Manufacturing method of food and beverage metal container

Abstract

The invention relates to the technical field of food and beverage container manufacturing, and discloses a food and beverage metal container manufacturing method which comprises the following steps: mixing butyl acrylate, methyl methacrylate or styrene, hydroxyethyl acrylate, n-butyl alcohol and benzoyl peroxide which form a component A, and heating and stirring to obtain a transparent resin glue solution; the preparation method comprises the following steps: uniformly mixing bisphenol A with methanol etherified melamine resin of a component B according to a mass part ratio of 10: 3, diluting with alcohol to obtain a coating, coating the coating on a metal belt by using coating equipment, feeding the coated metal belt into a stamping production line, and stamping and stretching to manufacture a container. Therefore, the potential endocrine interference risk is reduced, the health safety of consumers is improved, and the packaging bag is particularly suitable for packaging children food and beverages. The coating has good processability and can be used for manufacturing containers with different shapes and sizes to meet the packaging requirements of different products.

Description

Technical Field

[0001] The invention belongs to the technical field of food and beverage container manufacturing, and in particular relates to a method for manufacturing a metal food and beverage container. Background Art

[0002] With the improvement of people's living standards and health awareness, food safety and environmental protection of packaging materials are becoming more and more important. Traditional coatings on the inner wall of metal containers for food and beverages usually contain bisphenol A (BPA), and recent studies have shown that bisphenol A may migrate into food and beverages, causing potential impacts on human health, especially on the endocrine system and carcinogenic risks. Therefore, the development of bisphenol A-free inner wall coatings for food and beverage containers has become an important research direction.

[0003] A large number of existing food and beverage container inner wall coatings contain bisphenol A, which poses a potential threat to consumers' health. The solvents used in the production process of traditional coatings are often harmful to the environment and do not meet the requirements of green environmental protection. The processing performance and adhesion of coatings in the existing technology may not be sufficient to meet the needs of high-speed automated production. The curing speed of traditional coatings is slow, which affects production efficiency and energy consumption control. In the production process of metal containers, traditional processes such as welding may increase production costs and also cause certain environmental pollution.

[0004] In order to solve the defects of the above content, the present invention proposes a method for manufacturing a metal container for food and beverages that does not contain bisphenol A. By using environmentally friendly alcohol as a solvent and a new formula, the defects in the prior art are effectively solved. Through innovative formulas and production processes, the coating provided by the present invention does not contain bisphenol A, thereby reducing the health risks of consumers. The use of environmentally friendly alcohol as a solvent reduces the harmful effects on the environment during the production process. The coating has good processing performance and adhesion, and can meet the needs of high-speed automated production. The containers are directly produced through stamping technology without welding, which reduces production costs and also improves the green environmental protection of the production process. Summary of the invention

[0005] The present invention aims to solve the technical problem that a large amount of coatings on the inner wall of food and beverage containers in the prior art contain bisphenol A, which poses a potential threat to the health of consumers.

[0006] To achieve the above object, the present invention provides the following technical solutions: A method for manufacturing a metal container for food and beverages, comprising the following steps: S1. Preparation of coating for inner wall of food and beverage container: adding butyl acrylate, methyl methacrylate or styrene, hydroxyethyl acrylate, n-butanol and benzoyl peroxide constituting component A into a mixer, mixing uniformly to obtain a mixed material, adding the mixed material into a reactor in multiple batches, heating and stirring to obtain a transparent resin glue, mixing the resin glue with methanol-etherified melamine resin constituting component B in a mass ratio of 10:3, and diluting with alcohol to obtain a coating for inner wall of food and beverage container without bisphenol A; S2, coating: coating the food and beverage container inner wall coating that does not contain bisphenol A prepared in step S1 on the metal strip using a coating device, and baking the coated metal strip at 180 degrees Celsius for 5 minutes; S3, stamping and forming: the metal strip coated and dried in step S2 is sent to a stamping production line, and is subjected to multiple stamping and stretching by a stamping die to produce food and beverage containers.

[0007] The coating that does not contain bisphenol A (BPA) reduces the potential risk of endocrine disruption and is safer for consumer health. It is especially suitable for children's food and beverage packaging. The use of environmentally friendly alcohol for dilution reduces the use of environmentally harmful solvents, which helps to reduce the impact of the production process on the environment. The prepared coating has good processing properties and can be evenly coated on the metal strip. It can be quickly cured by baking at 180 degrees Celsius for 5 minutes, which improves production efficiency and energy consumption control. By mixing component A in a mixer, the uniformity of the mixture is ensured, which is conducive to the subsequent reaction and the stability of product quality. Adding the mixture in batches and heating and stirring can better control the reaction process and reduce the waste of reactants and the generation of by-products. Mixing components A and B in a specific ratio and diluting them with alcohol can obtain a coating with stable performance and easy application.

