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Discussion Starter #1
So we have been getting stains on pink shirts and occasional purpleish stains on red shirts from the Kornit pretreat, we think.

Anyone else encountered / overcome this problem?

THanks
 

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Can it come from your fabric because that shirt is not complete to fix by drying factory? Is this problem just found from your production or met it very often.
 

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Dear KenScott

Burn Out is a one of Printing Technique that we can dissolve another fiber that we mixed it on the fabric by chemical. For an example about with T/C shirt that we mixed 35% cotton with 65% Polyester in yarn. We can used a chemical that it can dissolve cotton by Screen printing. you can got another effect after we used this method.

I thinks this will cleared for you.
 

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This happens frequently on certain color shirts that I print for my company. Specifically Red, Gold, and light blues.

On red we will get dark purple spots. Gold we will get blue spots, and on light blues it will turn pinkish purple. I have found this happens when an area doesn't get dried well enough. On lighter colors it's hard because you either end up burning the shirts trying to get them to dry spot free or you live with the spots.

Our solution: If we see the shirt is discoloring before it even enters the printer (happens mostly on light blues.) we spray water on it before sending it through, and usually it will come out spot free. If we catch it after, we spray it with water and let it air dry. This gets rid of the spots about 90% of the time. I think it happens when areas are inconsistently sprayed, or if a bit of spray drips down while you are unloading the shirt from the pallet.
 

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hey, i was just going by the big *** letter i got from Kornit..
its as follows...


From the Desk of Paul Borucki, Kornit N.A.:

As we continue to work with customers each day we are seeing complaints of dull prints, dye migration and fixation burn out. It has become very obvious that all of these customers are over curing their garments. As we make the recommended changes to the customers from our office to change the way they are curing, the results have been dramatic and keep them from "the burn out look".

We have seen customers that have been told to set their dryer at 345 to 360 degrees and that is ruining their chances of success. Once we teach them to reduce the temperature to 300 degrees to 310 degrees on forced air dryers, the colors stay brilliant.

I want to take this time to go over curing digital prints:

The whole issue with electric dryer is scorching of the inks. If you combine too much raw heat without sufficient airflow impingement to the garment surface the inks will dull and burn off too quickly rather than slowly evaporating the water to leave the pigments behind.

Sensitive garments such as polyesters and poly acrylic blends require very low cure temperatures but at extended cure times. Depending on the dryer, conveyor belt or cabinet dryer, the temperature needs to be approximately 250 degrees for 5 to 10 minutes.

Every dryer installation is unique beginning with the power supply. If the owner does not run the proper power to the dryer and read the supply power “at the dryer” all temperature and cure times will be different. A drop in power will mean reduced cure in any electric dryer.

The atmosphere around the dryer directly impacts the cure rates. Hot, dry or cold temperatures in the shop will change the time of cure.

The surrounding equipment in the building or building complex can cause a power draw down will affect the cure specs.

The weight of the garment ( a 6.1 oz t shirt versus a 20 oz sweatshirt) and the saturation of the number of garments that are physically placed on the conveyor belt will change the thermal mass in the dryer and affect cure rates. There will be a difference in the cure of the one off print going down the belt versus a fully loaded dryer.

We always recommend the following

Turn the dryer belt to its slowest setting.
Set the temperature to 310 degrees.
Airflow set at maximum.
Run a shirt through the dryer and check for cure.
smell the garment when it is cool. Check for any vinegar odor
stretch the garment and look for cracking
The prints should be odor free and very stretchable.
Slowly increase belt speed to achieve the most efficient cure rate at that temperature setting.

As the garment weight, the amount of ink on the print and the more wetting solution that is applied, all of these will change your cure specs.

It has come down to one simple factor at several companies, they simply do not have the correct dryer and it needs to be replaced. Color correction or the very bad practice of double color is band aiding the fact that their dryer is not sufficient.

Best regards,
 

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Discussion Starter #11
hey, i was just going by the big *** letter i got from Kornit..
its as follows...


From the Desk of Paul Borucki, Kornit N.A.:

As we continue to work with customers each day we are seeing complaints of dull prints, dye migration and fixation burn out. It has become very obvious that all of these customers are over curing their garments. As we make the recommended changes to the customers from our office to change the way they are curing, the results have been dramatic and keep them from "the burn out look".

We have seen customers that have been told to set their dryer at 345 to 360 degrees and that is ruining their chances of success. Once we teach them to reduce the temperature to 300 degrees to 310 degrees on forced air dryers, the colors stay brilliant.

