T-Shirt Forums banner

1 - 16 of 16 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter · #1 ·
HELLO!

I recently started screen printing again...I'm using Ulano Proclaim emulsion and water-based inks. For wash-out/reclaiming, I'm using Ulano Stencil remover and a pressure washer.

My question is why am I not able to get all of the emulsion out? There are little spots and areas which seem to be stuck in there. I don't want to use haze remover because it is so caustic. Did I maybe do something wrong before I started washing out? Is it harder to wash out emulsion if the screen has been under/over-exposed?

Any tips?

THANX!!
 

·
Registered
Joined
·
935 Posts
Don't let the emulsion remover to sit on the emulsion too long. If you spray it on, and leave it on there long enough for it to dry, you won't be able to reclaim it at all.

But I'd say wet the screen, spray emulsion remover and scrub scrub scrub both sides, then powerspray up close, for a while. Don't get the spray stream too close to the mesh without keeping it moving, as that can mess up and distort the mesh.
 

·
Registered
Joined
·
861 Posts
how old is the emulsion your using? if it has expired it may not reclaim well. Usually you get 6 months shelf life for dual cure, and about a year for the pre-sensitized stuff.
 

·
Registered
Joined
·
8 Posts
First, it is very important that you degrease the emulsion on both sides before attempting to go into the removal process. Second, you pressue washer may not be strong enough. . .the self carwash would be your easiest choice. Third, yes . . . incorrect exposure time can lock the emulsion into the mesh making it unremovable.
 

·
Registered
Joined
·
214 Posts
First, it is very important that you degrease the emulsion on both sides before attempting to go into the removal process. Second, you pressue washer may not be strong enough. . .the self carwash would be your easiest choice. Third, yes . . . incorrect exposure time can lock the emulsion into the mesh making it unremovable.
Degrease the emulsion? I've never heard of that. That seems really unnecessary.

I just soak my screens in stencil remover for a couple minutes, then blast them out with a pressure washer.
 

·
Registered
Joined
·
175 Posts
this is hands down the best stuff to remove stubborn emulsion that wont come out during reclaiming.. be careful with it though cause u leave it on the mesh for more than about 5 minutes, it will actually burn holes right in the mesh and ruin the screen.. use it on a dry screen, apply generously wait 5 minutes and wash it off.. the higher the mesh, the less the waiting time.. 5 minutes on a 156 mesh makes the screen look brand new. Use with caution!! HO-500 Haze Remover Paste
 

·
Registered
Joined
·
1,810 Posts
Haze Remover
Haze remover is for ink or under exposed diazo stains, and should be used with caution after reclaiming the mesh by removing the stencil. It often won't remove solvent resistant stencils

Ulano has videos on direct emulsion and capillary film processing, (including reclaim), that you can download and play as many times as you like.
Support Menu of Screen Making Products

UNDEREXPOSURE
Under exposed stencils are harder to remove than completely cured/exposed stencils, because some of the emulsion did not cross link. This is always greatest on the inside of the stencil, away from the exposure lamp. Invisible UV energy didn't have enough time or power to move all the way through the stencil to the inside and make the stencil hold in the mesh. As always, the only good stencil is a completely cured stencil. Search this forum for 21 Stouffer scale.
Exposure FAQ of Screen Making Products

Thick edges harder to expose completely
Thicker, hard to reclaim stencil at the edges points to not enough exposure, because thicker stencil requires more exposure to cross link. It makes sense that the edges of the stencil where your coater left a thicker edge would be under exposed. It helps to smooth these edges with a scraper after coating rather than to let them dry thick. It take

Stencil remover attacks the bond in the emulsion that was created when you exposed the stencil and cross linked the emulsion. The stencil remover chemical creates another reaction with under-exposed stencil and forms a chemical bond with the mesh that is very difficult to remove.

It is very important to never let the stencil remover dry. It locks the stencil in the mesh with a permanent chemical bond and you have to remove the stencil with a razor blade.

Strong wash up chemicals can also fuse under-exposed stencil to the mesh.

Penetration
When you spray stencil remover on the stencil, it has to penetrate and attack the chemical cross links formed by UV exposure. No cross links - no easy stencil removal. It takes very little concentration of stencil remover to get the cross links to break, like a key in a lock - you don't have to force it. You have to balance waiting for the chemicals to penetrate vs. letting the stencil remover dry.

Using a stronger concentration of stencil remover doesn’t help much. Taking 5 aspirins doesn’t remove your headache faster.

Principles of reclaim
The process is described o the Ulano Stencil Remover web page and the Technical Data Sheet.
Stencil Removal Chemicals for Screen Making
Tech Data Menu USA of Screen Making Products


  • Remove ink with the proper solvent
  • Use mesh degreaser to remove any solvent or ink residue that are a barrier to stencil remover penetrating into the stencil. The important chemical the stencil remover that works better if it doesn’t have to penetrate through an oily, water repelling solvent or ink.
  • Degreaser is much cheaper than reclaiming chemicals and if there is a barrier of ink residue protecting the stencil it may take two or three attempts to remove the stencil.
  • Rinse degreaser off the stencil.
  • Spray a minimum amount of Stencil Remover Liquid No. 4 on the screen from both sides.
  • If you wet the stencil, you will dilute the stencil remover chemicals. It is already wet.
  • Wait for up to five minutes for the chemicals to penetrate– no longer.
  • If you see the stencil remover breaking down the stencil - start to scrub it with a flat brush. Because the stencil is on the bottom of the mesh, you will get the best result from scrubbing and spraying the inside of the screen so you don’t have to push the stencil through the mesh.
  • Do not allow the stencil remover to dry on the screen, as this can result in a permanent stencil.
  • Rinse away the stencil with a hard spray of water, preferably a power spray.

The emulsion movie at Support Menu of Screen Making Products shows how it is done.

Stencil Age
There is no reason that stencils are harder to remove the older they are if they were properly exposed. Again, they were weakened at exposure time.

An under-exposed stencil could become more difficult to reclaim over time because prolonged exposure to some chemicals could create a chemical bond with un-exposed emulsion and chemically bond to the mesh.
 

·
Registered
Joined
·
8 Posts
When you clean the ink from the screen you would normally use an oil based product. Emulsion is soluble in water when emulsion remover is applied. There is an oil film on the emulsion from the ink. If you degrease the emulsion on both sides the emulsion remover has a much easier time in the removal process
 

·
Registered
Joined
·
69 Posts
I have to agree with the above, why add an extra step?
Also my reclaimer acts as a degreaser so I never degrease, just ink degradent then reclaimer, no problems as long as the reclaimer is thoroughly rinsed.
 

·
Registered
Joined
·
1,810 Posts
I have to agree with the above, why add an extra step?
Also my reclaimer acts as a degreaser so I never degrease, just ink degradent then reclaimer, no problems as long as the reclaimer is thoroughly rinsed.
If you are having trouble removing a stencil from the mesh, or have to do the job twice, it helps to know the fundamentals.

If you are not having trouble - you don't need to question your procedure.

The stencil remover or ink degradant you are using includes a detergent to cut through solvent residue, your products have eliminated that step.
 
1 - 16 of 16 Posts
Top