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Arithian · May 8th, 2008

Ok we are in a funny situation. We have the pretreatment down to perfection. One coat with 1440x1440 (we have a 4880 print head so the dots are smaller, lower resolutions look choppy). It is smooth, solid, and the color coat couldn't look better.

The problems we are facing are after multiple washings, corners start to peel. Its not major, just very small peel ups from the corners but if you pull them it will pull a bigger piece and break off.

We have done over 30 different prints with different settings. We get the best wash tests from the following.

We are using a Blazer Express (which has the 4880 Print Head) with Hanes Tagless and Beefy T shirts.

1440x1440 White
1440x720 Color (tried 720x720 but didnt come out as good texture/color wise)
4 mins pressed at 330 with 100 PSI

Underbase Settings
100 Strength
100 Light
100 Dark
10 Choke
Underbase Black Checked

All shirts were washed 10 times, cold water, inside out, dried on delicate.

Some Notes:

With our testing we discovered the following things provided better wash results even though they tend to go against the recommended norm.

We found underbasing black was necessary because if you didnt then it just created more corners which then peeled.

We found higher pressure (100-115 PSI) worked a lot better than the lower PSI settings (25, 35, 40, etc). For lights, the lower PSI works better but for a white underbase, it was higher.

Like I said above, we also found it necessary to underbase 1440x1440 or it was choppy. I read in another post this was because the 4880 Print Head had a smaller dot size then most other print heads.

I am at a loss really for what it could be. We tried different shirts both combed and open ended, different amounts of pretreat, different print resolutions both color and white, different tempatures, different cure times, different pressures, etc, etc. Like I said, we literally tried over 30 different prints, all with different settings, and washed them all.

I am really starting to wonder if its just how it is or if there is some combination of settings we just haven't found yet.

Has anyone been able to get dark shirts that look great after the initial print to still look great after many washings?

sunnydayz · May 8th, 2008

It doesnt sound like your print settings. It sounds more like the pretreatment. Can you tell us your pretreatment method so we can see if maybe there is something there we can suggest?

Thanks

Arithian · May 8th, 2008

Thanks for the response BobbieLee,

Pretreatment is the following.

1) Press shirt for 5 seconds to remove moisture and flatten fibers.
2) Spray shirt with power sprayer back and forth several times.
3) Roll over shirt with silicone roller very lightly down then across.
4) Press for 10 seconds with medium pressure with non silicone sheet.
5) Press for another 5 seconds to flatten fibers without any sheet at all.

I have wondered whether it would be the pretreatment but a couple things I wonder about. First, it lays down like a dream. At first, when we first got the machine, we werent pretreating correctly and it was a nightmare. Now it lays down perfectly everytime, nice smooth sheet.

Second, we have tested well over 30 prints, I wonder if it would be pretreatment only because some of those prints would be more/less than others. However, if I am doing something wrong, please let me know.

BobbieLee, let me ask you, does your dark prints ever peel? I guess what I am looking for more than anything is that this isnt the norm and that its a user end error and not just the "way it is" with DTG.

Thanks again for the reply.

sunnydayz · May 8th, 2008

Hi Joe,

I have a couple of thoughts on this, first I will tell you how I pretreat.

First I lightly mist the area with distilled water just so you see a slight beading of the water, very light.
Then I spray my pretreatement just so I see a slight whiteness of the liquid.
I then use a boar bristle brush and brush down fairly firm to make sure to get it into the fibers. I only brush the one direction.
Then I use the quilan parchment paper and press at 330 for 15 seconds
Then I remove the paper and press another 5 to 10 seconds until I dont see any steam coming off.

Now my 2 thoughts are either the pretreatment may be too heavy or the white ink layer may be too heavy.

Have you thought about trying to print 2 passes at 720 x 720 or printing white at 1440 x 720?

I learned the misting of distilled water from one of the users that used to post here that was one of the original printers of these machines and it works really great as it makes sure you dont get that box look from your pretreatment, totally gets rid of that and in my opinion seems to make the pretreatment mesh better with the fabric for some reason. Hope this helps some Joe, hopefully I mentioned something you can try

Arithian · May 9th, 2008

BobbieLee,

Thanks for the reply. I sent you a PM for some details on certain things like the way you mist and what not.

As for lighter resolution on pretreatment. No I have not tried two coats but just one coat of the lesser resolution is too broken up. I read a post on dot sizes and the print heads that go with them. Apparently the 4880 Print Head has a smaller dot size than the print heads with the earlier T-Jets and the HM-1, therefore a higher resolution is needed to get a full coat.

This would also explain why the sample I got for the HM-1 had a full white coat but was very thin and the full white coat we get from the Blazer Express is thicker. More ink to get that full white coat, however I will try two passes of a lesser resolution.

Too much white ink may be the problem though. When it peels, if it is pulled it stretches and pulls off more white ink. I will try your pretreat method, if the problem persists I will try different ways to get less white ink.

Thanks again, much appreciated!

Peta · May 9th, 2008

Hi!

I see more than one reason in your mail why white ink peal of.

1. Way to much pretreatment
2. To much white in underbase
3. To much pressure on the heatpress
4. Have you checked your heatpress temp with any instrument?

Here is our method in general:
Pretreatment is the following.

