Nano-calcium sulfate packaging box composition, its preparation method and the obtained product

Abstract

The application provides a kind of nano calcium sulfate packing box composition, its preparation method and the product obtained, belong to modified material technical field.The nano calcium sulfate packing box composition provided by the application is prepared by using inorganic filler with anhydrous phosphogypsum as carrier, wherein the anhydrous phosphogypsum is nano calcium sulfate powder.The nano calcium sulfate packing box composition provided by the application uses nano calcium sulfate (anhydrous phosphogypsum) as main raw material, realizes waste recycling while achieving the purpose of green cycle transformation.Meanwhile, the pollution problem of by-products of phosphate industry is solved, and the pollution of traditional anhydrous phosphogypsum to the environment is also solved, so that the inorganic filler with gypsum-based carrier has real market value.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of modified materials, and particularly relates to a composition for a nano calcium sulfate packaging box, a preparation method thereof and a product obtained. BACKGROUND

[0002] The proposal of the "double carbon" strategy is both an opportunity and a challenge for the comprehensive utilization of anhydrous phosphogypsum resources. The production capacity and output of the cement industry under the "double carbon" background will certainly be affected, and the scale of thermal power will also gradually decline, which creates conditions for gypsum building materials products using anhydrous phosphogypsum as raw materials.

[0003] Due to the limited forest resources in China, the production of paper pulp cannot meet the demand for use, and the process of producing paperboard using paper pulp is complex, with large resource and energy consumption, and water, electricity, fuel and virgin wood pulp need to be added according to the process requirements, so the environmental and energy problems existing in paperboard production have become a serious social problem. Traditional paper boxes are not waterproof, not moisture-proof, have poor compression resistance, poor tear resistance, and poor freshness-keeping effect, so a scheme of using nano calcium sulfate packaging boxes to replace traditional paper boxes is proposed, which also solves the environmental pollution of anhydrous phosphogypsum and makes the inorganic filler with gypsum as the carrier truly market-oriented.

[0004] The nano calcium sulfate packaging box has the advantages of environmental protection, waterproofness, moisture resistance and strong compression resistance, but the plastic packaging box mentioned on the market is a calcium plastic box. The so-called calcium plastic box is processed from polypropylene resin raw materials and filling master batches. Since the filling master batch can only be added by 20%, it is called "filling material" in the industry. In this case, the polypropylene resin raw material is the main raw material, and the filling master batch is the auxiliary raw material, and the dispersion and plasticization effect is not stable. In addition, in the printing process, the water-based ink printing process is difficult to achieve the effect of traditional paper boxes, the petroleum-based resin content of the calcium plastic box is too high, the water-based ink adsorption is poor, the drying time is slow, the yield is low, and the calcium plastic box is easy to fall off. Therefore, although the calcium plastic box has the characteristics of waterproofness, moisture resistance, compression resistance, shock resistance, oil stain resistance and corrosion resistance, it has general hand feeling, is not easy to fold, has single printing tone pattern, is easy to crack, has poor tear resistance at the edges and corners, has high cost and is not economical. With the fluctuation of the price of polypropylene resin raw materials, the cost control is unstable, and the market price is more than twice that of traditional paper boxes. Therefore, how to provide a truly meaningful nano calcium sulfate packaging box that has good performance under the premise of low economic cost, solves the pollution of by-products of the phosphate industry, and makes inorganic fillers with anhydrous phosphogypsum as the carrier truly market-oriented is a problem to be solved in the field. SUMMARY

[0005] The application provides a nano calcium sulfate (anhydrous phosphogypsum) packaging box composition, a preparation method thereof and a product obtained by using the composition, and the nano calcium sulfate packaging box prepared by using the composition can greatly improve the strength, toughness, compression resistance, shock resistance, tear resistance and easy molding function, and can also improve the waterproof, moisture-proof and freshness locking function. The nano calcium sulfate packaging box prepared by using the composition provided by the application can effectively replace the traditional corrugated paper box, and is low in economic cost, high in function and environmentally friendly.

[0006] In order to achieve the above-mentioned purpose, the application provides a nano calcium sulfate packaging box composition prepared by using inorganic fillers with anhydrous phosphogypsum as a carrier, wherein the anhydrous phosphogypsum is nano calcium sulfate powder.

[0007] Preferably, the nano calcium sulfate packaging box composition is composed of the following components by weight:

[0008] The nano calcium sulfate powder is 30-75 parts, the powdered polypropylene copolymer resin is 5-8 parts, the powdered polypropylene homopolymer resin is 6-10 parts, the powdered fibrous polypropylene is 5-6 parts, the powdered composite modified high-solubility fat polypropylene resin is 5-8 parts, the coupling agent is 0.8-1.8 parts, the zinc stearate is 0.8-1.2 parts, the toughening agent POE is 4-7 parts and the lubricant is 1-3 parts.

[0009] Preferably, the particle size range of the powdered polypropylene copolymer resin, the powdered polypropylene homopolymer resin, the powdered fibrous polypropylene and the powdered composite modified high-solubility fat polypropylene resin is 25-30 mesh. It can be understood that the powdered high molecular substance is used because the oil absorption value of the anhydrous phosphogypsum is too high, and a large amount of functional additives is needed. By adding the powdered high molecular substance, the flowability can be improved, the cost can be reduced, the amount of functional additives can be reduced, and a better coating effect can be achieved.

[0010] Preferably, the powdered polypropylene copolymer resin, the powdered polypropylene homopolymer resin, the powdered fibrous polypropylene and the powdered composite modified high-solubility fat polypropylene resin are prepared by using a liquid nitrogen grinding method. It can be understood that the viscosity of polypropylene is large and it is not easy to grind powder. If a conventional grinding method is used, the resin particle size with the required particle size cannot be effectively ground. Therefore, the liquid nitrogen grinding method is innovatively proposed for preparation, and the process flow is specifically as follows:

[0011] The material particles are sucked into the pre-cooling bin by using a vacuum suction machine, and the material is pre-cooled by injecting liquid nitrogen from small to large;

[0012] The main machine is started at a slow speed and a small amount of liquid nitrogen is added at the same time to pre-cool the grinding cavity, and the material in the bin is sent into the grinding cavity by the screw machine for grinding after the grinding cavity is cooled to-50℃--60℃. The grinding speed is controlled according to the current level;

[0013] The ground powder is sucked out of the grinding chamber by a high-pressure fan and sent to a cyclone separator for air and powder separation, and the separated powder is sent to a vibrating screen by a closing fan for screening, and the particle size is controlled by the mesh of the vibrating screen, and the screened qualified product powder is bagged.

