Can You Heat Press Polyester?

Heat press business owners cringe at polyester even though the material can give some of the best prints you can imagine. The either love it or hate it depending on the equipment they have. That’s because it is made from plastic which tends to melt if high levels of heat are applied to it.

That being said, this does not mean that the material cannot be used as a substrate in a heat press.

However, there are certain things you need to consider before doing so. For one thing, unlike cotton, polyester is tougher to work with because it is more tightly woven. Plus, it is more sensitive to heat and can stick.

The good news is that by keeping these considerations in mind you can make a tidy profit using this material in your heat press business.

Here are some of them in detail:

What Temperature Do You Heat Press Polyester?

A heat press works to print designs on fabric if it is heated to a high temperature. That is the only way the design can adhere to a piece of garment firmly enough to look as if it is part of it.

The issue lies in the fact that not every fabric allows this. For instance, it does not take much heat to make polyester melt especially if it is applied for a while.

The damage can be extensive or minor depending on your skill. The heated part of the fabric to crinkle up or you can ruin the entire garment.

Needless to say, the best way to ensure this does not happen is to stick to a lower temperature.

As a general rule of thumb, this should be somewhere between 270 to 300°F.

However, unlike other garments, you cannot apply heat on this material for too long even at this temperature. Stick to 10 seconds per garment to prevent damage.

How to Avoid Heat Press Marks?

As a novice heat press business owner, you will damage a number of polyester shirts or fabric before perfecting your craft.

Unfortunately, unless you can turn back time, there is no way you can remove scorch marks from this material after a scalding heat transfer.

If the damage is minor (the shirt only has glossy iron marks from the heat and is not burned) you can try to save it by washing it.

Here is what you need to do.

Take a damp piece of pressing cloth (a thin fabric that is used in ironing to keep it from touching the fabric directly) and lay it on the glossy spots. Press a hot iron on it long enough for it to start steaming.

Remove the cloth and dry the area with a towel before scrubbing it gently with steel wool to remove the shine.

Thick cover sheets such as silicone application pads may prevent the material from burning, but it will also prevent enough heat from penetrating it to make the design adhere.

Therefore, if you want to prevent damage and ensure good design application, you will just need to be extra careful when applying heat.

Give the Fabric a Trial Run

So we have established that polyester can be heated if done safely. What most people don’t know is that even with these precautions, the polyester fabric can still get damaged or melt.

It depends on the percentage of polyester in the garment you are using. In general, the fabric should have 48% polyester to not burn otherwise it will melt at even low temperatures.

To ensure this does not happen, the first thing you need to do is give the material a trial run in your heat press.

Take a small piece of polyester and place it in the machine at different temperatures. See what happens to it as the heat rises.

That way you can pinpoint exactly when it starts to get damaged and thus determine the temperature you should stick with.

If you plan on selling printed polyester shirts in bulk, for instance, make sure that you get identical pieces. That way you can be confident of success – even if you manage to damage a few pieces, you can learn from your mistake and ensure it does not happen too often.

Like any business, you will need to learn and grow from trial and error.

Consider Possible Issues with Dye Migration

Even if you have the best polyester shirts and have perfected the heat press method, you can face issues with the dye when you upgrade to the colored fabric.

For example, you can face dye migration or bleeding problems. This is something that happens mostly in synthetic fibers such as polyester and particularly if you are using white ink on colored shirts.

What happens is that the dye in the polyester fabric sublimates or turns into a gas when it is heated at about 330°F. This gas seeps into the ink layer which compromises the color of the shirt.

While this is unavoidable in most cases, you can prevent it from happening too many times by controlling the amount of heat you are applying.

In other words, make sure that you do not press down on the heat press long enough for that ink to sublimate.

Or you can use a catalyst such as Nylobond to reduce the drying temperature of the plastisol ink (the ink you used for the printing).

This is the best defense against dye migration.

While you can use thicker layers of ink for the same effect, you will need to apply way more heat to make the design adhere to the fabric. Even the slightest delay can melt the garment in this manner.

On the other hand, you can just check if a polyester garment is susceptible to bleeding and save yourself all of that hard work.

All you need to do is check both sides.

A shirt is more at risk of dye migration if it is a solid color on one side and has a heavy pattern on the other. Plus, bleeding is imminent on garments that were heavily dyed during the manufacturing process.

Wrapping It Up...

While you can make a tidy profit with a heat press, you can make your business boom by experimenting with different materials.

Since most apparel is made of polyester today such as caps, shirts, bags, etc, advertising that you offer printing services for it can be a good business decision.

However, even though the material does not get ruined in the wash and can last for years, it has a volatile reaction to high temperatures.

To prevent your inventory from melting, use the tips given in this guide and train your workers in them as well.

Pretty soon, you will have a profitable heat press business that does not need to turn customers away.