Easily degradable transparent paper and preparation method thereof

Abstract

According to the easily degradable transparent paper and the preparation method thereof, wood pulp, cotton pulp, sugarcane pulp, regenerated fibers and the like are selected as raw materials, fine fibers are prepared after the raw materials are treated by a pulping machine and a pulping machine, then low-gram-weight paper is manufactured by adopting a wet-type fiber forming technology, and the easily degradable transparent paper is prepared through the processes of dipping, light curing, high-temperature calendering and the like. The environment-friendly degradable plastic has the advantages of being easy to degrade, low in cost, high in transparency, good in mechanical property and hydrophobic property and the like, almost no VOC is discharged in the preparation process, a large amount of water resources do not need to be consumed, and the raw material cost and the production cost are low. According to the application of the low-cost easily-degradable high-transparency paper, common plastic films used in various current outer packages can be replaced to a great extent, white pollution is relieved, and environmental protection and sustainable development are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of new environmentally friendly materials, and in particular to a degradable transparent paper and a preparation method thereof. Background Art

[0002] With the rapid development of society and economy, various types of plastic products are widely used due to their lightness, convenience and low price, and have penetrated into all aspects of human life. Statistics show that the total annual consumption of plastic products in the world has surged from about 2 million tons in 1950 to more than 300 million tons in 2015. Among these plastic products after consumption, 50% are used for disposable packaging and consumer goods, which are soon discarded and eventually flow into the ocean in large quantities. To this end, organizations such as the United Nations and the European Union and governments of various countries have successively introduced a series of policies to restrict or prohibit the production and use of certain plastic products in order to reduce their pollution to the environment.

[0003] In the packaging industry, plastic films are widely used in the outer packaging of food, medicine, daily chemicals and electronic products due to their advantages such as lightness, low price, high transparency, heat and cold resistance, and good sealing. These outer packaging plastic films are mainly made of materials such as BOPP and PET. According to statistics, the total annual consumption of BOPP films in my country exceeds 3 million tons. However, these plastic films are not easy to degrade, and most of them are eventually piled up or incinerated after being discarded, causing secondary pollution to the environment.

[0004] At the same time, some of the current degradable packaging film materials also have certain problems: (1) PLA film: PLA is derived from biomass and can be completely degraded. However, the light transmittance of PLA film is low, generally only about 80%, which cannot be compared with the light transmittance of PET film of more than 90%. In addition, the mechanical properties of PLA film are poor, its impact resistance and tear resistance are weak, and its service life is short. At the same time, the price of PLA film is also high, 2-4 times higher than that of ordinary plastic films such as PET and BOPP, and there is cost pressure for large-scale replacement application. (2) Cellophane: Cellophane can be rapidly degraded in the natural environment, but its preparation process requires the consumption of a large amount of strong acid and strong alkali, and at the same time, it will produce toxic hydrogen sulfide gas emissions, causing serious pollution to the environment. In addition, the price of cellophane is relatively high, about 3-6 times that of ordinary plastic film, which limits its large-scale replacement application. In addition, the above two materials themselves do not have hydrophobic properties and cannot meet the needs of some oil-proof and moisture-proof packaging.

[0005] In addition, the patent number: CN201610954052.1 discloses a method for preparing a degradable and anti-corrosion food packaging paper: palm leaves are used as raw materials, bleached after alkali washing and acid soaking to obtain bleached mixed fibers, and then montmorillonite and silicon dioxide are mixed and modified with castor oil under the action of microorganisms to obtain ultraviolet absorbers, and finally the two are mixed and supplemented with other raw materials to be pulped and made into paper to obtain degradable and anti-corrosion food packaging paper, palm fiber is used as the papermaking matrix, and cranberry juice rich in antioxidant ingredients is modified to increase the antioxidant effect of the fiber, and then the characteristics of montmorillonite shielding ultraviolet rays and silicon dioxide absorbing ultraviolet rays are used to mix the two and modify them with castor oil rich in hydrophobic ester groups to increase the hydrophobicity of the mixture, and finally the hydrophobic mixture and antioxidant fibers are compounded to make packaging paper. Although the material is naturally degradable, it is difficult to achieve a large-scale replacement for ordinary plastic films in terms of price and performance.

[0006] In view of this, there is an urgent need to develop a new type of degradable packaging film material that has excellent properties such as easy degradation, low cost, high transparency, good mechanical properties and hydrophobic properties. Summary of the invention

[0007] In view of the above-mentioned deficiencies in the prior art, the present invention provides a degradable transparent paper and a preparation method thereof, which can solve the performance defects and high price problems of existing degradable packaging film materials, and can fundamentally solve environmental problems such as white pollution, and has important practical significance.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A method for preparing easily degradable transparent paper, characterized by comprising the following steps:

[0010] S1, selecting wood pulp, cotton pulp, sugarcane pulp and recycled fiber as raw materials, preparing fine fibers after processing by a pulping machine and a pulping machine, and then using wet fiber forming technology to produce low-weight paper with fluffy fibers, good hygroscopicity and a gram weight of 15-40g / m2, and drying and rolling the low-weight paper;

[0011] S2. The low-weight paper at the unwinding position is brought into the impregnation station by the feed roller at a conveying speed of 6-12m / min, and the light-curable impregnation liquid in the impregnation tank is fully absorbed by the satellite pressure roller. After the impregnation is completed, a PET film is used for single-sided roll-to-roll lamination at the last satellite roller, and then the upper and lower limit pressure rollers are used to squeeze the excess impregnation liquid while controlling the thickness of the impregnated paper to be 15-40 microns, so as to form a single-sided coated paper;

[0012] S3, the single-sided coated paper is conveyed to the light curing station at a conveying speed of 6-12m / min for curing. After curing, the single-sided PET film is peeled off to form transparent paper, and the peeled single-sided PET film is rolled up and recycled, and can be reused after cleaning and drying;

[0013] S4. The cured transparent paper is transported to a high-temperature calendering device. After multiple high-temperature roller pressings, the transparent paper is trimmed and cut. After passing the inspection, the paper is rolled up to obtain easily degradable transparent paper.

[0014] Preferably, in the method for preparing the easily degradable transparent paper, the step S1 of preparing fine fibers after treatment with a pulper and a refiner specifically comprises:

[0015] S11, soaking the raw material in a certain amount of water, and dispersing the fibers through a high-speed deflaking machine;

[0016] S12, adjusting the slurry concentration to 2-5%, feeding it into the pulping machine pulp pool through the pulp supply pump, and beating it at a speed of 1500-2000 rpm for 10-30 minutes, and then discharging the beaten slurry;

[0017] S13, adjusting the concentration of the pulp after beating to 0.5-3%, conveying it to a disc refiner, using a cooling water temperature control system to grind the pulp in a temperature range of 20-25° C., wherein the rotation speed is 2000-4000 rpm, and the refining time is 2 hours as a cycle, and the generated fiber suspension is refined for multiple cycles according to the fiber size requirements;

[0018] S14, uniformly dispersing the finely refined cellulose suspension in a high shear homogenizer at a rotation speed of 6000-10000 rpm and a dispersion time of 10-40 minutes, adding polyvinyl alcohol as a dispersant and wet strength agent at a concentration of 0.05-0.5%; or adding polyurethane as a wet strength agent at a concentration of 0.5-2%.

[0019] Preferably, in the method for preparing the easily degradable transparent paper, the papermaking, drying and winding forming process using wet fiber forming technology in step S1 specifically includes:

[0020] S15, dilute the slurry with water to a concentration of 0.1-2%, and use a slurry supply pump to transport the slurry to the head box of the papermaking machine to ensure smooth flow of the slurry to avoid sedimentation and accumulation;

[0021] S16, the slurry is evenly dispersed in the head box and quantitatively and continuously supplied to the mesh surface through the slurry supply machine, wherein the mesh number of the mesh surface is above 80 meshes and the mesh speed is 10-50m / min;

[0022] S17, after the paper web is rubbed and cut, the paper web is wet pressed by multiple pressing rollers, and excess water is quickly removed by a vacuum part, and the pressing pressure is set to 500-2000 kPa to maintain the fluffy structure of the paper;

[0023] S18, sending the wet paper web into a drying oven composed of multiple groups of heating drying cylinders for hot air drying, controlling the moisture content within the range of 5-12%, and rolling up after trimming.