[0014] As preferred, the composite modified high-solubility fat polypropylene resin is composed of polypropylene powder 95-100 parts, peroxide di-t-butyl 1.2-1.6 parts, and antioxidant 1010 0.6-1.3 parts.

[0015] As preferred, the composite modified high-solubility fat polypropylene resin is prepared by the following method:

[0016] The low-speed mixer is added with the polypropylene powder, peroxide di-t-butyl, and antioxidant 1010 in sequence at a low speed of 100-150 rpm, and then extruded into a parallel double-screw extruder for transition extrusion after high-temperature high-speed shearing for 3-4 min, and then formed into strands, cut into particles, and ground into powder.

[0017] The low-speed mixer is added with the polypropylene powder, peroxide di-t-butyl, and antioxidant 1010 in sequence at a low speed of 100-150 rpm, and then extruded into a parallel double-screw extruder for transition extrusion after high-temperature high-speed shearing for 3-4 min, and then formed into strands, cut into particles, and ground into powder.

[0018] As preferred, the parallel triple-screw extrusion temperature is: first zone 225-230℃, second zone 225-230℃, third zone 220-225℃, fourth zone 215-220℃, fifth zone 190-200℃, sixth zone 180-190℃, seventh zone 170-180℃, eighth zone 160-170℃, ninth zone 130-140℃, tenth zone 130-140℃, first zone of the head 125-135℃, and second zone of the head 130-140℃.

[0019] The parallel double-screw extrusion temperature is: first zone 160-170℃, second zone 155-165℃, third zone 150-160℃, fourth zone 145-155℃, fifth zone 140-150℃, and sixth zone 140-150℃.

[0020] As preferred, the coupling agent is a silane coupling agent or a titanate coupling agent.

[0021] The lubricant is a mixture of polyethylene wax and paraffin wax, and the weight ratio is (0.5-1):(0.5-1.5).

[0022] As preferred, the mesh number of the calcium sulfate powder is 1000-1800 mesh.

[0023] The application further provides a preparation method of the nano calcium sulfate packaging box composition according to any one of the above technical solutions, comprising the following steps:

[0024] The nano calcium sulfate powder is mixed in a high-speed mixer at a speed of 200-700 rpm, and the temperature of the oil is heated by a machine or an electric heater to 100-110 DEG C, so that the moisture in the mixed powder is sufficiently dried to obtain material 1;

[0025] The coupling agent is added to the material 1, and mixed and stirred for 3-4 min, and the temperature is raised to 125-135 DEG C to obtain material 2;

[0026] The toughening agent POE, the lubricant, and the powdered composite modified high-solubility polypropylene resin are added to the material 2, and mixed and stirred for 3-4 min, and the temperature is raised to 125-135 DEG C to obtain material 3;

[0027] The powdered polypropylene copolymer resin, the powdered polypropylene homopolymer resin, and the powdered polypropylene fiber resin are added to the material 3, and mixed and stirred for 2-3 min, and the temperature is raised to 130-150 DEG C to obtain material 4;

[0028] The discharge port is opened, and the cooled mixer is put in to cool at a speed of 80-100 rpm to 35 DEG C, the cooled material 4 is taken out from the main feeding port, and is added into a parallel three-screw extruder to modify and extrude the material, and is taken out by a wind-cooled conveying belt, is cut into particles, and is dried and screened to obtain the nano calcium sulfate packaging box composition.

[0029] Preferably, the uniform speed feeding speed of the parallel three-screw extruder is 400-500 rpm, the screw speed is 800-1000 rpm, and the vacuum pressure is 2.8 Mpa; and the speed of the high-speed mixer is 550-650 rpm.

[0030] The application further provides a nano calcium sulfate plastic plate prepared from the nano calcium sulfate packaging box composition according to any one of the above technical solutions.

[0031] The application further provides a nano calcium sulfate packaging box prepared from the nano calcium sulfate packaging box composition according to any one of the above technical solutions or the nano calcium sulfate plastic plate prepared according to the above technical solution.

[0032] Compared with the prior art, the application has the following advantages and positive effects:

[0033] 1. The nano calcium sulfate packaging box composition provided by the application uses nano calcium sulfate (anhydrous phosphogypsum) as the main raw material, realizes waste recycling, and achieves the purpose of green cyclic transformation. It also solves the pollution problem of by-products of the phosphate industry and the pollution of traditional anhydrous phosphogypsum to the environment, and makes the inorganic filler based on the carrier of gypsum truly market-oriented and valuable.

[0034] 2. The nano calcium sulfate packaging box composition provided by the application can greatly improve the strength, toughness, compression resistance, shock resistance, tear resistance, and box forming function of the nano calcium sulfate packaging box after being added to the nano calcium sulfate packaging box. On the other hand, it improves the waterproof, moisture-proof, and fresh-keeping functions of the nano calcium sulfate packaging box, makes up for the shortcomings of the traditional paper box market, reduces the damage rate, and protects the environment.

[0035] 3. The nano calcium sulfate packaging box made of the nano calcium sulfate packaging box composition provided by the application can replace traditional corrugated paper boxes. Since only electric energy is used in the production process, there is no energy consumption, water consumption, and wastewater pollution problem of wood pulp paper, so the economic cost is low, and it is environmentally friendly. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 The material form diagram of the nano calcium sulfate packaging box composition provided by the application under different activation processes. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the application will be described below. Obviously, the described embodiments are only a part of the embodiments of the application, not all. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0038] The embodiment of the application provides a nano calcium sulfate packaging box composition, which is prepared from the following components by weight:

[0039] The nano calcium sulfate powder is 30-75 parts, the powdered polypropylene copolymer resin is 5-8 parts, the powdered polypropylene homopolymer resin is 6-10 parts, the powdered fiber polypropylene is 5-6 parts, the powdered composite modified high-solubility fat polypropylene resin is 5-8, the coupling agent is 0.8-1.8 parts, the toughening agent POE is 4-7 parts, and the lubricant is 1-3 parts.