[0008] The coating equipment can evenly coat the metal strip with coating to ensure coating quality. Baking at 180 degrees Celsius for 5 minutes can achieve rapid curing, reducing production cycles and improving production efficiency. Through stamping production lines and a variety of stamping dies, containers of different shapes and sizes can be produced as needed to meet the packaging needs of different products. Multiple stamping and stretching can improve the strength and shape accuracy of the container, ensuring the reliability of the container during transportation and storage.

[0009] Preferably, in step S1, the mass parts of the components of component A are: 30-70 parts of butyl acrylate, 20-60 parts of methyl methacrylate or styrene, 8-12 parts of hydroxyethyl acrylate, 37-43 parts of n-butanol, and 0.8-1.2 parts of benzoyl peroxide.

[0010] Preferably, the components of component A are as follows: 50 parts by weight of butyl acrylate, 40 parts by weight of methyl methacrylate or styrene, 10 parts by weight of hydroxyethyl acrylate, 40 parts by weight of n-butanol, and 1 part by weight of benzoyl peroxide.

[0011] Preferably, in step S1, 10% of the component A mixture of the total material is added to the reactor, heated to 85°C under stirring, and kept warm for 30 minutes, and then the remaining 90% of the component A mixture is added to the reactor in multiple batches, and the reaction temperature is controlled between 83-87°C for stirring and heating. After the addition of the component A mixture, the temperature is raised to 90°C and kept warm for 30 minutes to obtain a transparent and viscous resin glue.

[0012] The prepared coating is transparent and viscous, and can provide good coating uniformity and adhesion. The preferred mass ratio ensures stable performance of the coating and easy processing. Controlling the reaction temperature and time can ensure the quality of the resin and the completeness of the reaction, and reduce the generation of by-products.

[0013] Preferably, in step S1, during the mixing process of the resin glue and the methanol-etherified melamine resin, environmentally friendly alcohol is used as a solvent for dilution, and the mixture is diluted to a working viscosity for coating.

[0014] Environmentally friendly alcohol is used as a solvent to reduce the impact on the environment. Using environmentally friendly alcohol as a solvent not only reduces harmful emissions to the environment, but also during the construction process, alcohol can be recycled, further reducing the impact on the environment. Compared with traditional coatings containing bisphenol A (BPA), the coating provided by the present invention does not contain bisphenol A, thereby avoiding the migration of bisphenol A into food and beverages, reducing consumer health risks. As developed countries such as the European Union begin to ban the use of packaging materials containing bisphenol A, the present invention complies with regulatory requirements and provides a compliant solution for the food packaging industry. The new coating is synthesized in alcohol, and the formula ratio can be adjusted as needed to adapt to different application requirements, while maintaining the flexibility, corrosion resistance and chemical resistance of the coating.

[0015] Preferably, in step S2, the metal strip is an aluminum strip or aluminum foil.

[0016] Using aluminum strip or foil as the substrate can provide a more reliable product due to its good processability, strength and corrosion resistance.

[0017] Preferably, in step S3, a suitable stamping die is selected according to the shape and specification of the required container. By selecting a suitable stamping die, containers of various shapes and specifications can be produced according to market and production requirements, thereby increasing product diversity. Multiple stamping and stretching can ensure that the shape of the container is accurate and meets the strict requirements of food and beverage packaging.

[0018] Preferably, in step S3, after stamping, the quality of each container is checked to ensure that the container meets the requirements for food and beverage packaging.

[0019] Quality inspection ensures that each container meets safety and hygiene standards for food and beverage packaging, reducing the risk of defective products and recalls.

[0020] Direct stamping after coating: by coating on metal sheets and directly using molds for stamping, traditional welding and other processes are eliminated, the production process is simplified, and production efficiency is improved. Since no welding is required, it not only reduces production costs, but also reduces material waste, improves the overall production economy. The entire production process is more environmentally friendly and reduces environmental pollution, which is in line with the current concept of sustainable development. The coating has good scratch resistance and flexibility, making the manufactured food and beverage containers more reliable during transportation and storage, meeting strict quality requirements.