[0024] Preferably, in the method for preparing the easily degradable transparent paper, the method for preparing the photocurable impregnating liquid in step S2 is as follows: firstly, photopolymerizable monomers are mixed in a certain proportion; then, additives such as photoinitiator, crosslinking agent, surfactant, inorganic filler, natural polymer filler, etc. are added and stirred evenly; finally, the mixed liquid is transported to a high-speed centrifugal degasser for degassing;

[0025] The photopolymerizable monomer is one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, isooctyl acrylate, 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, polydipentaerythritol hexaacrylate, allyl cellulose, polyethylene glycol diacrylate, ethylene glycol methacrylate, polycaprolactone acrylate, etc.;

[0026] The photoinitiator is one or more of phenyl bisphosphine oxide, 2-hydroxy-2-methylpropiophenone, dibenzoyl peroxide, diphenylphosphine oxide, etc., and the added amount is 0.1-3% by mass; the crosslinking agent is one or more of tripropylene glycol diacrylate, polyethylene glycol diacrylate, dipropylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol phthalate diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, and the added amount is 0-2% by mass;

[0027] The surfactant is one or more of sorbitol, cetyl alcohol, polyethylene glycol laurate, polydimethylsiloxane, and polyether-modified silicone oil, and the added amount is 0-2% by mass;

[0028] The inorganic filler is one or more of silicon dioxide nanoparticles, aluminum oxide nanoparticles, zinc white powder, and montmorillonite nanosheets, and the added amount is 0-2% by mass.

[0029] Preferably, in the method for preparing the easily degradable transparent paper, the photopolymerizable monomer has a low viscosity, good wettability to paper fibers, high photocuring efficiency, and good hydrophobicity after curing.

[0030] Preferably, in the method for preparing the easily degradable transparent paper, the photopolymerizable monomer is compounded of a soft monomer and a hard monomer, and the mixing ratio is regulated according to the monomer type and performance requirements to meet the requirements of firmness, flexibility and mechanical strength of the transparent paper.

[0031] Preferably, in the method for preparing the easily degradable transparent paper, an impregnation liquid recovery device is arranged below the limiting pressure roller in step S2, and the impregnation liquid is recovered into the impregnation tank for recycling after filtering.

[0032] Preferably, in the method for preparing the easily degradable transparent paper, the light curing station in step S3 is a transparent quartz roller, which is internally equipped with a curing light source with a matching wavelength, and the uncoated side of the single-sided coated paper after impregnation is closely attached to the quartz roller, thereby achieving anaerobic curing conditions while ensuring the flatness of the paper surface.

[0033] Preferably, in the method for preparing the easily degradable transparent paper, the satellite pressure roller in step S2 is composed of a main roller and a plurality of satellite rollers, which are used to prevent the paper from breaking due to excessive tension after being soaked; a non-stop roll changing device is provided at the unwinding place, and multiple guide rollers are equipped to adjust the tension and offset.

[0034] A degradable transparent paper, wherein the paper is prepared by the above-mentioned preparation method.

[0035] Compared with the prior art, the present invention provides a kind of easily degradable transparent paper and its preparation method, which uses wood pulp, cotton pulp, sugarcane pulp and recycled fiber as raw materials, and is processed by a pulping machine and a pulping machine to prepare fine fibers, and then uses wet fiber forming technology to copy low-weight paper, and is prepared by processes such as impregnation, light curing, and high-temperature calendering. It has the advantages of easy degradation, low cost, high transparency, good mechanical properties and hydrophobic properties, and almost no VOC emissions during the preparation process, and does not require a large amount of water resources. The raw material and production costs are low. The application of the low-cost, easily degradable and highly transparent paper of the present invention can largely replace the ordinary plastic film currently used in various types of outer packaging, reduce white pollution, and achieve environmental protection and sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0037] Figure 1 The present invention provides a flow chart of a method for preparing the easily degradable transparent paper.

[0038] Figure 2 This is a schematic structural diagram of a satellite-type pressing roller in a preferred embodiment of the method for preparing the easily degradable transparent paper provided by the present invention.

[0039] Figure 3 The figure is a mechanical structure diagram of the impregnation process flow corresponding to the preferred embodiment of the method for preparing the easily degradable transparent paper provided by the present invention.

[0040] Figure 4 The schematic diagram of the mechanical structure of the light curing process flow corresponding to the preferred embodiment of the method for preparing the easily degradable transparent paper provided by the present invention.

[0041] Description of the accompanying drawings:

[0042] 10. Main roller; 20. Satellite roller; 30. Paper; 40. Photocurable impregnation liquid; 50. PET film; 60. Pressing roller; 70. Impregnation liquid recovery device; 80. Transparent quartz roller; 81. Curing light source lamp tube; 90. Single-sided PET film peeling device. DETAILED DESCRIPTION

[0043] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0045] In the present invention, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inside", "outside", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are mainly used to better describe the present invention and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation. Moreover, in addition to being used to indicate orientations or positional relationships, some of the above terms may also be used to express other meanings. For example, the term "upper" may also be used to indicate a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in the present invention can be understood according to specific circumstances.

[0046] In addition, the terms "first" and "second" etc. used in this application can be used to describe various elements in this article, but these elements are not limited by these terms. These terms are only used to distinguish the first element from another element. When used here, the singular "one", "one" and "said / the" can also include plural forms, unless the context clearly indicates another way. It should also be understood that the terms "include / comprise" or "have" etc. specify the existence of stated features, wholes, steps, operations, components, parts or combinations thereof, but do not exclude the possibility of existing or adding one or more other features, wholes, steps, operations, components, parts or combinations thereof.

[0047] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0048] In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0049] With the rapid development of social economy, plastic products are widely used in various fields due to their lightness, convenience and low price. However, the extensive use of plastic products has also brought serious environmental problems. Especially in the packaging industry, plastic films such as BOPP and PET are widely used in the outer packaging of food, medicine, daily chemicals and electronic products due to their excellent performance. These plastic films are not easy to degrade, and are often disposed of by stacking or incineration after being discarded, causing secondary pollution to the environment.

[0050] Faced with this problem, researchers began to look for degradable alternative materials. However, existing degradable packaging materials such as PLA film and cellophane also have some limitations. Although PLA film can be completely degraded, it has low light transmittance, poor mechanical properties, and high price. Although cellophane can be rapidly degraded in the natural environment, its preparation process will cause environmental pollution and is expensive. In addition, these materials also have problems such as insufficient hydrophobicity and cannot meet certain special packaging needs.

[0051] In this context, it is particularly important to develop a new packaging material that is easy to degrade, low-cost, highly transparent, has good mechanical properties and hydrophobic properties. This application proposes an innovative method for preparing easily degradable transparent paper, aiming to solve the above problems.

[0052] The core idea of ​​this application is to use natural fiber raw materials and prepare high-transparency paper through a special processing process. The key to this method is how to improve the transparency and mechanical properties of paper while maintaining its easy degradation. To this end, this application adopts a series of innovative technical means.

[0053] First, the present application selects easily degradable natural fibers such as wood pulp, cotton pulp, sugarcane pulp and recycled fiber as raw materials. These raw materials have good biodegradability and can effectively solve the problem that traditional plastic films are difficult to degrade. However, how to improve the transparency of paper made of these natural fibers is a technical difficulty.

[0054] In order to solve this problem, the present application adopts a special fiber processing process. The raw fiber is processed into fine fibers through a pulping machine and a pulping machine. In this process, the fiber is fully dispersed and refined, which is conducive to improving the transparency of the final paper. At the same time, the wet fiberization technology is used to make low-weight paper, which further increases the transparency of the paper.

[0055] In the paper preparation process, the present application also innovatively introduces a treatment step of a photocurable impregnation liquid. The purpose of this step is to further improve the transparency and mechanical properties of the paper. The use of the photocurable impregnation liquid can not only fill the gaps between fibers and reduce light scattering, but also form a network structure after photocuring to enhance the mechanical properties of the paper.

[0056] In order to ensure the uniformity and controllability of the impregnation process, the present application adopts satellite roller technology. This technology allows the paper to fully absorb the impregnation liquid while avoiding paper breakage due to excessive tension. In addition, through the single-sided lamination of the PET film and the control of the upper and lower limit rollers, the thickness of the impregnated paper can be accurately controlled to ensure the consistency of product quality.

[0057] During the light curing process, the present application adopts a precisely controlled curing process. By controlling the conveying speed and light intensity, it can ensure that the impregnation liquid is fully cured to form a stable network structure. This process not only improves the transparency of the paper, but also enhances its mechanical properties.

[0058] Finally, the present invention further improves the transparency and flatness of the paper through high temperature calendering treatment. Multiple high temperature roller pressing can not only make the paper surface smoother, but also further reduce the gaps between fibers and improve transparency.

[0059] An important advantage of this preparation method is its cost-effectiveness. Compared with traditional plastic films or other degradable materials, the raw materials and processes used in this application are relatively simple, which is conducive to reducing production costs. At the same time, the recycling of PET film also further reduces costs.

