# Emulsion curing wavelength



## in2infinity (Dec 8, 2009)

Anyone know the specific wavelength of UV that emulsion cures at (or the peak curing wavelength)? If it's different for the different types, what would the numbers be for each type?


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## InkedApparel (Mar 18, 2009)

UV belongs to a special category of radiation known as *actinic* light, or light that has the power to effect chemical change. Actinic light can be found only in a fairly narrow slice of the electromagnetic spectrum. It includes a bit of the lower end of the visible light spectrum as well as the upper part of the UV band, the area known as UVA radiation. Direct emulsions react to UV light between 350 and 420 nanometers (billionths of a meter) in wavelength. To give you a bit of perspective: Visible light ranges from 400 to 700 nanometers and UV runs from 400 nanometers down to 100 nanometers. 

Inked


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## in2infinity (Dec 8, 2009)

Thanks ... is there a specific peak of sensitivity? In other words, if I had a light that output a narrow wavelength range of 20 nm with the peak in the middle (say 360 nm - 380 nm with the peak at 370). If said light could be adjusted within the wavelength range you have provided and given constant output, where would I find the greatest efficacy in curing?


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## RichardGreaves (Nov 7, 2006)

Emulsions are all a little different when it comes to sensitivity and a narrow band is not as forgiving. A broader spectrum in the UV-A band is desired.


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## kaciemills (Dec 26, 2011)

Actually some emulsions are more forgiving than others while all emulsions have their own varied peak exposure wavelength depending on their intrinsic chemical properties and any emulsion dye used in them. Some UV light sources like Fluorescent, Incandescent, Candlelight, and Sunlight offer a broad range of UV bandwidth. Arc Halide Lamps, LED's, and LASER diodes offer narrow UV bandwidths, but their peak wavelengths can be overlapped to achieve greater effectiveness if you intend on dealing with a wide range of emulsions (405nm/385nm/370nm/etc). Some emulsion manufacturers can indicate the specific peak emulsion curing wavelength with/without dye if you intend on dealing with only one type of emulsion exclusively. To be more accurate the UV spectrum covers a fairly "wide" band of electromagnetic spectrum considering that it is nearly as wide as the Visible spectrum itself, but it is much narrower than the IR spectrum. UV-A, UV-B, and UV-C can be used for killing, healing, or annealing. UV-C can destroy bacteria, viruses, and virtually are biological proteins, but pulsed UV-C at 123nm can be used for internal healing and as a substitute for X-rays. LOW Low intensity UV light at 365nm also has healing effects.


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