A physically micro-nano modified and enhanced hybrid pulp-based packaging paper, preparation method and application

Abstract

The present invention provides a physically micro-nano modified and enhanced hybrid pulp-based packaging paper, a preparation method and an application, relating to the field of packaging materials. The preparation method of the physically micro-nano modified and enhanced hybrid pulp-based packaging paper is characterized by comprising the following steps: pulp preparation, beating treatment, refining treatment, papermaking treatment, and calendering treatment. The preparation method of the physically micro-nano modified and enhanced hybrid pulp-based packaging paper of the present invention does not add chemical drugs, does not contain polyethylene, does not have a coating film, does not involve non-renewable fossil materials and toxic materials, is biodegradable, has a simple preparation method, can be directly contacted with food, and is convenient and effective for recycling and reuse; the physically micro-nano modified and enhanced hybrid pulp-based packaging paper of the present invention has good gas barrier, waterproof and oil resistance properties.

Description

Technical Field

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

[0002] Due to the low cost, light weight and wide use of plastics, the global plastic consumption has doubled in the past five decades. However, its unreasonable disposal has also caused serious environmental threats. It is estimated that plastic waste will reach 1.3 billion tons by 2050. Most plastic waste cannot be composted and can only be treated by incineration and landfill, which will further lead to the continuous deterioration of the climate. At the same time, plastic waste will harm the marine ecosystem when discarded and finally reach and deposit in the human body through the food chain. Currently, about 70% of plastics globally are used to manufacture disposable plastic products. Among them, with the increasing consumption of pre-packaged food and beverages, plastics are usually 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 long tried various means to enhance the barrier properties of paper-based packaging materials to water vapor, gases and oils, such as methods like 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, the polymer coating also contains highly toxic toluene diisocyanate, posing a great potential danger to food safety. These laminates, multi-layer materials and coating materials have brought many challenges in the recycling of paper-based composite materials, especially in terms of sustainability, which is not ideal. A large part of these materials is ultimately landfilled or incinerated, thus exacerbating environmental pollution and being unfavorable for the effective management of waste. Currently, people have begun to attach importance to these problems and have gradually started to use sustainable, renewable and biodegradable materials. However, the current research focus of people mostly focuses 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, not only consuming a large amount of additional additives, but also increasing the cost correspondingly, and bringing greater difficulties and challenges to the subsequent recycling of paper-based packaging materials.

[0004] Therefore, it is of great significance and value to provide a paper-based packaging material that is free of added chemicals, free of polyethylene, free of coating film, biodegradable, has a simple preparation method, can be in direct contact with food, is convenient and effective for recycling and reuse, and at the same time has good gas barrier, waterproof and oil resistance functions, for the further development of barrier paper-based packaging materials and renewable paper in the field of food packaging. Summary of the Invention

[0005] To solve the technical problems existing in the prior art, in view of the problems of non-biodegradability of existing paper-based packaging materials, toxicity of coatings, and complexity of coating preparation processes, the present invention provides a physically micro-nano modified and enhanced hybrid pulp-based packaging paper, a preparation method, and an application. It does not add chemical agents, does not contain polyethylene, does not have a coating film, 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 for recycling and reuse; the physically micro-nano modified and enhanced hybrid pulp-based packaging paper has good gas barrier, waterproof, and oil resistance properties.

[0006] To solve the above technical problems, the technical solutions adopted by the present invention are as follows:

[0007] A preparation method of a physically micro-nano modified and enhanced hybrid pulp-based packaging paper includes the following steps: pulp mixing, beating treatment, refining treatment, paper making treatment, and calendering treatment;

[0008] The method of pulp mixing is to soak bleached hardwood pulp in water to obtain a first pulp; soak bleached softwood pulp in water to obtain a second pulp; and mix the first pulp and the second pulp to obtain a hybrid pulp;

[0009] The method of beating treatment is to adjust the concentration of the hybrid pulp and then perform beating treatment to obtain a beaten pulp;

[0010] The method of refining treatment is to adjust the concentration of the beaten pulp and then perform fine refining treatment to obtain a refined hybrid pulp;

[0011] The method of paper making treatment is to adjust the concentration of the refined hybrid pulp and then perform paper making treatment to obtain a base paper;

[0012] The base paper is subjected to calendering treatment to obtain a physically micro-nano modified and enhanced hybrid pulp-based packaging paper.