[0060] In summary, if Figure 1 As shown, the present invention provides a method for preparing a degradable transparent paper, comprising the following steps:

[0061] S1, selecting wood pulp, cotton pulp, sugarcane pulp and recycled fiber as raw materials, preparing fine fibers after processing by a pulping machine and a pulping machine, and then using wet fiber forming technology to produce low-weight paper with fluffy fibers, good hygroscopicity and a gram weight of 15-40g / m2, and drying and rolling the low-weight paper;

[0062] S2. The low-weight paper at the unwinding position is brought into the impregnation station by the feed roller at a conveying speed of 6-12m / min, and the light-curable impregnation liquid in the impregnation tank is fully absorbed by the satellite pressure roller. After the impregnation is completed, a PET film is used for single-sided roll-to-roll lamination at the last satellite roller, and then the upper and lower limit pressure rollers are used to squeeze the excess impregnation liquid while controlling the thickness of the impregnated paper to be 15-40 microns, so as to form a single-sided coated paper;

[0063] S3, the single-sided coated paper is conveyed to the light curing station at a conveying speed of 6-12m / min for curing. After curing, the single-sided PET film is peeled off to form transparent paper, and the peeled single-sided PET film is rolled up and recycled, and can be reused after cleaning and drying;

[0064] S4. The cured transparent paper is transported to a high-temperature calendering device. After multiple high-temperature roller pressings, the transparent paper is trimmed and cut. After passing the inspection, the paper is rolled up to obtain easily degradable transparent paper.

[0065] The method of the present application not only solves the problem that traditional plastic films are difficult to degrade, but also overcomes the defect of insufficient transparency of existing degradable materials. Through the use of special fiber processing technology and photocurable impregnation liquid, the present application successfully prepared highly transparent and easily degradable paper.

[0066] In the process of implementation, the present application overcomes multiple technical difficulties. The first is how to improve the transparency of paper made of natural fibers. Through the use of refined fibers, low-weight papermaking and photocurable impregnation liquid, the present application successfully improves the transparency of paper. The second is how to maintain the mechanical properties of paper while improving transparency. Through the network structure of the photocurable impregnation liquid and high-temperature calendering treatment, the present application successfully enhances the mechanical properties of paper.

[0067] Compared with the prior art, the method of the present application has significant advantages. Compared with traditional plastic films, the transparent paper prepared by the present application has good degradability. Compared with PLA films, the products of the present application have higher transparency and better mechanical properties. Compared with cellophane, the preparation process of the present application is more environmentally friendly and has lower costs.

[0068] The method of the present application also has good flexibility and adjustability. For example, the properties of the final product can be changed by adjusting the types and proportions of raw materials. Wood pulp can provide good strength, cotton pulp can increase flexibility, sugarcane pulp can improve transparency, and the use of recycled fibers can further reduce costs and improve environmental protection.

[0069] In the fiber processing process, the fineness and dispersion of the fibers can be controlled by adjusting the parameters of beating and refining, thereby affecting the transparency and strength of the final paper. For example, finer fibers can be obtained by extending the refining time or increasing the refining intensity, thereby improving transparency.

[0070] During the impregnation process, the properties of the final product can be changed by adjusting the formulation of the photocurable impregnation liquid. For example, the strength and water resistance of paper can be improved by increasing the proportion of crosslinking agent, or special properties such as antibacterial or oil-proof properties can be given to paper by adding specific functional monomers.

[0071] The method of the present application can also be adjusted according to different application requirements. For example, for applications requiring higher transparency, the amount of impregnation liquid can be increased or the light curing time can be extended. For applications requiring better mechanical properties, this can be achieved by adjusting the parameters of high temperature calendering.

[0072] The technical effects of this application are mainly reflected in the following aspects:

[0073] First, the transparent paper prepared in the present application has excellent degradability. Since natural fibers are used as raw materials, the transparent paper can be quickly degraded in the natural environment, greatly reducing environmental pollution.

[0074] Secondly, the transparent paper prepared by the present application has high transparency. Through the use of a special fiber processing process and a photocurable impregnation liquid, the present application successfully improves the transparency of the paper to a level comparable to that of traditional plastic films.

[0075] Third, the transparent paper prepared in the present application has good mechanical properties. Through the network structure formed by the photocurable impregnation liquid and the high-temperature calendering treatment, the transparent paper prepared in the present application has good strength and toughness, which can meet the needs of various packaging applications.

[0076] Fourth, the preparation method of the present application has good cost-effectiveness. Compared with other degradable materials, the raw materials and processes used in the present application are relatively simple, which can effectively reduce production costs.

[0077] Fifth, the method of the present application is environmentally friendly. Not only is the final product biodegradable, but the entire preparation process is also more environmentally friendly, avoiding the pollution problem in the traditional plastic film production process.

[0078] Sixth, the method of the present application has good adjustability. By adjusting the raw material ratio, process parameters and impregnation liquid formula, the performance of the final product can be flexibly adjusted to meet the needs of different applications.

[0079] The following is explained by 9 specific embodiments:

[0080] Example A

[0081] (1) Papermaking process: 50% recycled fiber pulp, 30% conifer fiber pulp, and 20% sugarcane pulp are selected as raw materials. The pulp board is soaked in a certain amount of water and the fibers are dispersed by a high-speed deflaker. The pulp concentration is adjusted to 3% and sent to the pulping machine pulp pool through a pulp supply pump. After beating for 10 minutes at a speed of 2000 rpm, the pulped slurry is discharged. The pulp concentration after beating is adjusted to 1% and sent to a disc pulping machine at a speed of 3000 rpm. The pulp is ground at 25°C for 2 hours. The pulp is diluted with water and then the pulp is pulverized. The slurry is diluted to a concentration of 0.5%, and a slurry pump is used to transport the slurry to the head box of the papermaking machine; after the slurry is evenly dispersed in the head box, it is quantitatively 20g / m2 and continuously supplied to the mesh surface through a slurry feeder, the mesh number is 100 mesh, and the mesh speed is 40m / min; after the paper web is rubbed and cut, the paper web is wet-pressed by a pressing roller with a pressing pressure of 1000kPa, and excess water is removed by a vacuum part; the pressed wet paper web is then sent to an oven composed of multiple groups of heating drying cylinders for hot air drying, the moisture content is controlled at 8%, and it is rolled up after trimming.

[0082] (2) Impregnation process: Through the non-stop roll changing device and the multi-guide rollers to adjust the tension and offset, the low-weight paper is brought into the impregnation station by the feed roller at a conveying speed of 10m / min. Figure 2 and Figure 3 As shown, the photocurable impregnation liquid 40 in the impregnation tank is fully absorbed by satellite-type pressing rollers (a main roller 10 with a diameter of 2m is above the paper 30, and 7 satellite rollers 20 with a diameter of 20cm are below). After the impregnation is completed, a 50-micron PET film 50 (the side in contact with the paper is a release layer) is used at the last satellite roller for single-sided roll-to-roll lamination, and then the paper is pressed by a pressing roller 60 with an upper and lower limit of 80 mm. The excess impregnation liquid squeezed out passes through an impregnation liquid recovery device 70 arranged below, and is recovered into the impregnation tank for recycling after filtration;

[0083] Wherein, the preparation method of the photocurable impregnation liquid is:

[0084] The photopolymerizable monomers are 2-octyl acrylate and 1,6-hexanediol diacrylate mixed in a mass ratio of 2:1, and 1 wt % of phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide is added and stirred evenly;

[0085] The mixed liquid is transported to a high-speed centrifugal degasser for degassing.

[0086] (3) Photocuring process:

[0087] like Figure 4 As shown, the impregnated single-sided coated paper is conveyed to the light curing station at a conveying speed of 10m / min, and is passed through a transparent quartz roller 80 with a curing light source lamp 81 arranged inside (the quartz roller squeezes the position of the upper surface of the paper, which is equivalent to anaerobic curing). After the curing is completed, the single-sided PET film is peeled off by a single-sided PET film peeling device 90, and is rolled up for recovery. It can be reused after cleaning and drying.

[0088] (4) Post-processing and winding process:

[0089] The cured transparent paper is transported to the high-temperature calendering device 100. After 5 high-temperature roller presses, the transparent paper roll is trimmed and cut, and then an online inspection is carried out to detect the thickness uniformity, transparency uniformity, moisture content, etc. of the paper. If the inspection is qualified, it is rolled up. If the inspection is unqualified, the machine automatically cuts and re-rolls.

[0090] Example B

[0091] (1) Papermaking process: 50% recycled fiber pulp, 30% conifer fiber pulp, and 20% sugarcane pulp are selected as raw materials. The pulp board is soaked in a certain amount of water and the fibers are dispersed by a high-speed deflaker. The pulp concentration is adjusted to 3% and sent to the pulping machine pulp pool through a pulp supply pump. After beating for 10 minutes at a speed of 2000 rpm, the pulped slurry is discharged. The pulp concentration after beating is adjusted to 1% and sent to a disc pulping machine at a speed of 3000 rpm. The pulp is ground at 25°C for 2 hours. The pulp is diluted with water and then the pulp is pulverized. The slurry is diluted to a concentration of 0.5%, and a slurry pump is used to transport the slurry to the head box of the papermaking machine; after the slurry is evenly dispersed in the head box, it is quantitatively 20g / m2 and continuously supplied to the mesh surface through a slurry feeder, the mesh number is 100 mesh, and the mesh speed is 40m / min; after the paper web is rubbed and cut, the paper web is wet-pressed by a pressing roller with a pressing pressure of 1000kPa, and excess water is removed by a vacuum part; the pressed wet paper web is then sent to an oven composed of multiple groups of heating drying cylinders for hot air drying, the moisture content is controlled at 8%, and it is rolled up after trimming.

