# Haze/smoke in print room?



## nkennedysnorg (Jul 23, 2010)

Back story to questions:

I have a brother GT-782 that i print hoodies and kids shirts with. The room I have it in also has a black body conveyor dryer set to 510 degrees. The belt is set for a three and a half minute cycle time. During the winter the two doors to the room have vinyl flaps hanging down from the door frames to help seal the room and keep the humidity up. We have a vent that has been connected to the dryer to help keep the room from getting too hot but the vent does not have a vent fan on it. After a long day of printing hoodies and kids shirt I may have a little bit of haze in the room. I am now starting to print some adult size shirts and the haze level goes up dramatically when I print them.

First off what is causing the haze? Is it left over pretreat moisture or the ink cooking off?

Should I install a vent fan on the vent connect to the dryer?

Should I have something else done to my HVAC system to move more air through the room?

I am possibly moving to a new space in the up coming months and if I do the dryer will me in an adjacent room that I will be able to load the garment into through a hole in the wall. I am doing this to help keep the heat of the dryer out of the print room to make it more comfortable and help with humidity. Will this also help with my haze problem?

Does any one have any other recommendations?

Am I using too much pretreat on the adult shirts considering their is less fabric to absorb the pretreat?

Any help is appreciated.


----------



## TahoeTomahawk (Apr 12, 2006)

Even though we vent our dryer outside, we still get the haze. It's because the shirt is still evaporating even after the shirt comes out. This happens for the first 10-12" after the shirt comes out. I think the only way around it would be to build a large hood to go over the dryer with an extraction fan and vent that out.

You also mentioned 510 degrees for 3 1/2, that is a very long time. How are you not burning the shirts to a crisp at that temp?


----------



## nkennedysnorg (Jul 23, 2010)

Does anyone use a stand alone air filtration unit to help with this problem?


----------



## Masco Sportswear (Aug 15, 2008)

510 degrees. That is extremely hot for sure.
I thought around 300 and depending on the speed of the belt. 

Steve


----------



## equipmentzone (Mar 26, 2008)

A conveyor dryer measures heat differently than a heat press. The temperature controller on a heat press should, more or less, indicate the exact temperature of the bottom of the heat platen that actually touches the garment. So 330 degrees shown on a digital temperature controller on a heat press will be 330 degrees + or -. Most conveyor dryers use IR heater panels. The temperature controllers on these dryers have a thermocouple (temperature sensor) that reads the bottom of the IR panels. The panel could be emitting 500 to 1000 degrees F but the panels are suspended above the garment as they travel through the dryer. They are not touching the garments. The air space between the panels and the garments take away a lot of the heat. So an indicated temperature of 510 degrees could be only 330 degrees on the garment itself. This is the norm for most IR conveyor dryers used in screen printing. I have seen many dryers set at 1000 degrees on the temperature controller to achieve an actual 350 degrees temperature on the shirts.

Harry
Equipment Zone


----------



## nkennedysnorg (Jul 23, 2010)

equipmentzone said:


> A conveyor dryer measures heat differently than a heat press. The temperature controller on a heat press should, more or less, indicate the exact temperature of the bottom of the heat platen that actually touches the garment. So 330 degrees shown on a digital temperature controller on a heat press will be 330 degrees + or -. Most conveyor dryers use IR heater panels. The temperature controllers on these dryers have a thermocouple (temperature sensor) that reads the bottom of the IR panels. The panel could be emitting 500 to 1000 degrees F but the panels are suspended above the garment as they travel through the dryer. They are not touching the garments. The air space between the panels and the garments take away a lot of the heat. So an indicated temperature of 510 degrees could be only 330 degrees on the garment itself. This is the norm for most IR conveyor dryers used in screen printing. I have seen many dryers set at 1000 degrees on the temperature controller to achieve an actual 350 degrees temperature on the shirts.
> 
> Harry
> Equipment Zone


Exactly. We are seeing about 320 degrees on the shirt when it comes out.


----------

