaging paper.

[0023] The aforementioned preparation method of the physical micro-nano modified enhanced mixed pulp-based packaging paper adopts two physical micro-nano modification methods: fine grinding and pulping treatment in conjunction with calendering treatment. Among them, fine grinding and pulping treatment can effectively disperse the pulp after decomposition, create more complex and tortuous channels for gas molecules, reduce the permeability of gas molecules, and form a more effective barrier to block air penetration; at the same time, during the fine grinding and pulping process, promoting the formation of fibrils and microfibrils can increase the surface area of ​​the fibers and enhance the barrier-forming ability of the fibers. Calendering treatment can effectively enhance the flatness of the surface of the light paper base and further improve the oil resistance of the light paper.

[0024] In a specific embodiment of the present invention, the ISO whiteness of the bleached conifer pulp raw material is 84-87%, the average fiber length is 2.0-2.5 mm, the average fiber width is 25-30 μm, and the fiber thickness is 250-300 mg / km. Depending on the origin, the bleached conifer pulp raw material includes: domestic bleached conifer pulp or imported bleached conifer pulp; depending on the raw material, the bleached conifer pulp raw material includes: bleached pine pulp, bleached fir pulp or other bleached conifer pulp; in order to make the industrialization cost of the present invention lower, in the specific embodiment of the present application, domestic bleached pine pulp is preferably used.

[0025] More preferably, the ISO brightness of the domestic bleached pine pulp is 86.5%; the average fiber length is 2.3 mm; the average fiber width is 28.5 μm; and the fiber thickness is 270 mg / km.

[0026] In a specific embodiment of the present invention, the ISO whiteness of the bleached hardwood pulp raw material is 83-87%, the average fiber length is 0.7-1.5 mm, the average fiber width is 12-20 μm, and the fiber thickness is 100-200 mg / km. Depending on the origin, the bleached hardwood pulp raw material includes: domestic bleached hardwood pulp or imported bleached hardwood pulp; depending on the raw material, the bleached hardwood pulp raw material includes: bleached poplar pulp, bleached eucalyptus pulp or other bleached hardwood pulp; in order to make the industrialization cost of the present invention lower, in the specific embodiment of the present application, domestic bleached poplar pulp is preferably used.

[0027] More preferably, the domestic bleached poplar pulp has an ISO brightness of 85%, an average fiber length of 1.1 mm, an average fiber width of 17 μm, and a fiber thickness of 155 mg / km.

[0028] The aforementioned method for preparing physically micro-nano modified reinforced mixed pulp-based packaging paper can further optimize the barrier properties of the packaging paper by adjusting the proportion of specific raw materials (bleached hardwood pulp, bleached coniferous pulp).

[0029] In a specific embodiment of the present invention, in the mixed pulp, the absolute dry mass ratio of bleached hardwood pulp to bleached softwood pulp is 1-10:1-10.

[0030] In a specific embodiment of the present invention, during the deflaking treatment, the deflaking speed is controlled to be 13000-16000 r / min, and the deflaking concentration is 0.8-1.6 wt%.

[0031] In a specific embodiment of the present invention, in the refining treatment, the refining concentration is controlled to be 7-14wt%, and the refining speed is controlled to be 8000-17000r / min.

[0032] In a specific embodiment of the present invention, in the papermaking process, the concentration of the refined mixed pulp is adjusted to 0.2-0.5wt%, and the papermaking process is performed to obtain a basis weight of 60g / m 2 The original paper.

[0033] In a specific embodiment of the present invention, the calendering treatment has a calendering temperature of 80-130° C., preferably 90-110° C.; a calendering pressure of 700-1400 PSI, preferably 900-1200 PSI; In a specific embodiment of the present invention, the calendering treatment is performed 2-7 times, preferably 4-6 times.

[0034] In another typical embodiment of the present invention, there is provided a physically micro-nano modified and reinforced mixed pulp-based packaging paper prepared by the aforementioned method; the physically micro-nano modified and reinforced mixed pulp-based packaging paper has a tensile strength of 2.4-3.5 KN / m, an air resistance of 5507-9030s, and a water vapor permeability of 287-384 g / m 2 ·sky.