[0092] (2) Impregnation process: Through the non-stop roll-changing device and the multi-guide rollers to adjust the tension and offset, the low-weight paper is brought into the impregnation station by the feed roller at a conveying speed of 10 m / min. The satellite rollers (a main roller with a diameter of 2 m above the paper and 7 satellite rollers with a diameter of 20 cm below) fully absorb the light-curable impregnation liquid in the impregnation tank. After the impregnation is completed, a 50-micron PET film (the side in contact with the paper is the release layer) is used at the last satellite roller for single-sided roll-to-roll lamination. Then, the excess impregnation liquid is squeezed out by the pressing roller with an upper and lower limit of 80 mm. The impregnation liquid recovery device is set below, and after filtration, it is recovered into the impregnation tank for recycling;

[0093] Wherein, the preparation method of the photocurable impregnation liquid is:

[0094] After mixing the photopolymerizable monomers hydroxyethyl acrylate and dipropylene glycol diacrylate in a mass ratio of 2:1, 1 wt % of phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide was added and stirred evenly;

[0095] The mixed liquid is transported to a high-speed centrifugal degasser for degassing.

[0096] (3) Photocuring process:

[0097] The impregnated single-sided coated paper is transported to the light curing station at a speed of 10m / min. It passes through a transparent quartz roller with a curing light source lamp inside (the quartz roller squeezes the upper surface of the paper, which is equivalent to anaerobic curing). After curing, the single-sided PET film is peeled off and rolled up for recycling. It can be reused after cleaning and drying.

[0098] (4) Post-processing and winding process:

[0099] The cured transparent paper is transported to the high-temperature calendering equipment. After 5 high-temperature roller presses, the transparent paper roll is trimmed and cut, and then online inspection is carried out to test the paper's thickness uniformity, transparency uniformity, moisture content, etc. The paper will be rolled up after passing the inspection. If the inspection fails, the machine will automatically cut and reroll it.

[0100] Example C

[0101] (1) Papermaking process: 50% recycled fiber pulp, 30% conifer fiber pulp, and 20% sugarcane pulp were selected as raw materials. The pulp board was soaked in a certain amount of water and the fibers were dispersed by a high-speed deflaker. The pulp concentration was adjusted to 3%, and the pulp was pumped into the pulp tank of the pulping machine. The pulping was carried out at a speed of 2000 rpm for 30 minutes, and the pulp was discharged. The pulp concentration after pulping was adjusted to 1%, and the pulp was transported to a disc pulping machine at a speed of 3000 rpm. The pulp was ground at 25°C for 2 hours for 5 cycles. ; Dilute the slurry with water to a concentration of 0.5%, and use a slurry pump to transport the slurry to the head box of the papermaking machine; After the slurry is evenly dispersed in the head box, it is quantitatively supplied to the mesh surface by a slurry supply machine at 20g / m2 and continuously. The mesh size is 500 meshes and the mesh speed is 40m / min; After the paper web is rubbed and cut, the paper web is wet-pressed by a pressing roller with a pressing pressure of 1000kPa, and excess moisture is removed by a vacuum part; The pressed wet paper web is then sent to an oven composed of multiple groups of heating drying cylinders for hot air drying, and the moisture content is controlled at 8%, and it is rolled up after trimming.

[0102] (2) Impregnation process: Through the non-stop roll-changing device and the multi-guide rollers to adjust the tension and offset, the low-weight paper is brought into the impregnation station by the feed roller at a conveying speed of 10 m / min. The satellite rollers (a main roller with a diameter of 2 m above the paper and 7 satellite rollers with a diameter of 20 cm below) fully absorb the light-curable impregnation liquid in the impregnation tank. After the impregnation is completed, a 50-micron PET film (the side in contact with the paper is the release layer) is used at the last satellite roller for single-sided roll-to-roll lamination. Then, the excess impregnation liquid is squeezed out by the pressing roller with an upper and lower limit of 80 mm. The impregnation liquid recovery device is set below, and after filtration, it is recovered into the impregnation tank for recycling;

[0103] Wherein, the preparation method of the photocurable impregnation liquid is:

[0104] The photopolymerizable monomers are 2-octyl acrylate and 1,6-hexanediol diacrylate mixed in a mass ratio of 2:1, and 1 wt % of phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide is added and stirred evenly;

[0105] The mixed liquid is transported to a high-speed centrifugal degasser for degassing.

[0106] (3) Photocuring process:

[0107] The impregnated single-sided coated paper is transported to the light curing station at a speed of 10m / min. It passes through a transparent quartz roller with a curing light source lamp inside (the quartz roller squeezes the upper surface of the paper, which is equivalent to anaerobic curing). After curing, the single-sided PET film is peeled off and rolled up for recycling. It can be reused after cleaning and drying.

[0108] (4) Post-processing and winding process:

[0109] The cured transparent paper is transported to the high-temperature calendering equipment. After 5 high-temperature roller presses, the transparent paper roll is trimmed and cut, and then online inspection is carried out to test the paper's thickness uniformity, transparency uniformity, moisture content, etc. The paper will be rolled up after passing the inspection. If the inspection fails, the machine will automatically cut and reroll it.

[0110] Example D

[0111] (1) Papermaking process: 50% recycled fiber pulp, 30% conifer fiber pulp, and 20% sugarcane pulp were selected as raw materials, the pulp board was soaked in a certain amount of water, and the fibers were dispersed by a high-speed deflaker; the pulp concentration was adjusted to 3%, and the pulp was sent to the pulping machine through a pulp supply pump. After beating for 30 minutes at a speed of 2000 rpm, the pulped slurry was discharged; the pulped slurry concentration was adjusted to 1%, and the pulp was sent to a disc pulper at a speed of 3000 rpm. The pulp was ground at 25°C for 10 cycles with a cycle of 2 hours; the finely ground cellulose suspension was evenly dispersed in a high shear homogenizer, wherein the rotary kneading machine was used to grind the cellulose suspension. The speed is 10000rpm, and after dispersion for 30 minutes, polyvinyl alcohol with a concentration of 0.2% is added; the slurry is diluted with water to a concentration of 0.5%, and the slurry is transported to the head box of the papermaking machine using a slurry pump; after the slurry is evenly dispersed in the head box, it is quantitatively 20g / m2 and continuously supplied to the mesh surface through a slurry supply machine, the mesh number is 8000 mesh, and the mesh speed is 40m / min; after the paper web is rubbed and cut, the paper web is wet-pressed by a pressing roller, the pressing pressure is 1000kPa, and excess water is removed by a vacuum part; then the pressed wet paper web is sent to an oven composed of multiple groups of heating drying cylinders for hot air drying, the moisture content is controlled at 8%, and it is rolled up after trimming.

[0112] (2) Impregnation process: Through the non-stop roll-changing device and the multi-guide rollers to adjust the tension and offset, the low-weight paper is brought into the impregnation station by the feed roller at a conveying speed of 10 m / min. The satellite rollers (a main roller with a diameter of 2 m above the paper and 7 satellite rollers with a diameter of 20 cm below) fully absorb the light-curable impregnation liquid in the impregnation tank. After the impregnation is completed, a 50-micron PET film (the side in contact with the paper is the release layer) is used at the last satellite roller for single-sided roll-to-roll lamination. Then, the excess impregnation liquid is squeezed out by the pressing roller with an upper and lower limit of 80 mm. The impregnation liquid recovery device is set below, and after filtration, it is recovered into the impregnation tank for recycling;

[0113] Wherein, the preparation method of the photocurable impregnation liquid is:

[0114] The photopolymerizable monomers are 2-octyl acrylate and 1,6-hexanediol diacrylate mixed in a mass ratio of 2:1, and 1 wt % of phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide is added and stirred evenly;

[0115] The mixed liquid is transported to a high-speed centrifugal degasser for degassing.

[0116] (3) Photocuring process:

[0117] The impregnated single-sided coated paper is transported to the light curing station at a speed of 10m / min. It passes through a transparent quartz roller with a curing light source lamp inside (the quartz roller squeezes the upper surface of the paper, which is equivalent to anaerobic curing). After curing, the single-sided PET film is peeled off and rolled up for recycling. It can be reused after cleaning and drying.

