The process and advantages of UV curable powder. It is enough to read this article.
the process and advantages of UV curable powder. It is enough to read this article.
april 7, 2021.
uv curable powder coating shortens the processing time of MDF.
original author: Lara Copeland, special author, Key words: UV curing powder coating MDF medium density fiberboard wood is also located in Cleveland, Ohio, and provides consumers with a better use experience. Keyland polymer and dvuv, which occupy adjacent buildings, have found a way of cooperation that is far beyond their spatial proximity. As an innovator in UV curable powder coatings applied to medium density fiberboard (MDF), dvuv focuses on customized powder coating components or parts for retail, store fixtures, pop displays, health care, education and office furniture industries
dvuv's largest application market is custom-made furniture coatings. This manufacturer of medium to high volume products with automated production lines also provides finished components for fixtures/displays, countertops, shelves, wallboards, cabinets and signage. Keyland polymers develops, compounds, manufactures and sells UV curable powder coatings to dvuv and other customers who paint MDF and substrates including plastics, composites, metals and other materials
rebecca lonczak, marketing manager of dvuv/keyland polymers, explained that dvuv does not paint natural wood, but only MDF substrates. Because the wood particle, density and moisture content of the latter are uniform
"MDF is easy to process and has uniform and homogeneous surface. Natural wood can also be coated with powder paint, but the finish may be uneven. Due to the change of resin and moisture content in natural wood, there may be problems of air bleeding and pinholes", Rebecca said
the density, fiber, resin and moisture content of natural wood vary with the type of wood. In addition, there is the influence of growth location. Even if the tree species are the same, each tree is different
since heat is used to melt the powder in the final coating process of powder steel parts, even at a low temperature and with a short exposure time, the heat will cause uncontrollable reactions in natural wood. This makes it particularly difficult to achieve a uniform surface when powder coating natural wood. The UV curable powder coating of MDF can produce a more consistent and visually pleasing surface
keyland polymer can produce UV curable powder coatings by combining resins, pigments, high-performance additives and photoinitiators. Photoinitiators are the key components, which absorb high-intensity ultraviolet rays, produce and activate free radicals to crosslink the coating. Curing is the cross-linking of the whole coating at the molecular level, which is an instantaneous curing stage. "Once the photoinitiator is exposed to ultraviolet light, cross-linking will occur and the coating will cure immediately," lonchak said
additives enhance the coating surface by improving or adjusting specific properties - scratch or scratch resistance, gloss and texture. Pigments produce color and opacity
UV curable powder coating is produced in the same way as thermosetting powder coating, and the type of equipment used is also the same - the process includes mixing, extrusion, cooling, slicing, grinding, grading, screening and packaging
in order to achieve good curing effect, it is necessary to match the type and dosage of photoinitiator with the UV light source, including the appropriate combination of UV energy dose, intensity and wavelength
there are several types of medium pressure mercury vapor UV lamps that can be used for UV curing of powder coatings. Mercury lamp (H lamp) provides short wavelength (nm) ultraviolet energy, which is suitable for varnish and transparent paint applications. The iron doped mercury lamp (d lamp) provides longer wavelength (nm) energy, which is conducive to the curing of the system with low pigment content. Gallium doped mercury lamp (V bulb) has a long wavelength (nm) of strong energy output, which is the main curing equipment of high pigment system. UV curable powder coatings with long wavelength energy can penetrate thick coatings and pigment coloring systems
mdf initial workpiece is UV cured in the powder coating process
dvuv UV UV cured powder coating process is very fast. Lonchak explained that this is a 20 minute one-step process, which can turn the initial MDF workpiece into a finished workpiece, and then it can be packaged and shipped at any time
first, the workpiece is suspended on the production line, and the residual dust particles in the processing process are removed by spraying compressed air. Surface grinding is usually not required before powder coating. Next, the MDF workpiece enters the low-temperature preheating oven for one minute. Lonchak added: This allows the plate to exhaust before painting and brings the moisture in the MDF to the surface, so that the plate can conduct electricity to absorb the powder coating
then, use the automatic spray gun system to electrostatic coat the UV curing powder coating. Melt the powder or gel in a low-temperature oven for one minute. Once melted, the workpiece will solidify immediately under the irradiation of UV lamp. In less than 20 minutes, the automatic transmission version will be launched. The processing of the workpiece has been completely completed, and it can be packaged and delivered to the customer immediately
UV curable powder coatings were developed more than 20 years ago as a substitute for heat curable powder coatings. Thermal curing needs to be completed at high temperature (2. Model: jb-w300cyz about 400 ° f/204 ° C) and takes minutes or more. The processing time is longer, and additional cooling time is required before the next operation processing
as ronchak pointed out, the main advantages of UV curing over thermal curing lie in time and temperature. The electrostatic powder coating processes of UV curable powder coatings and heat curable powder coatings are the same. However, the melting/flowing and curing processes are important different features that distinguish them functionally
the UV curing process is completed instantaneously. Before UV curing, it only needs to be preheated for one minute at a temperature of ° f (° C) to melt/level the powder coating. This makes it have the advantages of significantly shortening the process time and reducing the overall temperature, so that the UV curing powder coating process is very important in MDF processing and manufacturing. "Excessive heating and exposure time can lead to plate cracking and other defects," lonchak said
powder coating brings some challenges, but dvuv has mastered the measures and means to overcome these challenges. The change of humidity and temperature will affect the success of the process, but this problem can be easily solved through the process control operation in the factory with adjustable temperature. The humidifier ensures that the MDF board maintains the correct moisture content before powder coating
dvuv's parameter setting and testing during the first operation also ensure the production of stable and consistent products. The operation of dvuv for each link is customized according to the customer's parameter requirements for the workpiece. Ronchak concluded that the linear speed, spray gun distance and processing temperature are different and modified for each project we run
in addition to checking during operation to ensure quality, the production team also set up trial operation steps. The quality control of finished workpieces includes a series of destructive and non-destructive tests:
comparison of visual inspection of workpiece surface and standard parts
Trafigura thickness gauge test (measuring coating thickness)
MEK solvent resistance test
our production team also has preventive maintenance, traceability analysis and corrective action plans in case of quality or process problems
dvuv powder coating MDF has a bright future. The government and regulatory agencies are restricting or eliminating the use of solvent based liquid coatings
aqueous liquid coatings are difficult to use on MDF, which makes UV curable powder coatings an ideal processing scheme for MDF
UV curable powder coating is solvent-free, non-toxic, and does not contain volatile organic compounds (VOC) or harmful air pollutants. No special permission is required for production operations
dvuv is witnessing an increase in demand from furniture and MDF component manufacturers who are looking for a reliable supplier of high-quality, environmentally friendly and cost-effective finished MDF components