Carbon fiber prepregs are pretty standard fare at Salt Lake City’s Rock West Composites. As a leading provider of composite materials including carbon fiber and glass fiber, Rock West sells prepregs to commercial fabricators and DIY hobbyists alike. At some point they might find themselves supplying those customers with 3D woven composite fabrics.
3D weaving may prove to be the next ‘big thing’ in composites. It holds a tremendous amount of promise for creating a number of carbon fiber parts that, by design, need to exhibit certain properties. Even prepregs manufactured through a 3D weaving process are not out of the question.
Weaving Carbon Fiber Fabric
To create a carbon fiber prepreg, you start with a woven fabric you can infuse with epoxy resin. The fabric can be used in manual layups to create everything from car doors to surfboards. Making that fabric is no different than making any other kind of fabric. Industrial looms weave multiple carbon fiber threads together to create the fabric that forms the basis of many carbon fiber reinforced plastics (CFRPs).
These types of fabrics are very useful for creating all sorts of composite parts. But they are limited. Because they are woven only in two dimensions, manufacturers are prevented from weaving anything other than a flat, single layer fabric. But what if they could transform those two dimensions into three?
Traditional weaving utilizes only the X and Y axes. 3D weaving brings the Z axis into play. It is not easy to do without extensive tooling, but a small number of manufacturers are doing it. Through their efforts, they are coming up with ways to manufacture very impressive 3D parts that are woven rather than printed.
This is a big when you consider what goes into 3D printing composite parts. The challenge now is to take existing 3D weaving applications and make them better so as to also make them mainstream for composites manufacturing.
Further Weight Reduction
A big advantage of 3D weaving is further weight reduction. As you might already know, reducing weight is one of the primary reasons for choosing composites over steel and aluminum. 3D weaving reduces weight even further by creating a single piece rather than having to layer multiple 2D fabrics in order to create a part.
3D woven parts are already being used by the aerospace industry to build lighter aircraft engines. Composite parts are replacing titanium parts more than capable of withstanding the stresses of high-powered flight.
Better Structural Integrity
Another big advantage of 3D weaving is that it creates greater structural integrity. The best way to understand this is to consider how catastrophic carbon fiber failures occur. Imagine a bike frame that developed an internal crack not seen by the naked eye. Over time, that crack could gradually get worse until the bike frame completely collapses under the rider.
3D weaving produces finished parts with no empty pockets that would otherwise fill with epoxy resin that is subject to cracking. Resin saturation is more consistent throughout, reducing the risks of both cracking and catastrophic failure.
Tying everything together is the fact that 3D weaving lowers production time when you consider that it eliminates the need for manual layups. Looms can be automated, making it possible to create entire parts without the need for human intervention. The time savings translate into greater production at less expense.
3D weaving is by no means the default method of producing carbon fiber parts. But it looks to be the next big thing in composites if the industry plays its cards right.