Composite biomass aerogel cushion packaging material and preparation method thereof

Abstract

The application relates to a composite biomass aerogel buffer packaging material and a preparation method thereof, and relates to the technical field of packaging materials.The composite biomass aerogel buffer packaging material comprises an aerogel body and a reinforcing structure embedded in the aerogel body; the aerogel body comprises, in terms of weight parts, 2-10 parts of starch, 2-10 parts of fiber, 2-20 parts of a plasticizer, 1-5 parts of a preservative, and 0.5-3 parts of a thickening agent; and the reinforcing structure is at least one layer of hollow tube groups, at least one layer of fiber boards, at least one layer of gauze, or multiple layers of corrugated paper. The biomass aerogel material is combined with the reinforcing structure, the buffer packaging performance of the buffer packaging structure can be improved, the weight of the aerogel body can be reduced by virtue of the light weight and large volume of the internal reinforcing structure, the weight and cost of the buffer packaging structure under the same volume can be reduced, actual use requirements can be met, and the problems of poor environmental protection and buffer packaging effect of the buffer packaging material are solved.

Description

Technical Field

[0001] This application relates to the field of packaging materials technology, and in particular to a composite biomass aerogel cushioning packaging material and its preparation method. Background Technology

[0002] Currently, the most commonly used cushioning packaging material is polystyrene. These materials, once discarded, cause severe damage to the ecological environment, a phenomenon known as "white pollution" and a global nuisance. This waste cannot degrade in nature for a long time, thus becoming part of the food chain. Incinerating it produces toxic gases, causing secondary pollution and severely impacting the environment. Recycling it requires a significant investment of manpower and resources.

[0003] In related technologies, paper-based cushioning packaging materials can be used, as they are biodegradable. However, the cushioning and energy absorption properties of paper-based cushioning packaging materials are significantly lower than those of polystyrene and other plastic foam materials. They are mainly used as inner lining materials for small, lightweight electronic and communication products, and their effect on cushioning larger products is not ideal. Summary of the Invention

[0004] This application provides a composite biomass aerogel cushioning packaging material and its preparation method to solve the problem of poor cushioning effect of paper cushioning packaging materials in related technologies.

[0005] This application provides the following technical solution:

[0006] In a first aspect, this application provides a composite biomass aerogel cushioning packaging material, comprising an aerogel body and a reinforcing structure embedded within the aerogel body; the aerogel body comprises, by weight, the following components:

[0007] Starch 2-10 parts; Fiber 2-10 parts; Plasticizer 2-20 parts; Preservative 1-5 parts; Thickener 0.5-3 parts;

[0008] The aforementioned reinforcing structure comprises at least one layer of hollow tube assembly, at least one layer of fiberboard, at least one layer of mesh, or multiple layers of corrugated paper.

[0009] In conjunction with the first aspect, in one embodiment, when the above-mentioned reinforcing structure is a single hollow tube assembly, the multiple hollow tubes in the single hollow tube assembly are arranged in parallel and in sequence without pressure contact.

[0010] When the above-mentioned reinforcement structure is a multi-layer hollow tube group, the multiple hollow tubes in each layer of the hollow tube group are arranged in parallel and sequentially without pressure contact, the two adjacent layers of hollow tube groups do not contact each other, and the hollow tubes of the two adjacent layers of hollow tube groups are staggered or arranged perpendicular to each other.

[0011] In conjunction with the first aspect, in one embodiment, the hollow tube is an elastic tube with both ends sealed and filled with a filling material.

[0012] In conjunction with the first aspect, in one embodiment, the hollow tube is a circular tube made of a biodegradable material with a diameter of 5-15 mm and a unit length mass of 0.04-0.12 g / cm.

[0013] In conjunction with the first aspect, in one embodiment, the surface of the aforementioned aerogel body is coated with a polyvinyl alcohol waterproof coating.

[0014] In conjunction with the first aspect, in one embodiment, the starch is any one or a combination of several of the following: mung bean starch, potato starch, wheat starch, sweet potato starch, corn starch, and pea starch.

[0015] The aforementioned fibers are any one or a combination of several of the following: wood pulp fiber, waste paper fiber, straw fiber, sugarcane stalk fiber, and bamboo stalk fiber; the mesh size of the aforementioned fibers is 5-60 mesh.

[0016] The plasticizer mentioned above is glycerin;

[0017] The above-mentioned preservatives are any one or a combination of several of benzoic acid, sodium benzoate, sorbic acid, potassium sorbate, and calcium propionate;

[0018] The thickeners mentioned above are any one or a combination of several of the following: polyacrylamide, carboxymethyl cellulose, konjac powder, and agar.

[0019] Secondly, this application provides a method for preparing a composite biomass aerogel cushioning packaging material, comprising the following steps:

[0020] Take 2-10 parts by weight of fiber and disperse it in water. Then take 2-10 parts of starch, 2-20 parts of plasticizer, 1-5 parts of preservative and 0.5-3 parts of thickener and add them to water in sequence. Stir and disperse at room temperature. Then heat to the preset temperature while stirring. Continue stirring and then cool to obtain a gel-like liquid.

