Thermal Die Cutting
What is thermal die cutting?
Thermal die cutting is limited to materials that can be displaced thermally, allowing a precisely controlled heat source to displace a small amount of material with minimal distortion to the surrounding material. The thermal die is typically made from a chemically etched magnesium alloy plate of varied thickness, generally 11-pt. (approx. 1/8”). One side of the plate is coated with a photosensitive emulsion, when the emulsion is exposed to light the magnesium cannot be removed by the etching process as easily, leaving the desired thermal die image protruding from the plate. Typically, thermal dies are used to kiss cut graphic marking vinyl. Because thermal dies are priced by weight or square inches of material, very intricate patterns may be produced at very affordable prices.
What are some limitations of thermal die cutting?
Thermal die cutting does have limitations; the cut typically produces a slight ridge, only materials that can be displaced thermally may be die-cut, and numerous material variables effect the quality and success of the cut.
Does thermal die cutting require pressure?
Thermal die cutting utilizes heat to displace the vinyl therefore, only enough pressure to insure parallel cutting surface deflection is required.
What temperature is required to thermal die cut vinyl?
The temperature requirements to thermal die cut vinyl greatly depend on the characteristics of the vinyl. Cast and calendered, thickness, even color are factors, most vinyl film can be cut between 285° F and 320° F with varying dwell times, typically ranging from .05 to 2.5-seconds.
Can the dwell be shortened and the temperature increased?
Yes, in most cases the temperature can be increased and the dwell shortened, so long as the vinyl film isn’t damaged by the higher temperature. Be aware that excessive heat can destroy the adhesive and shrink the vinyl of intricate patterns, resulting in curled edges of the cut part.
How do I take proper care of my thermal dies?
Because thermal dies are produced from a relatively soft alloy, the cutting surface of the thermal die is very fragile and must be protected from contact with anything that may knick or chip it during storage. It is a good practice to store each die on edge in an envelope made from a durable paper or beverage board. Both sides of the die should be cleaned after each use, removing thermal tape residue from the back and, if used, any applied release agents. Cleaning the thermal tape residue from the back die helps to insure a flat, clean setup for the next run reducing unnecessary make-ready.
What cutting surfaces are suitable for thermal die cutting?
Because thermal die cutting uses little or no pressure, the cutting surface must be heat resistant to approximately 400° Fahrenheit. Preferably a 12 pt. beverage board with polyester laminate on both sides covering a rubber blanket. Laminating both sides of the beverage board will allow both sides to be used before discarding.
What can be done to stop material from sticking to the die?
Typically material sticking to the die is caused by incorrectly cured inks or clear coating that is applied prior to die cutting. If the material is not printed or coated yet sticks to the die there are a few possible solutions. The die can be coated with a temporary release agent, the release agents typically contain some form of oil resulting in an oily residue where the die contacts the material. Some die manufacturers can coat the die with a Teflon type material. If coating the die is not feasible, an alternative solution to sticking is to use a small amount of double-sided adhesive or sand blast adhesive under a corner of the material sheet.
What materials can be thermal die cut?
Materials that can be thermal die cut must be thermally displaceable (manipulated with heat). Typically, graphic-marking vinyl is thermal die cut.
What materials cannot be thermal die cut?
Materials that can be thermal die cut must be thermally displaceable (manipulated with heat). Some of the materials that cannot be thermal die cut are; Polycarbonate, polyester, foils, and paper.
How do I establish a register position?
A register position must be established from a known die position. Typically, the die is mounted in the press, a clear stable material is taped to one edge of the cutting surface, and a carbon impression is then made in the clear sheet. Locate the material sheet under the carbon impression to indicate the die position in relation to the cutting surface. Secure the material sheet in place with tape, place position the edge guide and cut to test the position.