Co-authors​ :

 Zijian WANG (CANADA), Zhengshu YAN (CANADA), Larry LESSARD (CANADA) 

As the world is faced with an increasingly dire need to minimize its carbon footprint, many countries have transitioned to various renewable energy sources to provide electricity to their industries. An effective method of generating renewable power used by economic leaders such as China, the United-States, and Germany has been to harness wind energy through wind turbines. However, accompanying this source of energy is the waste generated by the turbines’ end of life: millions of tonnes of decommissioned turbine blades. To achieve such lightweight and stiff structures, fiber-reinforced polymer composites (FRPC) are typically used, notably glass fiber (GFRPC’s) for its inexpensive cost. The disposal of such material has proven to be a difficult task as recycling GFRPC’s has not reached an economically effective supply nor demand. In addition to the energy sector and the accumulation of waste turbine blades, several other sources are contributing to the increasing mass of waste GFRPC’s annually including decommissioned aircraft and boats, automotive components, swimming pools and bathtubs, water tanks, and water slides. As these vehicles and structures reach their end of life, the landfilling method poses a growing risk to the environment through soil and water contamination, destruction of landscapes, and depletion of available landfilling space. Burying such large structures also limits access to the potentially reusable fiber reinforcements for a secondary use, reducing the carbon footprint of the manufacturing phase. One method of managing such waste that has shown economic efficiency and mass-processing capabilities is the mechanical grinding and milling of GFRPC structures such as waterslides and wind turbine blades into particulates. This material can then be re-introduced into the 3D printing filament production stream, notably that of fused filament fabrication (FFF), to improve the strength and stiffness of printed parts, an ongoing concern for this fabrication method. In this paper, the mechanical performance of several common polymers used in FFF reinforced with recycled GFRPC particulate (“recyclates”) was investigated. Recyclates produced from the grinding and milling process were graded through several steel meshes with decreasing aperture size using a vertical-horizontal dry sieving machine. The smallest fraction of recyclate were then dried in a dehumidifier and combined with the new polymers in a pelletizer to generate pellets less than 5mm in size. These pellets were then introduced into a filament extruder to produce filaments ready to use in the FFF process. Tensile test coupons were printed, and their mechanical performance was evaluated on a tensile testing machine. Strength, elasticity, and ductility measurements were recorded, and conclusions were made on the most optimal parameters for recyclate production, the ideal recyclate-polymer weight ratio, and the highest performing recyclate-polymer composition.