Post Curing Unit for Resins

[arn11]

Hi,

I am new to 3D printing and its processes and had a query regarding the post-print process. I use a B9 creator and printed a small model of 30*30*6 mm using photo-polymer resin. I cured the print overnight using a UV lamp, with a glass slide to hold it down and had foil surrounding this setup. However, the next day I observed that the edges curled up and thus I no longer have a flat surface, which is what I require. Also, I tried duct taping the edges to slow down the curing there but it did not help. What can be done to control the curing process? Is the curling due to over-curing? Is there any particular time limit that the print should be cured for under the lamp? How else can I prevent the curling?

I have posted a picture of the print below.

Any input would be of great help.

[CarterTG]

Without further details on this UV Lamp (single bulb?) you're using, most other users setup an inexpensive curing box. Basically consists of a pair of UV Nail Curing boxes with the bottom slide-out panel removed. Sit them upright and it creates a clamshell structure that surrounds the print blasting it with UV light. Each box typically costs around $25 and should be pre-populated from the factory with 5 fluorescent UV tubes.

Take this a step further with a $10 solar-powered display turntable in the middle.

I've been using this setup to fully cure prints from my envisionTEC and B9 machines for the past several years. 1-2 hours is usually all it needs.

With the B9 machine, mine's almost exclusively using their Black resin for fast prototyping projects. Others using the same resin have discovered it cures (better?) using heat. Some have ditched their curing box and swear by nuking the print submerged in a glass of water. Secondary reason for the water submersion is that B9's resins are inhibited from curing in the presence of oxygen. This property is what helps it release from the PDMS in the vat during printing.

I prefer an in-between method. Resin print into a glass of hot water and put that into the curing clamshells. The cumulative 10 UV lights keeps the glass and contents around 120F. The result after an hour is that the black resin print is nearly indistinguishable from manufactured hard plastic. Without the water submersion, the resin surface feels a bit tacky after hours in the curing "oven"

My point is if you're using B9's Green resin, see if it too is curable under heat which can be more evenly applied rather than a UV lamp from one direction. I doubt your foil reflectors are doing you any favors. There's a high chance that one factor in it's warping is the UV exposed side cures at a faster rate with your current gear. The clamshell setup I've described is a far better way of bathing the print from all directions with UV. For more extreme measures, it might be worthwhile to sandwich that print between two plates of plexiglass (acrylic).

I've printed medallion pendants flat on the B9 build table (Cherry and Black resins) and gone through the curing process with none of the warping I'm seeing in your image.

Check the B9 forum for discussion on the curing box setup.

[arn11]

Hi,

I am using a 40W UV lamp. What exactly did you mean by nuking the print underwater? I would like to try this method before I purchase the UV nail lamps.

Thanks for you reply. Yes, I have been looking into the B9 forum also, and there they mentioned the use of a unit.

[awerby]

"Nuking" is an affectionate term for heating something in a microwave oven. I've had pretty good luck boiling my parts for about 5 minutes that way, then sitting them in the sun for a while.

[arn11]

How long should it be cured for underwater, with UV light incident on it?

[arn11]

I tried the underwater curing process and obtained better results. However, there is still a whitish, rough surface instead of a smooth one and still a small amount of curling. Is there any way to prevent the rough surface that is formed?