[0118] (4) Post-processing and winding process:

[0119] The cured transparent paper is transported to the high-temperature calendering equipment. After 5 high-temperature roller presses, the transparent paper roll is trimmed and cut, and then online inspection is carried out to test the paper's thickness uniformity, transparency uniformity, moisture content, etc. The paper will be rolled up after passing the inspection. If the inspection fails, the machine will automatically cut and reroll it.

[0120] Example E

[0121] (1) Papermaking process: 50% recycled fiber pulp, 30% conifer fiber pulp, and 20% sugarcane pulp are selected as raw materials. The pulp board is soaked in a certain amount of water and the fibers are dispersed by a high-speed deflaker. The pulp concentration is adjusted to 3% and sent to the pulping machine pulp pool through a pulp supply pump. After beating for 10 minutes at a speed of 2000 rpm, the pulped slurry is discharged. The pulp concentration after beating is adjusted to 1% and sent to a disc pulping machine at a speed of 3000 rpm. The pulp is ground at 25°C for 2 hours. The pulp is diluted with water and then the pulp is pulverized. The slurry is diluted to a concentration of 0.5%, and a slurry pump is used to transport the slurry to the head box of the papermaking machine; after the slurry is evenly dispersed in the head box, it is quantitatively 20g / m2 and continuously supplied to the mesh surface through a slurry feeder, the mesh number is 100 mesh, and the mesh speed is 40m / min; after the paper web is rubbed and cut, the paper web is wet-pressed by a pressing roller with a pressing pressure of 1000kPa, and excess water is removed by a vacuum part; the pressed wet paper web is then sent to an oven composed of multiple groups of heating drying cylinders for hot air drying, the moisture content is controlled at 8%, and it is rolled up after trimming.

[0122] (2) Impregnation process: Through the non-stop roll-changing device and the multi-guide rollers to adjust the tension and offset, the low-weight paper is brought into the impregnation station by the feed roller at a conveying speed of 10 m / min. The satellite rollers (a main roller with a diameter of 2 m above the paper and 7 satellite rollers with a diameter of 20 cm below) fully absorb the light-curable impregnation liquid in the impregnation tank. After the impregnation is completed, a 50-micron PET film (the side in contact with the paper is the release layer) is used at the last satellite roller for single-sided roll-to-roll lamination. Then, the excess impregnation liquid is squeezed out by the pressing roller with an upper and lower limit of 80 mm. The impregnation liquid recovery device is set below, and after filtration, it is recovered into the impregnation tank for recycling;

[0123] Wherein, the preparation method of the photocurable impregnation liquid is:

[0124] After mixing the photopolymerizable monomers isooctyl acrylate and 1,6-hexanediol diacrylate in a mass ratio of 2:1, 1 wt % of phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide and 2 wt % of trimethylolpropane triacrylate were added, and stirred evenly;

[0125] The mixed liquid is transported to a high-speed centrifugal degasser for degassing.

[0126] (3) Photocuring process:

[0127] The impregnated single-sided coated paper is transported to the light curing station at a speed of 10m / min. It passes through a transparent quartz roller with a curing light source lamp inside (the quartz roller squeezes the upper surface of the paper, which is equivalent to anaerobic curing). After curing, the single-sided PET film is peeled off and rolled up for recycling. It can be reused after cleaning and drying.

[0128] (4) Post-processing and winding process:

[0129] The cured transparent paper is transported to the high-temperature calendering equipment. After 5 high-temperature roller presses, the transparent paper roll is trimmed and cut, and then online inspection is carried out to test the paper's thickness uniformity, transparency uniformity, moisture content, etc. The paper will be rolled up after passing the inspection. If the inspection fails, the machine will automatically cut and reroll it.

[0130] Example F

[0131] (1) Papermaking process: 50% recycled fiber pulp, 30% conifer fiber pulp, and 20% sugarcane pulp are selected as raw materials. The pulp board is soaked in a certain amount of water and the fibers are dispersed by a high-speed deflaker. The pulp concentration is adjusted to 3% and sent to the pulping machine pulp pool through a pulp supply pump. After beating for 10 minutes at a speed of 2000 rpm, the pulped slurry is discharged. The pulp concentration after beating is adjusted to 1% and sent to a disc pulping machine at a speed of 3000 rpm. The pulp is ground at 25°C for 2 hours. The pulp is diluted with water and then the pulp is pulverized. The slurry is diluted to a concentration of 0.5%, and a slurry pump is used to transport the slurry to the head box of the papermaking machine; after the slurry is evenly dispersed in the head box, it is quantitatively 20g / m2 and continuously supplied to the mesh surface through a slurry feeder, the mesh number is 100 mesh, and the mesh speed is 40m / min; after the paper web is rubbed and cut, the paper web is wet-pressed by a pressing roller with a pressing pressure of 1000kPa, and excess water is removed by a vacuum part; the pressed wet paper web is then sent to an oven composed of multiple groups of heating drying cylinders for hot air drying, the moisture content is controlled at 8%, and it is rolled up after trimming.

[0132] (2) Impregnation process: Through the non-stop roll-changing device and the multi-guide rollers to adjust the tension and offset, the low-weight paper is brought into the impregnation station by the feed roller at a conveying speed of 10 m / min. The satellite rollers (a main roller with a diameter of 2 m above the paper and 7 satellite rollers with a diameter of 20 cm below) fully absorb the light-curable impregnation liquid in the impregnation tank. After the impregnation is completed, a 50-micron PET film (the side in contact with the paper is the release layer) is used at the last satellite roller for single-sided roll-to-roll lamination. Then, the excess impregnation liquid is squeezed out by the pressing roller with an upper and lower limit of 80 mm. The impregnation liquid recovery device is set below, and after filtration, it is recovered into the impregnation tank for recycling;

[0133] Wherein, the preparation method of the photocurable impregnation liquid is:

[0134] After mixing the photopolymerizable monomers isooctyl acrylate and 1,6-hexanediol diacrylate in a mass ratio of 2:1, 1 wt % of phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide and 0.5 wt % of polydimethylsiloxane were added, and stirred evenly;

[0135] The mixed liquid is transported to a high-speed centrifugal degasser for degassing.

[0136] (3) Photocuring process:

[0137] The impregnated single-sided coated paper is transported to the light curing station at a speed of 10m / min. It passes through a transparent quartz roller with a curing light source lamp inside (the quartz roller squeezes the upper surface of the paper, which is equivalent to anaerobic curing). After curing, the single-sided PET film is peeled off and rolled up for recycling. It can be reused after cleaning and drying.

[0138] (4) Post-processing and winding process:

[0139] The cured transparent paper is transported to the high-temperature calendering equipment. After 5 high-temperature roller presses, the transparent paper roll is trimmed and cut, and then online inspection is carried out to test the paper's thickness uniformity, transparency uniformity, moisture content, etc. The paper will be rolled up after passing the inspection. If the inspection fails, the machine will automatically cut and reroll it.

[0140] Example G

[0141] (1) Papermaking process: 50% recycled fiber pulp, 30% conifer fiber pulp, and 20% sugarcane pulp are selected as raw materials. The pulp board is soaked in a certain amount of water and the fibers are dispersed by a high-speed deflaker. The pulp concentration is adjusted to 3% and sent to the pulping machine pulp pool through a pulp supply pump. After beating for 10 minutes at a speed of 2000 rpm, the pulped slurry is discharged. The pulp concentration after beating is adjusted to 1% and sent to a disc pulping machine at a speed of 3000 rpm. The pulp is ground at 25°C for 2 hours. The pulp is diluted with water and then the pulp is pulverized. The slurry is diluted to a concentration of 0.5%, and a slurry pump is used to transport the slurry to the head box of the papermaking machine; after the slurry is evenly dispersed in the head box, it is quantitatively 20g / m2 and continuously supplied to the mesh surface through a slurry feeder, the mesh number is 100 mesh, and the mesh speed is 40m / min; after the paper web is rubbed and cut, the paper web is wet-pressed by a pressing roller with a pressing pressure of 1000kPa, and excess water is removed by a vacuum part; the pressed wet paper web is then sent to an oven composed of multiple groups of heating drying cylinders for hot air drying, the moisture content is controlled at 8%, and it is rolled up after trimming.

[0142] (2) Impregnation process: Through the non-stop roll-changing device and the multi-guide rollers to adjust the tension and offset, the low-weight paper is brought into the impregnation station by the feed roller at a conveying speed of 10 m / min. The satellite rollers (a main roller with a diameter of 2 m above the paper and 7 satellite rollers with a diameter of 20 cm below) fully absorb the light-curable impregnation liquid in the impregnation tank. After the impregnation is completed, a 50-micron PET film (the side in contact with the paper is the release layer) is used at the last satellite roller for single-sided roll-to-roll lamination. Then, the excess impregnation liquid is squeezed out by the pressing roller with an upper and lower limit of 80 mm. The impregnation liquid recovery device is set below, and after filtration, it is recovered into the impregnation tank for recycling;

[0143] Wherein, the preparation method of the photocurable impregnation liquid is:

[0144] After mixing the photopolymerizable monomers isooctyl acrylate and 1,6-hexanediol diacrylate in a mass ratio of 2:1, 1 wt % of phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide and 0.5 wt % of silica nanoparticles were added, and stirred evenly;

[0145] The mixed liquid is transported to a high-speed centrifugal degasser for degassing.

