Heat Transfer Films: Hot, Warm or Cold Peel

Jim Hingst discusses the variables that affect how the carrier or hot mask peels from an applied heat transfer applique.

After you heat press an applique to a garment, how long should you wait before peeling the carrier or the hot mask from the applique?  A number of variables come into play. The answer depends in part on the physical properties of the hot melt adhesive and the type of carrier used on the heat transfer film. Of course, there’s more to it than that.

Each film is a little different from one manufacturer to the next, from one product line to the next.  You should refer to the information that the manufacturer provides.  In most cases the manufacturer’s guidelines are a good starting point.  For example, you can remove the carrier from most of the SEF polyurethane films, such as FlexCut Sticky and Tatoo, in three to five seconds after heat pressing. VelCut flock films require more cool down time after heat pressing. For the flock appliques, you should wait at least 20 seconds before removing the carrier.   These guidelines work for applications to most garments. 

This general rule may not work for every application, though.  How a hot melt adhesive adheres to a fabric can vary from one garment manufacturer to another. Fabrics colored with some dyes, may require modification of your heat press process. The weight of the fabric also affects the rate at which the garment and applique will cool down. Heavier fabric will require more time to cool down than thinner, lighter weight materials. That means you will probably need to wait a little longer before peeling the carrier.

The Role of the Liner or Carrier

The release value of the liner or carrier also plays an important role in determining the optimal peel temperature. Here’s why. When the heat press opens the hot melt adhesive is still in a very liquid. In this liquid state, the adhesive bond to the fabric is very low. As the hot melt adhesive cools, it re-solidifies very quickly and the adhesion builds.

What is Peel Adhesion?

The strength of adhesive bond to the fabric is opposed by the peel adhesion value of the liner. Peel adhesion is the amount of force, measured in grams, required to remove the film from its carrier. Peel adhesion of the liner depends on its physical properties, such as surface finish (glossy or matte), acrylic mass, silicone mass, high release chemical components.

Manufacturers use a variety of release liners with a wide range of release values.  If the release value of the carrier is low, a hot peel is generally possible, immediately after the heat press opens. If the release liner has a medium release value, a warm peel is recommended after three to five seconds after heat pressing.  The higher the peel adhesion value is, the longer you will need to wait before removing the liner or carrier. When the release strength of the liner or carrier is high, a cold peel is recommended, which can take twenty to thirty seconds.

Not all liners perform according in the manner that I just described. Some liners have unusual performance characteristics. For example, in some cases a liner can exhibit very low release strength when it is hot, but the release value can build dramatically as it cools. In this instance, a hot peel is required. Conversely, another liner may  have  very high release strength, when it is hot, but the release can decrease as it cools. In this case, a cold peel would be recommended.

What’s important, is that you carefully qualify the products that you are working with so that you understand the performance characteristics, before you use these materials in production.

Troubleshooting Heat Transfer Films Peel Problems.

When an applique does not adhere properly, here are some remedies that you may try:   

• Heat pressing is a function of time, temperature and pressure. First, check your heat press settings for time and temperature.  If these are set at the specified levels, then increase the pressure.  You may also need to test actual temperature of the platen with an IR temperature gun.
• Unusually large appliques may require an increase of the heat pressing time.  This will give the hot melt adhesive more time to transition from a solid non-sticky mass to a liquid that will flow out onto the surface of the fabric. I like to compare this to grilling a steak. It takes more time to cook a thick steak than a hamburger. Generally, increasing the press temperature will not help.
• Cool down time is important. After the adhesive flows into the texture of the garment, you must allow it time to solidify and mechanically grab onto or adhere to the garment.

