How To Make Polycarbonate Filament

Polycarbonate (PC) is a widely used strong, tough, stiff and durable thermoplastic polymer. Polycarbonate is used widely in construction, eyewear, consumer electronics, food packaging and the automotive industry (headlights, interiors). It can be transparent, be an electrical insulator and is known to have good thermal resistance and very good impact resistance.  There are hundreds of grades of PC varying from filled variants (carbon, carbon fiber, glass, fiber) to blends (PET, PBT) to alloys (with ABS, Acrylics). Inherently polycarbonate may have low scratch resistance and low long term UV resistance but this can be ameliorated by blends or additives (or by applying coatings to the final product). 

There are optically clear grades specifically for things such as safety glasses and grades that are flame retardant. If something needs to have high strength and impact resistance while being lightweight polycarbonate is often at the top of everyone’s list. If additionally it needs to be an insulator or have high optical clarity it is often the material of choice. Blow molding, injection molding and extrusion are all done with PC. Controversially polycarbonate is manufactured using bisphenol A. Even though many standards authorities consider the material safe for food contact applications there has been a consumer backlash against products in food contact applications that may contain bisphenol A.

Covestro’s Makrolon polycarbonate sheets are used in outdoor applications such as the cladding for the Allianz Arena.

There are a whole host of polycarbonate manufacturers including Sabic, Celanese, Quadrant, Schulman, ChiMei, Teijin, DSM, Covestro (formerly Bayer Material Science), Ineos, Asai Kasei, Lehmann & Voss, Mitsubishi and many others. Due to this polycarbonate is known under many brand names such as Lexan, Makrolon, and Cycoloy.

For many industries PC is a mainstay of their industrial plastics usage. With many grades being made and developed (because the material is so compatible with many other plastics) there is continual development in the Polycarbonate market as well. We’ve noted a high interest in PC from certain customers due to their high usage of the material.  Due to this we’ve been dialing in the material and extruding it on the 3devo Next Filament Extruder.

Drying polycarbonate granules is an absolutely essential step when trying to make filament.

We store our polycarbonate granules in airtight containers.

What we’ve found is that drying out polycarbonate before use is absolutely essential. Drying has a huge impact on the process-ability of the material. The surface and the brittleness of the material are adversely affected if the material is not sufficiently dry. Depending on the grade an additives five hours at 110 Celsius is recommended. With some grades longer drying times or drying times at a higher temperature such as 120 may be better.

One of our test filament extruders while making polycarbonate filament.

A roll of poly-carbonate 3D printing filament made on a 3devo filament extruder

Our Polycarbonate filament performs well and are waiting to see what our customers will develop with this material.