[0146] (3) Photocuring process:

[0147] The impregnated single-sided coated paper is transported to the light curing station at a speed of 10m / min. It passes through a transparent quartz roller with a curing light source lamp inside (the quartz roller squeezes the upper surface of the paper, which is equivalent to anaerobic curing). After curing, the single-sided PET film is peeled off and rolled up for recycling. It can be reused after cleaning and drying.

[0148] (4) Post-processing and winding process:

[0149] The cured transparent paper is transported to the high-temperature calendering equipment. After 5 high-temperature roller presses, the transparent paper roll is trimmed and cut, and then online inspection is carried out to test the paper's thickness uniformity, transparency uniformity, moisture content, etc. The paper will be rolled up after passing the inspection. If the inspection fails, the machine will automatically cut and reroll it.

[0150] Example H

[0151] (1) Papermaking process: 100% softwood fiber pulp is selected as the raw material, the pulp board is soaked in a certain amount of water, and the fibers are dispersed by a high-speed deflaker; the pulp concentration is adjusted to 3%, and the pulp is sent to the pulp tank of the beater through a pulp supply pump. After beating for 10 minutes at a speed of 2000 rpm, the pulped slurry is discharged; the pulp concentration after beating is adjusted to 1%, and the pulp is sent to a disc pulper at a speed of 3000 rpm, and the pulp is ground at 25°C for 2 hours; the pulp is diluted with water to a concentration of 0.5%, The pulp is transported to the head box of the paper machine by a pulp supply pump; after the pulp is evenly dispersed in the head box, it is quantitatively supplied to the mesh surface of 100 mesh and the mesh speed is 40m / min by a pulp supply machine at 20g / m2; after the paper web is rubbed and cut, the paper web is wet pressed by a pressing roller with a pressing pressure of 1000kPa, and excess water is removed by a vacuum part; the pressed wet paper web is then sent to an oven composed of multiple groups of heating drying cylinders for hot air drying, the moisture content is controlled at 8%, and it is rolled up after trimming.

[0152] (2) Impregnation process: Through the non-stop roll-changing device and the multi-guide rollers to adjust the tension and offset, the low-weight paper is brought into the impregnation station by the feed roller at a conveying speed of 10 m / min. The satellite rollers (a main roller with a diameter of 2 m above the paper and 7 satellite rollers with a diameter of 20 cm below) fully absorb the light-curable impregnation liquid in the impregnation tank. After the impregnation is completed, a 50-micron PET film (the side in contact with the paper is the release layer) is used at the last satellite roller for single-sided roll-to-roll lamination. Then, the excess impregnation liquid is squeezed out by the pressing roller with an upper and lower limit of 80 mm. The impregnation liquid recovery device is set below, and after filtration, it is recovered into the impregnation tank for recycling;

[0153] Wherein, the preparation method of the photocurable impregnation liquid is:

[0154] The photopolymerizable monomers are 2-octyl acrylate and 1,6-hexanediol diacrylate mixed in a mass ratio of 2:1, and 1 wt % of phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide is added and stirred evenly;

[0155] The mixed liquid is transported to a high-speed centrifugal degasser for degassing.

[0156] (3) Photocuring process:

[0157] The impregnated single-sided coated paper is transported to the light curing station at a speed of 10m / min. It passes through a transparent quartz roller with a curing light source lamp inside (the quartz roller squeezes the upper surface of the paper, which is equivalent to anaerobic curing). After curing, the single-sided PET film is peeled off and rolled up for recycling. It can be reused after cleaning and drying.

[0158] (4) Post-processing and winding process:

[0159] The cured transparent paper is transported to the high-temperature calendering equipment. After 5 high-temperature roller presses, the transparent paper roll is trimmed and cut, and then online inspection is carried out to test the paper's thickness uniformity, transparency uniformity, moisture content, etc. The paper will be rolled up after passing the inspection. If the inspection fails, the machine will automatically cut and reroll it.

[0160] Embodiment 1

[0161] (1) Papermaking process: 100% sugarcane pulp is selected as the raw material, the pulp board is soaked in a certain amount of water, and the fibers are dispersed by a high-speed deflaker; the pulp concentration is adjusted to 3%, and the pulp is sent to the pulp tank of the pulper through a pulp supply pump. After beating for 10 minutes at a speed of 2000 rpm, the pulped slurry is discharged; the pulp concentration after beating is adjusted to 1%, and the pulp is sent to a disc pulper at a speed of 3000 rpm, and the pulp is ground at 25°C for 2 hours; the pulp is diluted with water to a concentration of 0.5%, and the pulp is made into a pulp. The pulp is transported to the head box of the papermaking machine by a pulp supply pump; after the pulp is evenly dispersed in the head box, it is quantitatively 20g / m2 and continuously supplied to the mesh surface through a pulp supply machine, the mesh number is 100 mesh, and the mesh speed is 40m / min; after the paper web is rubbed and cut, the paper web is wet-pressed by a pressing roller with a pressing pressure of 1000kPa, and excess moisture is removed by a vacuum part; then the pressed wet paper web is sent to an oven composed of multiple groups of heating drying cylinders for hot air drying, the moisture content is controlled at 8%, and it is rolled up after trimming.

[0162] (2) Impregnation process: Through the non-stop roll-changing device and the multi-guide rollers to adjust the tension and offset, the low-weight paper is brought into the impregnation station by the feed roller at a conveying speed of 10 m / min. The satellite rollers (a main roller with a diameter of 2 m above the paper and 7 satellite rollers with a diameter of 20 cm below) fully absorb the light-curable impregnation liquid in the impregnation tank. After the impregnation is completed, a 50-micron PET film (the side in contact with the paper is the release layer) is used at the last satellite roller for single-sided roll-to-roll lamination. Then, the excess impregnation liquid is squeezed out by the pressing roller with an upper and lower limit of 80 mm. The impregnation liquid recovery device is set below, and after filtration, it is recovered into the impregnation tank for recycling;

[0163] Wherein, the preparation method of the photocurable impregnation liquid is:

[0164] The photopolymerizable monomers are 2-octyl acrylate and 1,6-hexanediol diacrylate mixed in a mass ratio of 2:1, and 1 wt % of phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide is added and stirred evenly;

[0165] The mixed liquid is transported to a high-speed centrifugal degasser for degassing.

[0166] (3) Photocuring process:

[0167] The impregnated single-sided coated paper is transported to the light curing station at a speed of 10m / min. It passes through a transparent quartz roller with a curing light source lamp inside (the quartz roller squeezes the upper surface of the paper, which is equivalent to anaerobic curing). After curing, the single-sided PET film is peeled off and rolled up for recycling. It can be reused after cleaning and drying.

[0168] (4) Post-processing and winding process:

[0169] The cured transparent paper is transported to the high-temperature calendering equipment. After 5 high-temperature roller presses, the transparent paper roll is trimmed and cut, and then online inspection is carried out to test the paper's thickness uniformity, transparency uniformity, moisture content, etc. The paper will be rolled up after passing the inspection. If the inspection fails, the machine will automatically cut and reroll it.

[0170] The easily degradable transparent papers made from the nine AI embodiments were tested respectively, and the following data were obtained (see Table 1, Table 2 and Table 3):

[0171]

[0172]

[0173] Table 1 Tensile strength of transparent paper prepared in Example AI

[0174] transparency(%) Haze(%) Example A 89.38 23.58 Example B 88.91 22.64 Example C 91.71 8.71 Example D 92.78 2.17 Example E 88.43 22.98 Example F 87.09 24.33 Example G 90.02 17.63 Example H 90.12 31.18 Embodiment 1 85.69 22.05

[0175] Table 2 Transparency and haze of transparent paper prepared in Example AI

[0176]

[0177]

[0178] Table 3 Transparency and haze of transparent paper prepared in Example AI

[0179] Weight loss (%) PET transparent film 0.9 (basically no degradation) Base paper Complete degradation Transparent paper 60.0

[0180] Table 4 Weight loss of PET transparent film, base paper and transparent paper prepared in Example B after being buried in the soil at a depth of 10 cm in the natural environment for 83 days

[0181] It can be seen from the above test data that the product obtained by the present invention has the advantages of easy degradation, high transparency, good mechanical properties, etc.

[0182] The fiber preparation method of the present application successfully solves the technical problem of how to prepare fine fibers for making easily degradable transparent paper through multiple finely controlled steps. Through high-speed pulping, precisely controlled pulping and refining processes, and final high-shear homogenization treatment, the present application can obtain fine fibers with uniform size and good dispersion. These fibers are the key raw materials for preparing highly transparent and easily degradable paper.