[0021] After pouring a layer of gel-like liquid into the mold and smoothing it out, at least one composite layer is formed on the smoothed gel-like liquid surface. Then, it is sequentially transferred to a cold storage room for low-temperature cooling, a freezer room for freezing, and a vacuum freeze-drying chamber for vacuum drying to obtain a composite biomass aerogel cushioning packaging material.

[0022] Each composite layer is formed by: laying a reinforcing member on the smoothed surface of the gel, then pouring in the gel and smoothing it.

[0023] In conjunction with the second aspect, in one embodiment, the aforementioned reinforcing member is a hollow tube assembly, fiberboard, mesh, or corrugated paper layer;

[0024] The thickness of the composite layer is 3-5 mm greater than the vertical thickness of the reinforcement.

[0025] In conjunction with the second aspect, in one embodiment, the stirring frequency of the above-mentioned room temperature stirring is 30Hz;

[0026] The preset temperature is 85-95℃;

[0027] During the above continuous stirring process, the stirring frequency is 50 Hz and the continuous stirring time is at least 40 min;

[0028] During the above cooling process, the temperature of the resulting gel-like liquid is not higher than 40°C, and the viscosity of the gel-like liquid is 45500~60500mpa.s.

[0029] In conjunction with the second aspect, in one embodiment, when transferring the item to a cold storage room for low-temperature cooling, the cooling temperature is 1-10°C and the cooling time is 2-4 hours.

[0030] When transferring to the freezer for freezing, the freezing temperature is -20 to -40°C, and the freezing time is 2-4 hours;

[0031] When transferring to the vacuum freeze chamber for vacuum freeze drying, the temperature of the radiation plate gradually increases from 20°C to 80°C, the temperature of the cold trap is -30°C, the vacuum degree is below 30Pa, and the drying time is 12-24h.

[0032] After vacuum freeze drying, the process also includes:

[0033] A polyvinyl alcohol waterproof coating is applied to the surface of the material after vacuum freeze-drying.

[0034] The composite biomass aerogel cushioning packaging material and its preparation method disclosed in this application involve embedding a reinforcing structure within the aerogel body. The aerogel body comprises, by weight, 2-10 parts starch, 2-10 parts fiber, 2-20 parts plasticizer, 1-5 parts preservative, and 0.5-3 parts thickener. This combination of biomass aerogel material and reinforcing structure not only improves some of the cushioning performance of the packaging structure but also reduces the amount of material used in the aerogel body due to the lightweight and large volume of the internal reinforcing structure. This reduces the weight and cost of the cushioning packaging structure for the same volume, meeting practical application needs and addressing the issues of poor environmental protection and cushioning effect in cushioning packaging materials. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a front view of an embodiment of the composite biomass aerogel cushioning packaging material of this application;

[0037] Figure 2 for Figure 1 Cross-sectional view;

[0038] Figure 3 This is a cross-sectional view of an alternative embodiment of the composite biomass aerogel cushioning packaging material of this application;

[0039] Figure 4 This is a schematic diagram of another alternative embodiment of the composite biomass aerogel cushioning packaging material of this application;

[0040] Figure 5 for Figure 4 Cross-sectional view.

[0041] In the diagram, 1 is the aerogel body; 2 is the hollow tube; and 3 is the mesh. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with the embodiments of this application. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0043] This application provides a composite biomass aerogel cushioning packaging material that combines biomass aerogel material with a reinforcing structure. This not only improves some of the cushioning performance of the packaging structure, but also reduces the amount of aerogel material used due to the lightweight and large volume of the internal reinforcing structure. This reduces the weight and cost of the cushioning packaging structure for the same volume, meeting practical application needs and solving the problems of poor environmental protection and cushioning effect of cushioning packaging materials.

[0044] like Figure 1As shown, the composite biomass aerogel cushioning packaging material provided in this application includes an aerogel body 1 and a reinforcing structure embedded in the aerogel body 1; the aerogel body 1 includes, by weight, 2-10 parts of starch; 2-10 parts of fiber; 2-20 parts of plasticizer; 1-5 parts of preservative; and 0.5-3 parts of thickener.

[0045] The aforementioned reinforcing structure comprises at least one layer of hollow tube assembly, at least one layer of fiberboard, at least one layer of mesh, or multiple layers of corrugated paper.

[0046] Based on the above embodiments, in this embodiment, each layer of hollow tube assembly includes multiple hollow tubes 2. Preferably, the hollow tubes 2 are hollow tubes with a certain degree of elasticity.

[0047] like Figure 1 and Figure 2 As shown, optionally, the above-mentioned reinforcing structure is a single layer of hollow tubes, and the multiple hollow tubes 2 in the single layer of hollow tubes are arranged in parallel in sequence, and each pair of adjacent hollow tubes 2 are in pressureless contact.

[0048] Optionally, the above-mentioned reinforcing structure is a multi-layer hollow tube group, in which multiple hollow tubes 2 in each layer of hollow tube group are arranged in parallel and sequentially without pressure contact, and the hollow tubes 2 of each two adjacent layers of hollow tube group do not contact each other.

