Preventing liquid leakage and food residue in the cylinder seal structure of a commercial slushy machine requires a two-pronged approach: material adaptation and structural design of the core sealing components. The industry prefers food-grade silicone rubber or fluororubber as the primary sealing ring material. These materials not only meet food contact safety standards but also exhibit excellent elastic recovery and weather resistance. They maintain stable performance in low-temperature environments (such as contact with ice cubes) and high-frequency stirring friction. They also elastically deform to tightly adhere to the sealing surface, filling the slightest gap between the cylinder and adjacent components, effectively blocking liquid penetration. Furthermore, the sealing ring often utilizes a "U-shaped" or "Y-shaped" cross-section design, rather than a traditional circular structure. This design creates multiple sealing contact lines after installation. Even if one area experiences minor wear due to long-term use, the remaining contact lines maintain a seal. The special-shaped structure also reduces the chance of food becoming lodged in the sealing gap, minimizing the risk of food residue.
The connection between the cylinder and base of a commercial slushy machine is a critical point for leak prevention, requiring precise structural design to enhance sealing reliability. This area is typically designed with a pre-set annular sealing groove, allowing the sealing ring to fit precisely within the groove, ensuring that it does not fail due to misalignment during installation. Some models also feature raised ribs at the bottom of the sealing groove. When the cylinder and base are secured via threads or clips, the ribs apply even and appropriate pressure to the sealing ring, forcing it to fit more tightly against the contact surface between the cylinder and base, thus preventing localized gaps caused by uneven pressure. Furthermore, the contact surface between the cylinder and base is meticulously polished to ensure surface flatness and minimize microscopic gaps caused by uneven contact surfaces. These gaps can not only serve as channels for liquid leakage but also easily accumulate food residue, posing a potential health hazard over long-term use.
The dynamic seal between the agitator shaft and the cylinder is a challenging task, balancing the dual requirements of preventing leakage and residue. During operation, the agitator shaft rotates at high speeds, and the seal must prevent liquid from leaking through the gap between the shaft and the cylinder while also preventing food from entangled on the shaft and forming residue. The current mainstream solution utilizes a dual lip seal + dust shield ring combination. Two lip seals are arranged in opposite directions, one primarily preventing leakage of liquid from the mixing cylinder, while the other prevents external impurities from entering the sealed area. The tiny cavity between the two seals also buffers pressure fluctuations during mixing, reducing seal wear. The dust shield ring is mounted on the outside of the seal ring, with an angled edge designed as a scraping mechanism. As the mixing shaft rotates, the shield ring actively scrapes away food debris adhering to the shaft surface, preventing it from entering the sealed gap. This reduces residue accumulation and protects the seal ring from scratches.
Optimizing the cylinder's internal structure plays a significant role in reducing food residue. The inner wall of a 1-tank commercial slushy machine features a seamless, rounded transition design. All corners and seams are polished to smooth, rounded surfaces, eliminating any right angles or grooves that can trap food. For example, the rounded corners at the bottom of the tank and the mixing shaft ensure that food is fully moved during mixing, preventing it from getting stuck in the gaps at the bottom. The edge of the tank opening features an outward-flashed step, which not only facilitates contact with the sealing ring for an effective seal but also prevents liquid from escaping and remaining on the edge. Furthermore, the inner wall of the tank is polished to a high finish to reduce food adhesion. Cleaning requires only a simple rinse to remove any residue, minimizing the risk of cross-contamination during subsequent use.
The easy-to-remove and easy-to-clean seal structure is crucial for maintaining long-term leak and residue prevention. Commercial slushy machines require frequent cleaning. If the sealing components are difficult to remove, not only will they be incompletely cleaned, but they may also be damaged during disassembly. Therefore, most models feature cylinder seals that are snap-on or snap-on, allowing for manual removal without tools. For cleaning, the seals can be completely removed and the gaps between the inner and outer surfaces flushed. The seal assembly on the agitator shaft is also modular, allowing for complete removal by unscrewing the retaining nut, making it easy to thoroughly clean or replace the seals and retaining rings. This design ensures thorough cleaning while extending the life of the seal components and preventing residue buildup and seal failure caused by untimely cleaning.
The pressure-adaptive design of the seal structure can withstand the dynamic pressure fluctuations experienced during operation in a 1-tank commercial slushy machine. When blending hard ice or high-viscosity ingredients (such as milkshakes and purees), transient pressure fluctuations can occur within the cylinder. If the seal is too rigid, gaps may form due to the pressure surge; if it is too elastic, it can easily be squeezed and deformed by the ingredients, leading to seal failure. Therefore, the seals feature a gradient elasticity design: the outer layer, near the contact surface, has higher elasticity to ensure a tight fit, while the inner layer incorporates a small amount of reinforcing material to enhance structural strength and resist pressure surges. Furthermore, a small buffer space is reserved in the sealing groove at the base of the tank. When the pressure inside the tank increases, the seal can deform slightly and enter the buffer space, preventing damage from excessive compression while maintaining the seal and preventing liquid leakage under pressure.
Rigorous pre-shipment sealing performance testing is a key step in ensuring that every device meets factory standards. After production, each 1-tank commercial slushy machine undergoes a static leak test: liquid (simulating food ingredients) is injected into the tank and allowed to sit for a period of time to observe for leaks at the bottom and joints. A dynamic leak test then takes place, simulating the smoothie machine's operation and checking the seal at the connection between the mixing shaft and the tank. A residue simulation test is also conducted: sticky food is stirred, the seal is disassembled, and the seal is inspected for any food residue to ensure that the seal gap design does not allow for food residue to accumulate. Only devices that pass all tests are released to the market, ensuring safe use in commercial scenarios.
