Light curing is a leap forward in pipe lining, improving consistency in the final liner, speeding installation times, lowering technician labour costs, and reducing risk by enhancing control over the lining process.
While there are some important differences between the light curing systems on the
market that should be considered, the wavelength or ‘colour’ of the light is not one of
them. The reality is that there is no inherent benefit to a particular wavelength of light,
whether it sits on the visible part of the light spectrum (e.g. blue, green, etc.) or if it is
in the UV part of the spectrum. What is important is irradiance per square centimetre,
sufficient power along the length of the liner and that the resin and the wavelength be
perfectly calibrated with each other for a full and dense cure.
While the UV part of the spectrum is indeed wide, the specific wavelength of light used
in a UV CIPP lining system is not. For example, the NuFlow NuCure system uses a very
specific wavelength of light within the UV portion of the spectrum, one that is precisely
calibrated to the resin developed to ensure an extraordinarily high density of cure.
If you bake cookies at 350oF (±180oC), the fact that your oven heats from 0 to 550oF
(288oC) is an irrelevant observation and in no way suggests a lack of precision or power.
You are going to use a very narrow and focused part of that total temperature range.
You just need to make sure your oven can hit 350oF (±180oC) and stay there for the time
it takes to bake the cookie and, importantly, that your cookie dough recipe is calibrated
to work at that temperature. If another cookie recipe calls for baking at 325oF (±160oC)
or 375oF (±190oC), it is not better or worse, it is just different and it will work just fine as
long as the cookie dough is calibrated to that temperature. There are not a lot of cookie
recipes that say ‘Pre-heat your oven to anywhere between 300oF (±150oC) and 375oF
(±190oC)’.
Light in the UV spectrum has a relatively shorter wavelength, which helps in penetration
of materials. In addition, the NuCure system has designed or sourced transparent lining
materials specifically to enable better light penetration through to the resin, ensuring an
extremely dense cure.
In summary, it is the overall system that should be evaluated when considering a light
cure system, not one attribute. Better to consider the wavelength/resin calibration, the
heat created by the reaction (peak exotherm) and exotherm duration, the transparency
of lining materials used, the robustness of the power sources, cables and connections
and, of course, the product and job site support that NuFlow is famous for.