[0049] like Figure 3 As shown, the above-mentioned reinforcement structure is a two-layer hollow tube assembly.

[0050] In this embodiment, the number of hollow tube assemblies can be determined based on the thickness and performance requirements required to ultimately form the cushioning packaging material.

[0051] In some embodiments, the hollow tubes 2 of each two adjacent hollow tube groups are staggered, that is, the central axes of any two hollow tubes 2 located in adjacent upper and lower layers are not in the same vertical plane.

[0052] In some embodiments, the hollow tubes 2 of each pair of adjacent hollow tube groups are arranged perpendicularly to each other.

[0053] Optionally, the two ends of the hollow tube 2 are sealed, and a filler can also be placed inside the hollow tube 2.

[0054] Furthermore, the hollow tube 2 is filled with aerogel powder or lightweight foam powder.

[0055] In this embodiment, the toughness of the cushioning packaging structure can be further increased by filling the hollow tube 2 with aerogel powder made from natural polysaccharides or other powder made from lightweight foam.

[0056] Alternatively, in addition to aerogel powder or lightweight foam powder, the filler can also be waste paper scraps, waste wood chips, chopped straw, etc.

[0057] In this embodiment, by adjusting the type of filling material inside the hollow tube 2, different elasticities and support levels can be assigned to the hollow tube 2. When an external force is applied to the cushioning packaging structure, the force is transmitted from the biomass aerogel on the surface to the hollow tube 2. Due to the good resilience of the hollow tube 2 itself, the material can return to its original state as much as possible when the external force is removed, thus giving the cushioning packaging structure containing the hollow tube 2 different elasticities and support levels. Combining aerogel with the hollow tube 2 effectively overcomes the problem that elasticity and hardness cannot be simultaneously achieved when the hollow tube 2 or biomass material is used alone.

[0058] In some embodiments of this application, the hollow tube is a paper tube, and the radial cross-section of the paper tube is circular, square, or irregular. The two ends of the paper tube are flattened, bent, and sealed.

[0059] Optionally, the hollow tube 2 is a circular tube made of biodegradable material, with a diameter of 4mm to 20mm. The hollow tube 2 is made of a three-layer spiral paper tube, which possesses excellent structural strength and can withstand radial or lateral pressure and tension effectively. The ratio of the basis weight to the diameter of the hollow tube 2 is (15-30):1; the larger the diameter of the hollow tube 2, the higher the corresponding basis weight, thereby increasing the strength and toughness of the paper tube. The basis weight of the hollow tube 2 refers to the weight per unit area of ​​the base paper rolled into the spiral paper tube. Optionally, the mass per unit length of the hollow tube 2 is 0.04-0.12 g / cm.

[0060] In this embodiment, both the aerogel body and the hollow tube material are environmentally friendly and biodegradable. Furthermore, by embedding the paper tube within the biomass aerogel, the biodegradability of the biomass material and the variability of the hollow tube's strength are fully utilized. ， This allows for diverse performance characteristics of packaging materials, and the material specifications can be adjusted according to actual needs. It not only solves the environmental protection issues of packaging cushioning materials, but also effectively addresses the problems of insufficient cushioning and support strength of packaging cushioning structures by using different materials for the filling inside the hollow tube.

[0061] Based on the above embodiments, in this embodiment, when the above-mentioned reinforcing structure is a multi-layer corrugated paper layer, the corrugation directions of each two adjacent corrugated paper layers are perpendicular to each other.

[0062] Optionally, the corrugations of two adjacent corrugated paper layers are parallel, and the crests of the upper corrugated paper layer are opposite to the troughs of the lower corrugated paper layer, in order to increase the elasticity and toughness of the cushioning packaging structure.

[0063] Optionally, in the upper and lower corrugated paper layers, vertical paper tubes are provided between the opposite crests and troughs. The upper and lower edges of the paper tubes are respectively bonded to the crests and troughs to prevent the paper tubes from collapsing. Multiple paper tubes are provided at intervals on each crest.

[0064] In this embodiment, by setting a paper tube, the compressive strength of the cushioning packaging structure can be further enhanced.

[0065] Preferably, the aforementioned multi-layer corrugated paper has at least three layers. In this embodiment, by filling the corrugated paper layers into the aerogel body, the weight of the cushioning packaging structure can be reduced, the elasticity and toughness of the cushioning packaging material can be enhanced, and the freeze-drying time in the production process can be reduced, thus saving costs.

[0066] Based on the above embodiments, in this embodiment, when the reinforcing structure is at least one layer of fiberboard, the fiberboard is a porous fiberboard. Preferably, the fiberboard is a corrugated porous fiberboard.

[0067] Optionally, a corrugated, porous, and fluffy fiberboard can be produced by crushing wheat straw, rice straw, and corn into a mixed powder of 1–10 mm using a pulverizer, and then bonding the mixed powder with an adhesive. The adhesive is prepared from one or more of polyvinyl alcohol, carboxymethyl cellulose, and pullulan, with a concentration of 2–10%.

[0068] In this embodiment, by placing a corrugated porous fiberboard within the aerogel body, the elasticity and toughness of the cushioning packaging structure can be effectively increased.

