PPGI sheet has the characteristics of light weight, beautiful appearance and good corrosion resistance, and is widely used in construction, light industry, home appliances and other industries.
In recent years, with the development of these industries and the improvement of consumption levels, their market demand has grown rapidly, attracting a large number of domestic and foreign companies to build or are building color-coated sheet production lines.
PPGI main products and applications
PPGI products mainly include polyester, silicon-modified polyester, epoxy resin, fluorocarbon resin, acrylic resin, plastic melt, household appliance polyester, surface film, embossing and other products. The finished product specifications are generally: thickness 0.3 ~ 1.6mm, width 750 ~ 1350mm, coating thickness 2.5 ~ 200μm, finished roll weight 3 ~ 10t.
In the production of color-coated sheets, the construction industry is the largest demand area for color-coated sheets. All kinds of buildings, including warehouses, supermarkets, stations, airports, stadiums, commercial buildings, residential buildings, etc., require color-coated steel plates, which are mainly used for the production of corrugated panels, sandwich panels, doors and windows, etc.
The thickness specifications of color plates required for residences and doors and windows are 0.7mm and 0.8mm; the thickness specifications of color plates required for mobile houses and workshops are 0.4mm, 0.5mm, 0.6mm, etc.
The color-coated boards used in the home appliance industry are mainly color-coated boards (PVC), which are mainly used for refrigerators, freezers, washing machines, disinfection cabinets, microwave ovens, DVD players, and high-end decoration.
The main production process of PPGI
During production, the raw material coil is hoisted to the receiving table of the color coating unit with a crane, and then the steel coil is transported to the coil seat in front of the color coating unit with a transport trolley, and the belt here is removed, and then the trolley is loaded to transport the raw steel. The coil is loaded onto the uncoiler, and the strip head is automatically guided to the cutting head by the tape guide. The strip is sewn with the previous loop on the sewing machine.
The stitched steel belt first enters the pre-cleaning section for alkaline water washing, alkaline water scrubbing, hot water washing, and then is dried with hot air and then enters the looper. After the looper, it enters the pretreatment section, where alkaline water treatment is performed.
Rinsing, alkaline water scrubbing, two-stage hot water rinsing, reconditioning treatment and two-stage hot water rinsing, and then hot air drying, enter the chemical coating machine, apply a layer of water-based chromium on the surface of the strip, and then pass through the chemical coating machine, enter Hot air dryer for drying.
The water-cooled roller set behind the hot air dryer cools the strip to below 40°C, enters the roller coater for one coating, and then enters the hanging curing oven for drying. Pendant curing ovens are equipped with sag detection. External curing
The temperature of the strip steel in the furnace is 260 °C, it enters the water quenching tank, air-drying, and then enters the fine coating machine through the turning roller for fine coating, and then enters the fine coating curing furnace to dry the paint.
For example, in the production of hot film panels, the strip steel from the curing furnace needs to be quenched. After the temperature is lowered to a certain temperature, it enters the hot film machine, and the strip steel from the film machine is cooled in the furnace. Water quench tank, then dry.
The strip enters the outlet looper, passes through the inspection table and the outlet shears, cuts the strip into the required small coils, and then transports the finished coils to the outlet coil seat by the unloading trolley. Finished rolls are transported by workshop crane to the packaging unit for packaging, and then sent to the finished product warehouse for storage.
PPGI preprocessing process
The main purpose of the pretreatment process is to remove the grease and impurities on the surface of the strip steel, and through passivation, a chemical conversion film is formed on the surface of the steel plate to improve the adhesion and peelability between the coating and the steel strip. Strip steel substrate.
Corrosion resistance of steel. The preprocessing process is:
Degreasing → brushing → hot water washing → surface adjustment → hot water washing → passivation → drying
Surface conditioning is a surface treatment process added prior to phosphate or chromate treatment in the manufacture of certain products.
The purpose of spraying the surface of the strip steel with a weak acid agent containing Ni and F ions is to improve the performance of the coating and the adhesion of the coating passivator, and to remove the Al precipitates and grain boundaries on the coating. The surface of the galvanized substrate. Lead and other substances, this process is represented by Japan.
Passivation typically requires the use of phosphates or chromates to treat the substrate. The main methods of passivation are spraying, dipping and coating.
Post time: May-26-2022