New Polymer Composites For 3D Printing

The technology offers an approach to prepare unique polymer composites for 3D printing consisting of a polymer matrix and a filler, whereby recycled polyethylene terephthalate glycol (rPETG) is used as the matrix and the filler is a mixture of expanded graphite and carbon fibers in a suitable ratio. As the polymer matrix, rPETG has a higher impact resistance and clarity than polyethylene terephthalate (PET) and its price is several times lower than non-recycled PET. The mechanical properties of the resulting 3D component are also similar to those printed from virgin material. To improve the mechanical properties (static and dynamic) and reducing the weight of the final product, carbon fibers in a suitable ratio with expanded graphite have been mixed into this polymer matrix. Expanded graphite reduces the abrasive properties of carbon fibers, improves the rheological properties of the polymer melt with carbon fibers and adds fine roughness to filaments, resulting in an easier feed into the nozzle. Thanks to the high thermal conductivity of the expanded graphite it is not necessary to change the temperature parameters of the processing. These composite filaments can be used in fused filament fabrication printers.

This technology is suitable for partners seeking to fabricate cost-effective, high performance materials through a 3D printing process.

Composite filaments produced from this technology comprise of the following components:

• Recycled polyethylene terephthalate glycol (matrix phase)
• Mixture of carbon fibers and expanded graphite (reinforcement phase)

The new polymer composites fabricated from the 3D printing process have the following attributes:

• Cost-effective (Cost of the polymer matrix rPETG is several times lower than virgin PET)
• Higher impact resistance and clarity than PET Weight reduction (saving about 15-20% of the final product weight)
• Improved mechanical properties
• Better surface appearance

Potential applications of the new polymer composites include (but are not limited to):

• Automotive industry
• Aerospace Structural components

The new polymer composites developed from this technology maintains the high mechanical performance of a composite fabricated with virgin material and offers a cost-effective solution as the polymer matrix utilized is a recycled material. The surface finishing of the final component is much smoother than those produced using commercially available PETG composite filaments.