[0035] In another specific embodiment of the present invention, there is provided use of the aforementioned physically micro-nano modified and reinforced mixed pulp-based packaging paper as packaging for oil-containing food.

[0036] The present invention is further described below in conjunction with specific examples, which are only intended to explain the present invention and are not intended to limit its contents. Any simple modifications, equivalent changes and modifications made to the implementation methods based on the technical essence of the present invention are within the scope of the technical solution of the present invention.

[0037] The test method used is as follows: (1) Thickness and apparent density: TAPPI 411om-21 "Thickness (caliper of paper, paperboard, and combined board").

[0038] (2) Water vapor transmission rate: ASTM E-96 method "Standard test methods for water vapor transmission of materials".

[0039] (3) Air resistance test: TAPPI T460 methodom-02 "Air resistance of paper (Gurley method)".

[0040] (4) Oil resistance test: TAPPI T 559cm-02 "Grease resistance test for paper and paperboard".

[0041] (5) Tensile strength: GB / T12914-2018 “Determination of tensile strength of paper and paperboard - Constant rate of tension method”.

[0042] Example 1 This embodiment provides a method for preparing physically micro-nano modified and reinforced mixed pulp-based packaging paper, specifically: The domestic bleached poplar kraft pulp and the domestic bleached pine kraft pulp were torn into small pieces, respectively soaked in water for 24 hours, and the moisture content was measured to obtain the first pulp (domestic bleached poplar kraft pulp) and the second pulp (domestic bleached pine kraft pulp); the first pulp and the second pulp were weighed and mixed according to the ratio of 10:1 of the absolute dry weight of the bleached domestic poplar kraft pulp and the bleached domestic pine kraft pulp, and an appropriate amount of water was added to adjust the concentration of the mixed pulp to 1.2wt%; then the mixed pulp was put into the deflaking cup of the deflaking machine, and the deflaking speed was set to 15000r / min, and the deflaking was carried out. After the deflaking treatment, a deflaked pulp is obtained; the deflaked pulp is filtered to remove part of the moisture, the pulp concentration is maintained at 10wt%, and then it is transferred to the PFI refiner, the refining speed is set to 13000r / min, and the pulping treatment is carried out; after the refining is completed, the refined mixed pulp is taken out, and an appropriate amount of water is added to adjust the concentration of the refined mixed pulp to 0.25wt%, and papermaking is carried out according to the quantitative weight of 60g / m² to obtain base paper; then the calendering temperature is set to 100℃, the calendering pressure is set to 1000PSI, and the base paper is calendered 5 times to obtain physically micro-nano modified reinforced mixed pulp-based packaging paper.

[0043] In the preparation method of the physically micro-nano modified and reinforced mixed pulp-based packaging paper, the relevant process parameters are shown in the following table:

[0044] This embodiment also provides physically micro-nano modified and reinforced mixed pulp-based packaging paper prepared by the aforementioned method.

[0045] This embodiment also provides the use of the aforementioned physically micro-nano modified and reinforced mixed pulp-based packaging paper as packaging for oil-containing foods.

[0046] Example 2 This embodiment provides a method for preparing physically micro-nano modified and reinforced mixed pulp-based packaging paper, specifically: The domestic bleached poplar kraft pulp and the domestic bleached pine kraft pulp were torn into small pieces, respectively soaked in water for 24 hours, and the moisture content was measured to obtain the first pulp (domestic bleached poplar kraft pulp) and the second pulp (domestic bleached pine kraft pulp); the first pulp and the second pulp were weighed and mixed according to the ratio of 1:10 of the absolute dry weight of the bleached domestic poplar kraft pulp and the bleached domestic pine kraft pulp, and a proper amount of water was added to adjust the concentration of the mixed pulp to 1.2wt%; then the mixed pulp was put into the deflaking cup of the deflaking machine, and the deflaking speed was set to 15000r / min, and the deflaking was carried out. After the deflaking treatment, a deflaked pulp is obtained; the deflaked pulp is filtered to remove part of the moisture, the pulp concentration is maintained at 10wt%, and then it is transferred to the PFI refiner, the refining speed is set to 13000r / min, and the pulping treatment is carried out; after the refining is completed, the refined mixed pulp is taken out, and an appropriate amount of water is added to adjust the concentration of the refined mixed pulp to 0.25wt%, and papermaking is carried out according to the quantitative weight of 60g / m² to obtain base paper; then the calendering temperature is set to 100℃, the calendering pressure is set to 1000PSI, and the base paper is calendered 5 times to obtain physically micro-nano modified reinforced mixed pulp-based packaging paper.

