Mention the possibility of manufacturing with composites and first thoughts are likely to be those of carbon and glass fiber. For the last several decades, manufacturers have been perfecting the art of making fiberglass and carbon fiber parts to replace steel and aluminum. But now there is a new kid in town, one finally poised to compete with carbon and glass fibers: flax fibers.
Glass and carbon fiber products are produced in many industries. From sporting goods to aerospace and everything in between, the market for composites is strong. But there are things that still inhibit the use of glass and carbon fiber. Two of them are cost and recycling concerns. Thus, manufacturers have been intensively studying the potential of natural fibers instead. Flax is one such fiber, a natural fiber that shows a lot of promise.
Grown Around the World
Rock West Composites, a Salt Lake City company that specializes in composite materials, says that flax fiber appears to be the leading choice among natural fiber composite makers. That should not be a surprise to anyone who knows how prevalent flax is.
Flax is a plant grown around the world. It is used in a ton of products, too. It is cheap to produce, it is versatile, and nearly every part of the plant can be utilized in some way, shape or form. Replacing carbon and glass fibers with flax fibers brings down the cost of composite manufacturing and simultaneously increases recycling potential.
Gizmodo recently reported on a couple of European companies that have gotten together to advance a flax-fiber composite that they believe will compete with carbon fiber for automotive manufacturing. Their material has already performed quite well in limited crash tests.
Reinforcing Flax Fibers
Creating a composite with flax fibers differs very little from creating glass and carbon fiber composites. The fibers themselves are spun into thread or yarn. Threads can be woven into fabrics which are then saturated with epoxy resin. Both resin and fabric are then cured in an autoclave to create a fiber reinforced polymer.
If there is one downside to using flax fibers, it is the fact that they are not as strong as carbon fibers. Indeed, strength is one of the primary reasons carbon fiber has taken off over the last few decades. Carbon fiber products boast an excellent strength-to-weight ratio that is not even matched by aluminum or steel.
So how do you overcome less strength in a flax-based product? According to Gizmodo, the two European companies they profiled in their piece have created a unique ribbing structure that they say adds the necessary strength. The ribbing structure is placed between two layers of flax fiber fabric.
Cheaper and More Recyclable
If strength were the only issue, there would be little sense in pursuing a natural fiber composite to replace glass and carbon fiber. But there is more to it than that. Carbon fiber’s two biggest negatives are cost and limited recycling opportunities. Natural fiber composites address both of those weaknesses.
Producing carbon fibers requires a tremendous amount of energy, and energy costs money. By comparison, you can grow flax by the acre for next to nothing. Thus, the raw materials for natural fiber composites are already cheaper than carbon or glass fibers. In terms recycling, it is also a lot easier to recycle natural fibers.
Natural fiber composites are not quite ready to fully compete against glass and carbon fiber. But they are quickly getting there. Within a couple of years, there should be natural fiber products with plenty of practical applications.