I want to take this time to go over curing digital prints:

The whole issue with electric dryer is scorching of the inks. If you combine too much raw heat without sufficient airflow impingement to the garment surface the inks will dull and burn off too quickly rather than slowly evaporating the water to leave the pigments behind.

Sensitive garments such as polyesters and poly acrylic blends require very low cure temperatures but at extended cure times. Depending on the dryer, conveyor belt or cabinet dryer, the temperature needs to be approximately 250 degrees for 5 to 10 minutes.

Every dryer installation is unique beginning with the power supply. If the owner does not run the proper power to the dryer and read the supply power “at the dryer” all temperature and cure times will be different. A drop in power will mean reduced cure in any electric dryer.

The atmosphere around the dryer directly impacts the cure rates. Hot, dry or cold temperatures in the shop will change the time of cure.

The surrounding equipment in the building or building complex can cause a power draw down will affect the cure specs.

The weight of the garment ( a 6.1 oz t shirt versus a 20 oz sweatshirt) and the saturation of the number of garments that are physically placed on the conveyor belt will change the thermal mass in the dryer and affect cure rates. There will be a difference in the cure of the one off print going down the belt versus a fully loaded dryer.

We always recommend the following

Turn the dryer belt to its slowest setting.
Set the temperature to 310 degrees.
Airflow set at maximum.
Run a shirt through the dryer and check for cure.
smell the garment when it is cool. Check for any vinegar odor
stretch the garment and look for cracking
The prints should be odor free and very stretchable.
Slowly increase belt speed to achieve the most efficient cure rate at that temperature setting.

As the garment weight, the amount of ink on the print and the more wetting solution that is applied, all of these will change your cure specs.

It has come down to one simple factor at several companies, they simply do not have the correct dryer and it needs to be replaced. Color correction or the very bad practice of double color is band aiding the fact that their dryer is not sufficient.

Best regards,
LOL. So...

We need specific dryer settings for each garment, and different settings if we are running garments fast enough to fill the belt AND different settings for different temp/humidity combos?!?!?!!

Didn't Kornit advertise this friggin machine as EASY! dubbahueteafFFFFFF!

What is next? Do I have to check the phase of the damn moon? No religious holidays? Do not feed after dark? Don't look at it and say bloody mary 3 times? Don't step on a crack or you'll break your kornit's back. Don't hit both green buttons at once. Don't expect an actual workable solution to getting consistent prints from your Kornit!
 

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i had found that if we do get a shirt ( usually yellow, light blue shirts ) with stains _ like the pre treatment had dirty water with it... don't know how to describe it... but i just take the shirt into our screen wash out room and wash it out with a water hose... and i have saved some shirts this way...it will wash out the stain...
 

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Discussion Starter #14
that's just it...each day your settings are different!! rainy days... hot days...shirts that are made (same brand - ex. gildan 2000 ) in different countries...require different settings... its a freaking headache... someone should publish the "real manual for this thing"
Hehe, "Real Manual" would be a 3000 page flow chart in 8pnt type.

You could write a logic testing program with lots of If/Or statements for it... but no computer currently in production is powerful enough to run it. Like in Hitch Hikers guide to the universe!

So I guess the answer is "PERFECT CUSTOM T SHIRT" we just don't really know the correct question.
 

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LOL. So...

We need specific dryer settings for each garment, and different settings if we are running garments fast enough to fill the belt AND different settings for different temp/humidity combos?!?!?!!

Didn't Kornit advertise this friggin machine as EASY! dubbahueteafFFFFFF!

What is next? Do I have to check the phase of the damn moon? No religious holidays? Do not feed after dark? Don't look at it and say bloody mary 3 times? Don't step on a crack or you'll break your kornit's back. Don't hit both green buttons at once. Don't expect an actual workable solution to getting consistent prints from your Kornit!
We have virtually no cure or burn issues with 5500CFM air flow. Too manny people have gone cheap on their dryers after spending big bucks on a machine and they get bad results. You need a gas oven to cure waterbase ink effectively in screen printing or DTG. We use 2 dryer settings- white shirts and dark shirts. Thats it.

As for the pretreat stains some brands and colors discolor with the fixation even if you just got perfect prints. Colors like light blue, safety orange- green pink and orange are notorious. Reduce your spray a few point and lower your temperature. This is important if it is a 2 sided print.

DTG printers probably have the worst curing issues in the biz. I got free shirts a SGIA from everyone and the ink fell off every shirt but the Kornit. They cured thru a 12 foot gas chamer with at least 5000cfm. We print thousands of shirts per week and cure is not an issue. Niether is staining.
 
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