[0047] In the preparation method of the physically micro-nano modified and reinforced mixed pulp-based packaging paper, the relevant process parameters are shown in the following table:

[0048] This embodiment also provides physically micro-nano modified and reinforced mixed pulp-based packaging paper prepared by the aforementioned method.

[0049] This embodiment also provides the use of the aforementioned physically micro-nano modified and reinforced mixed pulp-based packaging paper as packaging for oil-containing foods.

[0050] Example 3 This embodiment provides a method for preparing physically micro-nano modified and reinforced mixed pulp-based packaging paper, specifically: The domestic bleached poplar kraft pulp and the domestic bleached pine kraft pulp were torn into small pieces, respectively soaked in water for 24 hours, and the moisture content was measured to obtain the first pulp (domestic bleached poplar kraft pulp) and the second pulp (domestic bleached pine kraft pulp); the first pulp and the second pulp were weighed and mixed according to the ratio of 1:10 of the absolute dry weight of the bleached domestic poplar kraft pulp and the bleached domestic pine kraft pulp, and a proper amount of water was added to adjust the concentration of the mixed pulp to 1.2wt%; then the mixed pulp was put into the deflaking cup of the deflaking machine, and the deflaking speed was set to 15000r / min, and the deflaking was carried out. After the deflaking treatment, a deflaked pulp is obtained; the deflaked pulp is filtered to remove part of the water content, the pulp concentration is maintained at 10wt%, and then the pulp is transferred to the PFI refiner, the refining speed is set to 16000r / min, and the pulping treatment is carried out; after the refining is completed, the refined mixed pulp is taken out, and an appropriate amount of water is added to adjust the concentration of the refined mixed pulp to 0.25wt%, and papermaking is carried out according to a quantitative amount of 60g / m² to obtain base paper; then the calendering temperature is set to 100℃, the calendering pressure is set to 1000PSI, and the base paper is calendered 5 times to obtain physically micro-nano modified reinforced mixed pulp-based packaging paper.

[0051] In the preparation method of the physically micro-nano modified and reinforced mixed pulp-based packaging paper, the relevant process parameters are shown in the following table:

[0052] This embodiment also provides physically micro-nano modified and reinforced mixed pulp-based packaging paper prepared by the aforementioned method.

[0053] This embodiment also provides the use of the aforementioned physically micro-nano modified and reinforced mixed pulp-based packaging paper as packaging for oil-containing foods.

[0054] Example 4 This embodiment provides a method for preparing physically micro-nano modified and reinforced mixed pulp-based packaging paper, specifically: The domestic bleached poplar kraft pulp and the domestic bleached pine kraft pulp were torn into small pieces, respectively soaked in water for 24 hours, and the moisture content was measured to obtain the first pulp (domestic bleached poplar kraft pulp) and the second pulp (domestic bleached pine kraft pulp); the first pulp and the second pulp were weighed and mixed according to the ratio of 5:5 of the absolute dry weight of the bleached domestic poplar kraft pulp and the bleached domestic pine kraft pulp, and a proper amount of water was added to adjust the concentration of the mixed pulp to 1.2wt%; then the mixed pulp was put into the deflaking cup of the deflaking machine, and the deflaking speed was set to 15000r / min, and the deflaking was carried out. After the deflaking treatment, a deflaked pulp is obtained; the deflaked pulp is filtered to remove part of the water content, the pulp concentration is maintained at 10wt%, and then the pulp is transferred to the PFI refiner, the refining speed is set to 16000r / min, and the pulping treatment is carried out; after the refining is completed, the refined mixed pulp is taken out, and an appropriate amount of water is added to adjust the concentration of the refined mixed pulp to 0.25wt%, and papermaking is carried out according to a quantitative amount of 60g / m² to obtain base paper; then the calendering temperature is set to 100℃, the calendering pressure is set to 1000PSI, and the base paper is calendered 5 times to obtain physically micro-nano modified reinforced mixed pulp-based packaging paper.

