The sealing structure design of metal packaging mooncake jar is related to the shelf life and quality of mooncakes. Its core is to block the invasion of air, water vapor and microorganisms, and prevent the aroma of mooncakes from dissipating. To achieve this goal, it is necessary to comprehensively consider multiple dimensions such as the selection of sealing materials, the design of the tank structure, the optimization of the opening and closing method, the surface treatment process, the auxiliary sealing measures, the production quality control and the user experience design.
The selection of sealing materials is the basic guarantee to prevent the deterioration of mooncakes. High-quality sealing materials must have good elasticity, weather resistance and chemical stability. Common rubber sealing rings are commonly used sealing components for metal packaging mooncake jars. Their elastic properties can fit tightly to the edge when the tank is closed, fill in small gaps, and prevent air and water vapor from penetrating. Some high-end mooncake jars will use food-grade silicone materials. This material not only meets food safety standards, but also has stronger high temperature resistance and aging resistance. Even at different ambient temperatures, it can maintain a stable sealing effect, effectively avoiding sealing failure due to aging and hardening of the material, which in turn affects the quality of mooncakes.
The tank structure design plays a decisive role in the sealing effect. A reasonable can structure must ensure that the lid fits tightly with the can body to reduce the gap. Usually, the metal packaging mooncake jar will be designed with a concave-convex slot structure on the edge of the can mouth, and a matching buckle or fitting slot is set at the corresponding position of the lid. When the lid is closed, the buckle is embedded in the slot to form multiple physical barriers and enhance the sealing performance. At the same time, the shape and size accuracy of the can body will also affect the sealing effect. Regular round and square can bodies are easier to achieve accurate sealing, while complex and special-shaped can bodies need to fully consider the processing accuracy and assembly difficulty during design, and ensure the flatness and sealing of the edge by optimizing the mold design and production process.
The optimization of the opening and closing method is not only related to the convenience of use, but also closely related to the sealing performance. The traditional screw-on mooncake jar is sealed by threads. When designing the threads, it is necessary to ensure that the pitch is uniform, the tooth shape is complete, and the number of threads is sufficient to increase the path length for air and water vapor penetration and improve the sealing effect. The buckle-type opening and closing design requires accurate calculation of the elasticity and bite strength of the buckle. Too looseness can easily lead to poor sealing, and too tightness will increase the difficulty of opening. Some innovative mooncake jars use magnetic suction or push-and-pop opening and closing, which can quickly seal and open through built-in magnets or spring structures, and generate uniform and stable pressure when closing, ensuring that the sealing ring fits tightly and effectively preventing external pollution from invading.
The surface treatment process has an important impact on the durability and sealing of the sealing structure. The surface of the metal can body is polished, electroplated or sprayed, which can not only improve the aesthetics, but also enhance the anti-rust and anti-corrosion capabilities. For the parts in contact with the sealing ring, fine grinding is required to ensure that the surface is smooth and flat to avoid scratching the sealing ring due to the rough surface and destroying the sealing effect. In addition, a special coating treatment is performed in the sealing ring installation groove to increase friction, prevent the sealing ring from shifting or falling off during use, and further ensure the reliability of the sealing structure.
Auxiliary sealing measures can further enhance the anti-deterioration ability of metal packaging mooncake jar. Adding moisture-proof paper or deoxidizer bag to the inner wall of the can can actively absorb residual water vapor and oxygen, reduce the humidity and oxygen content in the can, and inhibit the growth of microorganisms and the oxidation of mooncakes. Some mooncake jars also have independent compartments or inner covers on the inside of the lid to form a double sealed space. Even if there is a small gap in the outer seal, the inner seal can still play a protective role. In addition, laser welding or seamless pressing technology is used at the joints of the jar body to eliminate welding pores and gaps, and prevent air and water vapor from penetrating from the structural defects of the jar body.
Production quality control is a key link to ensure the effectiveness of the sealing structure. During the production process, the mold accuracy and processing technology are strictly controlled, and the size and appearance of each jar body and lid are inspected to ensure that there are no burrs, deformations or gaps on the edges. In the assembly of the sealing ring, automated equipment is used for precise positioning and installation to avoid assembly errors caused by manual operation. Before the finished product leaves the factory, a sealing performance test is carried out. By means of vacuuming or pressure testing, different environmental conditions are simulated to test the sealing effect of the mooncake jar, and unqualified products are repaired or scrapped to ensure that the products entering the market have reliable sealing performance.
User experience design should also not be ignored. Reasonable design of the opening prompt and sealing status mark of the jar body can help consumers judge whether the mooncake jar is in a good sealing state. For example, a sealing indicator window is set on the lid to show whether the seal has failed through color changes; or an opening limit device is designed to issue a prompt when the lid is not completely closed to avoid sealing failure due to improper use. At the same time, clear instructions for use and storage are provided to guide consumers to correctly open and close the mooncake jar and store it properly when idle, extending the service life of the sealing structure and comprehensively protecting the mooncakes from deterioration due to external factors during storage.