[0013] Preferably, the bleached hardwood pulp is at least one of the following: bleached poplar pulp, bleached eucalyptus pulp;

[0014] The bleached softwood pulp is at least one of the following: bleached pine pulp, bleached fir pulp.

[0015] 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 coarseness is 100-200 mg / km;

[0016] The ISO brightness of the bleached softwood 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 coarseness is 250-300 mg / km.

[0017] Preferably, in the mixed pulp, the absolute dry mass ratio of bleached hardwood pulp to bleached softwood pulp is 1-10:1-10.

[0018] Preferably, in the beating treatment, the beating speed is controlled at 13000-16000 r / min, and the beating concentration is 0.8-1.6 wt%.

[0019] Preferably, in the refining treatment, the refining concentration is controlled at 7-14 wt%, and the refining speed is 8000-17000 r / min.

[0020] Preferably, in the paper-making treatment, the concentration of the refined mixed pulp is adjusted to 0.2-0.5 wt%, and paper-making treatment is carried out to obtain a base paper with a basis weight of 60 g / m 2 2.

[0021] Preferably, in the calendering treatment, the calendering temperature is 80-130 °C, the calendering pressure is 700-1400 PSI, and the number of calendering times is 2-7 times.

[0022] A physically micro-nano modified reinforced mixed pulp-based packaging paper is prepared by the foregoing preparation method; the tensile strength of the physically micro-nano modified reinforced mixed pulp-based packaging paper is 2.4-3.5 KN / m, the air resistance is 5507-9030 s, and the water vapor transmission rate is 287-384 g / m 2 2·day.

[0023] Use of a foregoing physically micro-nano modified reinforced mixed pulp-based packaging paper as an oil-containing food packaging.

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

[0025] (1) In the preparation method of the physically micro-nano modified reinforced mixed pulp-based packaging paper of the present invention, two physical micro-nano modification means are combined: refining treatment and calendering treatment. Among them, the refining treatment can effectively disperse the pulp after beating, create more complex and tortuous channels for gas molecules, reduce the permeability of gas molecules, and form a more effective air permeation barrier; at the same time, in the process of refining treatment, the promotion of the formation of fibrils and microfibrils can increase the surface area of fibers and enhance the barrier formation ability of fibers. The 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. Further, in the preparation method of the physically micro-nano modified reinforced mixed pulp-based packaging paper, by adjusting the mixing ratio of specific raw materials (bleached hardwood pulp, bleached softwood pulp), the barrier performance of the packaging paper can be further optimized.

[0026] (2)The physical micro-nano modified and enhanced hybrid pulp-based packaging paper of the present invention has a tensile strength of 2.4 - 3.5 KN / m, an air resistance of 5507 - 9030 s, and a water vapor transmission rate of 287 - 384 g / m 2 ·day, and the Kit oil resistance level can reach level 10.

[0027] (3)The physical micro-nano modified and enhanced hybrid pulp-based packaging paper of the present invention has good properties such as oil resistance, gas barrier, and waterproofness. Moreover, the materials used are only pulp materials, without the need to add additional chemicals, no polyethylene, no coating, and do not involve non-renewable fossil materials and toxic materials. It is biodegradable, can be directly in contact with food, and the pulp can be recycled with simple recycling operations and convenient and effective recycling and reuse.

[0028] (4)The preparation method of the physical micro-nano modified and enhanced hybrid pulp-based packaging paper of the present invention is simple, the process is easy to control, and there is no need for the coating process and coating equipment in the preparation of traditional gas barrier and waterproof greaseproof paper, which is easy to promote and apply and is conducive to large-scale industrial production; it can effectively replace the existing plastic film materials, aluminum-plastic materials, and coated paper-based packaging materials, and has good practical application value. Specific embodiments

[0029] 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 all illustrative and are intended to provide further explanations for the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs.