[0055] In the preparation method of the physically micro-nano modified and reinforced mixed pulp-based packaging paper, the relevant process parameters are shown in the following table:

[0056] This embodiment also provides physically micro-nano modified and reinforced mixed pulp-based packaging paper prepared by the aforementioned method.

[0057] This embodiment also provides the use of the aforementioned physically micro-nano modified and reinforced mixed pulp-based packaging paper as packaging for oil-containing foods.

[0058] Example 5 This embodiment provides a method for preparing physically micro-nano modified and reinforced mixed pulp-based packaging paper, specifically: The domestic bleached poplar kraft pulp and the domestic bleached pine kraft pulp were torn into small pieces, respectively soaked in water for 24 hours, and the moisture content was measured to obtain the first pulp (domestic bleached poplar kraft pulp) and the second pulp (domestic bleached pine kraft pulp); the first pulp and the second pulp were weighed and mixed according to the ratio of 10:1 of the absolute dry weight of the bleached domestic poplar kraft pulp and the bleached domestic pine kraft pulp, and an appropriate amount of water was added to adjust the concentration of the mixed pulp to 1.2wt%; then the mixed pulp was put into the deflaking cup of the deflaking machine, and the deflaking speed was set to 15000r / min, and the deflaking was carried out. After the deflaking treatment, a deflaked pulp is obtained; the deflaked pulp is filtered to remove part of the water content, the pulp concentration is maintained at 10wt%, and then the pulp is transferred to the PFI refiner, the refining speed is set to 10000r / min, and the pulping treatment is carried out; after the refining is completed, the refined mixed pulp is taken out, and an appropriate amount of water is added to adjust the concentration of the refined mixed pulp to 0.25wt%, and papermaking is carried out according to a quantitative amount of 60g / m² to obtain base paper; then the calendering temperature is set to 100℃, the calendering pressure is set to 1000PSI, and the base paper is calendered 5 times to obtain physically micro-nano modified reinforced mixed pulp-based packaging paper.

[0059] In the preparation method of the physically micro-nano modified and reinforced mixed pulp-based packaging paper, the relevant process parameters are shown in the following table:

[0060] This embodiment also provides physically micro-nano modified and reinforced mixed pulp-based packaging paper prepared by the aforementioned method.

[0061] This embodiment also provides the use of the aforementioned physically micro-nano modified and reinforced mixed pulp-based packaging paper as packaging for oil-containing foods.

[0062] Example 6 This embodiment provides a method for preparing physically micro-nano modified and reinforced mixed pulp-based packaging paper, specifically: The domestic bleached poplar kraft pulp and the domestic bleached pine kraft pulp were torn into small pieces, respectively soaked in water for 24 hours, and the moisture content was measured to obtain the first pulp (domestic bleached poplar kraft pulp) and the second pulp (domestic bleached pine kraft pulp); the first pulp and the second pulp were weighed and mixed according to the ratio of 10:1 of the absolute dry weight of the bleached domestic poplar kraft pulp and the bleached domestic pine kraft pulp, and an appropriate amount of water was added to adjust the concentration of the mixed pulp to 1.2wt%; then the mixed pulp was put into the deflaking cup of the deflaking machine, and the deflaking speed was set to 15000r / min, and the deflaking was carried out. After the deflaking treatment, a deflaked pulp is obtained; the deflaked pulp is filtered to remove part of the water content, the pulp concentration is maintained at 10wt%, and then the pulp is transferred to the PFI refiner, the refining speed is set to 16000r / min, and the pulping treatment is carried out; after the refining is completed, the refined mixed pulp is taken out, and an appropriate amount of water is added to adjust the concentration of the refined mixed pulp to 0.25wt%, and papermaking is carried out according to a quantitative amount of 60g / m² to obtain base paper; then the calendering temperature is set to 100℃, the calendering pressure is set to 1000PSI, and the base paper is calendered 5 times to obtain physically micro-nano modified reinforced mixed pulp-based packaging paper.