[0183] The innovation of this application is that: first, a multi-step fiber processing process is adopted, and each step specifically solves different aspects of fiber dispersion and refinement. Secondly, precise parameter control is adopted in each step, such as slurry concentration, processing temperature, rotation speed and time, which ensures the controllability and repeatability of the processing process. Finally, the use of high shear homogenization and dispersant is introduced to further improve the dispersion uniformity of the fiber.

[0184] The main advantages of this method include: it can produce smaller and more uniform fibers, thereby significantly improving the transparency of the final paper; high temperature and strong chemical treatment are avoided during the processing process, maintaining the biodegradability of the fibers; through flexible adjustment of parameters, it can adapt to different raw materials and different application requirements; the equipment and raw materials used in the whole process are relatively simple, which is conducive to reducing production costs.

[0185] In general, this application provides an efficient, controllable and flexible fiber preparation method, which lays the foundation for the production of high-performance and easily degradable transparent paper. It is expected to find wide application in packaging, printing and other fields, and provides new possibilities for solving the problem of plastic pollution.

[0186] In the preparation process of easily degradable transparent paper, the preparation of a photocurable impregnating liquid is a key step. Traditional impregnating liquid formulas often have problems such as poor photocuring effect, poor compatibility with fibers, and inability to impart the required properties to paper. In order to solve these problems, this application proposes an innovative method for preparing a photocurable impregnating liquid.

[0187] The technical solution of the present application successfully solves the problem of how to improve the transparency and mechanical properties of paper when preparing easily degradable transparent paper by adding a specific crosslinking agent to the photocurable impregnation liquid. The crosslinking agent forms chemical crosslinks between fibers, reduces the gaps between fibers, improves light transmittance, and at the same time strengthens the overall structure of the paper and improves the mechanical properties. By controlling the type and amount of the crosslinking agent added, the performance of the final product can be flexibly adjusted to meet the needs of different applications.

[0188] The main advantages of this method are: first, it can significantly improve the transparency and mechanical properties while maintaining the easy degradability of paper. Second, by selecting different cross-linking agent combinations, the performance can be finely controlled. Third, since the amount of cross-linking agent added is small, it will not significantly increase the production cost, maintaining good cost-effectiveness. Finally, this method can be seamlessly integrated with the existing production process, which is convenient for practical application.

[0189] In general, the method for preparing easily degradable transparent paper proposed in this application not only solves the key problems in the prior art, but also provides new ideas for developing high-performance, environmentally friendly packaging materials. The application of this method is expected to promote the packaging industry to develop in a more environmentally friendly and sustainable direction, and make an important contribution to solving the problem of plastic pollution.

[0190] In the method for preparing the easily degradable transparent paper of the present application, the formulation of the photocurable impregnating liquid plays a key role in the performance of the final product. In order to further optimize the performance of the impregnating liquid, the present application innovatively introduces a surfactant as an additive. The addition of a surfactant can significantly improve the performance of the impregnating liquid, thereby improving the quality of the transparent paper.

[0191] This application selects sorbitan, hexadecyl alcohol, polyethylene glycol laurate, polydimethylsiloxane, polyether modified silicone oil and the like as optional surfactants. These surfactants have their own characteristics and can be selected and combined according to specific needs. Nonionic surfactants such as sorbitan, hexadecyl alcohol and polyethylene glycol laurate can effectively reduce the surface tension of the impregnation liquid and improve its wettability and permeability to paper. This helps the impregnation liquid to be more evenly distributed on the surface and inside of the paper, thereby improving the transparency and uniformity of the final product. Silicon-based surfactants such as polydimethylsiloxane and polyether modified silicone oil can give transparent paper certain hydrophobic properties, which is very valuable for certain special packaging applications.

[0192] The present application controls the amount of surfactant added within the mass percentage range of 0-2%. This range is selected after careful consideration. Adding an appropriate amount of surfactant can significantly improve the performance of the impregnation liquid, but excessive addition may affect other properties of the impregnation liquid or increase costs. By controlling the addition amount within the range of 0-2%, the impregnation effect can be effectively optimized without significantly affecting other properties of the impregnation liquid.

[0193] The addition of surfactants can not only improve the performance of the impregnation liquid, but also indirectly improve the quality of transparent paper. By reducing the surface tension of the impregnation liquid, surfactants can promote the impregnation liquid to penetrate deeper into the fiber network, thereby more effectively filling the gaps between fibers. This can not only improve the transparency of the final product, but also enhance the mechanical properties of the paper. In addition, some surfactants can also form a thin film on the surface of the paper, further improving the gloss and smoothness of the transparent paper.

[0194] In practical applications, one or more surfactants can be selected according to specific needs. For example, for applications that require high transparency, non-ionic surfactants such as sorbitan or polyethylene glycol laurate can be selected. These surfactants can significantly reduce the surface tension of the impregnation liquid and promote a more uniform distribution of the impregnation liquid in the paper, thereby improving transparency. For applications that require a certain degree of hydrophobicity, silicon-based surfactants such as polydimethylsiloxane or polyether-modified silicone oil can be selected. These surfactants can form a hydrophobic film on the surface of the paper, improving the waterproof performance of transparent paper.

[0195] The amount of surfactant added can also be adjusted according to specific needs. For example, for applications that require higher transparency, the amount of surfactant added can be appropriately increased, but not more than 2%. For general applications, the amount added can be controlled within the range of 0.5-1%, which can effectively improve the performance of the impregnation solution and control costs.

[0196] The present application also found that different types of surfactants can produce synergistic effects. For example, nonionic surfactants and silicon-based surfactants can be added simultaneously, which can not only improve the wettability and permeability of the impregnation liquid, but also give the transparent paper a certain hydrophobic property. This combination can meet a wider range of application needs.

[0197] In the preparation process of biodegradable transparent paper, the impregnation step is a key link to improve the transparency and mechanical properties of paper. However, the traditional impregnation method often faces some technical challenges. First, when the paper is soaked, its strength will be significantly reduced, and it is easy to break due to excessive tension. Secondly, in the continuous production process, how to maintain the stability of paper tension and avoid deviation is also an important issue. These problems not only affect product quality, but may also lead to reduced production efficiency.

[0198] In order to solve these problems, the present application proposes an improved impregnation method. Specifically, in step S2, a satellite pressure roller structure consisting of a main roller and a plurality of satellite rollers is adopted, such as Figure 2 As shown in the figure. The core idea of ​​this design is to reduce the risk of excessive tension on a single point of the paper by dispersing the stress points. The main roller 10 is the center, and multiple satellite rollers 20 are distributed around it to form a uniformly stressed system. When the paper 30 passes through this system, the tension is dispersed to multiple contact points, greatly reducing the possibility of paper breakage.

[0199] In addition, the present application also sets up a non-stop roll changing device at the unwinding position and is equipped with multiple guide rollers. The introduction of the non-stop roll changing device solves the problem of stopping the machine during the traditional roll changing process, significantly improving the continuity and efficiency of production. The setting of multiple guide rollers makes it possible to accurately adjust the tension and position of the paper. By adjusting the position and tension of the guide rollers, the paper transmission path can be corrected in real time, effectively avoiding the deviation problem.

[0200] The combined application of these technical features not only solves the problem of paper being easily broken after being soaked, but also improves the stability and efficiency of the production process. The satellite pressure roller structure can be designed according to actual needs. For example, the number and distribution of satellite rollers 20 can be adjusted to adapt to paper of different thickness and strength. The non-stop roll changing device can adopt various forms, such as flying shear type or double-arm type, to adapt to different production line layouts. The multi-guide roller system can be controlled by a motor to achieve automatic adjustment, further improving production accuracy and efficiency.

[0201] In practical applications, the implementation of these technical features has achieved remarkable results. Figure 2 As shown, in one embodiment, a satellite roller structure consisting of a main roller 10 and seven satellite rollers 20 is used. The diameter of the main roller is 2m, and the diameter of the satellite roller is 20cm. This configuration allows the paper to be evenly stressed during the impregnation process, and no breakage occurs even when the moisture content of the paper reaches 60%. At the same time, the non-stop roll changing device adopts a double-arm design, combined with four adjustable guide rollers, to achieve 24-hour uninterrupted production, thereby improving production efficiency.

[0202] The technical solution of this application performs well in solving problems such as easy breakage, unstable tension and deviation of paper after soaking. The satellite pressure roller structure effectively avoids the problem of paper breaking due to excessive local tension in the soaked state by dispersing the stress points. The main roller serves as the central support point to provide stability for the entire system, while multiple satellite rollers ensure full contact between the paper and the impregnation liquid while evenly distributing the tension. This design is particularly suitable for processing paper whose strength is reduced after soaking, and can minimize the risk of breakage while ensuring the impregnation effect.

