Composite Additive Manufacturing: A way to move forward in high-performance parts production
by Merve Canalp, Researcher at AMEXCI
In recent years, with the rapid development of additive manufacturing (AM) technologies and materials, we see that the use of additively manufactured light weight and low-cost parts produced with high-performance polymeric materials, such as composites, has been increasing in various applications. As a rule of thumb, additive manufacturing offers a faster adoption of new part designs for prototyping, and a smoother fabrication of complex geometries, eliminating the need for molds, as seen in the case of conventional production methods. Therefore, Composite Additive Manufacturing potentially ensures cost and time efficient production flow compared to the conventional manufacturing processes.
As AMEXCI, we have been working on different research projects to build a comprehensive understanding of Composite AM processes and materials available in the market. In May 2021, with the aim to provide an overview and a preliminary evaluation of different composite printing technologies, materials, as well as original equipment manufacturers, we finalized the project “Composite Printing Pre-study”. Following this research project, during Autumn 2021, we agreed to collaborate with different companies, which are providing a virtual workshop and introduction to their AM processes and materials.
The Composites AM market, .i.e., materials, hardware, software, services and applications, is expected to grow from $480 million in 2020 to over $10.6 billion by 2030 as stated in the “Composites AM” Insights published in spring 2021 by 3dpbm. During this span of almost ten years, our goal is to keep track of the developments and trends happening in Composite AM market in order to help our customers in finding suitable applications and optimization of end-use parts production.
Composite Additive Manufacturing Technologies
In general, Composite Additive Manufacturing technologies can be divided into six main categories: Robotic Material Extrusion, Composite Based Additive Manufacturing, Fiber Placement Additive Manufacturing, Composite Powder Bed Fusion, Composite Thermoplastic Material Extrusion, and Photopolymerization (see fig 2 below). These technologies offer different printing processes which affect the dimensionality/quality of the parts, printing time, size/quantity of the end-use parts fit in a printer, machine/material/printing costs, availability of different materials, post processing operations, surface quality, mechanical properties of end-use parts and many more. Some of the prominent technology providers and original equipment manufacturers of Composite Additive Manufacturing are Ai Build, CEAD, Electroimpact, Moi Composites, Thermwood, Impossible Objects, 9T Labs, Desktop Metal, EOS, 3d Systems, HP, ARBURG, BLB Industries, Markforged, Roboze, Stratasys, Essentium, Bigrep, BCN3D, Ultimaker, 3D Systems, and Fortify.
Additively Manufactured Composite Materials
Thanks to their intrinsic material properties, i.e., polymer matrix reinforced with fillers, composites show excellent mechanical performance and durability under various environmental conditions, such as high-to-low temperatures and harsh chemicals. Unlike metal parts, components made in composites are lightweight, and yet they can demonstrate outstanding tribological and mechanical properties. The final composite structure, i.e., particle reinforced, sheet reinforced or fiber (continuous or chopped) reinforced, of the printed components eventually depends on the utilized AM technology, e.g., FFF, MJF, CBAM, SLS, SLA, etc., and the type of composite materials, e.g., filament with chopped fiber, fiber tape/filament, fiber sheets; fiber-polymer mixed powder, pellet, and resin. Some of the commonly used composite reinforcement materials are glass or carbon fibers, particles, tapes, continuous filaments, sheets as well as carbon nanotubes. The reinforcement volumes can vary from as low as 3% to as high as 60%, depending on the AM technology in use. Some of the common composite AM matrices are thermoplastics, e.g., PA12, PEKK, PEEK, PA6, PET, and biopolymers.
Developments in Composite Additive Manufacturing
Additively manufactured composite parts have already been commonly used in tooling and prototyping. Recently, with the utilization of robotic extrusion or large-scale AM, we see that conventionally produced parts such as mold toolings can be replaced by additively manufactured composites or high-performance polymers. Other than innovative transformation of manufacturing methods, mold tooling by AM benefits from cost and lead time reductions, as well as complex design freedom and rapid iteration. In addition to this, the use of additively manufactured composites potentially eliminates the need for metal tooling in many industrial applications, which offers the ability to produce lightweight structures. Thanks to AM’s flexibility in production, storage and transportation of additively manufactured composites make them much more efficient for companies.
The effective utilization of additively manufactured composite parts relies on optimization of printing processes. In order to realize functional and reliable parts production, the processes and materials are still being validated through collaborative R&D projects.
One of the important aspects of improving the quality of printed composites is to enhance surface quality of end-use parts. For large components, e.g., molds, this is possible by milling the surface to get rid of printed layers allowing average roughness (Ra) as low as 0,6-0,8 µm. For small scale printed composites, smoothing the surface can be realized either by physical -, e.g., blasting, thumbling, or chemical surface finishing operation, e.g., chemical dipping, vapor smoothing. The effect of post-processing on the surface and mechanical properties of Onyx was probed by Post-Processing CFR Composite Parts with AMT PostPro 3D For Surface Finishing Project. Similarly, in 2020, AMEXCI had also utilized Onyx benchmark samples and investigated different surface finishing operation as well as suppliers in “212006-Polymer Surface Finishing Project”.
Recyclability of composite materials, including the printing consumables, e.g., powder from SLS, is a key for sustainable Composite AM. Recycling processes will continue to progress as new methods emerge for employing fibers and composite materials. For instance, companies like Vartega, and, Shocker Composites have been employing processes to allow re-usability and recyclability of composite wastes.[1]
According to the AMPOWER’s AM Polymer Maturity Index 2021, well-known printing processes, like filament extrusion technologies (FFF/FDM) offering broad range of available composite materials, have already showcased first applications in various industries. In the upcoming years, with the help of advancements in new composite AM materials and printing processes, AM technologies, which are still in the system prototyping phase, have the potential to emerge as new methods for producing composite parts.
There is still place for further developments, especially in qualification of materials/processes/end-use parts and in standards for testing different additively manufactured composites. As AMEXCI, it is our aim to always keep track of such developments and technological advancements in Composite AM to support our customers in Research projects as well as other areas.
It is vital to build a strong and stable connection in between technology providers/owners and end-users, while building a thorough understanding of Composite AM capabilities in order to realize possible application areas of additively manufactured composites. Thus, as Amexci, we have been collaborating with several different OEMs and printing service bureaus in preparing Composites AM Workshop during Autumn 2021. We are looking forward to the outcomes of this workshop and to following future updates in Composite AM.
[1] “Recycling of Carbon Fiber Reinforced Composite Polymers—Review—Part 1: Volume of Production, Recycling Technologies, Legislative Aspects”
About Merve Canalp
Merve Canalp works as a Researcher at AMEXCI and her expertise lies in the field of polymer materials. Her daily tasks include investigating Polymer AM applications and managing corporate R&D projects.
For more information, or if you would like to discuss polymer AM, get in touch with Merve at: merve.canalp@amexci.com