[0040] The nano calcium sulfate packaging box composition formula described above uses nano calcium sulfate as the main raw material, aiming to reduce cost and improve the hardness and strength of the product; the auxiliary raw materials are powdered polypropylene copolymer resin, powdered polypropylene homopolymer resin, powdered polypropylene fiber resin, and powdered composite modified high-solubility polypropylene resin, aiming to improve the compatibility of nano calcium sulfate powder and polypropylene resin; the functional additives are coupling agent, zinc stearate, toughening agent, and lubricant, aiming to improve the overall dispersibility, coating property, and anti-aging property, improve the stability of the material, and solve the stability of the plate during the plate-making process, flatness, and extrusion amount.

[0041] The nano calcium sulfate packaging box composition obtained based on the above formula not only achieves the purpose of waste recycling, but also realizes the purpose of green and circular transformation of high-pollution industries such as mining. The nano calcium sulfate packaging box prepared from the obtained nano calcium sulfate packaging box composition can greatly improve the strength, toughness, compression resistance, shock resistance, tear strength, and box forming function of the nano calcium sulfate packaging box, enhance the printing effect, and also improve the waterproof, moisture-proof, and fresh-keeping functions of the nano calcium sulfate packaging box, making up for the shortcomings of traditional paper boxes, reducing the damage rate, and protecting the environment.

[0042] It can be understood that during the preparation of the nano calcium sulfate packaging box composition, the weight parts of each component in the formula can be adjusted by the person skilled in the art within the above range according to the actual situation, for example, the weight parts of the added nano calcium sulfate can also be 30, 35, 40, 45, 50, 55, 60, 65, 70, 75 parts or any point value within the above range, the weight parts of the powdered composite modified high-solubility polypropylene resin can also be 5, 5.5, 6, 6.5, 7, 7.5, 8 parts or any point value within the above range, the weight parts of the powdered polypropylene copolymer resin can also be 5, 5.5, 6, 6.5, 7, 7.5, 8 parts or any point value within the above range, the weight parts of the powdered polypropylene homopolymer resin can also be 6, 7, 8, 9, 10 parts or any point value within the above range, the weight parts of the powdered polypropylene fiber resin can also be 5, 5.5, 6 parts or any point value within the above range, the coupling agent can be 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8 parts or any point value within the above range, the weight parts of the toughening agent POE can also be 4, 4.5, 5, 5.5, 6, 6.5, 7 parts or any point value within the above range, the weight parts of the lubricant can also be 1.5, 2, 2.5 parts or any point value within the above range, and the weight parts of the zinc stearate can also be 0.8, 0.9, 1.0, 1.1, 1.2 parts or any point value within the above range.

[0043] To ensure that the obtained nano calcium sulfate packaging box composition can obtain the expected performance of nano calcium sulfate packaging box when preparing nano calcium sulfate packaging box, the weight parts of each component added in the formula should be ensured within the above range, too much or too little is not allowed, for example, if the weight parts of nano calcium sulfate powder added are too much, the strength and brittleness of the product will increase, it is easy to break, the extrusion pressure of the extruder increases during the processing of the product, the flowability of the material decreases, the dispersion effect is poor, the nano calcium sulfate packaging box plate is slow to shape, and the yield is low; if it is too little, the product is strong in toughness and not easy to break, the extrusion pressure of the extruder is small during the processing of the product, the flowability of the material is strong, the dispersion effect is good, the toughness is strong, the forming process is poor, the material cost is high, the practicality and economic effect are poor, and the product price is 2-3 times that of ordinary cartons. If the weight parts of the added powdered polypropylene copolymer resin, powdered polypropylene homopolymer resin and powdered polypropylene fiber resin are too much, the cost will increase, the toughness of the nano calcium sulfate packaging box plate will increase, the nano calcium sulfate box forming process will be poor, it will not be easy to print, the water ink adhesion will be poor, and it will be easy to fade; if it is too little, the toughness of the nano calcium sulfate packaging box plate will decrease, the nano calcium sulfate packaging box plate hardness will be too strong, the forming process will be poor, it will not be easy to fold, the surface smoothness will be poor, the water ink adhesion will be poor, it will be easy to fade, and there will be no texture. If the weight parts of the added powdered composite modified high-solubility polypropylene resin are too much, the overall nano calcium sulfate packaging box modification solubility will increase, the nano calcium sulfate packaging box modification material strength will decrease, it will be easy to be brittle, the extruder pressure will be too small, the overall pressure of the mold will not be enough, and the molding will be difficult; if it is too little, the nano calcium sulfate packaging box modification solubility will also decrease, the nano calcium sulfate packaging box modification material will not be evenly dispersed, the coating will not be complete, it will be easy to be brittle, the extruder pressure will increase, the yield will be low, the mold cavity flow rate will not be enough, and the molding will be difficult.

[0044] In a preferred embodiment, the composite modified high-solubility polypropylene resin is composed of polypropylene powder 95-100 parts, peroxide di-t-butyl 1.2-1.6 parts and antioxidant 1010 0.6-1.3 parts.

[0045] In this embodiment, the purpose of adding the composite modified high-solubility polypropylene resin is to improve solubility. Adding it to the high-filled nano calcium sulfate composition formula can effectively improve the overall flowability and dispersibility. It can be understood that the weight parts of the added polypropylene powder can also be 95, 95.5, 96, 96.5, 97, 97.5, 98, 98.5, 99, 99.5 parts or any point value within the above range, the weight parts of peroxide di-t-butyl can also be 1.2, 1.3, 1.4, 1.5, 1.6 parts or any point value within the above range, and the weight parts of antioxidant 1010 can also be 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3 parts or any point value within the above range.

[0046] It can be understood that the composite modified high-solubility polypropylene resin involved in the above embodiments has high selectivity for the composition formula. As can be seen from the formula thereof, the composite modified high-solubility polypropylene resin is composed of polypropylene powder, di-tert-butyl peroxide and antioxidant, wherein the main component polypropylene powder is the same as the main raw material in the composition formula, the di-tert-butyl peroxide functions to increase the flowability of polypropylene and the melt flow rate as the molecular weight of the polypropylene molecular chain is reduced after the chain is broken, so that the di-tert-butyl peroxide is completely consumed and no free radicals are generated, so that the molecular weight of the polypropylene is degraded to a lower value, and the viscosity is also reduced accordingly. In combination with a specific subsequent preparation process, the excess di-tert-butyl peroxide is effectively removed. That is, the composite modified high-solubility polypropylene resin prepared based on the above specific formula can also assist in improving the flowability of the composition as a whole under the premise of introducing additional components into the composition formula.

