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screen printing => Ink and Chemicals => Topic started by: 3Deep on March 22, 2016, 12:07:51 PM
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Just got a sample last week of ChromaBlue Pure Polymer, did a few screens and notice it is pretty solid and really takes a long time to dry even this morning after a few days it's still kind of sticky with the film pos. Any of you use this and can give me some pointers, I'm pretty happy with the HXT but I don't mine trying a new to me product never know.
d
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I don't use this one, but have pretty much used pure photopolymer high solids emulsions almost exclusively for the last ten years.
How do you dry your screens? Do you have a cabinet? Dehumidifier?
I have a dehumidifier and fan in a small cabinet and my screens are dry in an hour.
Nonetheless, even after a few days, I have learned to use a small dusting of talcum powder, to prevent sticking and subsequent ink transfer from the film (in case I may use the film again as the ink, in and of itself, does not hurt the stencil)
Some films and inks seem to more susceptible to this, but the powder pretty much makes it a moot point and allows us to use the film, ink, and emulsion we choose.
Some may call this a band-aid, but, hell, who doesn't use have band-aids in the medicine cabinet to use when needed?
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I know this isn't the answer you are looking for, but when I looked up ChromaBlue it is in the $80+ dollar a gallon range?
We have been using Kiwo Multi-Tex with great results, no hardening on most of our jobs since they are sub 500 pieces, Waterbase, EKO, HSA, Solvent, holds up great. We are now exposing on LED (SAATI) in 10-40 seconds, with just as good of results as MH 5K. Best part is, you can get it for $49 a gallon from GSG or possibly cheaper if you shop it.
We went from an expensive emulsion, to a much lower cost one when this came out and have the same results. (Better in reclaim) We were using a $80+ dollar emulsion previous to this, so since we go through a lot of emulsion it is quite the cost savings.
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@ Frog I have a cabinet with a fan build in, but no dehumidfier, with the HXT emulsion it dries in 30 minutes to an hour, guess I'll head over to the dollar store for some baby powder.
Thanks Zane I might try the Kiwo, sounds like it works about the same as the HXT
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If you have issues with inkjet film sticking to the screen, after vacuum and exposure I would recommend trying Chromaline's Chroma Tech TD emulsion. It is a pure photopolymer with 50% solids, for plastisol printing. It was designed to combat the problem of film sticking to the screen. Contact Chromaline and they will be happy to give you a sample.
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Darryl, what ever you do, don't try and do a water based job with Chromablue, WILL NOT WORK. I have a new favorite for an all in one emulsion now. Cost is the same as Chromablue, it's a purephotopolymer, but with a post expose you can run discharge and wb for tens of thousands of prints, no hardeners needed. T-9 but Murikami. Freakin awesome stuff man. I'll be doing a write up about it soon, but it's the beezneezz!!! Halftone work with it is so much better now. My I-Image images awesome on it and I am able to hold every single stinkin dot on it. High solids, very thick, 1/1 coating will work with about anything, that's what I'm doing on all my S mesh, and any T Mesh we still use, doing a 2 and 1. I think this is the best emulsion I've tried yet. Super fast exposing too. The times are just about right on with Chromablue which is what we used to use for plastisol. I can't say enough about how great this stuff is. We don't get 10,000 and 20,000 piece jobs, but there are plenty of shops hitting those numbers in water base with the use of T-9.
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You all should try the cryocoat we are using..... 1 emulsion for everything, our sim process, spot color, hsa, waterbase, discharge, plastic, etc..... This emulsion does everything we need, straight out of the bucket its good to go
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Whats this Cryocoat you talk about here Danny, never heard of it until now
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Whats this Cryocoat you talk about here Danny, never heard of it until now
http://www.screenprinting.com/green-galaxy-cryocoat-emulsion-gallon#.VvGp3GQrLXU (http://www.screenprinting.com/green-galaxy-cryocoat-emulsion-gallon#.VvGp3GQrLXU)
Price comes down quite a bit when you buy in bulk from them
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cryocoat = rebranded/recolored saati phu.
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cryocoat = rebranded/recolored saati phu.
With some mods - I went through multiple modifications improving coating ability and viscosity where I like to see it..... So while it's very close it's not the same
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cryocoat = rebranded/recolored saati phu.
With some mods - I went through multiple modifications improving coating ability and viscosity where I like to see it..... So while it's very close it's not the same
does that help with the super-thick build that the phu normally exhibits?
also, how do you feel about the exposure times vs the red or blue colors?
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cryocoat = rebranded/recolored saati phu.
With some mods - I went through multiple modifications improving coating ability and viscosity where I like to see it..... So while it's very close it's not the same
does that help with the super-thick build that the phu normally exhibits?
also, how do you feel about the exposure times vs the red or blue colors?
