Combo UV/LED lamps

#1
Hello geeks,
I wonder if anyone could explain how combo uv led lamps work? I can't seem to find much information? Thank in advance
 

CadenceAlex

Well-Known Member
#2
I think they are lower UV - not entirely sure but they work quicker than the UV lamps so much less exposure.
 

BobSweden

Managing Director
#3
Before gel polishes were invented, all hard gels and soak-off gels contained a photoinitiator chemical that required UV light with a peak wavelength of 365nm to cure. The UV lamps of that time, used one or more 9W CFL bulbs (Compact Fluorescent Light) that actually produced UV over a wavelength range of around 360 to 410nm.

The along came gel polishes. Around the same time, electronic manufacturers had started to produce LED's (Light Emitting Diode) devices that could produce UV with a range of 395 to 410nm. While this meant that these could not be used to cure the old gels that needed UV at a 365nm wavelength. So the gel polish manufacturers decided to produce a new type of UV lamp - the LED-UV lamp - to cure these. However, this meant than instead of using the same photoinitiator used in older gels, the new gel polishes had a photo initiator that was matched to the new LED-UV lamps.

The advantage of the new LED-UV lamps was:

a) LED's produce UV over a more focused wavelength range, this in turn meant that they were brighter (scientific term, had a higher UV Illuminance) and cured the gel polishes faster.
b) cheaper to produce
c) CFL bulbs contain mercury which is nasty for the environment, LED's don't
d) CFL tubes need replacing every 6 months, LED's work for 50,000 hours
e) because of d), the risk of under curing the gels or gel polishes is less than with CFL bulbs, where you are never entirely sure when to replace them

CCFL UV lamps
However, this left something of a problem. Most nail salons wanted to use gels AND gel polishes. While they could cure the gel polishes in the CFL UV lamp, it was much slower - 2 minutes instead of perhaps 10 to 30 seconds. And remember, the LED-UV lamps didn't cure the older gels. So many nail salons ended up using both CFL UV lamps and LED-UV lamps - depending which service the customer wanted.

The along came the CCFL (Cold Compact Fluorescent Light) UV bulbs! Rather than 9W, these CCFL bulbs were usually 12W. That meant to make a 36W UV lamp, you needed three CCFL bulbs rather that 4 CFL bulbs. But CCFL had a new more advantages:

a) like LED's they work for up to 50,000 hours
b) no heat is generated, hence the name Cold Compact Fluorescent Light
c) unlike LED's, these babies generated UV light across a wavelength from 360nm up to 410nm.

So the first Combo UV lamps were born. A mixture of CCFL bulb(s) and LED's - that could cure both older gels and gel polishes, with no need to replace the bulb every 6 months. Hallelujah!

The only downside, was that curing times for the old gels using CCFL where not as fast as the LED-UV lamps.

UV and LED-UV gels
Now at this point, you could ask why didn't the gel manufacturers make gels that also contained a 405nm photo initiator? In hindsight, that seems like an obvious thing to do, as then folks could have used these LED-UV gels with their shiny fast LED-UV lamps. While a few companies did this, this was an idea that has taken a while to become popular - even today, many gels on the market were developed before LED-UV lamps existed (some were developed before even 36W UV lamps existed, and were designed for single CFL bulb UV lamps - which is why these gels produce a big heat spike when used in 36W CFL lamps or LED-UV lamps).

Then along came Dual Wavelength / Dual Band LED UV lamps
A few years ago, electronic manufacturers started to also produce LED's that could create UV from 360nm to 380nm. So UV lamps started to appear that contained two sets of LED's - one set producing UV at 365nm wavelength and the other set that produced UV at 405nm.

This now means, that these Dual Wavelength or Dual Band LED-UV lamps can cure older gels much faster, and also cure gel polishes. There are no glass bulbs to break, and these are cheaper to produce than the Combo CCFL + LED UV lamps.

The fly in the ointment
Imagine you are a chemist tasked to produce a new gel. Your company has customers who are using all different brands of UV lamps, CCFL lamps, CCFL + LED UV lamps and LED-UV lamps. Given that all of these UV lamps will have very different levels of UV brightness (Illuminance), how on earth can you know how much of the 365 photo initiator and 405nm photo initiator to use?

As an analogy, imagine trying to bake bread that has an unknown amount of yeast, in ovens that many different fixed temperatures - some too cold, some too hot and not many "just right".

So, the simple answer is that it is impossible to develop a gel that will correctly cure in all UV lamps. The gel and UV lamp have to be matched. This means that the chemist will develop the gel to suit the UV lamp that the company sells, unless they want to design a new UV lamp as well. Companies that tell you otherwise, either don't understand the basics of gel chemistry or are not being honest.

And NT who might say that they "know" that their 3rd party UV lamp cures their gels are also not correct. It is not enough to cure a blob of gel in a UV lamp and see if it is hard. Gels are hard enough to file when only 50% to 55% cured - that means any gel dust can and does cause allergies. To really know if a specific UV lamp correctly cures a specific gel, you need scientific equipment (and someone who knows how to use it :)).
 

