[artichap]

Hi All
New to this forum, some great information. I have a question for any chemistry lovers.. I am sure some do exist...

If curing waterbased inks using a forced air conveyor dryer removes only water.. why is it not possible to cure waterbased inks in a conventional dryer if the fabric is left in there long enough? What does the heat do to the inks other than evaporate the water and what other gases are given off?

Any chemistry takers?
Thanks
Graham

 

[artichap]

If none of us know what actually happens to the ink, or what is 'given off', then maybe the hype about 'eco-friendly' and waterbased is just that.... hype!

 

[artichap]

If none of us know what actually happens to the ink, or what is 'given off', then maybe the hype about 'eco-friendly' and waterbased is just that.... hype!

 

[thutch15]

I cure my waterbase ink with a regular conveyor dryer...I just run it through twice. Also I have heard Mr. Greaves in person make the same argument that you are making...also heard him say he would eat a spoon full of plastisol, but he would not do that with "eco friendly" waterbase ink.

 

[Flagrant-T]

Not sure about the chemistry and what is given off, but you can cure water based with a conventional dryer, it is just not ideal. You must get all the water evaporated out, and have the ink reach 300 deg or so. Water evaporates very slowely in still air. If you don't have a temperature control on a standard dryer to turn down the heat, if you leave the shirt in too long you will skorch the shirt.

A forced air dryer is almost like using a blow dryer on your hair. If you get out of the shower and air dry your head in a hot room, it will take a while to get dry (but it will get dry). If you blast your hair with a blow dryer, it is dry in seconds.

 

[artichap]

Thanks for your input folks. I have a forced air dryer on the way to me, with venting, it just seems that the MSDS sheets for the inks we use refer to their contents, but not the bi-products after the heating process.

 

[JantexInks]

Two things happen when you cure waterbase inks. First, as mentioned, you are removing the water from the ink. This works best with forced air because the air circulates removing the moisture from the dryer. In addition, forced air allows for more even heat distribution. Secondly, some binders (glue) are heat activated and this usually happens around 300 F.

They key is to get the ink to reach 320-350F. This happens through a mixture of proper heat and time settings.

Good luck,

 

[artichap]

Hi Jantex

Thanks for the reply. Waterbased Inks are marketed as eco-friendly and non-toxic. Does this also include the heating process of binders?
Thx

 

[JantexInks]

Hi Jantex

Thanks for the reply. Waterbased Inks are marketed as eco-friendly and non-toxic. Does this also include the heating process of binders?
Thx

In the case of regular waterbase inks, yes they are still fine during the heating process. Discharge does give off an irritating smell when heat activated. It is not toxic but can be irritating.

Usually, there are more nasty things in the garment that get burned off then in the ink. Things such as fibers, silicon agents, starches. But all in all, nothing would be classified as toxic.

 

[artichap]

Hi Jantex
Thanks for the information. It is much appreciated.
Rgds
Graham

 

[Neon Bible]

With out proper air circulation the water vapor just hangs around in your dryer like a couple of teenagers in front of a little champ durring a humid Florida summer. Gas is best, you can probably pull it off without using forced air and binders by blasting the heat levels, running the gates high and placing a fan in front of the dryer to force the vapor out of the tunnel. Look for steam and you will be queen. Run through twice is nice to insure you can be sure. Discharge is a sacrifice to Eco to say the least.

 

[artichap]

Thanks Atlas. I have a forced air dryer on order, so I should be OK. What do you mean when you say 'Discharge is sacrifice with eco'? I am not printing with discharge inks, just normal waterbased. Do you mean the steam?
Thx
G

 

[Neon Bible]

Discharge is not very environmental although it is debatable. Its a little nasty to work with even with proper ventilation. We whear masks and its kind of like printing during red tide. Some of the discharges are better then others but you don't hear a lot of printers talking about the negative health impacts on the respiratory system that discharge printing may have.

 

[artichap]

Thanks. I intend to steer clear of discharge and stick with conventional water-based. Thanks for the info.
G

 

[Neon Bible]

Thanks. I intend to steer clear of discharge and stick with conventional water-based. Thanks for the info.
G

What will you do when someone wants a black shirt?

 

[JantexInks]

There is nothing wrong with using discharge. People have been using it for over 20 years. We are all surrounded by products on a daily basis that are way worse than discharge. Discharge isn't toxic, it isn't regulated.

You just simply need to use common sense when you work with any chemicals.

To not include discharge in your offerings can really limit your customer base. It is good to learn about all aspects of printing from discharge to plastisol because each has its own place in the market.

 

[artichap]

Hi Atlas

Sorry for late reply, been trying to print a job for a client.
I use Permaset for dark colours. Still trying though. Will let you know how it goes.

Thx
G