About SEF Americas SEF Americas is the exclusive distributor of SEF heat transfer material in North America.  SEF Americas sells and services their product line through a network of distributors across the United States and Canada.  The company's product line includes an array of  flex and flock films for plotter cutting and digital printing and cutting.  Popular SEF brands include Tatoo, Classicprint, Clearflex, Fiberplus, Metalflex and Reflexcut. About SEF-France.  For more than 35 years, SEF has provided the screen printing and garment industries with high quality flex films and flock films. Manufacturing at SEF is totally integrated. The factory formulates, casts and adhesive coats its own polyurethane (PU) films. SEF even manufactures its own flock fibers. With a corporate commitment to a greener environment, all of its film and adhesive formulations are water based. This ensures that no solvents pollute the atmosphere. Its only emission is water vapor. Today, SEF is recognized as a leading producer of heat transfer films for used in the fabrication of heat press appliqués for textile decoration. Its ultra-thin polyurethane films and super soft flock films are easy to plotter cut and digitally print.

ARTICLES ABOUT HEAT TRANSFER FILMS

Printing Heat Transfer Films with Latex Inks

Changing Printer Settings in Roland Versaworks

Tips for Cutting Flock Material

Heat Transfers on Neoprene

Stretching Garments Prior to Heat Pressing

The Differences Between Polyurethane and Vinyl Films

How to Flash Press FlexCut StickyLT  

Laminating Application Tape and Hot Mask Films
Stretching Garments Prior to Heat Pressing
The Differences Between Polyurethane and Vinyl Films
Printing Tatoo with Seiko Fluorescent Inks
Reflective Heat Transfer Films
SEF Heat Transfer Films Instructions
Introducing Tatoo Printable Heat Transfer Films
HotMask Polyester Transfer Tapes
Correcting Plotter Cutting Problems When Cutting H...
Which Films Stick to Coated Fabrics? 
The Difference between FlexCut Sticky and FlexCut ...
Heat Transfer Films Product Application Chart
Rules for Overlaying Heat Transfer Films 
Comparing Heat Transfer Films with Screen Printed ...
Peel Recommendations for Heat Transfer Films
Heat Pressing Appliques on Leather 

Heat Pressing on Dye Sublimated Fabrics

Heat Transfer Films: Hot, Warm or Cold Peel

Processing Printable Heat Transfer Films

Shopping for a Heat Press 

Pressing Heat Transfer Films

Evaluating Heat Transfer Films

Plotter Cutting Heat Transfer Films
Cutting & Weeding Tips for Heat Transfer Films
The Trouble with Shrinking Shirts
Caring for Garments with Heat Transfers

For More Information About SEF Americas:

14476-201 Duval Place West

Jacksonville, FL 32218

904-423-0211 - Phone

904-423-0899 - Fax

844-720-9600 - Toll Free

Ordering: sales@SEFamericas.com

Web: NEW SEF Americas Website

Click Here: SEF Americas Shared Public Folder

Click Here: SEF Product Application Guide

Click Here: SEF FlexCut Product Color Guide

Click Here: SEF Print & Cut Product Guide

Click Here: For SEF Documents
Click Here: Access Printer Profiles

About Jim Hingst: After fourteen years as Business Development Manager at RTape, Jim Hingst retired. He was involved in many facets of the company’s business, including marketing, sales, product development and technical service.

Hingst began his career 42 years ago in the graphic arts field creating and producing advertising and promotional materials for a large test equipment manufacturer.  Working for offset printers, large format screen printers, vinyl film manufacturers, and application tape companies, his experience included estimating, production planning, purchasing and production art, as well as sales and marketing. In his capacity as a salesman, Hingst was recognized with numerous sales achievement awards.

Drawing on his experience in production and as graphics installation subcontractor, Hingst provided the industry with practical advice, publishing more than 150 articles for  publications, such as  Signs Canada, SignCraft,  Signs of the Times, Screen Printing, Sign and Digital Graphics and  Sign Builder Illustrated. He also posted more than 325 stories on his blog (hingstssignpost.blogspot.com). In 2007 Hingst’s book, Vinyl Sign Techniques, was published.

© 2015 Jim Hingst