[0021] Compared with the prior art, the technical effects and advantages of the present invention are: The method for making a metal food and beverage container uses environmentally friendly alcohol as a solvent to replace traditional benzene ester solvents to synthesize a food and beverage container inner wall coating that does not contain bisphenol A. During the construction process of the food and beverage container inner wall coating that does not contain bisphenol A, the alcohol can be recycled, reducing emissions and not causing pollution to the environment. Unlike traditional coatings, the new food and beverage container inner wall coating does not contain bisphenol A, thereby avoiding the impact of bisphenol A on health.

[0022] The coating for the inner wall of food and beverage containers that does not contain bisphenol A has good flexibility, corrosion resistance and chemical resistance, and has good adhesion to the metal surface. The metal sheet coated with this coating can be directly punched and stretched into a container through a die without welding, which not only simplifies the production process and reduces production costs, but also realizes a green and environmentally friendly production process.

[0023] The production and use of traditional coatings have a great impact on the environment, while the new coating uses environmentally friendly alcohol as a solvent, which meets the current demand for green and environmentally friendly materials. The new coating of the present invention does not contain bisphenol A, which can reduce the risk of public exposure to harmful chemicals and improve the safety of food and beverage packaging. Developed countries such as the European Union have proposed to ban the use of packaging materials containing bisphenol A from 2024, which has prompted related industries to seek alternative materials and processes. The new coating and production method can reduce production costs, improve production efficiency, and bring economic benefits to food and beverage container manufacturers. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic structural diagram of a container cup coated with a coating on the inner wall of a food and beverage container that does not contain bisphenol A according to the present invention; Figure 2 It is a schematic structural diagram of the colored container cup of the present invention. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] The following is combined with Figure 1-2 To further explain this application in detail, Example

[0027] Prepare component A materials: weigh 50 parts of butyl acrylate, 40 parts of methyl methacrylate or styrene, 10 parts of hydroxyethyl acrylate, 40 parts of n-butanol and 1 part of benzoyl peroxide according to mass.

[0028] Add the material of component A into the mixer, start the mixer and stir evenly to obtain the mixed material of component A. Add 10% of the mixed material of component A into the reactor, start stirring and heat to 85°C while stirring, and keep warm for 30 minutes. Gradually add the remaining 90% of the mixed material of component A into the reactor in multiple batches, control the reaction temperature between 83-87°C, and continue stirring and heating. After all the mixed materials of component A are added, heat to 90°C and keep warm for 30 minutes to obtain a transparent and viscous resin glue. Mix the resin glue with the methanol-etherified melamine resin of component B in a mass ratio of 10:3, dilute with alcohol as a solvent, and adjust to the working viscosity for coating; Use a special coating device to coat on a 0.22 mm thick aluminum plate, and after drying at 180 degrees Celsius for 5 minutes, obtain an aluminum plate material that can be used to punch containers; The coated aluminum plate is punched and stretched several times on a punch press specially used for resetting containers to obtain a container cup that can be used to hold beverages, such as Figure 1 shown.

[0029] Example 1 reduces potential health risks by using a formula that does not contain bisphenol A, and provides consumers with safer food contact materials. The process flow in Example 1 optimizes the preparation of the resin glue solution, and improves the reaction efficiency and product quality by adding in batches and heating at controlled temperature. It can be dried by baking at 180 degrees Celsius for 5 minutes, which reduces energy consumption and time compared to traditional processes. Using 0.22 mm thick aluminum plate as the substrate can not only ensure the strength of the material but also reduce the cost. The obtained aluminum plate material can be used to produce various food and beverage containers to meet market demand. Example

[0030] Prepare component A materials: weigh 50 parts of butyl acrylate, 40 parts of methyl methacrylate or styrene, 10 parts of hydroxyethyl acrylate, 40 parts of n-butanol and 1 part of benzoyl peroxide according to mass.