[0069] Based on the above embodiments, in this embodiment, when the reinforcing structure is at least one layer of mesh 3, the mesh 3 is cotton yarn with a mesh structure, the mesh number of the mesh 3 is 10-120 mesh, and the thickness is 0.2-2mm, so as to effectively increase the toughness of the cushioning packaging structure.

[0070] like Figure 4 and Figure 5 As shown, in this embodiment, the above-mentioned reinforcing structure is two layers of mesh 3.

[0071] Optionally, the transverse dimensions of the fiberboard, mesh 3, and corrugated paper layer may be smaller than the transverse dimension of the aerogel body, or they may be the same as the transverse dimension of the aerogel body.

[0072] In some embodiments of this application, the surface of the aerogel body is coated with a polyvinyl alcohol (PVA) waterproof coating. The PVA waterproof coating enhances the waterproof performance of the composite biomass aerogel cushioning packaging material.

[0073] Optionally, the starch mentioned above is any one or a combination of several of the following: mung bean starch, potato starch, wheat starch, sweet potato starch, corn starch, and pea starch.

[0074] The aforementioned fibers are any one or a combination of several of the following: wood pulp fiber, waste paper fiber, straw fiber, sugarcane stalk fiber, and bamboo stalk fiber; the mesh count of the aforementioned fibers is 5-60 mesh. Preferably, the mesh count of the aforementioned fibers is 10-30 mesh.

[0075] In this embodiment, the main matrix of the aerogel body includes starch and fiber. Not only are the raw materials widely available, renewable and inexpensive, but the fiber is also a secondary utilization of agricultural waste. At the same time, these two substances are easily decomposed by microorganisms under natural conditions, and the decomposition products are non-toxic, harmless and environmentally friendly.

[0076] The plasticizer mentioned above is glycerin.

[0077] The above-mentioned preservatives are any one or a combination of several of benzoic acid, sodium benzoate, sorbic acid, potassium sorbate, and calcium propionate.

[0078] The thickeners mentioned above are any one or a combination of several of the following: polyacrylamide, carboxymethyl cellulose, konjac powder, and agar.

[0079] This application provides a method for preparing a composite biomass aerogel cushioning packaging material, comprising the following steps:

[0080] S1. Take 2-10 parts of fiber by weight and disperse them in water. Then take 2-10 parts of starch, 2-20 parts of plasticizer, 1-5 parts of preservative and 0.5-3 parts of thickener, and add them to water in sequence. Stir and disperse at room temperature. Then heat to the preset temperature while stirring. Continue stirring and then cool to obtain a gel-like liquid.

[0081] S2. After pouring a layer of gel-like liquid into the mold and smoothing it out, at least one composite layer is formed on the smoothed gel-like liquid surface. Then, it is sequentially transferred to a cold storage room for low-temperature cooling, a freezer room for freezing, and a vacuum freeze-drying chamber for vacuum drying to obtain a composite biomass aerogel cushioning packaging material.

[0082] Each composite layer is formed by: laying a reinforcing member on the smoothed surface of the gel, then pouring in the gel and smoothing it.

[0083] Preferably, the reinforcing member is a hollow tube assembly, fiberboard, mesh, or corrugated paper layer. The thickness of the composite layer is 3-5 mm greater than the vertical thickness of the reinforcing member.

[0084] In this embodiment, multiple hollow tubes 2 in the hollow tube assembly are arranged in parallel and sequentially without pressure contact. This arrangement of multiple hollow tubes 2 without pressure contact avoids increasing the vacuum freeze-drying time.

[0085] In this embodiment, when the reinforcing member is a hollow tube assembly, the vertical thickness value of the hollow tube 2 is its diameter value, that is, the distance from the upper surface of the gel liquid to the hollow tube of each composite layer is 3-5mm.

[0086] In this embodiment, when the reinforcing member is a fiberboard, the thickness of the composite layer is 3-5 mm greater than the vertical thickness of the fiberboard, that is, the distance from the upper surface of the adhesive liquid to the fiberboard of each composite layer is 3-5 mm; when the reinforcing member is a corrugated paper layer, the thickness of the composite layer is 3-5 mm greater than the vertical thickness of the corrugated paper layer, that is, the distance from the upper surface of the adhesive liquid to the corrugated paper layer of each composite layer is 3-5 mm; when the reinforcing member is a mesh, the thickness of the composite layer is 3-5 mm greater than the thickness of the mesh, that is, the distance from the upper surface of the adhesive liquid to the mesh of each composite layer is 3-5 mm.

[0087] In this embodiment, fibers and reinforcing elements can enhance the performance of the cushioning material, while starch and thickeners can increase the compressive strength. The viscosity of the adhesive mainly depends on the total number of parts of starch, fiber, and thickener; the higher the total number of parts, the greater the overall viscosity of the adhesive.

[0088] Biomass aerogels are prepared sequentially through low-temperature cooling, freezing, and vacuum freeze-drying. By utilizing the sublimation of ice crystals to leave pores, a honeycomb-like porous structure is obtained. This not only allows for controllable pore-forming methods but also endows the biomass aerogels with certain compressive strength and elasticity. Furthermore, embedding reinforcing components within the biomass aerogels can reduce the cost of aerogel materials.

