If you follow our blog, you know that cost has been the one thing preventing carmakers from going all-in on carbon fiber. They simply cannot justify raising the price of consumer vehicles to accommodate more expensive carbon fiber parts. However, there may be a solution on the horizon. Nissan claims to have developed a fabrication process that cuts the cost of automotive carbon fiber significantly.
Car Scoops published an article about Nissan’s announcement in early September 2020. The article offered very few details as to how the fabrication process actually works. From what we can tell, Nissan seems to be working with a process known as compression resin transfer molding. It is fairly new to our industry.
Why Carbon Fiber Is So Expensive
Carbon fiber is stronger and lighter than both aluminum and steel. However, it is also more expensive to produce. The extra expense is incurred in both the production and fabrication stages. Allow us a brief moment to explain.
Raw Carbon Fibers
Before you can make carbon fiber fabric, filament, etc., you have to produce the fibers themselves. This is no easy task. Manufacturers start with some sort of precursor – usually polyacrylonitrile (PAN). They process PAN using high heat, pressure, and a number of chemicals for the purposes of burning away unwanted material to gain access to its carbon molecules.
During the process, carbon molecules are forced to align end-to-end. This creates the fibers that are then spun to make carbon fiber tow. The tow then becomes filament, thread, and fabric.
As you might imagine, it takes a tremendous amount of energy to create first-stage carbon fibers. So long before you even think about fabricating car parts, you have to consider the cost of the raw materials. And they are not cheap.
Carbon Fiber Fabrication
Carbon fiber is also expensive when it comes to fabrication. Until recently, automation was unheard of for most carbon fiber parts. Manual processes were used to fabricate them. With manual processes come high labor costs. On the other hand, automated processes for fabricating with aluminum and steel were mastered a long time ago.
The Nissan Plan
If we understand the Car Scoops article correctly, Nissan does not plan to manufacture its own raw carbon fibers. Rather, their plan only calls for a new way of fabricating parts using carbon fiber fabrics sourced from other vendors.
Their system appears to be a die-based system in which carbon fiber fabric is placed across a lower die in the shape of the desired part. An upper die is lowered to create pressure, leaving just enough space between itself and the fabric. Epoxy resin is then injected into that space in order to saturate the fabric. Even pressure then ensures that the resin is fully distributed throughout.
Nissan engineers say they are able to visualize resin flow through the assembly with an in-die temperature sensor. They also use a transparent die that enables them to clearly see what is going on. They believe their system is capable of consistently producing parts in less time.
Automating the Process
Car Scoops seems to think that financial problems at Nissan will prevent them from utilizing the system in the short term for their most affordable cars. Like most other auto industry forays into the carbon fiber space, it will be reserved for high-end Nissan models catering to consumers willing to spend.
However, if they can automate the process well enough to bring down costs significantly, they could start increasing the amount of carbon fiber they use in affordably priced cars. Will they actually do so? Time will tell.
Image Source: Nissan