[0063] In the preparation method of the physically micro-nano modified and reinforced mixed pulp-based packaging paper, the relevant process parameters are shown in the following table:

[0064] This embodiment also provides physically micro-nano modified and reinforced mixed pulp-based packaging paper prepared by the aforementioned method.

[0065] This embodiment also provides the use of the aforementioned physically micro-nano modified and reinforced mixed pulp-based packaging paper as packaging for oil-containing foods.

[0066] Example 7 This embodiment provides a method for preparing physically micro-nano modified and reinforced mixed pulp-based packaging paper, specifically: The domestic bleached poplar kraft pulp and the domestic bleached pine kraft pulp were torn into small pieces, respectively soaked in water for 24 hours, and the moisture content was measured to obtain the first pulp (domestic bleached poplar kraft pulp) and the second pulp (domestic bleached pine kraft pulp); the first pulp and the second pulp were weighed and mixed according to the ratio of 10:1 of the absolute dry weight of the bleached domestic poplar kraft pulp and the bleached domestic pine kraft pulp, and a proper amount of water was added to adjust the concentration of the mixed pulp to 1.2wt%; then the mixed pulp was put into the deflaking cup of the deflaking machine, and the deflaking speed was set to 15000r / min, and the deflaking was carried out. After the deflaking treatment, a deflaked pulp is obtained; the deflaked pulp is filtered to remove part of the water content, the pulp concentration is maintained at 10wt%, and then the pulp is transferred to the PFI refiner, the refining speed is set to 16000r / min, and the pulping treatment is carried out; after the refining is completed, the refined mixed pulp is taken out, and an appropriate amount of water is added to adjust the concentration of the refined mixed pulp to 0.25wt%, and papermaking is carried out according to a quantitative amount of 60g / m² to obtain base paper; then the calendering temperature is set to 90℃, the calendering pressure is set to 1200PSI, and the base paper is calendered 5 times to obtain physically micro-nano modified reinforced mixed pulp-based packaging paper.

[0067] In the preparation method of the physically micro-nano modified and reinforced mixed pulp-based packaging paper, the relevant process parameters are shown in the following table:

[0068] This embodiment also provides physically micro-nano modified and reinforced mixed pulp-based packaging paper prepared by the aforementioned method.

[0069] This embodiment also provides the use of the aforementioned physically micro-nano modified and reinforced mixed pulp-based packaging paper as packaging for oil-containing foods.

[0070] Example 8 This embodiment provides a method for preparing physically micro-nano modified and reinforced mixed pulp-based packaging paper, specifically: The domestic bleached poplar kraft pulp and the domestic bleached pine kraft pulp were torn into small pieces, respectively soaked in water for 24 hours, and the moisture content was measured to obtain the first pulp (domestic bleached poplar kraft pulp) and the second pulp (domestic bleached pine kraft pulp); the first pulp and the second pulp were weighed and mixed according to the ratio of 10:1 of the absolute dry weight of the bleached domestic poplar kraft pulp and the bleached domestic pine kraft pulp, and a proper amount of water was added to adjust the concentration of the mixed pulp to 1.2wt%; then the mixed pulp was put into the deflaking cup of the deflaking machine, and the deflaking speed was set to 15000r / min, and the deflaking was carried out. After the deflaking treatment, a deflaked pulp is obtained; the deflaked pulp is filtered to remove part of the water content, the pulp concentration is maintained at 10wt%, and then the pulp is transferred to the PFI refiner, the refining speed is set to 13000r / min, and the pulping treatment is carried out; after the refining is completed, the refined mixed pulp is taken out, and an appropriate amount of water is added to adjust the concentration of the refined mixed pulp to 0.25wt%, and papermaking is carried out according to a quantitative amount of 60g / m² to obtain base paper; then the calendering temperature is set to 110℃, the calendering pressure is set to 900PSI, and the base paper is calendered 5 times to obtain physically micro-nano modified reinforced mixed pulp-based packaging paper.

[0071] In the preparation method of the physically micro-nano modified and reinforced mixed pulp-based packaging paper, the relevant process parameters are shown in the following table:

[0072] This embodiment also provides physically micro-nano modified and reinforced mixed pulp-based packaging paper prepared by the aforementioned method.

[0073] This embodiment also provides the use of the aforementioned physically micro-nano modified and reinforced mixed pulp-based packaging paper as packaging for oil-containing foods.