[0089] When the reinforcement is a hollow tube assembly, fiberboard, or corrugated paper layer, the elasticity and support of the reinforcement can be utilized to amplify the overall compressive strength and elasticity of the material.

[0090] In one embodiment, the stirring frequency of the above-mentioned room temperature stirring is 30 Hz; the preset temperature is 85-95°C; during the above-mentioned continuous stirring treatment, the stirring frequency is 50 Hz, and the continuous stirring time is at least 40 min. During the above-mentioned cooling, the temperature of the resulting gel-like liquid is not higher than 40°C, and the viscosity of the above-mentioned gel-like liquid is 45500~60500 mPa·s; the above-mentioned hollow tube is a round tube made of biodegradable material, with a diameter of 5-15 mm and a unit length mass of 0.04-0.12 g / cm.

[0091] In this embodiment, the viscosity of the above-mentioned gel-like liquid is configured to support the reinforcing member so that the reinforcing member will not sink or settle.

[0092] This application also provides a method for preparing the above-mentioned gel-like liquid, including the following steps:

[0093] Step S101: Add a certain amount of water to the mixing tank, weigh 2-10 parts of the treated fiber according to the weight, and stir and disperse it in the water at room temperature; preferably, the mass of water is 30-70 times the mass of fiber, so as to facilitate uniform fiber dispersion.

[0094] Step S102: Add 2-10 parts of starch, 2-20 parts of plasticizer, 1-5 parts of preservative, and 0.5-3 parts of thickener to a mixing tank in sequence. First, stir and disperse at room temperature with a stirring frequency of 30 Hz. Then, while stirring, heat to the preset temperature, increase the stirring frequency to 50 Hz, and continue stirring for at least 40 minutes to obtain a high-temperature adhesive solution.

[0095] Step S103: The high-temperature adhesive liquid is cooled by passing it through a coil to reduce its temperature to no higher than 40°C, resulting in a high-viscosity gel-like liquid. During this process, the viscosity of the adhesive liquid gradually increases from 11680 to 15600 mPa·s to 45500 to 60500 mPa·s.

[0096] In this embodiment, since the hollow tube has a unit length mass of 0.04-0.12 g / cm, which is relatively light, and the gel liquid has a high viscosity, the hollow tube will not sink or settle on the surface of the high-viscosity gel liquid.

[0097] In one embodiment, when transferring to the cold storage room for low-temperature cooling, the cooling temperature is 1-10°C and the cooling time is 2-4 hours; when transferring to the freezer room for freezing, the freezing temperature is -20 to -40°C and the freezing time is 2-4 hours; when transferring to the vacuum freezer chamber for vacuum freeze-drying, the temperature of the radiant plate gradually increases from 20°C to 80°C, the cold trap temperature is -30°C, the vacuum degree is below 30 Pa, and the drying time is 12-24 hours.

[0098] In this embodiment, step S2 specifically includes:

[0099] Step S201: Pour a layer of gel-like liquid into the mold and smooth it with a scraper to form the first gel-like liquid layer;

[0100] Step S202: Form at least one composite layer on the surface of the first gel-like liquid layer;

[0101] Step S203: Transfer the mold carrying the material from step S202 to a cold storage room for low-temperature cooling; wherein the cooling temperature is 1-10℃ and the cooling time is 2-4h.

[0102] Step S204: Transfer the material that has been cooled at low temperature in step S203 to a freezing room for freezing; wherein the freezing temperature is -20 to -40°C and the freezing time is 2-4 hours.

[0103] Step S205: The material frozen in step S204 is transferred to a vacuum freeze-drying chamber for vacuum freeze drying. The temperature of the radiant plate gradually increases from 20°C to 80°C, the cold trap temperature is -30°C, the vacuum degree is below 30 Pa, and the drying time is 12-24 hours. The aforementioned vacuum freeze-drying chamber is a vacuum drying freeze-drying chamber.

[0104] Taking a hollow tube assembly as an example of a reinforcing component, further, when a composite layer is formed on the surface of the first gel-like liquid layer, the specific steps include: laying a row of hollow tubes flat on the surface of the first gel-like liquid layer, with the row of hollow tubes arranged parallel to each other; then pouring in the gel-like liquid and smoothing it out to form a composite layer, wherein the thickness of the composite layer is 3-5 mm greater than the diameter of the hollow tubes. Preferably, in each row of hollow tubes, there is no extrusion contact between adjacent hollow tubes.

[0105] Furthermore, when two composite layers are formed on the surface of the first gel-like liquid layer, the specific process includes:

[0106] First, a row of hollow tubes is laid flat on the surface of the first gel-like liquid layer. The row of hollow tubes is arranged parallel to each other. After the hollow tubes are laid, the gel-like liquid is evenly laid and smoothed with a scraper to form the first composite layer.

[0107] Then, a row of parallel hollow tubes is laid flat on the surface of the first composite layer, and a gel-like liquid is poured in and smoothed out to form the second composite layer. This process can be repeated to obtain more composite layers.