#4
Before gel polishes were invented, all hard gels and soak-off gels contained a photoinitiator chemical that required UV light with a peak wavelength of 365nm to cure. The UV lamps of that time, used one or more 9W CFL bulbs (Compact Fluorescent Light) that actually produced UV over a wavelength range of around 360 to 410nm.

The along came gel polishes. Around the same time, electronic manufacturers had started to produce LED's (Light Emitting Diode) devices that could produce UV with a range of 395 to 410nm. While this meant that these could not be used to cure the old gels that needed UV at a 365nm wavelength. So the gel polish manufacturers decided to produce a new type of UV lamp - the LED-UV lamp - to cure these. However, this meant than instead of using the same photoinitiator used in older gels, the new gel polishes had a photo initiator that was matched to the new LED-UV lamps.

The advantage of the new LED-UV lamps was:

a) LED's produce UV over a more focused wavelength range, this in turn meant that they were brighter (scientific term, had a higher UV Illuminance) and cured the gel polishes faster.
b) cheaper to produce
c) CFL bulbs contain mercury which is nasty for the environment, LED's don't
d) CFL tubes need replacing every 6 months, LED's work for 50,000 hours
e) because of d), the risk of under curing the gels or gel polishes is less than with CFL bulbs, where you are never entirely sure when to replace them

CCFL UV lamps
However, this left something of a problem. Most nail salons wanted to use gels AND gel polishes. While they could cure the gel polishes in the CFL UV lamp, it was much slower - 2 minutes instead of perhaps 10 to 30 seconds. And remember, the LED-UV lamps didn't cure the older gels. So many nail salons ended up using both CFL UV lamps and LED-UV lamps - depending which service the customer wanted.

The along came the CCFL (Cold Compact Fluorescent Light) UV bulbs! Rather than 9W, these CCFL bulbs were usually 12W. That meant to make a 36W UV lamp, you needed three CCFL bulbs rather that 4 CFL bulbs. But CCFL had a new more advantages:

a) like LED's they work for up to 50,000 hours
b) no heat is generated, hence the name Cold Compact Fluorescent Light
c) unlike LED's, these babies generated UV light across a wavelength from 360nm up to 410nm.

So the first Combo UV lamps were born. A mixture of CCFL bulb(s) and LED's - that could cure both older gels and gel polishes, with no need to replace the bulb every 6 months. Hallelujah!

The only downside, was that curing times for the old gels using CCFL where not as fast as the LED-UV lamps.

UV and LED-UV gels
Now at this point, you could ask why didn't the gel manufacturers make gels that also contained a 405nm photo initiator? In hindsight, that seems like an obvious thing to do, as then folks could have used these LED-UV gels with their shiny fast LED-UV lamps. While a few companies did this, this was an idea that has taken a while to become popular - even today, many gels on the market were developed before LED-UV lamps existed (some were developed before even 36W UV lamps existed, and were designed for single CFL bulb UV lamps - which is why these gels produce a big heat spike when used in 36W CFL lamps or LED-UV lamps).

Then along came Dual Wavelength / Dual Band LED UV lamps
A few years ago, electronic manufacturers started to also produce LED's that could create UV from 360nm to 380nm. So UV lamps started to appear that contained two sets of LED's - one set producing UV at 365nm wavelength and the other set that produced UV at 405nm.

This now means, that these Dual Wavelength or Dual Band LED-UV lamps can cure older gels much faster, and also cure gel polishes. There are no glass bulbs to break, and these are cheaper to produce than the Combo CCFL + LED UV lamps.

The fly in the ointment
Imagine you are a chemist tasked to produce a new gel. Your company has customers who are using all different brands of UV lamps, CCFL lamps, CCFL + LED UV lamps and LED-UV lamps. Given that all of these UV lamps will have very different levels of UV brightness (Illuminance), how on earth can you know how much of the 365 photo initiator and 405nm photo initiator to use?

As an analogy, imagine trying to bake bread that has an unknown amount of yeast, in ovens that many different fixed temperatures - some too cold, some too hot and not many "just right".

So, the simple answer is that it is impossible to develop a gel that will correctly cure in all UV lamps. The gel and UV lamp have to be matched. This means that the chemist will develop the gel to suit the UV lamp that the company sells, unless they want to design a new UV lamp as well. Companies that tell you otherwise, either don't understand the basics of gel chemistry or are not being honest.

And NT who might say that they "know" that their 3rd party UV lamp cures their gels are also not correct. It is not enough to cure a blob of gel in a UV lamp and see if it is hard. Gels are hard enough to file when only 50% to 55% cured - that means any gel dust can and does cause allergies. To really know if a specific UV lamp correctly cures a specific gel, you need scientific equipment (and someone who knows how to use it :)).
Thank you so much for your comprehensive answer!
 

The Geek

Grand Master Geek
Staff member
#5
So, the simple answer is that it is impossible to develop a gel that will correctly cure in all UV lamps. The gel and UV lamp have to be matched.
It is so frustrating that this is still the most misunderstood fact in the industry. Thanks for your detailed answer!
 
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