Is it true that Eastman Spectar™ copolyester can be flame polished to give sheets a glossy, shiny edge? How is it done?

Yes! Sheet made from Eastman Spectar™ copolyester can be easily flame polished using easy-to-find tools. Beautiful results can be obtained when the correct techniques and tools are used.

Flame polishing is a method used to shine the edge of a plastic material by exposing it to a flame or heat. By melting the surface of the material, surface tension smooths out the surface.

Because Spectar has a lower softening temperature (T_g) than acrylic, it is important to use a lower-temperature flame and quicker passes than typically used with acrylic. Polishing Spectar can be accomplished equally as fast as polishing acrylic—sometimes even faster—which means using Spectar for a project could enhance production efficiencies.

Step-by-step instructions for flame polishing Eastman Spectar™ copolyester:

1. Use a standard handheld torch that emits a flame of 150°–250°F. A standard butane torch, propane torch, or hot nitrogen welder works well.
   
   
2. Keep accurate control of the distance between the sheet and the heat source—otherwise bubbling or distortion could occur.
   
   
3. Keep the flame moving; do not dwell on one spot.
   
   
4. Thicker-gauge sheet may require an additional step before polishing. Round the edge of the sheet or deburr. For example, you may use the following tool (Shaviv Vargus deburring tool). This step improves material distribution when polishing.
   
   
5. A smooth, shiny edge results! See picture of the flame-polished Spectar copolyester twist.

Shaviv Vargus deburring tool

​Flame-polished Spectar copolyester twist

A visual tutorial on flame polishing Spectar is available in our Video Gallery.

For additional tips, download our Fabrication Guide.