[0047] In a preferred embodiment, the composite modified high-solubility polypropylene resin is prepared by the following method: the polypropylene powder, di-tert-butyl peroxide and antioxidant 1010 are sequentially added to a parallel triple-screw extruder in the order of weight parts and low-speed mixing machine at low speed, high-temperature high-speed shearing, and then sent to a single-screw extruder for temperature reduction extrusion. After mixing sufficiently, the product is formed, drawn, cut and ground.

[0048] In the above preparation method, a specific parallel triple-screw extruder and double-screw extruder double-stage combination is used. The temperature during the extrusion of the parallel triple-screw extruder is relatively high, and the high-strength shearing thread combination block is used to complete the peroxide reaction, generate free radicals, and make the free radicals attack the tertiary carbon atoms on the polypropylene molecular chain, so that the polypropylene free radical molecular chain is broken. According to the combination form of the double-screw thread components, the transition cooling after the double-screw extrusion is used to make up for the incomplete peroxide reaction during the extrusion of the parallel triple-screw extruder, so that the di-tert-butyl peroxide is completely consumed and no free radicals are generated, so that the molecular weight of the polypropylene is degraded to a lower value to improve the flowability.

[0049] In a preferred embodiment, the low-speed rotation speed is 100-150 rpm, the high-temperature high-speed shearing time in the parallel triple-screw extruder is 3-4 min, and the transition extrusion time in the double-screw extruder is 1-3 min.

[0050] In a preferred embodiment, the parallel triple-screw extruder has the following extrusion temperatures: 225-230°C for the first zone, 225-230°C for the second zone, 220-225°C for the third zone, 215-220°C for the fourth zone, 190-200°C for the fifth zone, 180-190°C for the sixth zone, 170-180°C for the seventh zone, 160-170°C for the eighth zone, 130-140°C for the ninth zone, 130-140°C for the tenth zone, 125-135°C for the first die zone, and 130-140°C for the second die zone.

[0051] The twin-screw extruder has the following extrusion temperatures: 160-170°C for the first zone, 155-165°C for the second zone, 150-160°C for the third zone, 145-155°C for the fourth zone, 140-150°C for the fifth zone, and 140-150°C for the sixth zone.

[0052] In a preferred embodiment, the coupling agent is a silane coupling agent or a titanate coupling agent; and the lubricant is a mixture of polyethylene wax and paraffin wax, with a weight ratio of (0.5-1):(0.5-1.5).

[0053] In the above embodiments, the lubricant is a mixture of polyethylene wax and paraffin wax, and the main component of the paraffin wax is straight-chain alkane, which can effectively improve the processing performance and surface gloss of the nano calcium sulfate packaging box masterbatch. The PE wax is a low-molecular-weight polyethylene with a molecular weight of about 2000-5000, and the paraffin wax is a mixture of hydrocarbons with a carbon atom number of about 18-30, mainly composed of straight-chain alkane (about 80%-95%). The paraffin wax has low viscosity, high softening point, good hardness, good thermal stability, low volatility at high temperature, strong dispersibility, excellent external lubricity, and strong internal lubrication, which can improve the processing performance, surface gloss, lubricity, and thermal stability of the nano calcium sulfate packaging box masterbatch. It can be understood that the weight ratio of the components in the above lubricant can also be 1:1, 0.5:1, 1:3, 0.8:0.5, 0.8:1, 0.8:1.5, 1:0.5, 1:1.5, or any ratio within the above range.

[0054] In a preferred embodiment, the nano calcium sulfate has a mesh number of 1000-1800. It can be understood that the mesh number of the nano calcium sulfate is limited within the above range, and the purpose is that the nano calcium carbonate with the mesh number has a simple structure, a small packing volume, a fine and uniform particle size, a high whiteness, a low oil absorption value, good smoothness, good flowability, strong water ink absorption, and stronger tearing, compression deformation, and flex resistance than general nano calcium carbonate. Further, since the crystal structure of talc is layered, it has a tendency to split into flakes and special lubricity.

[0055] The embodiment of the present application also provides a preparation method of the nano calcium sulfate packaging box composition according to the above embodiments, which comprises the following steps:

[0056] Mix the nano calcium sulfate powder by weight parts in a high-speed mixer, the speed is 200-700 rpm, the oil temperature is hot or electric heating to raise the temperature to 100-110℃, dry the mixture powder sufficiently to remove the water, get material 1;

[0057] Add coupling agent to material 1, mix and stir for 3-4 min, wait for the temperature to reach 125-135℃, get material 2;

[0058] Add zinc stearate, toughening agent POE, lubricant, and powdered composite modified high-solubility polypropylene resin to material 2, mix and stir for 3-4 min, wait for the temperature to reach 125-135℃, get material 3;

[0059] Add powdered polypropylene copolymer resin, powdered polypropylene homopolymer resin, and powdered polypropylene fiber resin to material 3, mix and stir for 2-3 min, wait for the temperature to reach 130-150℃, get material 4;

[0060] Open the discharge port and put it into the cooling mixer, the speed is 80-100 rpm, cool to 35℃, put the cooled material 4 into the main feeding port, add it to the parallel three-screw extruder to modify and extrude the material, and use air-cooled conveying belt to pull the granules, dry and screen, get the nano calcium sulfate packaging box composition.

[0061] In the above method, the nano calcium sulfate packaging box composition is prepared by first adding the main raw material (nano nano calcium sulfate), then adding functional additives (coupling agent, zinc stearate, toughening agent POE elastomer, lubricant, and powdered composite modified high-solubility polypropylene resin) to improve the dispersibility, flowability, and toughness of the raw material, which helps the auxiliary raw materials to completely coat the nano calcium sulfate and form a mature material form, then adding auxiliary raw materials such as powdered polypropylene copolymer resin, powdered polypropylene homopolymer resin, and powdered polypropylene fiber resin to improve the overall dispersibility, flowability, and toughness, and finally further modifying the material by three-screw extruder extrusion granulation to further improve the solubility.