[0108] In this embodiment, each composite layer contains a hollow tube, and the thickness of each composite layer is 3-5 mm larger than the diameter of the hollow tube. That is, the distance between the upper surface of each composite layer and the hollow tube is 3-5 mm.

[0109] Preferably, the hollow tube is a biodegradable paper tube with sealed ends, and may also contain filler.

[0110] Taking a three-layer corrugated paper structure as an example, the formation of each composite layer specifically includes: laying a corrugated paper layer flat on the surface of the first adhesive liquid layer, then pouring in the adhesive liquid and smoothing it out to form a composite layer, and the thickness of the composite layer is 3-5 mm greater than the vertical thickness of the corrugated paper layer.

[0111] In one embodiment, the fiber is further pretreated before being added, namely, the fiber is crushed by a pulverizer and passed through a sieve of up to 60 mesh.

[0112] In this embodiment, if the fiber size is small, it cannot be effectively used to make a skeleton; if the fiber size is large, it is not conducive to the preparation of cushioning packaging materials.

[0113] In one embodiment, after vacuum freeze-drying, the method further includes step S3: coating the surface of the material after vacuum freeze-drying with a polyvinyl alcohol waterproof coating.

[0114] In this embodiment, a waterproof layer can be formed by surface spraying or brushing to improve waterproof performance.

[0115] The preparation method of this embodiment is applicable to the above-mentioned composite biomass aerogel cushioning packaging materials. It is not only controllable in preparation process and can be industrialized, but also green and environmentally friendly.

[0116] The technical solutions provided in this application will be described in detail below with reference to the embodiments.

[0117] Example 1:

[0118] Embodiment 1 of this application provides a composite biomass aerogel cushioning packaging material, comprising an aerogel body 1 and a row of hollow tubes 2 embedded within the aerogel body. The aerogel body comprises, by weight, 5 parts potato starch; 5 parts wood pulp fiber; 10 parts glycerol; 3 parts potassium sorbate; and 0.5 parts carboxymethyl cellulose.

[0119] The specific preparation method of this composite biomass aerogel cushioning packaging material is as follows:

[0120] (1) Add a certain amount of water to the mixing tank and disperse the crushed wood pulp fibers that have passed through a 10-mesh sieve in the water at room temperature.

[0121] (2) Potato starch, glycerol, potassium sorbate and carboxymethyl cellulose were added to the mixing tank in sequence. The mixture was first stirred and dispersed at room temperature at a stirring frequency of 30 Hz. Then, while stirring, it was heated to 90 ℃, and the stirring frequency was increased to 50 Hz. The mixture was stirred and treated for 1 hour to obtain a high-temperature adhesive with a viscosity of 11200 mPa·s.

[0122] (3) The high-temperature adhesive liquid is cooled by a coil to obtain a high-viscosity gel liquid with a viscosity of 45500 mpa.s;

[0123] (4) Pour a layer of gel liquid into the mold and smooth it with a scraper to form a first gel liquid layer with a thickness of 3 mm.

[0124] (5) Lay a row of hollow tubes on the surface of the first gel layer, then spread a layer of gel evenly and scrape it flat to form a composite layer. The thickness of the composite layer is 3 mm larger than the diameter of the hollow tube. The diameter of the hollow tube is 5 mm, the mass per unit length is 0.04 g / cm, and there is no filling inside the tube.

[0125] (6) Transfer the mold carrying the material in (5) to a cold storage room for low-temperature cooling; wherein the cooling temperature is 4°C and the cooling time is 2 hours.

[0126] (7) Transfer the material that has been cooled at low temperature in (6) to a freezing room for freezing; wherein the freezing temperature is -20℃ and the freezing time is 2h;

[0127] (8) Transfer the material frozen in (7) to a vacuum freeze-drying chamber for vacuum freeze-drying, wherein the temperature of the radiation plate is gradually increased from 20°C to 80°C, the temperature of the cold trap is -30°C, the vacuum degree is below 30Pa, and the drying time is 18h.

[0128] (9) A polyvinyl alcohol waterproof coating is applied to the surface of the material after vacuum freeze-drying to obtain a composite biomass aerogel cushioning packaging material.

[0129] The preparation methods of the composite biomass aerogel cushioning packaging materials in Examples 2-4 are similar to those in Example 1, but the specific formulations and process parameters are different. The specific differences are described below and in Table 1.

[0130] Example 2

[0131] The composite biomass aerogel cushioning packaging material provided in Embodiment 2 of this application includes an aerogel body and a row of hollow tubes embedded in the aerogel body. The aerogel body comprises, by weight, 2 parts corn starch; 10 parts straw fiber; 2 parts glycerol; 1 part sodium benzoate; and 1.5 parts konjac flour.

[0132] The difference between the preparation method in Example 2 and that in Example 1 is:

[0133] The straw fiber has a mesh size of 30; the viscosity of the high-temperature adhesive is 16680 mpa.s; the viscosity of the gel-like liquid obtained after cooling is 54500 mpa.s; the diameter of the hollow tube is 15 mm, the mass per unit length is 0.12 g / cm, and the tube is filled with waste paper scraps.