[0030] 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 "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0031] Specifically, in a typical specific embodiment of the present invention, the preparation method of the physical micro-nano modified and enhanced hybrid pulp-based packaging paper includes the following steps: pulp preparation, beating treatment, refining treatment, papermaking treatment, and calendering treatment;

[0032] The method of pulp preparation is to soak bleached hardwood pulp in water to obtain the first pulp; soak bleached softwood pulp in water to obtain the second pulp; and mix the first pulp and the second pulp to obtain hybrid pulp;

[0033] The method of refining treatment is to adjust the concentration of the mixed pulp and then conduct refining treatment to obtain refined pulp;

[0034] The method of grinding treatment is to adjust the concentration of the refined pulp and then conduct fine grinding treatment to obtain fine-ground mixed pulp;

[0035] The method of papermaking treatment is to adjust the concentration of the fine-ground mixed pulp and then conduct papermaking treatment to obtain base paper;

[0036] The base paper is subjected to calendering treatment to produce a physically micro-nano modified and enhanced mixed pulp-based packaging paper.

[0037] In the specific embodiment of the present invention, the ISO brightness of the bleached softwood 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 coarseness is 250-300 mg / km. According to different origins, the bleached softwood pulp raw material includes: domestic bleached softwood pulp or imported bleached softwood pulp; according to different raw materials, the bleached softwood pulp raw material includes: bleached pine pulp, bleached fir pulp or other bleached softwood pulp; in order to make the industrial cost of the present invention lower, in the specific embodiment of this application, it is preferred to use domestic bleached pine pulp.

[0038] In the specific embodiment of the present invention, 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; the fiber coarseness is 270 mg / km.

[0039] 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; the fiber coarseness is 270 mg / km.

[0040] In the specific embodiments of the present invention, the ISO brightness 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 coarseness is 100-200 mg / km. According to different origins, the bleached hardwood pulp raw material includes: domestic bleached hardwood pulp or imported bleached hardwood pulp; according to different raw materials, the bleached hardwood pulp raw material includes: bleached poplar pulp, bleached eucalyptus pulp or other bleached hardwood pulp; in order to make the industrial cost of the present invention lower, in the specific embodiments of this application, domestic bleached poplar pulp is preferably used.

[0041] More preferably, the ISO brightness of the domestic bleached poplar pulp is 85%, the average fiber length is 1.1 mm, the average fiber width is 17 μm, and the fiber coarseness is 155 mg / km.

[0042] The preparation method of the aforementioned physically micro-nano modified enhanced mixed pulp-based packaging paper can further optimize the barrier performance of the packaging paper by adjusting the mixing ratio of specific raw materials (bleached hardwood pulp, bleached softwood pulp).

[0043] In the specific embodiments 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.

[0044] In the specific embodiments of the present invention, in the beating treatment, the beating speed is controlled at 13000-16000 r / min, and the beating concentration is 0.8-1.6 wt%.

[0045] In the specific embodiments of the present invention, in the refining treatment, the refining concentration is controlled at 7-14 wt%, and the refining speed is 8000-17000 r / min.

[0046] In the specific embodiments of the present invention, in the papermaking treatment, the concentration of the refined mixed pulp is adjusted to 0.2-0.5 wt%, and papermaking treatment is carried out to obtain a base paper with a basis weight of 60 g / m 2 2.

[0047] In the specific embodiments of the present invention, in the calendering treatment, the calendering temperature is 80-130 °C, preferably 90-110 °C; the calendering pressure is 700-1400 PSI, preferably 900-1200 PSI;

[0048] In the specific embodiments of the present invention, in the calendering treatment, the number of calendering times is 2-7 times, preferably 4-6 times.

[0049] In yet another typical specific embodiment of the present invention, there is provided a physically micro-nano modified and reinforced hybrid pulp-based packaging paper prepared by the aforementioned method; the tensile strength of the physically micro-nano modified and reinforced hybrid pulp-based packaging paper is 2.4 - 3.5 KN / m, the air resistance is 5507 - 9030 s, and the water vapor transmission rate is 287 - 384 g / m 2 ·day.

[0050] In yet another specific embodiment of the present invention, there is provided the use of the aforementioned physically micro-nano modified and reinforced hybrid pulp-based packaging paper as an oil-containing food packaging.

[0051] The present invention will be further described below in conjunction with specific embodiments. The following embodiments are only for explaining the present invention and do not limit its content. Any simple modification, equivalent change and modification made to the embodiments according to the technical essence of the present invention shall fall within the scope of the technical solution of the present invention.