[0062] It is explained here that the polymer has a long molecular chain and a high molecular weight, the macromolecular structure has a high viscosity, and the flow resistance in the processing process comes from two aspects, one is the mutual entanglement between molecules which affects the fluidity, and the other is the friction between the polymer solution and the surface of the processing machinery. These frictions reduce the fluidity of the solution, and severe friction can make the surface rough and lack of gloss. The addition of lubricant reduces friction, reduces interfacial adhesion, etc. Among them, paraffin wax as an external lubricant is an interfacial lubricant, which has poor compatibility with polymers. During processing, it is easy to migrate from the inside of the polymer to the surface, and the polar group moves to the metal surface to form a lubricating molecular layer through physical adsorption or chemical bonding. Because the intermolecular energy of the lubricant is low, it can reduce the friction between the polymer and the equipment surface, thereby improving the fluidity. PE wax as an internal lubricant has a certain compatibility with polymers, which is generally small at room temperature, and the compatibility increases at high temperature, which has a certain plasticizing effect, weakens the cohesion between polymer molecules, reduces friction, reduces the viscosity of the solution, and increases the fluidity.

[0063] In addition, POE and lubricant are also introduced to play a synergistic effect. POE is a copolymer of ethylene and octene, which is a polyolefin elastomer with very narrow molecular weight distribution and certain crystallinity and thermoplasticity. The crystalline ethylene chain in its structure acts as a physical crosslinking point to bear the load. POE has a soft chain curl structure of octene and a crystalline ethylene chain as a physical crosslinking point, excellent toughness and good processability, and no unsaturated double bonds in the molecular structure of POE, strong thermal stability, excellent optical performance and excellent anti-cracking. In addition, POE has a narrow molecular weight distribution, good flowability, good compatibility with polyolefins, and a great improvement in impact strength and elongation at break of the system with the increase of POE content. It has good compatibility with nano calcium carbonate and nano talc powder, and the bending modulus and tensile strength amplitude decrease with a certain amount of addition.

[0064] It can also be understood that in the above preparation method, the feeding sequence of each step and the process parameters used in each step are strictly limited, and the range of these strict process parameters is very small. For example, the activation time of the coupling agent is limited to 3-4 min, because the activation time of the coupling agent is crucial. If the activation is proper, the viscosity of the synthetic resin solution can be reduced during resin processing, the dispersion of the filler can be improved, the processing performance can be improved, and thus the product can obtain good surface quality and mechanical properties. Otherwise, the corresponding performance cannot be achieved. Further, if the activation time is limited within the above time range, the coupling agent can act as a molecular bridge to improve the interfacial action between inorganic and organic materials, activate the inorganic powder, increase the compatibility and coating of the inorganic powder and the organic powder. Otherwise, if the activation time is not enough or too long, the activation effect will be affected.

[0065] The material form of the nano calcium sulfate packaging box composition obtained based on the complete steps under the activation process is shown in the following figure, wherein the left figure is the material form of the unshaped and unqualified nano calcium sulfate packaging box composition under the activation process which is not obtained under the above production process conditions (i.e. out of the above process condition parameter value range), and the right figure is the material form of the shaped and qualified nano calcium sulfate packaging box composition under the activation process which is prepared under the present production process. Figure 1

[0066] In a preferred embodiment, the uniform feeding rotation speed of the parallel triple-screw extruder is 400-500 rpm, the screw rotation speed is 800-1000 rpm, and the vacuum pressure is 2.8 Mpa; the rotation speed of the high-speed mixer is 550-650 rpm.

[0067] The embodiment of the present application also provides a nano calcium sulfate packaging box prepared by using the nano calcium sulfate packaging box composition according to the above embodiment. The nano calcium sulfate packaging box prepared by using the obtained nano calcium sulfate packaging box composition can greatly improve the strength, toughness, compression resistance, shock resistance, tear strength and forming function of the nano calcium sulfate packaging box, and can also improve the waterproof, moisture-proof and freshness-keeping function of the nano calcium sulfate packaging box, thereby making up for the shortcomings of the traditional paper box market, reducing the damage rate, and protecting the environment.

[0068] Embodiment 1

[0069] The nano calcium sulfate packaging box composition is prepared from the following components by weight: 50 parts of nano calcium sulfate powder, 6.5 parts of powdered polypropylene copolymer resin, 8 parts of powdered polypropylene homopolymer resin, 5.5 parts of powdered fiber polypropylene, 6.5 parts of powdered composite modified high-solubility fat polypropylene resin, 1.4 parts of coupling agent, 1.0 part of zinc stearate, 5.5 parts of toughening agent POE, and 1.5 parts of lubricant.

[0070] Preparation method:

[0071] Mix the nano calcium sulfate powder in the high-speed mixer at a rotation speed of 200-700 rpm, heat the oil to a temperature of 100-110℃ by using a hot oil machine or electric heating, and sufficiently dry the water in the mixed powder to obtain material 1;

[0072] Add the coupling agent to the material 1, mix and stir for 3-4 min, and wait for the temperature to reach 125-135℃ to obtain material 2;

[0073] Add zinc stearate, toughening agent POE, lubricant, and powdered composite modified high-solubility fat polypropylene resin to the material 2, mix and stir for 3-4 min, and wait for the temperature to reach 125-135℃ to obtain material 3;

[0074] ​To the material 3, add the powdered polypropylene copolymer resin, the powdered polypropylene homopolymer resin, and the powdered polypropylene fiber resin, mix and stir for 2-3 minutes, and when the temperature reaches 130-150°C, obtain material 4;

[0075] Open the discharge port, put it into the cooling mixer, and cool it to 35°C at a speed of 80-100 rpm. Then, from the main feeding port, add the cooled material 4 into the parallel three-screw extruder to modify and extrude the material into granules. Then, use the air-cooled conveying belt to pull the strands, dry and screen them, and obtain the composition for the nano calcium sulfate packaging box.

[0076] Example 2

[0077] The composition for the nano calcium sulfate packaging box is prepared from the following components by weight: 55 parts of nano calcium sulfate powder, 6.8 parts of powdered polypropylene copolymer resin, 8 parts of powdered polypropylene homopolymer resin, 5.4 parts of powdered fiber polypropylene, 6 parts of powdered composite modified high-solubility fat polypropylene resin, 1.3 parts of coupling agent, 0.9 parts of zinc stearate, 5.2 parts of toughening agent POE, and 1.8 parts of lubricant.

[0078] The preparation method is the same as that in Example 1.

