Thermal Die Cutting Tips

Learn about the thermal die cutting process and tips for cutting cast, calendered and reflective films...

In the thermal die cutting process, a magnesium die is heated and pressed against a  pressure-sensitive vinyl, such as RTape Vinylefx® films. Aided by the pressure of the die, the heat melts the film. Typically the film shrinks away from the cut line, which makes the process of weeding the unwanted film much easier and faster than when films are computer cut.

In making a thermal magnesium die, a photosensitive metal plate is exposed to light  and then chemically etched in an acid bath.  After etching  is complete, all that remains are the very fine beveled cutting edges of the die. 

In making a thermal die a magnesium plate is etched. To “kiss cut” vinyl graphics, the heated die is pressed against the pressure-sensitive vinyl film. To prevent sticking, dies are available with a release coating. Photo courtesy of Earl Mich Co.

Although thermal die cutting is a much slower process than steel rule die cutting, the cost of the tooling is significantly less, especially if the die has many lines of small type and intricate shapes. In many cases, achieving the same fine detail by bending steel cutting blades is either impossible or cost prohibitive.

The thermal die is attached to the bottom of the heated platen using a thermal bonding tape. Photo courtesy of Earl Mich Co.

In thermal die cutting, the two most important variables are heat setting and the dwell time. Heat settings will vary from one type of vinyl to another. A two mil cast vinyl will generally cut at 275°F or 135° C.  Calendered vinyl usually requires higher cutting temperature of approximately 300° F or 149°C, which is the same recommended heating setting for Vinylefx® films.    The typical temperature for cutting reflective sheeting  is about 325° F  or 163°C.  

Please note that I qualified my statements with the modifiers: generally, typical and usually.  These temperature settings should be regarded as starting points, when you are setting up for production.  Temperatures and dwell times will vary depending on the die cutting press and the material that you are cutting.  Adjusting the temperature and dwell times in many cases is a matter of trial and error.

Careful inspection of the cut vinyl  is important not only during the set up stage but also throughout the production run.  The press operator should periodically inspect the material that he is cutting to ensure that he is getting the desired results, regardless of what type of material he is  cutting.  Some printers will spot check their work every twenty to forty sheets.  Printed sheets  and sheets with intricate copy and designs should be inspected more frequently.

The rule of thumb is that as the thickness of the vinyl increases, so does the require cutting temperatures and dwell times.  Here’s another rule. Your settings will vary depending on whether or not the vinyl is printed and clear coated and what type of ink is used. 

Dwell  is the time that the press is closed. Dwell time can vary greatly depending on your cutting temperature and the composition of the material that you are trying to cut. Dwell times can vary from a half of a second to as long as six seconds.  If you are cutting a two mil cast vinyl at a temperature of 275° F, the typical dwell time can be between a half of a second to one second. At 300° F, calendered vinyl will require about a second. At 325° F, reflective sheeting can take two seconds. The dwell time and temperatures for cutting Vinylefx™ films varies from one machine to another. At 300° F, cutting time can be as short as a half of a second. Other machines can require temperatures as high as 325° F for three seconds.

Common sense should be employed when adjusting temperatures and dwell time. For example, if the material starts to  burn around the edges, lower the heat or decrease the dwell time. 

Vinyl materials can release differently from different liners.  Some printers claim that the release from a 90lb. poly-coated liner is tighter than a 78lb. clay coated liner. For that reason, these printers believe that film on a clay liner weeds easier.  While some printer swear by clay liners, others swear at it, claiming that the liner curls in humid weather. 

Sometimes, when cutting at high temperatures, vinyl films and reflective sheeting can stick to the thermal die. Printed and clear coated films are more likely, to stick to the die than unprinted material. To prevent sticking, dies are available with a release coating.

To prevent damage to dies, try taping a rubber mat  on the bottom bed of the press. Using a rubber mat or 20 pt. board will provide some cushioning for the die.

In thermal die cutting, the film shrinks away from the cut line, which makes the process of weeding the unwanted film much easier and faster than when films are computer cut.

Photo courtesy of Earl Mich Co.

Transferring thermal die cut graphics can be problematic.  The melting process creates a noticeable lip on the edge of the vinyl, which is referred to as a burled edge.  The pressure of the die against the release liner will usually break through the siliconization layer, exposing the fibers of the liner’s paper base.  Over time the adhesive of the vinyl  flows into the cutline, bonding with the paper fibers.

The burled edge and the adhesive flow into the cutlines can make transferring of the film difficult. To aid transfer of thermal die cut graphics, RTape (www.rtape.com)  developed its 4885 heavyweight paper premask.  4885 is a super high tack tape with 20+ oz of adhesion. Die cutters are also using RTape AT75, which is a high tack film application tape. When using AT75, apply the film with a squeegee and wait at least 30 minutes for the adhesion to build to the graphic before attempting to transfer the die cut.

Vinyl Application Videos

Squeegee Technique. Nothing is more basic in vinyl application than the squeegee. But some squeegees work better than others. And there are right ways and wrong ways to use this simple tool. This video clip reviews squeegee selection, squeegee care and squeegee technique. Click to Link

Wet Applications. Dry applications are typically recommended for most vinyl applications. For those exceptions to the rule, this instructional video explains the right way to perform a wet application. Click to Link

Application of Window Graphics. Installing vinyl graphics on glass can be challenging, because the adhesive aggressively grabs onto this high energy surface. Repositioning graphics on window is generally difficult, if not impossible. This instructional video explains how to dry apply window graphics right the first time. It also describes the necessary steps required for surface preparation. Click to Link

Transferring Frosted Window Graphics Films.  Because frosted window films are highly textured, transferring cut vinyl graphics can be problematic. This video provides direction in selection of the right application tape and how to apply these films quickly, easily and without problems. Click to Link

3-Step Surface Prep. This instructional video describes how to properly clean the surface of a vehicle before applying pressure sensitive vinyl graphics to a trailer or doing a full wrap of a car or van. This three step surface prep involves detergent washing, solvent cleaning and a final wipe down with IPA. Click to Link

Vinyl Application Over Rivets. Applying vinyl graphics on vehicle surfaces with rivets is challenging for most sign makers. Vinyl failures to these surfaces are all too common. This video demonstrates some tips and procedures, used by professional decal installers, which will make these demanding applications easier and more trouble-free.  Click to Link

Vinyl Application to Corrugations. Learn how to apply vinyl graphics to corrugations in a relaxed state. Forcing films into the valleys of corrugations puts too much mechanical stress on the film. Sooner or later, the vinyl will lift or tent in valleys. Click to Link

Applying Air Egress Vinyls. Vinyl films with air egress release liners have almost eliminated bubbles and wrinkles from applied graphics. Air egress release liners with their highly textured surface structure are problematic. Not much will stick to these liners other than the vinyl film. At RTape our best premask solution for air egress liners is a special Conform® tape called 4761RLA. Click to Link

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.  Vinyl Sign Techniques is available at sign supply distributors and at Amazon. 

Slides of Jim's Artwork

© 2016 Jim Hingst