[0052] The test methods adopted are as follows:

[0053] (1) Thickness and apparent density: TAPPI 411om-21 《Thickness (caliper of paper, paperboard, and combined board》.

[0054] (2) Water vapor transmission rate: ASTM E-96 method 《Standard test methods for water vapor transmission of materials》.

[0055] (3) Gas barrier test: TAPPI T460 methodom-02 《Air resistance of paper (Gurley method)》.

[0056] (4) Oil resistance test: TAPPI T 559cm-02 《Grease resistance test for paper and paperboard》.

[0057] (5) Tensile strength: GB / T12914-2018 《Determination of tensile strength of paper and paperboard - Constant speed tensile method》.

[0058] Example 1

[0059] This example provides a preparation method of a physically micro-nano modified and reinforced hybrid pulp-based packaging paper, specifically as follows:

[0060] 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 contents, 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 respectively according to the ratio of the absolute dry mass of bleached domestic poplar kraft pulp to bleached domestic pine kraft pulp of 10:1, and add an appropriate amount of water to adjust the concentration of the mixed pulp to 1.2 wt%; Then put the mixed pulp into the beating cup supporting the beater, set the beating speed at 15000 r / min, and carry out beating treatment to obtain beaten pulp; Filter to remove part of the water of the beaten pulp, keep the pulp concentration at 10 wt%, and then transfer it to a PFI refiner, set the refining speed at 13000 r / min, and carry out refining treatment; After the refining is completed, take down the refined mixed pulp, add an appropriate amount of water to adjust the concentration of the refined mixed pulp to 0.25 wt%, and make paper according to a basis weight of 60 g / m² to obtain base paper; Then set the calendering temperature at 100 °C and the calendering pressure at 1000 PSI, and calender the base paper 5 times to produce a physically micro-nano modified and enhanced mixed pulp-based packaging paper.

[0061] In the preparation method of the physically micro-nano modified and enhanced mixed pulp-based packaging paper, the relevant process parameters are shown in the following table:

[0062]

[0063] This example also provides a physically micro-nano modified and enhanced mixed pulp-based packaging paper prepared by the aforementioned method.

[0064] This example also provides the use of the aforementioned physically micro-nano modified and enhanced mixed pulp-based packaging paper as packaging for oil-containing foods.

[0065] Example 2

[0066] This example provides a preparation method of a physically micro-nano modified and enhanced mixed pulp-based packaging paper, specifically:

[0067] 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.

[0068] 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:

[0069]

[0070] This embodiment also provides physically micro-nano modified and reinforced mixed pulp-based packaging paper prepared by the aforementioned method.

[0071] 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.

[0072] Example 3

[0073] This embodiment provides a method for preparing physically micro-nano modified and reinforced mixed pulp-based packaging paper, specifically:

[0074] Tear domestic bleached kraft pulp made from poplar and domestic bleached kraft pulp made from pine into small pieces, soak them in water for 24 h respectively, measure their water contents, and obtain the first pulp (domestic bleached kraft pulp made from poplar) and the second pulp (domestic bleached kraft pulp made from pine); Weigh and mix the first pulp and the second pulp respectively according to the ratio of the absolute dry mass of bleached domestic poplar kraft pulp to bleached domestic pine kraft pulp of 1:10, and add an appropriate amount of water to adjust the concentration of the mixed pulp to 1.2 wt%; Then put the mixed pulp into the beating cup supporting the beater, set the beating speed to 15,000 r / min, and perform beating treatment to obtain beaten pulp; Filter to remove part of the water in the beaten pulp, keep the pulp concentration at 10 wt%, and then transfer it to a PFI refiner, set the refining speed to 16,000 r / min, and perform refining treatment; After the refining is completed, take down the well-refined mixed pulp, add an appropriate amount of water to adjust the concentration of the refined mixed pulp to 0.25 wt%, and make paper at a basis weight of 60 g / m² to obtain base paper; Then set the calendering temperature to 100 °C and the calendering pressure to 1000 PSI, and calender the base paper 5 times to make a physically micro-nano modified and enhanced mixed pulp-based packaging paper.

[0075] In the preparation method of the physically micro-nano modified and enhanced mixed pulp-based packaging paper, the relevant process parameters are shown in the following table:

[0076]

[0077] This example also provides a physically micro-nano modified and enhanced mixed pulp-based packaging paper prepared by the aforementioned method.