[0074] Comparative Example 1 The technical solution of Comparative Example 1 corresponds to Example 1, except that no calendering treatment is performed.

[0075] The specific technical scheme is as follows: tear domestic bleached poplar kraft pulp and domestic bleached pine kraft pulp into small pieces, soak them in water for 24 hours respectively, measure their water content, and obtain the first pulp (domestic bleached poplar kraft pulp) and the second pulp (domestic bleached pine kraft pulp); weigh and mix the first pulp and the second pulp according to the ratio of 10:1 of the absolute dry weight of bleached domestic poplar kraft pulp and bleached domestic pine kraft pulp, add appropriate amount of water to adjust the concentration of the mixed pulp to 1.2wt%; then put the mixed pulp into the deflaking machine equipped with a deflaking machine. In the deflaking cup, the deflaking speed is set to 15000r / min, and after the deflaking treatment, a deflaked pulp is obtained; the deflaked pulp is filtered to remove part of the moisture, the pulp concentration is maintained at 10wt%, and then transferred to the PFI refiner, the refining speed is set to 13000r / min, and the pulp is refined; after the refining is completed, the refined mixed pulp is taken out, and an appropriate amount of water is added to adjust the concentration of the refined mixed pulp to 0.25wt%, and papermaking is carried out according to a quantitative amount of 60g / m² without calendering treatment, to obtain the mixed pulp-based packaging paper of Comparative Example 1.

[0076] In the preparation method of Comparative Example 1, the relevant process parameters are shown in the following table:

[0077] Comparative Example 2 The technical solution of Comparative Example 2 corresponds to Example 1, except that no fine grinding is performed.

[0078] The specific technical scheme is as follows: tear domestic bleached poplar kraft pulp and domestic bleached pine kraft pulp into small pieces, soak them in water for 24 hours respectively, measure their water content, and obtain the first pulp (domestic bleached poplar kraft pulp) and the second pulp (domestic bleached pine kraft pulp); weigh and mix the first pulp and the second pulp according to the ratio of 10:1 of the absolute dry mass of bleached domestic poplar kraft pulp and bleached domestic pine kraft pulp, add appropriate amount of water to adjust the concentration of the mixed pulp to 1.2wt%; then put the mixed pulp into the deflaking cup of the deflaking machine, set the deflaking speed to 15000r / min, and after deflaking treatment, obtain deflaked pulp, add appropriate amount of water to adjust the concentration of the deflaked pulp to 0.25wt%, and make paper according to the quantitative weight of 60g / m² to obtain base paper; then set the calendering temperature to 100℃ and the calendering pressure to 1000PSI, calender the base paper 5 times, and prepare the mixed pulp-based packaging paper of Comparative Example 2.

[0079] In the preparation method of Comparative Example 2, the relevant process parameters are shown in the following table:

[0080] Comparative Example 3 The technical solution of Comparative Example 3 corresponds to Example 1, except that no refining and calendering treatment is performed.

[0081] The specific technical scheme is as follows: tear domestic bleached poplar kraft pulp and domestic bleached pine kraft pulp into small pieces, soak them in water for 24 hours respectively, measure their water content, and obtain the first pulp (domestic bleached poplar kraft pulp) and the second pulp (domestic bleached pine kraft pulp); weigh and mix the first pulp and the second pulp according to the ratio of 10:1 of the absolute dry mass of bleached domestic poplar kraft pulp and bleached domestic pine kraft pulp, add appropriate amount of water to adjust the concentration of the mixed pulp to 1.2wt%; then put the mixed pulp into the deflaking cup of the deflaking machine, set the deflaking speed to 15000r / min, and after deflaking treatment, obtain deflaked pulp, add appropriate amount of water to adjust the concentration of the deflaked pulp to 0.25wt%, and make paper according to the quantitative amount of 60g / m² without calendering treatment to obtain the mixed pulp-based packaging paper of Comparative Example 3.