1) Press shirt for 5 seconds to remove moisture and flatten fibers.
2) Moist the shirt with a water bottle sprayer (old windex-bottle) Not wet, just moist.
3) Spray shirt with wagner power sprayer back and forth ONE time so it shows a mediumgray surface.
4) Moist the shirt again with a water bottle sprayer.
5) Roll over shirt with foam roller down then across (don´t need to be gentle).
6. Let the shirt rest for a minute or more. Hang it up and do the next shirt. (important step that let the pretreatment sink in to the garment).
7) Press for 15 seconds with medium pressure with non silicone sheet.
8) Press for another 15 seconds to flatten fibers without any sheet at all.
Now the shirt should be dry and ready to print on.

Image preparation:
Be sure to save image in un-profiled RGB color space and around 150-200 dpi in scale 1:1

Printer preparation:
Make sure that you have a 100% perfect nozzlecheck. If not, you don´t even have to try to print white. Fill up ink to the right levels.

Print settings:
When using a Blazer Express (which has the 4880 Print Head) it lays down alot of ink if needed.

1440x720 dpi Cartoon HS White
720x720 dpi Cartoon HS Color

Underbase Settings
30 Strength
60 Light
3 Dark
3 Choke
Underbase Black UN-Checked

if using overlap highlight:
0 Strength
70 in 100% white
0 Light areas
0 Dark areas

Curing shirt:
If the shirt is very wet (big image with alot of white) let it air dry until the surface is dry.

Then heat press with a silicon treated paper, low pressure (not more than 5psi), 165 degrees celsius (330 farenheit) in 180-240 seconds (time depends on how much ink is used in the image.

This is waterbased ink and if you use to much pressure, to short time or/and to low temperature the water can´t escape from the heatpress and that will affect the washability.

Washing instructions:
Wash in low temperatures, 30-40° celsius with color detergent and inside out. Don´t iron directly on print. Don´t use bleaching.

This is how we do it in general

Arithian · May 9th, 2008

Peta,

I will certainly try that, thanks!

One note about the pressure. We have tried everything from 25 PSI all the way to 115 PSI. Consistently, everytime, anything lower than 50ish bubbles when washed. This happens even if it is dried upwards of 6 mins. I am not sure, but we always get the best wash results if its higher PSI.

BTW by bubble I mean, gets like a funny texture, not actual bubbles.

I will certainly try the lower PSI, less pretreat, and even those settings you suggested.

Thanks a ton guys, this certainly gives us a whole new set of things to test! Which is a good thing! Thanks again!

Peta · May 9th, 2008

Hi!

Regarding the pressure: Maybe it´s a different kind of scale??! We use HIX presses and 100psi is absolutely maximum (we use 40psi for workwear transfers).

Good luck with your tests and have a nice weekend!

zhenjie · May 10th, 2008

Joe, just wanted to let you know you are not the only one experience white ink peeling.

I've had it happen on t-shirts where when it was first printed it looked great. Fantastic coverage of white ink and looked smooth as anything. After washing it would peel at the edges, and the whole entire layer could be peeled off. This problem I found only on certain types of t-shirts, mostly the ones with very tight knits (thus good coverage) and those that were enzyme treated.

I think overpretreatment might have been an issue with my t-shirts as well. I need to do more testing.

Also, I agree with you on the higher PSI = better washability. I did some test with low PSI, almost just touching the t-shirt and the results were pretty bad. However, that was with Teflon sheets and I'm now converting to silicone parchment paper for final curing. It seems to let the moisture escape more.

sunnydayz · May 10th, 2008

Yep I agree with zhenjie, the parchment paper works great

I only tried a teflon sheet a couple of times when I first got my machine and it was horrible.

PinkFreud · May 11th, 2008

secret revealed

always use a lighter weight shirt when using the underbase.....5.6 oz disperses into the fabric better and has better results including washability....AND...they are cheaper!.....6.1 oz is perfect for white shirts but not black

over and out

Peta · May 11th, 2008

Quote:

Originally Posted by PinkFreud


	secret revealed always use a lighter weight shirt when using the underbase.....5.6 oz disperses into the fabric better and has better results including washability....AND...they are cheaper!.....6.1 oz is perfect for white shirts but not black over and out

Hey Pink, what was that?
You can´t come in here shouting out figures then leave again

Tell us what brand and model you have used for this result. Our experience is that weight has very little to do with print result, it´s all in the cotton quality (length of fibres etc.) and how its knitted.

zhenjie · May 11th, 2008

I'm with Peta on this one. I've had some light weight shirts that have printed and washed beautifully. While other light weight tees had either bad coverage when printed, or excellent coverage but bad wash results. I'm amazed sometimes at how cotton quality can affect the wash results.

I have this black t-shirt that washes great. The only problem is that its a bit rough, and fibres can sometimes show through the white ink layer. But most of my customers are more happy with excellent wash results rather then a perfectly smooth print.

treadhead · May 11th, 2008

One of the first things I remember about DTG and white ink is that if you put too much pretreatment / ink down it will produce "perfect" prints but they will not hold up for very long.

However, there have been alot of improvements since then so not sure if that still applies.....

Don-SWF East · May 12th, 2008

Hi Arithian,

A couple of things here - the 4880 head actually can produce a larger dot at 1440 than the 2400 (HM-1) head as the firmware info is available to programers to access this droplet size (I want to say 20-21 pl versus 14-15 pl) so you should be able to get decent white at 1440 x 720. Secondly - you may be putting a bit too much pre-treatment down, instead of changing your method, try cutting your pre-treatment 25-40% with distilled water and keep everything else he same.

Hope this helps!