[0078] This example also provides the use of the aforementioned physically micro-nano modified and enhanced mixed pulp-based packaging paper as packaging for oil-containing foods.

[0079] Example 4

[0080] This example provides a preparation method of a physically micro-nano modified and enhanced mixed pulp-based packaging paper, specifically:

[0081] Tear domestic bleached poplar kraft pulp and domestic bleached pine kraft pulp into small pieces, soak them in water for 24 h respectively, measure their water contents, 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 respectively according to the ratio of the absolute dry mass of bleached domestic poplar kraft pulp and bleached domestic pine kraft pulp of 5:5, and add an appropriate amount of water to adjust the concentration of the mixed pulp to 1.2 wt%; Then put the mixed pulp into the beating cup supporting the beater, set the beating speed at 15000 r / min, and perform beating treatment to obtain beaten pulp; Filter out part of the water of the beaten pulp to keep the pulp concentration at 10 wt%, and then transfer it to a PFI refiner, set the refining speed at 16000 r / min, and perform refining treatment; After the refining is completed, take down the refined mixed pulp, add an appropriate amount of water to adjust the concentration of the refined mixed pulp to 0.25 wt%, and make paper according to a basis weight of 60 g / m² to obtain base paper; Then set the calendering temperature at 100 °C and the calendering pressure at 1000 PSI, and calender the base paper 5 times to prepare a physically micro-nano modified and enhanced mixed pulp-based packaging paper.

[0082] In the preparation method of the physically micro-nano modified and enhanced mixed pulp-based packaging paper, the relevant process parameters are shown in the following table:

[0083]

[0084] This example also provides a physically micro-nano modified and enhanced mixed pulp-based packaging paper prepared by the foregoing method.

[0085] This example also provides the use of the foregoing physically micro-nano modified and enhanced mixed pulp-based packaging paper as packaging for oil-containing foods.

[0086] Example 5

[0087] This example provides a preparation method of a physically micro-nano modified and enhanced mixed pulp-based packaging paper, specifically:

[0088] Tear domestic bleached kraft pulp of poplar and domestic bleached kraft pulp of pine into small pieces, soak them in water for 24 h respectively, measure their water contents, and obtain the first pulp (domestic bleached kraft pulp of poplar) and the second pulp (domestic bleached kraft pulp of pine); Weigh and mix the first pulp and the second pulp respectively according to the ratio of the absolute dry mass of bleached domestic kraft pulp of poplar to that of bleached domestic kraft pulp of pine being 10:1, and add an appropriate amount of water to adjust the concentration of the mixed pulp to 1.2 wt%; Then put the mixed pulp into the beating cup supporting a beater, set the beating speed at 15000 r / min, and after carrying out beating treatment, obtain beaten pulp; Filter to remove part of the water of the beaten pulp, keep the pulp concentration at 10 wt%, and then transfer it to a PFI refiner, set the refining speed at 10000 r / min, and carry out refining treatment; After the refining is completed, take down the well-refined mixed pulp, add an appropriate amount of water to adjust the concentration of the refined mixed pulp to 0.25 wt%, and make paper according to a basis weight of 60 g / m² to obtain base paper; Then set the calendering temperature at 100 °C and the calendering pressure at 1000 PSI, and carry out calendering treatment on the base paper for 5 times to prepare a physically micro-nano modified and enhanced mixed pulp-based packaging paper.

[0089] In the preparation method of the physically micro-nano modified and enhanced mixed pulp-based packaging paper, the relevant process parameters are shown in the following table:

[0090]

[0091] This example also provides a physically micro-nano modified and enhanced mixed pulp-based packaging paper prepared by the aforesaid method.

[0092] This example also provides the use of the aforesaid physically micro-nano modified and enhanced mixed pulp-based packaging paper as packaging for oil-containing foods.

[0093] Example 6

[0094] This example provides a preparation method of a physically micro-nano modified and enhanced mixed pulp-based packaging paper, specifically as follows:

[0095] 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.

[0096] 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:

[0097]

[0098] This embodiment also provides physically micro-nano modified and reinforced mixed pulp-based packaging paper prepared by the aforementioned method.

[0099] 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.

