TSB
screen printing => Screen Making => Topic started by: ftembroidery on August 28, 2017, 03:21:06 PM
-
I happen to have a daughter that is a pastry chef (no comments about my waistline....I'm watching my weight....I'm also watching my feet disappear).
Now to the point...I was watching a video of cake icing being made. The stuff has the same consistency of emulsion. In order to mix it up, an immersion blender was used which puts a lot of bubbles into the mixture.
In order to eliminate the bubbles, the mix was poured thru a screen/mesh sieve. The act of going thru the mesh breaks the surface tension of the liquid and eliminates the bubbles completely.
I don't see why this wouldn't work for emulsion. Get a sieve with a handle on it that fits your scoop coaters and pour the emulsion thru it. There are all sizes and shapes of sieves from pointed "China Caps" or Chinois, to big enough to hold a pumpkin.
Google "images of sieves" if you don't know what I'm talking about.
-
Makes sense to me.
-
It's been a while for me personally, but after mixing, I would leave the lid slightly ajar overnight and in the morning, no bubbles.
Steve
-
Yes you are right. You can pour emulsion through mesh to speed up the elimination of bubbles in a diazo or dual cure emulsion caused by mixing in the diazo. It also can filter out dried in emulsion chips from the lid that can cause lines in the coating process, or diazo that did not dissolve properly.
The other cause of bubbles is coating too fast. Too many screen rooms coat by hand way to fast. An auto coat machine takes 6-8 seconds on a 23x31, yet most hand coaters coat in a second or two. This whips air into the emulsion and puts a bubble behind the mesh knuckle usually. A slow firm coat works better for more even EOM thickness and reduction of pinholes.
-
Yes you are right. You can pour emulsion through mesh to speed up the elimination of bubbles in a diazo or dual cure emulsion caused by mixing in the diazo. It also can filter out dried in emulsion chips from the lid that can cause lines in the coating process, or diazo that did not dissolve properly.
The other cause of bubbles is coating too fast. Too many screen rooms coat by hand way to fast. An auto coat machine takes 6-8 seconds on a 23x31, yet most hand coaters coat in a second or two. This whips air into the emulsion and puts a bubble behind the mesh knuckle usually. A slow firm coat works better for more even EOM thickness and reduction of pinholes.
Yes, I noticed the speedy coating sucked the air through the mesh a number of years ago and slowed down, with much better results. Because of that, I used to coat the coarsest meshes first, so the finer meshes would break down the bubbles, sort of like through a strainer, no?
Steve
-
It's been a while for me personally, but after mixing, I would leave the lid slightly ajar overnight and in the morning, no bubbles.
Steve
Thanks Steve-That's exactly what I have done for 30 years. works great and ZERO mess
-
I've never really had any problems with bubbles. I will mix emulsion the day before if it's 2 part, but when single part separates a little I just gently mix it in and pour it into the coater.
I'm sure the mesh idea would work, but they you have to clean that too, or toss it out.
-
It's been a while for me personally, but after mixing, I would leave the lid slightly ajar overnight and in the morning, no bubbles.
Steve
And
Thanks Steve-That's exactly what I have done for 30 years. works great and ZERO mess
Make that 3 of us.
Or you can drag your finger along the top and pop all the bubbles.. then lick your fingers if that's your thing.
(https://i.pinimg.com/originals/75/ea/5c/75ea5c26fee33ab3acb2bbcc15c2e266.jpg)