Comparisons and advantages of U.V. coating as compared to waterborne and solvent based coatings

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UV coating cures and is chemically crosslinked. This provides for a coating film which has much higher chemical resistance than the waterborne. For example: you can actually wipe our cured coating many times with either Acetone or MEK (both very strong solvents) and the result will be that you will clean the coating but see absolutely no change in the gloss or corrosion resistance of the coating. If you try this with waterborne or solvent based coatings you will remove or severely degredate the film to the point where you have no corrosion resistance at all.

UV coating is 100% solids. This allows for more exacting film thickness application and control. Everything which is applied to the tube stays on the tube at whatever film thickness you desire. The waterborne and sovent based coatings can be low solids which means in order to apply a desire film thickness, you must apply many times your desired film thickness and then force the volatiles out of the coating to come back down to an approximate film thickness.

The U.V. coating does not include any volatiles, therefore it does not change its composition over time or with use. This consistency will improve the quality of your final product. Since it does not change its composition, you do not have to constantly monitor the viscosity to ensure application will be consistent.

The application of the U.V. will be far easier, require far less time and labor monitoring its liquid state and will significantly reduce application problems due to evaporation of the viscosity control chemicals used in the waterborne or solvent based coating. The U.V. will not dry in the system, therefore you do not have to be concerned with applying a clear coating to a tube which may not have a consistent film thickness 360 degrees around the tube during production.

The U.V. can be quality control checked immediately after it passes through the U.V. lights. This means you can check the tube coating for quality control immediately after production. The waterborne requires about 24 hours to produce its properties after the production process. The waterborne and solvent based coatings are also affected by the humidity in the air during production. The higher the humidity the longer the waterborne and solvent based coatings can take to develop their final properties.

The U.V. is immediately cured in line. The U.V. will be cured by the time it reaches the support roller after the curing lights. The U.V. will be hard and mar resistant to allow for no removal of the coating from the tube and have the properties necessary at high line speeds to resist natural impact support rollers will have. The waterborne and solvent based coatings do not have the immediate resistance to the support rollers. The waterborne may be dry to the touch after exiting the induction heater, however it will not have developed the physical properties to resist the natural physical damage the support rollers have immediately after exiting the induction heaters in line. This will result in much higher risk of scratching to the film and thus a loss of corrosion resistance. The induction heaters also use much, much more energy thus increase your utility costs which in turn must be included in the cost of the coating application process.

The U.V. can be left in the coating application system during down time or change over time to different size rollers and tubes. The U.V. can be left in the coating application system overnight, over the weekend, for a week, for a month, etc… without affecting the coating application system or start up of production when desired. Since the U.V. does not dry or change its liquid properties over time, you maximize your employee’s time doing what you do best, your business of producing and selling high quality galvanized tubing.

Minimization of risk. All the above factors are reasons why you should use U.V. coating system. If your goal is to install the most trouble free, highest quality coating system to reduce your chance of claims, U.V. coating system is the way to go.

What is UV Curing

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Ultraviolet (UV) curing is a photochemical process in which high intensity UV is used to instantly cure inks, coatings or adhesives in a wide range of industries. In the process, the first step is the absorption of UV light of specific wavelengths by the photoinitiators in the coating, this generates highly reactive free radicals which go on to start the crosslinking process of the resins and monomers. Thus creating a highly cross-linked network within the coating and converting the liquid film to a dry, solid film in-situ on the surface of the substrate. Offering many advantages over traditional drying methods, UV curing has been shown to increase production speed, reduce reject rates, improve scratch and solvent resistance, and facilitate superior bonding.

UV curing is a multi-billion dollar worldwide industry and has grown more than 10% per year, displacing conventional water and solvent-based thermal drying processes due to its increased productivity, improvement of product quality and performance, and environmentally friendly characteristics. In UV curing, there is no solvent to evaporate, no environmental pollutants, no loss of coating thickness, and no loss of volume. This results in higher productivity in less time, with a reduction in waste, energy use and pollutant emissions.

UV curing is already widely used in coating many plastic components; delivering benefits of reduced floor space, lower energy consumption, improved coating quality and lower reject rates. The challenge is to deliver coated products that can meet ever higher performance specifications including exterior automotive applications and more complicated 3-dimensional parts.