[0079] Example 3

[0080] The composition for the nano calcium sulfate packaging box is prepared from the following components by weight: 60 parts of nano calcium sulfate powder, 7.2 parts of powdered polypropylene copolymer resin, 8.5 parts of powdered polypropylene homopolymer resin, 5.6 parts of powdered fiber polypropylene, 6.5 parts of powdered composite modified high-solubility fat polypropylene resin, 1.5 parts of coupling agent, 1.0 parts of zinc stearate, 5.8 parts of toughening agent POE, and 2.1 parts of lubricant.

[0081] The preparation method is the same as that in Example 1.

[0082] Example 4

[0083] The composition for the nano calcium sulfate packaging box is prepared from the following components by weight: 65 parts of nano calcium sulfate powder, 7.5 parts of powdered polypropylene copolymer resin, 9 parts of powdered polypropylene homopolymer resin, 5.8 parts of powdered fiber polypropylene, 7.3 parts of powdered composite modified high-solubility fat polypropylene resin, 1.6 parts of coupling agent, 1.1 parts of zinc stearate, 6.2 parts of toughening agent POE, and 2.4 parts of lubricant.

[0084] The preparation method is the same as that in Example 1.

[0085] Example 5

[0086] A nano calcium sulfate packing box composition is prepared from the following components in parts by weight: nano calcium sulfate powder 75 parts, powdered polypropylene copolymer resin 8 parts, powdered polypropylene homopolymer resin 10 parts, powdered fibrous polypropylene 6 parts, powdered composite modified high-solubility fat polypropylene resin 8 parts, coupling agent 1.8 parts, zinc stearate 1.2 parts, toughening agent POE 7 parts, and lubricant 3 parts.

[0087] The preparation method is the same as in Example 1.

[0088] Example 6

[0089] A nano calcium sulfate packing box composition is prepared from the following components in parts by weight: nano calcium sulfate powder 30 parts, powdered polypropylene copolymer resin 5 parts, powdered polypropylene homopolymer resin 6 parts, powdered fibrous polypropylene 5 parts, powdered composite modified high-solubility fat polypropylene resin 5 parts, coupling agent 0.8 parts, zinc stearate 0.8 parts, toughening agent POE 4 parts, and lubricant 1 part.

[0090] The preparation method is the same as in Example 1.

[0091] Example 7

[0092] A nano calcium sulfate packing box composition is prepared from the following components in parts by weight: nano calcium sulfate powder 45 parts, powdered polypropylene copolymer resin 5.8 parts, powdered polypropylene homopolymer resin 7 parts, powdered fibrous polypropylene 5.5 parts, powdered composite modified high-solubility fat polypropylene resin 5.5 parts, coupling agent 1.0 part, zinc stearate 0.8 part, toughening agent POE 4.5 parts, and lubricant 1.5 parts.

[0093] The preparation method is the same as in Example 1.

[0094] Comparative Example 1

[0095] A nano calcium sulfate packing box composition is prepared from the following components in parts by weight: nano calcium sulfate powder 67 parts, powdered polypropylene copolymer resin 4 parts, powdered polypropylene homopolymer resin 5 parts, powdered fibrous polypropylene 4.3 parts, powdered composite modified high-solubility fat polypropylene resin 4.5 parts, coupling agent 0.8 part, zinc stearate 0.8 part, toughening agent POE 4 parts, and lubricant 1 part.

[0096] The preparation method is the same as in Example 1.

[0097] Comparative Example 2

[0098] A nano calcium sulfate packing box composition is prepared from the following components in parts by weight: nano calcium sulfate powder 73 parts, powdered polypropylene copolymer resin 8 parts, powdered polypropylene homopolymer resin 10 parts, powdered fibrous polypropylene 6 parts, powdered composite modified high-solubility fat polypropylene resin 8.5 parts, coupling agent 1 part, zinc stearate 1 part, toughening agent POE 5 parts, and lubricant 3 parts.

[0099] Preparation method same as Example 1.

[0100] Comparative Example 1

[0101] The nano calcium sulfate packaging box composition has the same component formula as Example 1, except that the polypropylene copolymer resin, the polypropylene homopolymer resin, the fibrous polypropylene, and the composite modified high-solubility fat polypropylene resin are all in the form of particles with a particle size of 40 mesh, rather than in the form of powder.

[0102] Preparation method same as Example 1.

[0103] Comparative Example 1

[0104] The nano calcium sulfate packaging box composition has the same component formula as Example 1, except that the polypropylene copolymer resin, the polypropylene homopolymer resin, the fibrous polypropylene, and the composite modified high-solubility fat polypropylene resin are all in the form of particles with a particle size of 40 mesh, rather than in the form of powder.

[0105] Preparation method same as Example 1.

[0106] Comparative Example 1

[0107] The nano calcium sulfate packaging box composition has the same component formula as Example 1, except that the polypropylene copolymer resin, the polypropylene homopolymer resin, the fibrous polypropylene, and the composite modified high-solubility fat polypropylene resin are all in the form of particles with a particle size of 40 mesh, rather than in the form of powder.

[0108] Preparation method same as Example 1.

[0109] Comparative Example 1

[0110] The nano calcium sulfate packaging box composition has the same component formula as Example 1.

[0111] The preparation method is the same as Example 1, except that the composite modified high-solubility fat polypropylene resin is prepared by the following method: the low-speed mixer is used to add the polypropylene powder, the peroxide di-t-butyl, and the antioxidant 1010 into the parallel three-screw extruder in the order of weight and at low speed, and after high-temperature and high-speed shearing, the material is drawn and cut.

[0112] Comparative Example 1

[0113] The nano calcium sulfate packaging box composition has the same component formula as Example 1.

[0114] The preparation method is the same as Example 1, except that the discharge port is opened, the cooled mixer is used for cooling at a speed of 80-100 rpm until the temperature is lowered to 35°C, the cooled material 4 is added into the single-screw extruder for granulation, and the air-cooled conveying belt is used for drawing and cutting, and the dried and screened material is obtained as the nano calcium sulfate packaging box composition.

[0115] Performance test

[0116] The performance of the nano calcium sulfate packaging box compositions prepared in the above examples 1-5 and comparative examples 1-7 was compared and analyzed from the following aspects, and the specific results are shown in Tables 1-3:

[0117] Table 1 Performance analysis of the nano calcium sulfate packaging box compositions prepared in examples 1-5

[0118]

[0119] Table 2 Performance analysis of the nano calcium sulfate packaging box compositions prepared in comparative examples 1-5

[0120]

[0121] Table 3 Performance analysis of the nano calcium sulfate packaging box compositions prepared in comparative examples 6-8

[0122]

[0123] The reference range of each parameter in the above table is fat dissolving 2.6-22.9 g / 10 min, tensile strength 23-35.5 Mpa, elongation at break 80-95%, cleanliness (color particles) visual 10 / Kg, Rockwell hardness 88-103, Izod impact strength (notch) 23℃ 34-53, and no odor for hygiene requirements.