[0134] The thickness of the first gel-like liquid layer is 5 mm, and the thickness of the composite layer is 5 mm greater than the diameter of the hollow tube.

[0135] When performing low-temperature cooling, the cooling temperature is 10℃; when performing freezing, the freezing temperature is -30℃; when performing vacuum freeze drying, the drying time is 19h.

[0136] Example 3

[0137] The composite biomass aerogel cushioning packaging material provided in Embodiment 3 of this application includes an aerogel body 1 and two rows of hollow tubes 2 embedded in the aerogel body. The aerogel body comprises, by weight, 2 parts corn starch; 10 parts straw fiber; 2 parts glycerol; 1 part sodium benzoate; and 3 parts konjac flour.

[0138] The difference between the preparation method in Example 3 and that in Example 2 is:

[0139] The viscosity of the high-temperature adhesive is 19680 mpa.s; the viscosity of the gel obtained after cooling is 60500 mpa.s; the thickness of the first gel layer is 3 mm; in the two composite layers, the thickness of each composite layer is 3 mm greater than the diameter of the hollow tube.

[0140] When performing vacuum freeze drying, the drying time is 20 hours.

[0141] Example 4

[0142] The composite biomass aerogel cushioning packaging material provided in Embodiment 4 of this application includes an aerogel body and two rows of hollow tubes embedded in the aerogel body. The aerogel body comprises, by weight, 10 parts wheat starch; 2 parts bamboo fiber; 20 parts glycerol; 5 parts potassium sorbate; and 1 part polyacrylamide.

[0143] The difference between the preparation method in Example 4 and that in Example 1 is:

[0144] The bamboo pole fiber has a mesh size of 20; the viscosity of the high-temperature adhesive is 14600 mpa.s; the viscosity of the gel-like liquid obtained after cooling is 50100 mpa.s; the diameter of the hollow tube is 8 mm, the mass per unit length is 0.10 g / cm, and the tube is filled with waste straw.

[0145] The thickness of the first gel-like liquid layer is 4 mm; the composite layer formed has two layers. The thickness of the first composite layer, which is closer to the first gel-like liquid layer, is 3 mm greater than the diameter of the hollow tube; the thickness of the second composite layer, which is farther from the first gel-like liquid layer, is 4 mm greater than the diameter of the hollow tube.

[0146] When performing low-temperature cooling, the cooling temperature is 1℃ and the cooling time is 4 hours; when performing freezing, the freezing temperature is -25℃ and the freezing time is 3 hours; when performing vacuum freeze-drying, the drying time is 22 hours.

[0147] Comparative Examples 1-3

[0148] Comparative Examples 1 and 2 were prepared using the same method as Example 1, except for the specific formulation and process parameters. Comparative Example 3 was prepared using the same method as Example 1, except for the specific formulation, process parameters, and whether or not a hollow tube was embedded (see Table 1).

[0149] Table 1

[0150]

[0151]

[0152] Note: The first thickness difference is the distance from the upper surface of the first composite layer to the hollow tube in that layer;

[0153] The second thickness difference is the distance from the upper surface of the second composite layer to the hollow tube in that layer;

[0154] / indicates that this item does not exist in this embodiment.

[0155] The compressive strength, elasticity, material water contact angle, and biodegradability of the products from Examples 1-4, Comparative Examples 1 and 3 were tested, and the test results are shown in Table 2. Among them, the product of Comparative Example 2 was generally brittle and prone to crumbling, making it unsuitable for cushioning packaging materials.

[0156] Table 2

[0157] <![CDATA[Density (g / cm 3 )]]> 0.088 0.075 0.065 0.089 0.184 0.118 Compressive strength (MPa) 2.14 1.80 1.75 2.51 4.5 2.24 elasticity(%) 88 92 94 82 60 68 Water contact angle (°) 135.7 132.4 132.5 134.5 133.1 135.7 Biodegradation rate (%) 92 95 95 93 93 92

[0158] As can be seen from Table 2, in Example 1, the appropriate ratio combined with the single-layer pipe installation can result in good compressive strength and elasticity of the cushioning packaging material. In addition, the waterproof performance and biodegradability are also high.

[0159] The data from Example 1 and Comparative Example 1 show that, due to the excessive starch content and low fiber content in Comparative Example 1, the material is generally stiff, and the internally embedded paper tube does not play a role in increasing elasticity. The elasticity of the material is significantly reduced compared to Example 1.

[0160] The data from Example 1 and Comparative Example 3 show that the preparation processes are the same. However, since Comparative Example 3 did not have a pre-embedded paper tube, the overall density of the material increased, the compressive strength was slightly improved, but the elasticity decreased significantly.

[0161] The cushioning packaging material obtained in Example 3 is a double-layer tube. The thickness of the first gel-like liquid layer and the difference between the two thicknesses are both small. Compared with Example 2, the overall elasticity is better due to the increase in the number of tube layers. However, the reduction in the thickness of the outer aerogel layer leads to an increase in the overall elasticity of the material and a slight decrease in the compressive strength.

[0162] Example 4 has the highest starch and thickener content, and through double-layer paper tube embedding, it has the highest compressive strength and moderate elasticity, making it suitable for cushioning packaging materials with high strength requirements.

