M&R Mini Sprint

[cbjamel]

Looking at doing some cci white discharge with our M&R Mini-Sprint std size so 8' chamber. What should my speed and temps be I usually run 19-20ft/min@400 fro t-shirts.
Any suggestion on base and activators.
Thanks,
Shane

[Admiral]

I have 12' of heat but I would try a 60 second dwell to start so speed 8.  Temp wise I would think 350-360 should do it.

[Doug S]

It may be overkill, but I have that exact same dryer and I run mine at 335 degrees and a belts speed of 4 for a 2 minute dwell.   I've only tried ryonet's discharge so I can't be much help with any other brands although I'm looking to try some soon. 

[Gilligan]

It may be overkill, but I have that exact same dryer and I run mine at 335 degrees and a belts speed of 4 for a 2 minute dwell.   I've only tried ryonet's discharge so I can't be much help with any other brands although I'm looking to try some soon.

I think that is CCI as well.

How many pcs per hour can you do at that pace?  This is the dryer I will be looking at after the move.

[Doug S]

It may be overkill, but I have that exact same dryer and I run mine at 335 degrees and a belts speed of 4 for a 2 minute dwell.   I've only tried ryonet's discharge so I can't be much help with any other brands although I'm looking to try some soon.

I think that is CCI as well.

How many pcs per hour can you do at that pace?  This is the dryer I will be looking at after the move.

If the print is a full back or front we can manage around 30 dozen per hr with creative belt loading but if they are smaller prints then we can pull off around 36 dozen per hr.  We could probably push it a little faster if we wanted to, but I feel pretty comfortable at that speed.   You'll love that dryer, it has been a great upgrade for us compared to the fusion with a 6 ft chamber.

[Lizard]

Straight discharge you can run faster (around a minute dwell) but if you are printing color I would keep it in for 90 seconds.

[ZooCity]

Discharge ideally needs 3min at 320-350˚F. 

Can you get away with less?  Sure.  You can go with a shorter dwell down to the point where the reaction is still successful (probably something around 90s at 350˚ in a gas dryer) but at some point you'll need to consider adding fixers to ensure colorfastness.  The further you get away from the above the less success you get with the initial discharge and also with the longevity of the printed color.  Wash test before serious production and go for it.

The key to understanding this is that the discharge process takes place in the presence of correct heat, airflow and water.  The activating chemical needs water present to perform the dye discharging.  The pigment loaded waterbase ink needs the rest of the equation to seal the deal, replacing the garments dyestuffs.  This is why a 3min cook gets it done best- more time for the activator to due it's thing and cured enough before exit to ensure the wb ink replacing the dye is fully encapsulating the now greige colored fibers. 

So can you just run it through twice?  Yep that works sometimes but you won't get the consistency doing it this way as you've changed the variables the ink is working with, decreased the water present to allow the ZFS to work. Discharging garments is easy.  Discharging 1000s of pcs consistently, order after re-order, is the real challenge

I have no idea how big the squirrel cage blower on a mini sprint is but, if it's mini as well, check it frequently and keep it clean, you're going to need every cfm of airflow the dryer can offer. 

*I only have a layman's understanding of this so far and certainly don't mean to sound like a know it all. It's just what I've found from actual shop testing + research.  I hope it helps. 

[alan802]

I set our temp at 350 and belt speed at 10'/minute which allows us to print as fast as the auto will run but the belt is full.  I've brought the belt speed down so the shirts are in for 90 seconds with no noticeable difference by eye but I haven't tested a lot of colors for washfastnessessessnessesness so I need to do some testing with Zoo's numbers.  Most of our DC prints recently are white and I haven't done any spot color stuff in at least 2 months.  No doubt our production numbers would go down signicantly if we have a dwell time of 2 minutes and our dryer is 12' and 60' wide.  I don't mind running at 600-700 pcs/hr.

[tonypep]

With regards to retention time you're all missing two critical factors

[alan802]

Temp & air flow?

[tonypep]

You're half right Alan (the 2nd part that is)

[ScreenFoo]

Wouldn't ink penetration make a huge difference as to your 'ideal' dryer setup?

[Doug S]

Do most of you lower your entrance and exit gates or raise them higher on your dryer when curing discharge?

[alan802]

Do most of you lower your entrance and exit gates or raise them higher on your dryer when curing discharge?

Haven't touched that since we installed the dryer.  Something to consider doing though.

[Rockers]

I assume it would matter as well what mesh count you are using?