[0124] The nano calcium sulfate packaging box, calcium plastic box and finished paper box prepared by using the nano calcium sulfate packaging box composition prepared in the above example 1 were compared in the following aspects, and the results are shown in Tables 4-6, and the methods used are as follows:

[0125] Table 4 Test result analysis of nano calcium sulfate packaging box, stone plastic box, calcium plastic box and paper box

[0126]

[0127] Explanation: 1, corrugated board classification

[0128] 1.1: Classification by flute type: A, C, B, E and their combinations, such as: AB flute, BC flute, BBC flute, etc.

[0129] 1.2: Classification by the number of base paper layers: three-layer paperboard, four-layer paperboard, five-layer paperboard, seven-layer paperboard, etc.

[0130] 1.3: Classification by flute shape: U-shaped, V-shaped, UV-shaped; the commonly used UV-shaped on the market;

[0131] 2, nano calcium sulfate packaging box classification

[0132] 2.1: Classification by thickness: 2 mm, 2.2 mm, 2.5 mm, 2.7 mm, 3 mm, 3.3 mm, 3.5 mm, 3.7 mm, 4 mm, 4.3, 4.5 mm, 4.8 mm, 5 mm;

[0133] 2.2: Classification by matching thickness and number of paper layers: three layers of paperboard correspond to 2 mm, 2.2 mm, 2.5 mm, four layers of paperboard correspond to 2.7 mm, 3 mm, five layers of paperboard correspond to 3 mm, 3.3 mm, 3.5 mm, seven layers of paperboard correspond to 3.7 mm, 4 mm, 4.3, 4.5 mm;

[0134] 2.3: Nano calcium sulfate packaging box shape: hollow square lattice shape;

[0135] 2. Calcium plastic box classification

[0136] 2.1: Classification by thickness: 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm;

[0137] 2.2: Classification by matching thickness and number of paper layers: three layers of paperboard correspond to 2.5 mm, four layers of paperboard correspond to 3 mm, five layers of paperboard correspond to 3.5 mm-4 mm, seven layers of paperboard correspond to 4.5 mm-5 mm;

[0138] 2.3: Calcium plastic box shape: hollow square lattice shape.

[0139] Table 5 Comparison of functions of nano calcium sulfate packaging box, stone plastic box, calcium plastic box and finished paper box

[0140]

[0141] Table 6 Comparison of prices of nano calcium sulfate packaging box, calcium plastic box, stone plastic box and finished paper box

[0142] Take 320 (length) x 220 (width) x 150 (height) units: (mm) size as an example:

[0143]

[0144] The specific calculation is as follows:

[0145] The formula for estimating the material of the carton is (length + width + 0.04) x (width + height + 0.03) x 2, the units of length, width and height are meters, and the unit of material area is square meters. Here +0.04 is the length of the reserved tongue (joint), and +0.03 is the width of the reserved edge. (Not necessarily +0.04 +0.03, but also +0.03 +0.03 or +0.08 +0.04, etc., depending on the specific situation).

[0146] Take a paper box of 32 x 22 x 15 cm as an example, and the cost of the paper box is calculated according to ordinary materials:

[0147] (0.32+0.22+0.04) x (0.22+0.15+0.03) x 2 = 0.464 square meters, i.e. an area of 0.46 square meters, the cost of the paperboard is 3.3 yuan per square meter, a total of 1.53 yuan, plus a 20% profit, a total of 1.83 yuan (ex-factory price), if under the pressure of environmental protection according to the rising price of paper, the cost rises by 20%, i.e. the cost of a single paper box is 2.2 yuan (ex-factory price).

[0148] Take a stone plastic box of 32 x 22 x 15 cm as an example:

[0149] Select a stone plastic box board thickness of 2.2 mm, a grammage of 750 g / m2, and the cost of a nano calcium sulfate packaging box is calculated:

[0150] (0.32+0.22+0.04) x (0.22+0.15+0.03) x 2 = 0.464 square meters, i.e. an area of 0.46 square meters, the cost of the stone plastic box board is 4800 yuan per ton, (including factory building, electricity, loss, wages and other expenses) a total of 4.8*0.348 (the weight of the box) = 1.67 yuan, plus a 20% profit, a total of 1.87 yuan (ex-factory price), if according to the rising price trend of chemical raw materials, the cost rises by 5%, i.e. the cost of a single nano calcium sulfate packaging box rises to 1.96 yuan (ex-factory price).

[0151] Take a nano calcium sulfate packaging box of 32 x 22 x 15 cm as an example:

[0152] Select a nano calcium sulfate packaging box board thickness of 2.2 mm, a grammage of 750 g / m2, and the cost of a nano calcium sulfate packaging box is calculated:

[0153] (0.32+0.22+0.04) x (0.22+0.15+0.03) x 2 = 0.464 square meters, i.e. an area of 0.46 square meters, the cost of the nano calcium sulfate packaging box board is 4100 yuan per ton, (including factory building, electricity, loss, wages and other expenses) a total of 4.1*0.348 (the weight of the box) = 1.43 yuan, plus a 20% profit, a total of 1.6 yuan (ex-factory price), if according to the rising price trend of chemical raw materials, the cost rises by 5%, i.e. the cost of a single nano calcium sulfate packaging box rises to 1.76 yuan (ex-factory price).

[0154] The cost of a nano calcium sulfate packaging box of the same size and a paper box differs by 0.44 yuan, and the price of the calcium sulfate packaging box is cheaper than that of the traditional packaging box, and is also better than that of the stone plastic box.

[0155] The nano calcium sulfate packaging box grammage table is shown in Table 7.