[0100] Example 7

[0101] This embodiment provides a method for preparing physically micro-nano modified and reinforced mixed pulp-based packaging paper, specifically:

[0102] Tear domestic bleached kraft pulp of poplar and domestic bleached kraft pulp of pine into small pieces, soak them in water for 24 hours respectively, measure their water contents, and obtain the first pulp (domestic bleached kraft pulp of poplar) and the second pulp (domestic bleached kraft pulp of pine); Weigh and mix the first pulp and the second pulp respectively according to the ratio of the absolute dry mass of bleached domestic kraft pulp of poplar to that of bleached domestic kraft pulp of pine being 10:1, and add an appropriate amount of water to adjust the concentration of the mixed pulp to 1.2 wt%; Then put the mixed pulp into the beating cup supporting the beater, set the beating speed at 15000 r / min, and carry out beating treatment to obtain beaten pulp; Filter to remove part of the water of the beaten pulp, keep the pulp concentration at 10 wt%, and then transfer it to a PFI refiner, set the refining speed at 16000 r / min, and carry out refining treatment; After the refining is completed, take down the refined mixed pulp, add an appropriate amount of water to adjust the concentration of the refined mixed pulp to 0.25 wt%, and make paper according to a basis weight of 60 g / m² to obtain base paper; Then set the calendering temperature at 90 °C and the calendering pressure at 1200 PSI, and calender the base paper 5 times to prepare a physically micro-nano modified and enhanced mixed pulp-based packaging paper.

[0103] In the preparation method of the physically micro-nano modified and enhanced mixed pulp-based packaging paper, the relevant process parameters are shown in the following table:

[0104]

[0105] This example also provides a physically micro-nano modified and enhanced mixed pulp-based packaging paper prepared by the foregoing method.

[0106] This example also provides the use of the foregoing physically micro-nano modified and enhanced mixed pulp-based packaging paper as packaging for oil-containing foods.

[0107] Example 8

[0108] This example provides a preparation method of a physically micro-nano modified and enhanced mixed pulp-based packaging paper, specifically:

[0109] 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 respectively according to the ratio of the absolute dry mass of bleached domestic poplar kraft pulp to bleached domestic pine kraft pulp of 10:1, and add an appropriate amount of water to adjust the concentration of the mixed pulp to 1.2 wt%; Then put the mixed pulp into the beating cup supporting the beater, set the beating speed at 15000 r / min, and carry out beating treatment to obtain beaten pulp; Filter to remove part of the water of the beaten pulp, keep the pulp concentration at 10 wt%, and then transfer it to a PFI refiner, set the refining speed at 13000 r / min, and carry out refining treatment; After the refining is completed, take down the refined mixed pulp, add an appropriate amount of water to adjust the concentration of the refined mixed pulp to 0.25 wt%, and make paper according to a basis weight of 60 g / m² to obtain the base paper; Then set the calendering temperature at 110 °C and the calendering pressure at 900 PSI, and calender the base paper 5 times to prepare a physically micro-nano modified and enhanced mixed pulp-based packaging paper.

[0110] In the preparation method of the physically micro-nano modified and enhanced mixed pulp-based packaging paper, the relevant process parameters are shown in the following table:

[0111]

[0112] This embodiment also provides a physically micro-nano modified and enhanced mixed pulp-based packaging paper prepared by the foregoing method.

[0113] This embodiment also provides the use of the foregoing physically micro-nano modified and enhanced mixed pulp-based packaging paper as an oil-containing food packaging.

[0114] Comparative Example 1

[0115] The technical solution of Comparative Example 1 corresponds to that of Example 1, and the difference is that no calendering treatment is carried out.

[0116] The specific technical solution 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 respectively according to the ratio of the absolute dry mass of bleached domestic poplar kraft pulp to bleached domestic pine kraft pulp of 10:1, and add an appropriate amount of water to adjust the concentration of the mixed pulp to 1.2 wt%; Then put the mixed pulp into the defibrator cup supporting the defibrator, set the defibrating speed to 15,000 r / min, and after defibrating treatment, obtain the defibrated pulp; Filter to remove part of the water of the defibrated pulp, keep the pulp concentration at 10 wt%, and then transfer it to a PFI refiner, set the refining speed to 13,000 r / min, and carry out refining treatment; After the refining is completed, take down the well-refined mixed pulp, add an appropriate amount of water to adjust the concentration of the refined mixed pulp to 0.25 wt%, and after papermaking according to a basis weight of 60 g / m² without calendering treatment, the mixed pulp-based packaging paper of Comparative Example 1 is prepared.

