Ryonet | #PoweringThePrint
More and more exposure units now come with LED bulbs. Why? Tons of reasons like their spectrum of light output, energy usage, and speed and consistency. Let's learn why screen printers should invest in LED exposure units.
One benefit of choosing LED exposure is the ability to optimize the spectrum of light output. Exposure time and correct curing of emulsion are both heavily dependent on using light of the correct wavelengths. This light must be able to both penetrate the coating, as well as promote cross-linking.
The ability of light to penetrate and crosslink the emulsion is directly related to its wavelength, and also how the light is able to react with the diazo, or photopolymer, that is used to ‘sensitize’ the emulsion.
UV light is too strongly absorbed to penetrate thicker coatings. In this case, we require longer wavelength violet/blue light that is better able to penetrate and crosslink the emulsion. Using 405nm light we can cure the emulsion surface, as well as deeper layers, to effectively crosslink the emulsion that is in contact with the mesh. This way we encapsulate the mesh threads after wash out, in order to guarantee robust screens that are able to withstand the rigors of printing and cleaning on press. Using 405nm LED, we also get the benefit of wider exposure latitude, because during exposure we are curing the front, middle, and back of the coating simultaneously, as result of the deeper light penetration.
LED bulbs last way longer than a halogen bulb, which saves you money since you won't have to replace the bulbs as often. Plus, LED bulbs are better for the environment since 95% of their energy is used for light, and only 5% is wasted, according to Solar Electric Power Company. Better for you and better for the environment, can't argue with that!
First off, the LED bulbs in our exposure units were designed specifically for exposing screens. Again, the bulbs produce an optimal UV wavelength (which works for both dual cure and photopolymer emulsions). Having optimal UV wavelengths mean you're able to expose your screens faster and produce better detail. You'll be able to replicate the same quality burns from a great exposure platform, each and every time.
When you're ready for a new exposure unit, go with an LED one. You won't regret it.