How many times have you run into situations where you say, “I work with composites”, and no one knows what that means? Not only to friends and family, but even many mechanical, structural and automotive engineers don't know much about composites, let alone start using them in their work.
The dream of bringing composites mainstream has been brewing since its commercial inception in the 1960's. Composites have always been the wonder material that is going to disrupt the manufacturing industry next year. However, the reality has been a slow realization and adaptation, as composites are still very limited in their application and general knowledge across the industry.
The 3D printing dud and 3D printing composite miracle
Starting with major hype in 2009, 3D printing was assumed to be the manufacturing of the future, However, we ended up mostly printing toys with an even cheaper 3D printer in the race to the bottom of quality/cost.
However, after the hype died down in 2014, real applications started emerging, starting with dentistry and machining clamps, etc.
Machining clamps needed higher strength for securing the part at much higher impact forces. This was pioneered by Markforged when they introduced continuous fiber 3D printing. Essentially, we have a thermoplastic composite printer at hand, making it easier to explain to users how the fiber orientation in each layer would affect the final stiffness of the part, by being able to create samples on the spot.
A growing opportunity
Fast forward to today, there are many continuous fiber 3D printers that are trying to replicate the success Markforged has so far, only at a larger scale with a focus on quality.
Hybrid of 3D printing and tape laying: combining the printing capabilities of Markforged with an ATL head producing preforms, launched by Desktop Metal for stronger 3D printed parts.
Additionally, accessible fiber placement systems are available that can enable thermoplastic tape laying production, for the cost of an industrial 3D printer.
Plug-n-play AFP-XS fiber placement head from Addcomposites for thermoplastic tape laying for larger-scale production of composites.
All of the above systems are making it easier to work with composite materials, no longer requiring highly skilled labor to manufacture these parts. The above systems are getting more into the hands of the users/engineers, so next time you say “I work with composites” people might just understand that you are working at the cutting edge of advanced material manufacturing.
Starting your composites journey: Steps to industrialize production
Now is the best time to begin your composites journey, and here's why:
- Markets have become ever-demanding for higher strength, lower weight parts
- Availability of the advanced production system at an accessible cost
- No need to have a skilled composites craftsman, with a basic physics understanding and some practice, you can scale the production.
Considerations when choosing a fiber reinforcement and matrix
In the majority of the cases, customer application defines the material, but in case you have a say in the material, the following points might be helpful to consider:
Cost — What cost will the final product go for? Many commodity thermoplastics are lower in cost than thermoset polymers,
Performance — What temperature does it have to endure? Is UV degradation a factor? Does it need to be fire retardant? And lastly, is it suitable for the process chosen?
Availability — Is it economically available in the form required (pellet, fiber, flake, textile, sheet, liquid), and in the correct quantities?
Manufacturing processes in order of adoption
Even simply starting to manufacture composite parts used to be a really challenging. In the past, you needed to have a lot of equipment and materials with short shelf-life, requiring heavy up front investment and a high refrigeration footprint. With the following systems, you no longer need to heavily invest in tooling and material up front:
Additive manufacturing: 0–500 parts: Very high shape complexity, high porosity, high strength compared to non-reinforced FDM prints.
Tape placement: 100–100 000 parts with gentle continuous shape, low porosity very high strength to weight. Tapes are laid in flat or shaped molds, and consolidated in-situ into layers by special robot-mounted heads. This technology is very versatile, and can make complete parts on its own, or reinforce parts and other substrates by providing local reinforcement.
Injection molding: 100 000–1 000 000 parts. High shape complexity and high strength. However, only short (0.5 to 15 mm) reinforcement fibers can be used, limiting the mechanical properties.
Thermoforming: 100 000–1 000 000 parts. High shape complexity, very high strength. This process can be carried out with a variety of precursors, such as textiles, pre-consolidated sheets (oregano sheets) or dough-like extrudate. The thermoplastic materials can be heated inside or outside the tool, and they might be premixed with the fiber or mixed at the point of processing.
Depending on your business model, desired market, and customer base, this information should provide a good foundation in order to get started in your own manufacturing that is easy to begin, and easier to scale.