The production of lightweight composites has high requirements in the aerospace, automotive, and defense fields. In these areas, reducing weight and ensuring strength and durability are key factors in completing the task. However, this is a very time consuming and expensive process.
ExOne is a US-based additive manufacturing company specializing in 3D printing in the field of metal and sand adhesive spraying. ExOne has now developed an alternative that makes it possible to make complex carbon or glass fiber reinforced parts, thereby eliminating the need for costly tools to build complex geometries. This means that no auxiliary methods such as solvents, degassing tools or chisels are required.
3D printed new pipeline for composite parts
The technology is a scouring process that uses a strong but soluble 3D printed silica or ceramic sand core. According to specific strength requirements, 3D printing of water-soluble spraying agent or Te prior to composite lay-up to leave a surface without voids, and then add the composite material on the surface by means of fabric or superposition. After curing, the soluble support material is easily washed away with tap water, leaving a hollow composite part. And the dissolved media can be recycled and reused for future 3D printing.
Exick Chief Technology Officer Rick Lucas said: "This is a time we have been working on, this is the market we are targeting and pursuing. We have engineers who have worked in the composites industry and understand people Deeper demand for the status quo of composite materials manufacturing. "
For the first time since 2013, ExOne engineers have found that they can bond silica or ceramic grit to a 180 ° C water-soluble solvent, but the difficulty lies in the coating step and the use of adhesive spray 3D printing to optimize the material. "The ceramic sand we usually use is porous. So if you just spread the composite on top and autoclave it under pressure and heat, then cure it; then the resin will penetrate Composite material, and it is no longer washed away. Therefore, we must apply a coating on top to prevent this from happening. In the past year or so, we have been spending a lot of time to improve the coating Methods and processes, and ensuring that customers have a good coating option. "
Composite pipe parts made of water-soluble process
This method is now used to make carbon fiber and glass fiber reinforced composites, including aircraft ducts, pressure tanks, shrouds, struts, and mandrels, especially for designs that were previously unsuitable for manufacturing using traditional techniques. For example, REC, a company that supplies ducts for heavy-duty helicopters, used ExOne's flushing tools to create mandrels for ducts on two CH-35K helicopters and successfully delivered these helicopters to the United States Marine Corps for demonstration.
Carbon fiber composite pipes made with 3D printed water-soluble pipes
ExOne also seeks to address another common challenge encountered in traditional autoclaving processes-thermal expansion and the effect on part geometry. Through the rinsing process, swelling can be controlled and deformation can be minimized by changing the powder. For example, the high thermal expansion coefficient of silica sand may be suitable for some materials, but in other cases where a lower thermal expansion coefficient is required, ceramic sand may be a more suitable choice.
Currently, the technology is mainly available on demand through the ExOne Adoption Center in the United States. But the company said it hopes to expand these capabilities to Europe in the near future and may work with partners as demand grows. ExOne is also working to further refine the adhesive solution with the next version, which will provide higher strength, finer resolution, and higher temperature performance.