[0117] In the preparation method of Comparative Example 1, the relevant process parameters are shown in the following table:

[0118]

[0119] Comparative Example 2

[0120] The technical solution of Comparative Example 2 corresponds to that of Example 1, and the difference is that no refining is carried out.

[0121] The specific technical solution 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 respectively according to the ratio of the absolute dry mass of bleached domestic poplar kraft pulp to bleached domestic pine kraft pulp of 10:1, and add an appropriate amount of water to adjust the concentration of the mixed pulp to 1.2 wt%; Then put the mixed pulp into the defibrator cup supporting the defibrator, set the defibrating speed to 15,000 r / min, and after defibrating treatment, obtain the defibrated pulp, add an appropriate amount of water to adjust the concentration of the defibrated pulp to 0.25 wt%, and after papermaking according to a basis weight of 60 g / m², obtain the base paper; Then set the calendering temperature to 100 °C and the calendering pressure to 1000 PSI, and calender the base paper 5 times to prepare the mixed pulp-based packaging paper of Comparative Example 2.

[0122] In the preparation method of Comparative Example 2, the relevant process parameters are shown in the following table:

[0123]

[0124] Comparative Example 3

[0125] The technical solution of Comparative Example 3 corresponds to Example 1, and the difference is that fine grinding and calendering are not carried out.

[0126] The specific technical solution is as follows: Tear domestic bleached kraft poplar pulp and domestic bleached kraft pine pulp into small pieces, soak them in water for 24 h respectively, measure their water content to obtain the first pulp (domestic bleached kraft poplar pulp) and the second pulp (domestic bleached kraft pine pulp); Weigh and mix the first pulp and the second pulp respectively according to the ratio of the absolute dry mass of bleached domestic poplar kraft pulp to bleached domestic pine kraft pulp of 10:1, and add an appropriate amount of water to adjust the concentration of the mixed pulp to 1.2 wt%; Then put the mixed pulp into the disintegrating cup equipped with a disintegrator, set the disintegrating speed to 15,000 r / min, after disintegrating treatment, obtain the disintegrated pulp, add an appropriate amount of water to adjust the concentration of the disintegrated pulp to 0.25 wt%, and make a paper by hand according to a basis weight of 60 g / m² without calendering treatment to obtain the mixed pulp-based packaging paper of Comparative Example 3.

[0127] After testing, the performance indexes of the physically micro-nano modified and enhanced mixed pulp-based packaging papers prepared in Examples 1-8 and Comparative Examples 1-3 are shown in the following table:

[0128]

[0129] It can be seen from the above table results that the physically micro-nano modified and enhanced mixed pulp-based packaging paper prepared by the present invention has good gas barrier, waterproof and oil resistance characteristics, can be effectively applied to the field of oil-containing food packaging, is safe and environmentally friendly, and is simple to recycle, suitable for large-scale popularization and application; At the same time, by using the preparation method of the physically micro-nano modified and enhanced mixed pulp-based packaging paper of the present invention, the waste paper rate during the preparation process is below 10%, and the cellulose recovery rate is above 85%.

[0130] Unless otherwise specified, the percentages used in the present invention are all mass percentages.

[0131] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within 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 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; In the mixed pulp, the absolute dry mass ratio of bleached hardwood pulp to bleached softwood pulp is 10:1; The method of the deflaking treatment is to adjust the concentration of the mixed pulp, control the deflaking speed to 13000-16000 r / min, and the deflaking concentration to 0.8-1.6wt%, and perform the deflaking treatment to obtain the deflaked pulp; The pulping method comprises adjusting the concentration of the debonded pulp, controlling the concentration of the refined pulp to be 7-14wt%, and the speed of the refined pulping to be 8000-17000r / min, and performing the refined pulping treatment to obtain the refined 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: 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.

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

5. 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 4 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.

6. Use of the physically micro-nano modified and reinforced mixed pulp-based packaging paper as claimed in claim 5 as packaging paper for oil-containing food.

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