[0082] After testing, the performance indicators of the physically micro-nano modified and reinforced mixed pulp-based packaging paper prepared in Examples 1-8 and Comparative Examples 1-3 are shown in the following table:

[0083] It can be seen from the results in the above table that the physically micro-nano modified and reinforced mixed pulp-based packaging paper prepared by the present invention has good gas barrier, waterproof and oil-resistant properties, can be effectively applied to the field of oil-containing food packaging, is safe and environmentally friendly, and is easy to recycle, and is suitable for large-scale promotion and application; at the same time, by adopting the preparation method of the physically micro-nano modified and reinforced mixed pulp-based packaging paper of the present invention, the waste paper rate in the preparation process is less than 10%, and the cellulose recovery rate is more than 85%.

[0084] Unless otherwise specified, all percentages used in the present invention are by mass.

[0085] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing physically micro-nano modified and reinforced mixed pulp-based packaging paper, characterized in that: The process includes the following steps: pulping, decomposition, refining, papermaking and calendering. The pulping method comprises soaking bleached hardwood pulp in water to obtain a first pulp; soaking bleached softwood pulp in water to obtain a second pulp; mixing the first pulp and the second pulp to obtain mixed paper pulp; The method of the deflaking treatment is to adjust the concentration of the mixed pulp and then perform the deflaking treatment to obtain the deflaked pulp; The pulping method comprises adjusting the concentration of the deflaked pulp and then performing fine grinding to obtain a finely ground mixed pulp; The papermaking method comprises adjusting the concentration of the refined mixed pulp and then performing papermaking to obtain base paper; The base paper is subjected to calendering treatment to prepare physically micro-nano modified and reinforced mixed pulp-based packaging paper.

2. The method for preparing physically micro-nano modified and reinforced mixed pulp-based packaging paper according to claim 1, characterized in that: The bleached broadleaf pulp is at least one of the following: bleached poplar pulp, bleached eucalyptus pulp; The bleached coniferous wood pulp is at least one of the following: bleached pine wood pulp and bleached fir wood pulp.

3. The method for preparing physically micro-nano modified and reinforced mixed pulp-based packaging paper according to claim 1, characterized in that: The ISO brightness of the bleached hardwood pulp is 83-87%, the average fiber length is 0.7-1.5 mm, the average fiber width is 12-20 μm, and the fiber thickness is 100-200 mg / km; The ISO brightness of the bleached coniferous wood pulp is 84-87%, the average fiber length is 2.0-2.5 mm, the average fiber width is 25-30 μm, and the fiber thickness is 250-300 mg / km.

4. The method for preparing physically micro-nano modified and reinforced mixed pulp-based packaging paper according to claim 1, characterized in that: In the mixed pulp, the absolute dry mass ratio of bleached broadleaf pulp to bleached coniferous pulp is 1-10:1-10.

5. The method for preparing physically micro-nano modified and reinforced mixed pulp-based packaging paper according to claim 1, characterized in that: During the deflaking treatment, the deflaking speed is controlled to be 13000-16000 r / min, and the deflaking concentration is 0.8-1.6 wt%.

6. The method for preparing physically micro-nano modified and reinforced mixed pulp-based packaging paper according to claim 1, characterized in that: In the refining treatment, the refining concentration is controlled to be 7-14wt%, and the refining speed is controlled to be 8000-17000r / min.

7. The method for preparing physically micro-nano modified and reinforced mixed pulp-based packaging paper according to claim 1, characterized in that: During the papermaking process, the concentration of the refined mixed pulp was adjusted to 0.2-0.5wt%, and the papermaking process was performed to obtain a paper having a basis weight of 60g / m 2 The original paper.

8. The method for preparing physically micro-nano modified and reinforced mixed pulp-based packaging paper according to claim 1, characterized in that: In the calendering treatment, the calendering temperature is 80-130° C., the calendering pressure is 700-1400 PSI, and the calendering times are 2-7 times.

9. A physically micro-nano modified and reinforced mixed pulp-based packaging paper, characterized in that: The preparation method according to any one of claims 1 to 8 is used; the physical micro-nano modified and enhanced mixed pulp-based packaging paper has a tensile strength of 2.4-3.5 KN / m, an air resistance of 5507-9030s, and a water vapor permeability of 287-384 g / m 2 ·sky.

10. Use of the physically micro-nano modified and reinforced mixed pulp-based packaging paper as claimed in claim 9 as packaging paper for oil-containing food.

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