2、 Application and performance advantages of cabinet material Outer 304 stainless steel plate: Select 304 (06Cr19Ni10) austenitic stainless steel, containing 18% -20% chromium and 8% -10.5% nickel, with excellent corrosion resistance and oxidation resistance. After 2B cold rolling treatment on the surface, the drawing process is carried out to improve aesthetics and reduce fingerprint residue. Intermediate polyurethane foam layer: Adopting full water foaming technology, using water as the foaming agent, to avoid the damage of traditional fluorocarbons to the ozone layer. Inner food grade 304 stainless steel liner: The surface of the inner liner is treated with electrolytic polishing, with a roughness Ra ≤ 0.4 μ m, reducing bacterial adhesion. Combined with ultraviolet disinfection lamps and activated carbon filter plates, the inhibition rate of Staphylococcus aureus and Escherichia coli reaches 99.6%. 3、 Selection and Integration of Refrigeration Systems The refrigeration unit adopts a fully enclosed scroll compressor, paired with R410A environmentally friendly refrigerant, with a cooling capacity covering the range of 1.2kW to 6kW. The refrigeration pipeline adopts seamless copper pipe welding technology, and the weld seam is inspected by X-ray to ensure no leakage. The microcomputer temperature control system integrates PID intelligent algorithm, which can achieve ± 0.5 ℃ temperature fluctuation control, and is equipped with power-off memory function. It automatically restores the set parameters after unexpected power failure. 4、 Manufacturing process and quality control The production of the warehouse board adopts a fully automatic high-pressure foaming machine, and the polyurethane raw materials are mixed in a 1:1.05 ratio of A/B. They are cured and formed in a mold at 55 ℃ for 30 minutes. After laser cutting (accuracy ± 0.1mm) and CNC bending (angle deviation ≤ 0.5 °), the stainless steel plate is combined with the foam storage plate through a dual process of structural adhesive bonding and rivet fixation. The load-bearing test shows that a single storage plate can withstand a static load of 500kg. The refrigeration system assembly is completed in a Class 10000 clean workshop, and the connection between the compressor and condenser is made using silver based brazing (melting point 645 ℃), with the welds inspected by X-ray inspection. The entire machine needs to undergo a 48 hour continuous operation test before leaving the factory, including 12 testing items such as -30 ℃ extreme temperature test, 3000 door opening and closing durability test, electromagnetic compatibility test, etc.