Here are some "insider tips" from Eastman's Technical Service Team for cutting composites and fibers with the Eastman automated cutting systems:

Fiberglass – Eastman recommends cutting fiberglass with a round blade. The blades will dull quickly but this is not a problem since the round knife crushes the fibers, causing the fibers to break. As the blade dulls, increased cutting pressure can extend the blade life. Blade exposure and pressure will vary based on material weave, density and thickness. Once a blade is used for cutting fiberglass it can no longer be used to cut other materials because it dulls.

Dry Carbon – Dry Carbon weave is cut with a 1” or 2” round knife.  A harder surface such as Porex or Lexan is recommended for cutting.

Prepreg Carbon – An Eastman drag knife is used to cut Prepreg Carbon material, used for a variety of aerospace, automotive and general industry applications. The Prepreg Carbon needs to have a release film (peel ply) top and bottom so that the vacuum holes do not clog and the cutting knife does not gum up.  

Kevlar – Kevlar is cut with a drag knife and may require plastic overlay for small pieces. There are many variations of Kevlar which may take some testing to determine the optimum pressure and blade exposure for cutting on an Eastman automated cutting system. A hard cutting surface like Porex is preferred. A belt or Lexan can cause hangers when cutting over perforations. Different loose weaves may require both a paper underlayment and plastic overlay for handling purposes.

The Eastman M9000 static cutting table that we purchased is being used to cut Kevlar® fabric. This fabric is cut and sewn into targets used for the ballistic testing in the development of Military body armor. The M9000 has reduced our labor costs and increased our uptime for this development work. This is critical in meeting the needs of the U.S. Military.

Pat Fitzgerald - DuPont Company
Kevlar® Life Protection, Research & Development

Spectra – Eastman recommends cutting Spectra with a drag on a hard surface like Porex. With plastic overlay, it is possible to cut multiple layers depending on pieces size and the intricacy of the cuts.

Fiberglass Insulation – The compressible Fiberglass Insulation that comes off rolls and used for insulating HVAC boxes is cut with a round knife. The fiber board insulation that come in sheets are cut with a drag blade. Thicker sheets up to 1” thick are cut with Eastman's specially designed 1” drag blade.