UV Wave length


#1

I´m new with Resin curing, I´m going to build a curing box, but I have 2 options for UV leds:

Make a lamp with 9 UV leds of 3W 400-405nm or 9 UV leds of 10W 385-390nm.

I will appreciate your help

Regards


#2

9 UV leds of 10W 385-390nm would be way better


#3

Thank you


#4

Based on what?
This contradicts your own experiments.

I quote:
“While 365 nm and 385 nm light both produce post-cured modulus and tensile strengths that are higher than uncured “green” state samples shown at t=0, neither approach the properties obtained with a 405 nm source post-cure.”

According to page six and the final recommendation, 405nm is ‘way’ better as the resin is designed for 405nm, based on an equal amount of light.

Also:
“The optimum radiant power that produces the maximum modulus and tensile strength is 1.25 mW/cm2. This is the ux generated by a single 10W LED array in the TCC. When radiant power decreases below this level, there is not enough light to post-cure well, and there is a decrease in mechanical properties. Using a higher ux also results in lesser mechanical properties. This is counterintuitive to the common assumption that more light will post-cure parts better.”

“When designing a cure chamber, this value of 1.25 mW/cm2 should be used to achieve the best possible post-cure properties.”

“The results clearly show that the post-cured mechanical properties of parts printed with Formlabs resins on Form 1+ and Form 2 printers are maximized by the use of increased temperature and a 405 nm wavelength light source.”

So before we can take this conclusion we need to know the radiant power of these LED’s. According to the document, 1x10Watt LED-array is the optimum amount of radiant power. So that would mean 93Watt is better than 910Watt and both might be overkill.


#5

I have to admit…while I am getting decent results with the nail curing box I created…I am confused by the slew of varying advice floating out there.

Someone (Formlabs? ZVat? Me?) needs to start producing solid, well built, scientifically tested UV boxes for sale. I know I’d buy one.


#6

@mario_masquita and @fantasy2 I am wrong here. I just checked in with Zac who wrote the white paper you referenced. Generally, post curing is a complicated topic. It’s best to follow the advice of the white paper.


#7

I haven´t received the printer yet, but I´m setting up what I´ll need…In order to be able to check up what a resin cured means, is there a physycal parameter (color, tone, shine or some others) that I can use as reference to know whe a resin is full, half or none cured??

Regards


#8

Most of our resins have different characteristics after being post-cured so if you’re looking for more specific information, you’ll find it on the material pages and in the support articles for each specific material.

Castable will go from a blue to a dark green after being post-cured. DentalSG goes from a yellow to more of a dark amber. High Temp will go from almost clear to a dark amber similar to DentalSG. Tough V3 will go from a sort of bright teal to dark green.

Each of the other materials (Standard Resins and Flexible) undergo changes in mechanical properties but not necessarily visual properties. Typically, they become more stiff after post-curing.


#9

I´ll be awaiting to the printer to arrive but always is really helpful to hear what others users hvae faced to learn from their experience.

Regards


#10

“The optimum radiant power that produces the
maximum modulus and tensile strength is 1.25 mW/cm2. This is the flux generated by a single 10W LED array
in the TCC”

Does anyone know how they did the calculation for that? I’m trying to wrap my head around how they got this number, and I trying to figure out what UV lightning I should but in my UV Box, should I be using the UV LED strips that are 0.2W/LED for 120-300 LEDS? or should I be using a 10W LED Lamp type of light.


#11

With many decades (5+) of experience behind me (40+ yrs as P.E.), I have generally found that it is much more cost effective to purchase a product developed, tested, and manufactured to do the job intended, than design and construct what I think will work and then being frustrated trying to tweak it to perfection. I’m a E.E. and lighting designer with more than 10 years as an electronics technician. I CAN design and build a curing chamber that would probably be better than the Form Cure. I considered it and decided that my time and money were better spent developing our products and turning them into a good revenue stream. Consider your time as I assume that it has some value. My last consulting gig paid more than $160/hr… FWIW We purchased the complete Form 2 package and it has sped up our product development immeasurably, in spite of the problems and frustrations. It’s not perfect, but it is very good.

Mind you, none of the above applies to my custom, big block, '71 Scamp resto-rod, road racer. Every thing in/on it is in some way custom and designed and built by me. LOL