[0156] Table 7 Nano calcium sulfate packaging box grammage table

[0157]

[0158] From the above analysis, the nano calcium sulfate packaging box prepared from the composition prepared from the specific material can greatly improve the strength, toughness, compression resistance, shock resistance, tear strength and forming function of the nano calcium sulfate packaging box, and can improve the waterproof and moisture-proof function of the nano calcium sulfate packaging box, make up for the deficiency of the traditional paper box market, reduce the damage rate, and protect the environment. The prepared nano calcium sulfate packaging box can effectively replace the traditional corrugated paper box and the calcium plastic box on the market, which is not only low in economic cost and friendly to the environment, but also only uses electric energy in the production process, and does not involve the problems of energy consumption, water consumption and wastewater pollution of wood pulp paper. The present application realizes the recycling of waste, and effectively achieves the purpose of green and cyclic transformation of high-pollution industries such as mining.

Claims

1. A composition for a calcium sulfate packaging box, characterized by, An inorganic filler is prepared by using anhydrous phosphogypsum as a carrier, wherein the anhydrous phosphogypsum is calcium sulfate powder; The calcium sulfate packaging box composition is composed of the following components by weight: 30-75 parts of calcium sulfate powder, 5-8 parts of powdered polypropylene copolymer resin, 6-10 parts of powdered polypropylene homopolymer resin, 5-6 parts of powdered polypropylene fiber, 5-8 parts of powdered composite modified high-solubility fat polypropylene resin, 0.8-1.8 parts of coupling agent, 0.8-1.2 parts of zinc stearate, 4-7 parts of toughening agent POE, and 1-3 parts of lubricant; The calcium sulfate powder has a mesh size of 1000-1800 mesh; The powdered polypropylene copolymer resin, the powdered polypropylene homopolymer resin, the powdered polypropylene fiber, and the powdered composite modified high-solubility fat polypropylene resin have a particle size range of 25-30 mesh and are prepared by a liquid nitrogen grinding method; The powdered composite modified high-solubility fat polypropylene resin is composed of 95-100 parts of polypropylene powder, 1.2-1.6 parts of di-tert-butyl peroxide, and 0.6-1.3 parts of antioxidant 1010. The powdered composite modified high-solubility fat polypropylene resin is prepared by the following method: At a low rotation speed of 100-150 rpm, the components are added in the order of polypropylene powder, di-tert-butyl peroxide, and antioxidant 1010 into a parallel three-screw extruder, and then high-temperature high-speed shearing is performed for 3-4 min, after which the mixture is sent into a parallel double-screw extruder for cooling extrusion, mixed for 1-3 min, and then formed, drawn, cut, ground, and packaged. The preparation method of the calcium sulfate packaging box composition comprises the following steps: The calcium sulfate powder is mixed in a high-speed mixer at a rotation speed of 200-700 rpm, and the oil temperature is heated to 100-110℃ by an oil heater or an electric heater to sufficiently dry the water in the mixed powder to obtain material 1; Coupling agent is added to material 1 and mixed and stirred for 3-4 min until the temperature reaches 125-135℃ to obtain material 2; Zinc stearate, toughening agent POE, lubricant, and powdered composite modified high-solubility fat polypropylene resin are added to material 2 and mixed and stirred for 3-4 min until the temperature reaches 125-135℃ to obtain material 3; Powdered polypropylene copolymer resin, powdered polypropylene homopolymer resin, and powdered polypropylene fiber are added to material 3 and mixed and stirred for 2-3 min until the temperature reaches 130-150℃ to obtain material 4; The discharge port is opened, and the cooled material 4 is placed into a cooling mixer and cooled to 35℃ at a rotation speed of 80-100 rpm. The cooled material 4 is then added to a parallel three-screw extruder for modification and extrusion granulation, and then drawn, cut, dried, and sieved by a wind-cooled conveying belt to obtain the calcium sulfate packaging box composition.

2. The composition for a calcium sulfate packaging box according to claim 1, characterized by, The powdered composite modified high-solubility fat polypropylene resin preparation method further comprises: The temperature of the triple-screw extrusion is: 225-230℃ in the first zone, 225-230℃ in the second zone, 220-225℃ in the third zone, 215-220℃ in the fourth zone, 190-200℃ in the fifth zone, 180-190℃ in the sixth zone, 170-180℃ in the seventh zone, 160-170℃ in the eighth zone, 130-140℃ in the ninth zone, 130-140℃ in the tenth zone, 125-135℃ in the first zone of the head, and 130-140℃ in the second zone of the head; The temperature of the double-screw extrusion is: 160-170℃ in the first zone, 155-165℃ in the second zone, 150-160℃ in the third zone, 145-155℃ in the fourth zone, 140-150℃ in the fifth zone, and 140-150℃ in the sixth zone.

3. The composition for a calcium sulfate packaging box according to claim 1, characterized by, The coupling agent is a silane coupling agent or a titanate coupling agent; The lubricant is a mixture of polyethylene wax and paraffin wax, and the weight ratio is (0.5-1):(0.5-1.5).

4. The method of producing the composition for calcium sulfate packaging boxes according to any one of claims 1 to 3, characterized by, The preparation method of the calcium sulfate packaging box composition comprises the following steps: Mix the calcium sulfate powder in a high-speed mixer at a speed of 200-700 rpm, and heat the oil to a temperature of 100-110℃, and dry the mixture to obtain material 1; Add the coupling agent to the material 1 and mix for 3-4 min, and when the temperature reaches 125-135℃, obtain material 2; Add zinc stearate, toughening agent POE, lubricant, and powdered composite modified high-solubility polypropylene resin to the material 2 and mix for 3-4 min, and when the temperature reaches 125-135℃, obtain material 3; Add powdered polypropylene copolymer resin, powdered polypropylene homopolymer resin, and powdered polypropylene fiber to the material 3 and mix for 2-3 min, and when the temperature reaches 130-150℃, obtain material 4; Open the discharge port and put it into a cooling mixer, and cool it to 35℃ at a speed of 80-100 rpm, and then put the cooled material 4 into a parallel triple-screw extruder to modify and extrude the material, and use an air-cooled conveying belt to pull the granules, dry and screen them to obtain the calcium sulfate packaging box composition; The uniform feeding speed of the parallel triple-screw extruder is 400-500 rpm, the screw speed is 800-1000 rpm, and the vacuum pressure is 2.8 Mpa; the speed of the high-speed mixer is 550-650 rpm.

5. A calcium sulfate plaster, characterized in that, The calcium sulfate packaging box composition prepared by any one of claims 1-3 is used.

6. A calcium sulfate packaging box characterized by The calcium sulfate packaging box composition prepared by any one of claims 1-3 or the calcium sulfate plastic plate prepared by the method of claim 5 is used.

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