[0163] The above results show that, with the pre-embedding of hollow tubes and when the aerogel bulk formulation is within a suitable range, the overall compressive strength of the resulting cushioning packaging material is between 1.80 and 2.51 MPa, and the elasticity is between 82 and 94%, both of which are generally good.

[0164] In the description of this specification, the references to terms such as "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment / mode or example is included in at least one embodiment / mode or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments / modes or examples described in this specification, as well as the features of different embodiments / modes or examples.

[0165] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. In this application, "a plurality of" means at least two, such as two, three, etc., unless otherwise expressly specified.

[0166] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A composite biomass aerogel cushioning packaging material, characterized in that: It includes an aerogel body and a reinforcing structure embedded within the aerogel body; the aerogel body comprises, by weight: Starch 2-10 parts; Fiber 2-10 parts; Plasticizer 2-20 parts; Preservative 1-5 parts; Thickener 0.5-3 parts; The reinforcing structure comprises at least one layer of hollow tube assembly, at least one layer of fiberboard, at least one layer of mesh, or multiple layers of corrugated paper. When the reinforcing structure is a single-layer hollow tube assembly, the multiple hollow tubes in the single-layer hollow tube assembly are arranged in parallel and sequentially without pressure contact. When the reinforcing structure is a multi-layer hollow tube assembly, multiple hollow tubes in each layer of the hollow tube assembly are arranged in parallel and sequentially without pressure contact. Adjacent hollow tube assemblies do not contact each other, and the hollow tubes in adjacent hollow tube assemblies are staggered or arranged perpendicular to each other. The hollow tube is an elastic tube with both ends sealed and filled with a filling material inside. The surface of the aerogel body is coated with a polyvinyl alcohol waterproof coating.

2. The composite biomass aerogel cushioning packaging material as described in claim 1, characterized in that: The hollow tube is a round tube made of biodegradable material with a diameter of 5-15 mm and a unit length mass of 0.04-0.12 g / cm.

3. The composite biomass aerogel cushioning packaging material as described in claim 1, characterized in that: The starch is any one or a combination of several of the following: mung bean starch, potato starch, wheat starch, sweet potato starch, corn starch, and pea starch. The fiber is any one or a combination of several of the following: wood pulp fiber, waste paper fiber, straw fiber, sugarcane stalk fiber, and bamboo stalk fiber; the mesh number of the fiber is 5-60 mesh. The plasticizer is glycerin; The preservative is any one or a combination of several of the following: benzoic acid, sodium benzoate, sorbic acid, potassium sorbate, and calcium propionate. The thickener is any one or a combination of several of the following: polyacrylamide, carboxymethyl cellulose, konjac powder, and agar.

4. A method for preparing the composite biomass aerogel cushioning packaging material according to claim 1, characterized in that, It includes the following steps: Take 2-10 parts by weight of fiber and disperse it in water. Then take 2-10 parts of starch, 2-20 parts of plasticizer, 1-5 parts of preservative and 0.5-3 parts of thickener and add them to water in sequence. Stir and disperse at room temperature. Then heat to the preset temperature while stirring. Continue stirring and then cool to obtain a gel-like liquid. After pouring a layer of gel-like liquid into the mold and smoothing it out, at least one composite layer is formed on the smoothed gel-like liquid surface. Then, it is sequentially transferred to a cold storage room for low-temperature cooling, a freezer room for freezing, and a vacuum freeze-drying chamber for vacuum drying to obtain a composite biomass aerogel cushioning packaging material. Each composite layer is formed by: laying a reinforcing member on the smoothed surface of the gel, then pouring in the gel and smoothing it.

5. The preparation method of the composite biomass aerogel cushioning packaging material as described in claim 4, characterized in that: The reinforcing component is a hollow tube assembly, fiberboard, mesh, or corrugated paper layer; The thickness of the composite layer is 3-5 mm greater than the vertical thickness of the reinforcement.

6. The preparation method of the composite biomass aerogel cushioning packaging material as described in claim 4, characterized in that: The stirring frequency of the room temperature stirring is 30Hz; The preset temperature is 85-95℃; During the continuous stirring process, the stirring frequency is 50Hz and the continuous stirring time is at least 40 minutes. During the cooling process, the temperature of the resulting gel-like liquid is not higher than 40°C, and the viscosity of the gel-like liquid is 45500~60500 mPa·s.

7. The preparation method of the composite biomass aerogel cushioning packaging material as described in claim 4, characterized in that: When transferring to a cold storage room for low-temperature cooling, the cooling temperature should be 1-10℃ and the cooling time should be 2-4 hours. When transferring to the freezer for freezing, the freezing temperature is -20 to -40°C, and the freezing time is 2-4 hours; When transferring to the vacuum freeze chamber for vacuum freeze drying, the temperature of the radiation plate gradually increases from 20°C to 80°C, the temperature of the cold trap is -30°C, the vacuum degree is below 30Pa, and the drying time is 12-24h. After vacuum freeze drying, the process also includes: A polyvinyl alcohol waterproof coating is applied to the surface of the material after vacuum freeze-drying.

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