Yeah, I will say I was not much of a fan of the standard PHU when we put it through it's paces. The phu2 was improved but we could not hold the detail that we could with our dual cures. We found that the green color actually improved the resolution compared to the standard phu colors and the viscosity mods that I made I feel help how well it coats. Also I worked on dialing in the viscosity to work well with thin thread mesh and t thread mesh. With some of the previous emulsions we had been using we would see huge swings in EOM from thin thread to standard thread and this emulsion has helped bridge that gap. We've been using it for several months now on everything we do in our shop. There's nothing magical about it, but for my shop it's awesome to have 1 emulsion that can be used for any type of ink or project we throw at it. Nothing like getting an hsa job ripping on press only to see the guys in the coating room used the wrong emulsion and we have breakdown a few hundred pcs in. Cryocoat has eliminated all headaches for us as far as that goes.
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ChromaBlue is a great emulsion for medium to low details. We've used it for 2 years, thousands of prints. It can hold its own on the 55/60lpi stuff, but not as well as other emulsions.
We did have the same problems you are. You absolutely need a DE-humidifier and a humidity gauge in your room/cabinet. Takes us about half a day to get 90 or so screens completely dry.
ChromaBlue we had mixed results with it sticking to our exposure glass and our film. Keep humidity to a minimum and try not to have real hot glass. Switching to an LED exposure unit helped us tremedously.
We are however shopping for a new dual cure...
We absolutely love WR-14, but we can't figure out how to get it to reclaim as easy as our chromablue. ChromaBlue literally melts off the screen...even after thousand piece runs/cleanings etc.
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Water resistant emulsions Do Not reclaim as easily as standard emulsions.
The WR-14 will not melt, but it will still reclaim just fine.... you just have to have a little patience ;)
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Most customers using inkjet film and a pure photopolymer emulsion will have some issues with the film sticking to the emulsion during exposure. That is because the inkjet film has an aqueous receptive coating on it so that it can absorb the inks themselves to create a dark (dense) positive or negative. Pure photopolymer emulsions will absorb moisture from the air. When you put the two together they are both trying to absorb each others moisture, thus causing them to stick together.
We at Chromaline developed the Chroma Tech TD emulsion with this in mind. It does a great job of keeping the film from sticking. We coated a screen with 110 mesh on it with the TD emulsion and placed a piece of imaged AccuJet film on it. We then placed the screen inside a 100% humidity chamber overnight. The next morning we took the screen from the chamber and immediately drew vacuum and exposed it. Upon completion of the exposure we removed the film and it did not stick to the exposed TD emulsion at all. I knew that there had to be a better and cleaner way of keeping film from sticking than using powder. The answer was to create an emulsion that would not stick to the film.
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Murikami T-9 melts right off just like chromablue. Best of both worlds. I haven't tried the cryo stuff, but can say we are loving the T-9 for sure!! Nice to have one fast exposing emulsion that can be used for both plastisol and discharge and hold amazing detail.
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How is the T-9 coating for you? Any issues?
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Most customers using inkjet film and a pure photopolymer emulsion will have some issues with the film sticking to the emulsion during exposure. That is because the inkjet film has an aqueous receptive coating on it so that it can absorb the inks themselves to create a dark (dense) positive or negative. Pure photopolymer emulsions will absorb moisture from the air. When you put the two together they are both trying to absorb each others moisture, thus causing them to stick together.
We at Chromaline developed the Chroma Tech TD emulsion with this in mind. It does a great job of keeping the film from sticking. We coated a screen with 110 mesh on it with the TD emulsion and placed a piece of imaged AccuJet film on it. We then placed the screen inside a 100% humidity chamber overnight. The next morning we took the screen from the chamber and immediately drew vacuum and exposed it. Upon completion of the exposure we removed the film and it did not stick to the exposed TD emulsion at all. I knew that there had to be a better and cleaner way of keeping film from sticking than using powder. The answer was to create an emulsion that would not stick to the film.
I am betting that way more folks use ink jets than photographic image setters, so building this characteristic into a wider selection of photopolymer emulsions seems like the thing to do.
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How is the T-9 coating for you? Any issues?
I use a Monster Coater, doesn't really have a sharp or dull edge, I would guess somewhere in the middle. My dark room stays pretty warm with the dehumidifier running all the time, so I think storing the container that is in use in there helps a little with the thickness. I was told you can add a small amount of distilled water if you want, but I'd rather not. I really haven't had any issues coating though, it flows really smooth. EOM seems to be awesome, I don't have a gauge, but by touch it's getting what I used to get with Chromablue easily. When coating S-Mesh, I only go 1/1 and flip the screen to coat the opposite side reverse direction. Any T mesh one directional 2 and 1. Not sticky at all when read for production. Chromablue sometimes would be kinda sticky, so like say an underbase screen, when boards got warm would stick to the shirt until a little lint got on the emulsion, always happened with chroma blue no matter what we did. This stuff seems nice and hardened, even though we aren't using a hardener.