My first question is...could those black dots be caused by the crystalization?

No.
Crystalization has nothing to do with the print itself.
Looks like you have a few fibers showing through, but mostly holes in your pretreatment.
Applying the pretreatment in two coats, and possibly using more pretreatment should fix the issue.

Second question, my noozle check keeps showing me these messy results.(pic attached). Could those black dots be caused by this?...(head need to be changed or dampers?)

Missing a few nozzles, but not enough to make a noticeable difference.
You may want to perform a printhead alignment though.

 

No.
Crystalization has nothing to do with the print itself.
Looks like you have a few fibers showing through, but mostly holes in your pretreatment.
Applying the pretreatment in two coats, and possibly using more pretreatment should fix the issue.


Missing a few nozzles, but not enough to make a noticeable difference.
You may want to perform a printhead alignment though.

Thanks mate for your answer, well...how is that, i cant press those fibers in with the hight pressure, and i literally tried more combinations of pressure and times, and still can see those fibers..also tried more shirt brands (still ringspun combed 100% cotton)...i was thinking about the print head alignment, doing it today so lets see the results...
The pretreament, i also tried more options...from less to literally flooding the garment.
The nozzle check, i was thinking it should be nice and symmetrical, as it is on this picture..pls see..and my one is not...anyways, i will do the head alignment and i will update this post after.

 

Try brushing the wet pretreated area with a paint brush and in one direction (top to bottom for example).
Then press to dry and remove the cover sheet by sliding it instead of peeling.
The sliding must be done in the same direction as the brushing.
This should flatten the fibers much better.

 

Hello there hope you all are doing fine today!

I would like to share my experience with these "pinholes", perhaps it can help. I almost never got a good print - easily - when this issue happened. I always got pinholes on the underbase, over different colors, and more with some specific t-shirt brands.
Perhaps way too many softeners or silicone finishing used on, or maybe a bad batch (over several colours). I can not be sure, but I did extensive tests on some colours and brands over weeks while doing my job.
My best solution to optimize the final result was this:

• Use a lint roller to remove all the loose fibers in the printable area.
• Apply pretreatment. (you must test your pretreatment to water ratio in order to get the best results, and without crystallization or poor coverage. My suggestion would be, perhaps, 2:1)
• Use a paint roller to spread it evenly. (in one direction as pointed out by TABOB)
• Dry it partially in the tunnel dryer. (I noticed that most of the times, heat pressing the t-shirt a little damp gives better results to keep the fibers down)
• Heat press it.
• Repeat all the above.
• Print and cure.
• Wait 24 hours and do a washing test. (10 pieces minimum, normal washing settings and NO detergent for whites)

Now then, as I am sure you might agree, there is no point mentioning settings for this fluid and that machine. Too many different parameters everywhere. You have to fine-tune your machines accordingly to your print room environmental conditions, the inks and pretreatment you use, and all the machines involved in the process. Again, the best way to do so is through washing tests. Try, Test, Fail, Learn.

I hope these guidelines can somehow help, someone!

 

Use a lint roller to remove all the loose fibers in the printable area.

Very good point.

Perhaps way too many softeners or silicone finishing used on, or maybe a bad batch (over several colours). I can not be sure, but I did extensive tests on some colours and brands over weeks while doing my job.

The term you are looking for is "sizing agents". They are a headache, especially with the cheaper lightweight t-shirts.
Applying the pretreatment in 2 layers does help a little bit, but you have to be careful, as applying too much will affect washability.

The best thing to do would be to print only shirts you have tested and know print well.
Trying to print on every shirt available might cause hair loss.

 

Thanks for the insight TABOB!

 

@DTG Merch thanks mate for the input,well I do use the lint roller actually all the time, just forgot to mention it..shirt brands..as said I use organic shirts only..do u think they use softeners and silicone..if its organic? anyway I got your point, still new to it so there is lot of space for an improvement and testing.
Today I did the head alignment and did some prints.
I used the firebirds universal pretreatment without diluting as recommended by the "firebirds"
Before pressing, drying the shirt, after press 3 x 20 sec - 1 x light, 2 x heavy
Curing on the light press setting for 100secs.
GC settings:
White level 2
uni-direction
density at 100%
brightness 20
..and here is the result...still the holes are visible, but Id say its an improvement.
@TABOB Im slowly finding out the DTG printing is a whole alchemy

 

Quick questions guys...do you cure ink with light pressure or just hoover cure ink or uv tunnel? also what type of paper do you use if using heat pressure curing..I tried teflon paper kraft paper parchment paper and still sticking to the print..what is causing those holes and fibers poping ups as well, i suppose. Im about to try option: hover cure for 30 secs, following with light pressure for 50-60 secs.

 

Pretreatment:
The best way to dry the pretreatment is using a forced air conveyor drier.
Then you do a quick 5 second press with a Teflon sheet and you are ready to print.
The same applies when using "ready to print" shirts, which have actually been dried in a tumble dryer.

Ink:
The best way to cure DTG ink is using a forced air dryer, followed by 15 seconds on the heat press.
However, you may have washabillity issues if you are using too much pretreatment, as there is nothing to push the ink into the fabric.

No pressure is needed when curing with a heat press, but it does help when excessive pretreat has been applied.
Pressure affects the colors, but will push the ink into the fabric, improving washability

 

Hello Gigantwear, hope you doing well today!
Well... I can't agree more with TABOB. All is said in his message. (and WELL said!)

What I can add is this; during my trips installing machines around the world, I have seen a lot of "ideas" on drying and curing t-shirts. However, I never tried these methods, since I had all the machinery I needed back in the factory. So, do it "at your own risk"

• Pretreat and hang dry the t-shirts. Then, the next day, heat press it and print on.
• Hover the printed area for a few seconds and then push down the heat press plate with the press paper you like.
• The press paper to use: In my opinion, it depends on how do you want your print looks like after the HP. When you use the Teflon sheet, you gonna get a shiny look (like on screenprint). When you use parchment paper you get a mate/dull look on the print.

Hope that helps!

 

@TABOB @DTG Merch thanks a lot guys for your help, im gonna try all the tips..I will update what works best. Stay Safe!