It is well-known that since the birth of the electrostatic powder coating process in the 1960s, almost 100% has been applied to metal surface coating. Although many powder manufacturers and equipment suppliers have long claimed that “electrostatic powder coating can be applied to non-metal surfacesâ€, none of them can form industrialized products. In the late 1990s, with the development of powder coatings and spraying equipment, it has become possible to apply the electrostatic powder coating process to non-metal surfaces. For the coating of non-metallic materials, in the past two years, Yudong Gao Tingshi and British Elodea have devoted themselves to the electrostatic powder coating of medium density fiberboard (MDF), and have entered the industrial production to become a reality. This article mainly introduces the latest situation in spraying MDF to promote the development of electrostatic powder coating technology in China.
1. The related factors of electrostatic powder coating Electrostatic powder spraying is the process of applying a powder coating on a coated object by electrostatic action and baking the coating for a certain period of time. The factors involved in this process include coated objects, powder coatings, spray guns, and baking equipment. Analyzing these factors helps to understand the entire process.
2. Confirmation of the object to be coated From an economic point of view, the tone of the object to be coated is determined as a commodity. In addition to metals, wood and plastic should be selected. Plastics, due to temperature problems at the current stage, cannot be considered for the time being. For wood, MDF (medium density fiberboard) becomes the first choice. The reasons are as follows: Electrostatic powder spraying requires the material to be conductive, and wood is a hygroscopic material that exchanges moisture with the surrounding environment. After a certain period of time, it absorbs moisture in a specific environment at a certain temperature. Achieve balance. Therefore, under normal circumstances, the moisture content of Kimura's finished products will maintain a proper balance with the local climate. It can be considered that by adjusting the moisture content of the substrate of the wood product, the wood can be made to approach or correspond to the state of the conductor. MDF is a wood product that also has the above characteristics. In addition, as an environmentally friendly green building material, MDF has a huge amount of application, and its growth in wood-based wood-based panels is also very fast. Moreover, MDF is a large-scale industrialized product. The quality of its products and the tunability of the product process are also important factors. It is these factors that contribute to our belief that MDF is the preferred choice for powder coating.
3. Technological advances in powder coatings Thermosetting powder coatings have long been affected by the curing temperature (conventional curing temperature of 180 °C, 20min), limiting the range of process applications. In recent years, more and more low temperature curing powder coatings have been available. According to relevant reports, 120°C x 20min solidified powders can be prepared. Of course, low temperature solidification powders still have problems such as poor storage stability, which restricts the application range to some extent. I believe there will be improvement in the near future. In the MDF plate coating, the powders used are ultraviolet curable and ultra-low temperature curable. It has been reported that DSM has published information on maleic acid/vinyl ether-based UV-curable powder coatings, which are applied to MDF. The current use of EMD for MDF (medium density fiberboard) is epoxy/polyester hybrid powder whose curing temperature is controlled within the maximum curing temperature range (150°C) for general paints.
4. New Breakthroughs in Electrostatic Powder Spraying Equipment Corona charging torches have undergone several stages of voltage charging, current charging, and total energy controlled charging (T.E.C.). The first two charging methods limit the painted parts to metal parts, while the TOTAL ENERGY CONTROL technology overcomes these limitations. The technology mainly lies in that when the distance between the spray gun and the workpiece (electrical contact point) changes, the current and the voltage can be automatically adjusted to maintain the total charging energy, and the charge amount of the powder can be effectively controlled to ensure the efficiency of powder application. The specific spray distance and current and voltage changes are shown in Figure 1.
5. Baking equipment For ultra-low temperature curable powders, they are cured by the use of special drying tunnels (IR Curing tunnels mentioned in the Corings report) and eliminate the volatile components of MDF produced in continuous high-temperature conditions. That is, the volatile matter is consumed inside the drying tunnel, and at the same time, the curing temperature is stabilized at the process temperature. This is different from ultraviolet (UV) curing, which uses an infrared lamp to melt and level the powder (below 100°C) and then cure it with a UV lamp for several seconds.
Based on the above points, MDF's industrial production of electrostatic powder coating (ultra-low temperature curing) began in the late 1990s. In August 1999, the UK's first fully automated MDF plate production line was successfully put into production. It can be foreseen that in the next two or three years, the MDF dusting process will have a rapid development. Of course, the MDF dusting process needs to be improved in the future: low temperature curing of paints (including further development and utilization of UV curing powders); diversification of paint types; spray guns through selection of TEC charging technology and modification of existing curing Equipment, so that the production line can spray metal products and spray MDF and so on. At the same time, we can also foresee that there will be other non-metallic products into the field of electrostatic powder coating.
Rhein Lighting has developed a line of 4 inchLed Slim Panel Light 5cct. This panel Led Downlight is IC rated, which is permitted to be in contact with insulations in ceilings.
The led down light use the new generation of LED chips with higher lumen ouput and lower power, saving you up to 88% in energy costs.
The ultra-thin smart downlights is only 0.47 inches and requires as small as 2 inches ceiling spaces, fits various ceilings, and around joists. 5%-100% smooth dimming meets kinds of needs in applications such as kitchen, living room, bedroom, bathroom and common areas in your home or office.
Rhein Lighting is a professional manuafacturer of slim LED downlight, LED panel down light, Led Panel Light, Led Strip Light, LED rope light, LED plant light and Led Grow Light etc.
Led Slim Panel Light 5cct,Eyeball Gimbal Light,LED Recessed Gimbal,Eyeball Gimbal LED Recessed Light
Rhein Lighting Technology Co.,Ltd. , https://www.rheinlighting.com