# Is it safe to heat press on 87% polyester/13% spandex ?



## CELEBRATIONS (Feb 16, 2011)

Is it safe to heat press on 87% polyester/13% spandex ? I f so what temperature is best?
Is it safe to heat press on 100% double knit polyester?


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## D.Evo. (Mar 31, 2006)

It is safe and it's done with dye-sublimation printing all the time.

For Spandex and Lycra blends the temperature should be a little lower than regular polyester and you may need to pre-shrink the fabric before applying the print as some of these fabrics shrink a bit and you may get ghosting.

What type of transfer media are you using? 

I do dye-sublimation printing on the fabrics you ask about and my settings are 195-200C for 60 sec for polyester and 180-190C for 60 sec for Lycra/Spandex-rich polyester or nylon, light pressure.


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## GordonM (May 21, 2012)

Like Tania said. But when you say "safe," what do you mean? Spandex (and Lycra) both have a much lower "sticking point"* than polyester, about 340-350 degrees, and its melting point of only 450 degrees, so be mindful to turn down the temp a bit. Otherwise, you could get excessive shrinkage that puckers the fabric, which looks particularly unsightly for swimwear. The higher heat also permanently weakens the Spandex content, making it less stretchy.

*The sticking point of a polymer is when it starts to soften and get tacky, but does not actually start to melt. At this point the plastic can undergo changes that permanently alter the characteristics of the material. So while Spandex has a melting point a full 50 degrees above the typical temperature for sublimation, it can be changed/damaged by prolonged temperatures as low as 350 degrees.


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## CELEBRATIONS (Feb 16, 2011)

i am applying rhinestones


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## GordonM (May 21, 2012)

CELEBRATIONS said:


> i am applying rhinestones


One of those times it would have been useful to say that up front! 

In any case, most rhinestone/stud transfers are well under any "danger" temperature for Spandex (about 325-330). Whether or not the stones will stay stuck when the fabric is really stretched out is another matter, and you'll need to test.


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## menorris (Oct 2, 2015)

Hi guys, I'm searching this thread, looking for an answer to a similar question. I have some jerseys of this same material that I need to heat press some art on. I'm using ThermoFLEX as the media on a plain old heat press. Is 330-335 degrees F safe for this kind of shirt?


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## Laughing Palm (May 4, 2007)

It's probably safer to use ThermoFlex Xtra instead of ThermoFlex Plus. It applies at a lower temp (310-315 F), but it may or may not come in the color(s) you need. Remember that you may still have to contend with dye migration...and press marks on poly garments!

Good luck,


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## supplies (Dec 2, 2015)

doesn't a sublimation piece have a coating specific to that process? For instance, if you have a soft shell jacket that is 97% polyester and 3% spandex, that doesn't necessarily mean you can sublimate it, does it? We are trying to decide how to apply a customer's digital design to this jacket. Heat transfer was the first thought and the temp recommendation is 320 degrees maximum. It would be great to just use sublimation instead, but I am sure there is no special coating.


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