[0203] The introduction of the non-stop roll changing device solves the problem of stopping the machine during the traditional roll changing process, and significantly improves the continuity of production. This not only improves production efficiency, but also reduces the fluctuation of paper quality caused by stopping and restarting. In the continuous production process, the tension and position control of the paper is very important. The setting of the multi-guide roller system provides strong support for this control. By adjusting the position and tension of the guide roller, the paper transmission path can be corrected in real time to effectively avoid the deviation problem. This precise control not only ensures the consistency of product quality, but also reduces the waste caused by paper deviation.

[0204] In actual operation, the satellite roller system works as follows: the paper first contacts the main roller and then passes through each satellite roller in turn. Each satellite roller exerts a certain amount of pressure on the paper, but the single-point pressure is greatly reduced due to the dispersed force points. This design allows the paper to be fully soaked in the impregnation liquid while avoiding breakage caused by excessive local tension. The non-stop roll change device achieves a seamless connection between the expiring paper roll and the new paper roll through precise timing control. During the roll change process, the multi-guide roller system plays a key role, ensuring the stability of the paper tension and position through real-time adjustments.

[0205] In general, the technical solution proposed in this application effectively solves the key technical problems in the preparation process of easily degradable transparent paper by innovatively combining satellite pressure rollers, non-stop roll changing devices and multi-guide roller systems. This method not only improves production efficiency and product quality, but also enhances the stability and controllability of the entire production process. Through these improvements, this application provides reliable technical support for the large-scale production of easily degradable transparent paper and makes an important contribution to the development of environmentally friendly packaging materials.

[0206] In summary, the easily degradable transparent paper and its preparation method provided by the present invention use wood pulp, cotton pulp, sugarcane pulp and recycled fiber as raw materials, prepare fine fibers after being processed by a pulper and a pulping machine, and then use wet fiber forming technology to copy low-weight paper, and prepare it through processes such as impregnation, light curing, and high-temperature calendering. It has the advantages of easy degradation, low cost, high transparency, good mechanical properties and hydrophobic properties, and there is almost no VOC emission during the preparation process, and it does not require a large amount of water resources. The raw material and production costs are low. The application of the low-cost, easily degradable and highly transparent paper of the present invention can largely replace the ordinary plastic films currently used in various types of outer packaging, reduce white pollution, and achieve environmental protection and sustainable development.

[0207] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, which all belong to the protection scope of the present invention.

Claims

1. A method for preparing easily degradable transparent paper, characterized in that: The following steps are involved: S1, selecting wood pulp, cotton pulp, sugarcane pulp and recycled fiber as raw materials, preparing fine fibers after processing by a pulping machine and a pulping machine, and then using wet fiber forming technology to produce low-weight paper with fluffy fibers, good hygroscopicity and a gram weight of 15-40g / m2, and drying and rolling the low-weight paper; S2. The low-weight paper at the unwinding position is brought into the impregnation station by the feed roller at a conveying speed of 6-12m / min, and the light-curable impregnation liquid in the impregnation tank is fully absorbed by the satellite pressure roller. After the impregnation is completed, a PET film is used for single-sided roll-to-roll lamination at the last satellite roller, and then the upper and lower limit pressure rollers are used to squeeze the excess impregnation liquid while controlling the thickness of the impregnated paper to be 15-40 microns, so as to form a single-sided coated paper; S3, the single-sided coated paper is conveyed to the light curing station at a conveying speed of 6-12m / min for curing. After curing, the single-sided PET film is peeled off to form transparent paper, and the peeled single-sided PET film is rolled up and recycled, and can be reused after cleaning and drying; S4. The cured transparent paper is transported to a high-temperature calendering device. After multiple high-temperature roller pressings, the transparent paper is trimmed and cut. After passing the inspection, the paper is rolled up to obtain easily degradable transparent paper.

2. The method for preparing the easily degradable transparent paper according to claim 1, characterized in that: The step S1 of preparing fine fibers after being processed by a pulper and a refiner specifically includes: S11, soaking the raw material in a certain amount of water, and dispersing the fibers through a high-speed deflaking machine; S12, adjusting the slurry concentration to 2-5%, feeding it into the pulping machine pulp pool through the pulp supply pump, and beating it at a speed of 1500-2000 rpm for 10-30 minutes, and then discharging the beaten slurry; S13, adjusting the concentration of the pulp after beating to 0.5-3%, conveying it to a disc refiner, using a cooling water temperature control system to grind the pulp in a temperature range of 20-25° C., wherein the rotation speed is 2000-4000 rpm, and the refining time is 2 hours as a cycle, and the generated fiber suspension is refined for multiple cycles according to the fiber size requirements; S14, uniformly dispersing the finely refined cellulose suspension in a high shear homogenizer at a rotation speed of 6000-10000 rpm and a dispersion time of 10-40 minutes, adding polyvinyl alcohol as a dispersant and wet strength agent at a concentration of 0.05-0.5%; or adding polyurethane as a wet strength agent at a concentration of 0.5-2%.

3. The method for preparing the easily degradable transparent paper according to claim 1, characterized in that: The papermaking, drying and winding forming process using wet fiber forming technology in step S1 specifically includes: S15, dilute the slurry with water to a concentration of 0.1-2%, and use a slurry supply pump to transport the slurry to the head box of the papermaking machine to ensure smooth flow of the slurry to avoid sedimentation and accumulation; S16, the slurry is evenly dispersed in the head box and quantitatively and continuously supplied to the mesh surface through the slurry supply machine, wherein the mesh number of the mesh surface is above 80 meshes and the mesh speed is 10-50m / min; S17, after the paper web is rubbed and cut, the paper web is wet pressed by multiple pressing rollers, and excess water is quickly removed by a vacuum part, and the pressing pressure is set to 500-2000 kPa to maintain the fluffy structure of the paper; S18, sending the wet paper web into a drying oven composed of multiple groups of heating drying cylinders for hot air drying, controlling the moisture content within the range of 5-12%, and rolling up after trimming.

4. The method for preparing the easily degradable transparent paper according to claim 1, characterized in that: The preparation method of the photocurable impregnation liquid in step S2 is as follows: firstly, photopolymerizable monomers are mixed in a certain proportion; then, additives such as photoinitiator, crosslinking agent, surfactant, inorganic filler, natural polymer filler, etc. are added and stirred evenly; finally, the mixed liquid is transported to a high-speed centrifugal degasser for degassing; The photopolymerizable monomer is one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, isooctyl acrylate, 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, polydipentaerythritol hexaacrylate, allyl cellulose, polyethylene glycol diacrylate, ethylene glycol methacrylate, polycaprolactone acrylate, etc.; The photoinitiator is one or more of phenyl bisphosphine oxide, 2-hydroxy-2-methylpropiophenone, dibenzoyl peroxide, diphenylphosphine oxide, etc., and the added amount is 0.1-3% by mass; the crosslinking agent is one or more of tripropylene glycol diacrylate, polyethylene glycol diacrylate, dipropylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol phthalate diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, and the added amount is 0-2% by mass; The surfactant is one or more of sorbitol, cetyl alcohol, polyethylene glycol laurate, polydimethylsiloxane, and polyether-modified silicone oil, and the added amount is 0-2% by mass; The inorganic filler is one or more of silicon dioxide nanoparticles, aluminum oxide nanoparticles, zinc white powder, and montmorillonite nanosheets, and the added amount is 0-2% by mass.

5. The method for preparing the easily degradable transparent paper according to claim 4, characterized in that: The photopolymerizable monomer has low viscosity, good wettability to paper fibers, high photocuring efficiency and good hydrophobicity after curing.

6. The method for preparing the easily degradable transparent paper according to claim 4, characterized in that: The photopolymerizable monomer is compounded of a soft monomer and a hard monomer, and the mixing ratio is regulated according to the monomer types and performance requirements to meet the requirements of firmness, flexibility and mechanical strength of the transparent paper.

7. The method for preparing the easily degradable transparent paper according to claim 1, characterized in that: In the step S2, an impregnation liquid recovery device is arranged below the limiting pressure roller, and the impregnation liquid is recovered into the impregnation tank for recycling after filtering.

8. The method for preparing the easily degradable transparent paper according to claim 1, characterized in that: The light curing station in step S3 is a transparent quartz roller, which is equipped with a curing light source with a matching wavelength. The uncoated side of the single-sided coated paper after impregnation is close to the quartz roller, achieving anaerobic curing conditions while ensuring the flatness of the paper surface.

9. The method for preparing the easily degradable transparent paper according to claim 1, characterized in that: The satellite pressure rollers in step S2 are composed of a main roller and multiple satellite rollers, which are used to prevent the paper from breaking due to excessive tension after being soaked; a non-stop roll changing device is provided at the unwinding position, and multiple guide rollers are equipped to adjust the tension and offset.

10. A degradable transparent paper, characterized in that: Prepared by the preparation method according to any one of claims 1 to 9.

Images