[0031] Add the material of component A into the mixer, start the mixer and stir evenly to obtain the mixed material of component A. Add 10% of the mixed material of component A into the reactor, start stirring and heat to 85°C while stirring, and keep warm for 30 minutes. Gradually add the remaining 90% of the mixed material of component A into the reactor in multiple batches, control the reaction temperature between 83-87°C, and continue stirring and heating. After all the mixed materials of component A are added, heat to 90°C and keep warm for 30 minutes to obtain a transparent and viscous resin glue. Mix the resin glue with the methanol-etherified melamine resin of component B in a mass ratio of 10:3, dilute with alcohol as a solvent, and adjust to the working viscosity for coating; Divide the prepared paint into two parts, add colored pigment to one part and mix well; Using a special coating device, a non-pigmented transparent coating is applied on one side of a 0.22 mm thick aluminum plate, and a pigmented coating is applied on the other side. After drying at 180 degrees Celsius for 5 minutes, an aluminum plate material that can be used to punch containers is obtained; The coated aluminum plate is placed with the color facing outwards on a punch press specially used for resetting containers. After multiple punching and pulling, a colored container cup that can be used to hold beverages is obtained, such as Figure 2 shown.

[0032] Example 2 provides a colorful appearance for the container by adding pigments, increases the diversity of the product, and meets the aesthetic needs of different consumers. The colored container cup is more attractive in the market and helps to enhance the brand image. Like Example 1, Example 2 also uses environmentally friendly alcohol as a solvent to reduce the impact on the environment. By coating different coatings on both sides of the aluminum plate, the overall structure and strength of the container can be improved to ensure the reliability of the container during use. The coated aluminum plate is stamped and stretched with the colored side facing outward, demonstrating the flexibility and applicability of the coating process.

[0033] Both embodiments demonstrate the advantages of the present invention in terms of food safety, production efficiency and cost control, and also demonstrate its potential in terms of product diversification and market adaptability.

[0034] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for making a metal container for food and beverage, characterized in that: The steps include: S1. Preparation of coating for inner wall of food and beverage container: adding butyl acrylate, methyl methacrylate or styrene, hydroxyethyl acrylate, n-butanol and benzoyl peroxide constituting component A into a mixer, mixing uniformly to obtain a mixed material, adding the mixed material into a reactor in multiple batches, heating and stirring to obtain a transparent resin glue, mixing the resin glue with methanol-etherified melamine resin constituting component B in a mass ratio of 10:3, and diluting with alcohol to obtain a coating for inner wall of food and beverage container without bisphenol A; S2, coating: coating the food and beverage container inner wall coating not containing bisphenol A prepared in step S1 on the metal strip using a coating device, and baking the coated metal strip at 180 degrees Celsius for 5 minutes; S3, stamping and forming: the metal strip coated and dried in step S2 is sent to a stamping production line, and is subjected to multiple stamping and stretching by a stamping die to produce food and beverage containers.

2. The method for manufacturing a metal container for food and beverage according to claim 1, characterized in that: In step S1, the weight parts of each component of component A are: 30-70 parts of butyl acrylate, 20-60 parts of methyl methacrylate or styrene, 8-12 parts of hydroxyethyl acrylate, 37-43 parts of n-butanol, and 0.8-1.2 parts of benzoyl peroxide.

3. The method for manufacturing a metal container for food and beverage according to claim 2, characterized in that: The weight parts of the components of component A are: 50 parts of butyl acrylate, 40 parts of methyl methacrylate or styrene, 10 parts of hydroxyethyl acrylate, 40 parts of n-butanol, and 1 part of benzoyl peroxide.

4. The method for manufacturing a metal container for food and beverage according to claim 1, characterized in that: In step S1, 10% of the component A mixture of the total material is first added to the reactor, heated to 85°C under stirring, and kept warm for 30 minutes, and then the remaining 90% of the component A mixture is added to the reactor in multiple batches, and the reaction temperature is controlled between 83-87°C for stirring and heating. After the addition of the component A mixture, the temperature is raised to 90°C and kept warm for 30 minutes to obtain a transparent and viscous resin glue.

5. The method for manufacturing a metal container for food and beverage according to claim 1, characterized in that: In step S1, during the mixing process of the resin glue and the methanol-etherified melamine resin, environmentally friendly alcohol is used as a solvent for dilution, and the mixture is diluted to a working viscosity for coating.

6. The method for manufacturing a metal container for food and beverage according to claim 1, characterized in that: In step S2, the metal strip is an aluminum strip or an aluminum foil.

7. The method for manufacturing a metal container for food and beverage according to claim 1, characterized in that: In step S3, a suitable stamping die is selected according to the shape and specification of the required container.

8. The method for manufacturing a metal container for food and beverage according to claim 1, characterized in that: In step S3, after stamping, the quality of each container is checked to ensure that the container meets the requirements for food and beverage packaging.

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