DTF with Epson F2100 Questions and Issues

[MaxQ]

We've been printing DTG for a few years now and just started with DTF. We use an Epson F2100 and get some great results (mostly).

Issues we've seen are,

 

1. The powder always cures as a yellow color (except when just using white ink). This does not seem to affect the print on the shirts, the yellow ink does seem to transfer to the T-Seal sheet even though the instructions don't say it's not compatible.

That said again does not seem to transfer back to the printed item.

2. We use a DTFPRO HEAT STATION V2 where it says the temp should be 248 for 120 seconds, instructions on the manufacturer film contradict these.
I.e 300-315°F, 1min so not sure what temp and time to use. Get pretty good results but frequent "pin holes" in the ink. 
Can anyone advise on how to avoid those?

3. Issues with Magenta and White, we found recently any design with red or colors using Magenta print ok but when the white is printed over the top the red starts to bleed through the white. Tried leaving 60 second drying time between color and white with no difference.

Hoping someone can help us out.
DTF is a game changer and suddenly we can print on all kinds of fabrics and substrates, just have to iron out the bugs for those perfect prints.

[johnson4]

4 hours ago, MaxQ said:

We've been printing DTG for a few years now and just started with DTF. We use an Epson F2100 and get some great results (mostly).

Issues we've seen are,

 

1. The powder always cures as a yellow color (except when just using white ink). This does not seem to affect the print on the shirts, the yellow ink does seem to transfer to the T-Seal sheet even though the instructions don't say it's not compatible.

That said again does not seem to transfer back to the printed item.

2. We use a DTFPRO HEAT STATION V2 where it says the temp should be 248 for 120 seconds, instructions on the manufacturer film contradict these.
I.e 300-315°F, 1min so not sure what temp and time to use. Get pretty good results but frequent "pin holes" in the ink. 
Can anyone advise on how to avoid those?

3. Issues with Magenta and White, we found recently any design with red or colors using Magenta print ok but when the white is printed over the top the red starts to bleed through the white. Tried leaving 60 second drying time between color and white with no difference.

Hoping someone can help us out.
DTF is a game changer and suddenly we can print on all kinds of fabrics and substrates, just have to iron out the bugs for those perfect prints.

1-2: sounds like overheating. Lower temperature increase time. Problem with machines like that is it’s not the “temperature” it’s the cycle that cures. Those bulbs heat up to 700F in a few seconds easily. If the bulb stays on for 15-20 seconds before actually heating up the unit and temperature probe, then you’ve just put your transfer in a 700F oven for 20 seconds. The bulbless machines aren’t as bad, but still develop hot spots. So while the probe may read and stay at 248F, the temperature at the film can have easily reached 700+ before it registered that. 
 

my recommendation: for testing, pre heat machine by turning it on as if you were curing a sheet but with nothing in it. Then, immediately after while it’s still hot, try to cure a sheet and see if it changes. 

2. I cure mine at about 71C ( preheated, always on) for 3 minutes. The bulbs only cycle on to maintain the temperature, which is about 3-5 seconds on time. Perfect cure. Another machine I have cures at 98C, about 3 minutes. If I did 75C on the first machine, my film would be kinda crinkly, yellow, and pinholes. 
 

it’s not really about the temperature, it’s about the cycling of the bulbs and the airflow. Each machine design will be a bit different. Testing is required, especially for a Chinese machine. 
 

the other issue is probably a compatibility issue with the film/ink.