Refrigerator shell material——
Most of the high-quality cold-rolled steel plates of 0.5~0.8mm are used. After being processed by the box forming production line, the surface is heat treated, and then a decorative protective layer is formed on the surface through the spraying process. The spraying process currently adopts electrostatic spraying or plastic spraying.
spray paint -
Acrylic resin paint is generally used, which is not easy to rust, not easy to change color, has low painting cost, and is convenient for color preparation, but has poor corrosion resistance and is easy to fall off when scratched; epoxy resin or acrylic resin powder is generally used for spraying; Good performance, strong adhesion, not easy to touch and scrape, but high cost and inconvenient to change the color.
Refrigerator Liner Material
The inner tank of the refrigerator is the inner wall of the refrigerator box. It requires good adaptability to temperature. Not only does it not deform in a high temperature environment, but it also needs to keep the inner wall of the box flat under low temperature conditions. The refrigerator liner is mainly made of polyurethane (PU), ABS, HIPS and other materials.
PU——
Polyurethane plastics have low thermal conductivity and good processability, making them ideal production materials. The refrigerator insulation layer uses polyols, isocyanates and cyclopentane as the main raw materials, which are foamed and formed at high temperature, and a good insulation effect is obtained through strict proportioning. Generally speaking, the density of the most ideal insulation layer foam is 33~35Kg/cm3, which can ensure the best guiding coefficient and good insulation effect.
ABS——
ABS is a thermoplastic polymer material with high strength, good toughness and easy processing. From the morphological point of view, ABS resin is a yellowish solid with a certain toughness and a density of about 1.04~1.06 g/cm3. It has strong corrosion resistance to acids, alkalis and salts, and can also be dissolved in organic solvents to a certain extent. ABS resin can perform normally in the environment of -25 ℃ ~ 60 ℃, and has good formability, the surface of the processed product is smooth, easy to dye and electroplating.
The inner tank made of ABS has smooth surface, beautiful color, good physical properties, oil resistance, corrosion resistance and long service life, but the price is relatively expensive, and it needs pretreatment (such as heating and drying, etc.) because ABS is easy to absorb moisture before extrusion. ), the pretreatment of heating and drying must be carried out again when the board is formed into the inner tank and the lining, so there are many auxiliary processing equipment and high production cost.
HIPS material——
HIPS engineering plastic, the cost of this material is lower, but the overall performance of the inner liner produced is lower than that of ABS material. However, the stress cracking effect of Freon 11 needs to be overcome or reduced. Refrigerators produced in some European countries often use printed aluminum plates instead of HIPS engineering plastics in the freezer, and only use HIPS engineering plastics on the liner of the refrigerator.
refrigerator insulation
At present, the insulation material of 304 stainless steel beer keg domestic refrigerators is mainly rigid polyurethane foam, but because of its fluoride content, it will destroy the ozone layer, and there is a risk of being restricted in use. In fact, in recent years, developed countries such as Europe and the United States have begun to gradually replace polyurethane with new environmentally friendly products. Among them, VIP board is currently the most cost-effective insulation material for refrigerators.
①Polyurethane foam: The thermal conductivity is usually 0.018-0.022W/mK, which is the main domestic refrigerator insulation material. Zero ODP and biodegradable polyurethane foam are the two main research directions at present.
② Aerogel: The thermal conductivity is only 1/12 of that of PU, which can well block heat transfer and achieve the effect of energy saving and capacity expansion, but it is expensive.
③Vacuum Insulation Board (VIP board): The thermal conductivity is below 0.005W/mK, using polystyrene (PS), polyurethane foam, glass fiber, etc. as the core material, built-in gas adsorbent and desiccant, under vacuum The surface is sealed into a plate with gas insulating material; it can further release 20-30% of the effective volume.