The Boeing 787 Dreamliner and the Airbus A350 airplanes are two early examples. What sets these planes apart from older planes is that their body and wings are made of composite materials rather than aluminum. They are more fuel efficient and fly farther. This reduces the cost of travel and opens up new routes. Passengers also enjoy benefits like increased humidity and cabin pressure. Humidity is increased from 4% to 15% and cabin pressure is increased from the equivalent of 8,000 feet above sea level to 6,000 feet above sea level. The bottom line is that these planes cost less to operate and provide passengers with ground level comfort and less jet leg.
So what are composite materials? Composite materials are lightweight materials made of fiber-reinforced polymer resins. These fibers are usually carbon or glass. The fiber reinforcement gives the part much better strength and stiffness properties. The fibers are traditionally impregnated with the resin into a so-called prepreg. These prepregs are placed in molds and then cured at a high temperature and pressure to form a part.
There are two main types of polymers used in these composite materials: thermosets and thermoplastics. Thermosets usually cannot be recycled because they form a cross-link during the curing process to form an irreversible chemical bond. The end product is durable; chemically resistant, and heat resistant. Typical thermoset resins are polyester and epoxy.
On the other hand, thermoplastics soften when heated. No chemical bond is created and the process is reversible making the product easily recyclable. Thermoplastic resins have somewhat different properties and include Polyphenylene sulfide (PPS), Polyetherimide (PEI), Polyetherketoneketone (PEKK), Polyether ether ketone (PEEK), Polyethylene terephthalate (PET), Polyethylene (PE), Polypropylene (PP), and Polyamide (PA). Thermoplastics have aesthetically superior finishes and are more sustainable than thermosets.
The main benefit of composite materials is that they are much lighter than aluminum and other metals with comparable or better strength. This makes for more fuel-efficient transportation.
The first I heard of composite materials many years ago was in bike frames that some friends purchased for thousands of dollars. They were willing to pay 2-3 times the normal bike price just to squeeze out a kilogram or two of weight.
Boeing and Airbus spent more. Boeing came out with the first primarily composite materials plane, the 787 in 2011. Airbus followed in 2015 with the A350. Both planes have composite bodies and wings.
Composite materials are also found in boats and cars. Most car manufacturers salivate at the thought of using composite materials to reduce weight. They are obligated to meet CAFE standards in the US and similar standards in Europe. Stiff penalties are assessed if they don’t meet the standards. Some people speculate that the composite material market in automotive could be over $11B by 2020.
However, large-scale adoption in cars has been held back by one major issue: cost. While aerospace and marine have been willing to pay $300 - $6,000/kg, the automotive industry is much more cost sensitive and won’t pay more than $20-30/kg for composite material parts.
Let’s break down the material cost of a carbon fiber reinforced thermoplastic. The price for carbon fiber can vary significantly between industrial grades and high performance grades. The price for industrial grade Carbon fiber is running at about $20-25/kg and a structural thermoplastic polymer like PA is running at about $10-12/kg. Clearly with these prices, the traditional ratio between raw material price and product price of aerospace does not work for automotive. The conversion cost, which nowadays is mainly driven by hand labor, needs to be drastically reduced.The parts are almost entirely hand made. Labor is required to lay the fiber and resin in molds, move the molds into autoclaves, remove the molds and parts, and finish the product.
The only way for composite part manufacturers to meet the automotive target is to reduce labor by using automated manufacturing. Companies that successfully automate composite production lines with robotics will be in a much better position to achieve these price targets. Think of Ford in the early 1900s and the Model 10.
Airborne International, one of Pangaea’s portfolio companies, is doing just that. It is creating a digital factory using robotics for composite material manufacturing. These robots use proprietary end-effectors that are devices at the end of a robotic arm designed to interact with the environment. You can see this in Airborne’s space panel animation video. They perform a wide range of functions including automatic tape laying, ultrasonic cutting, welding, pick & place, and adhesive bonding. Airborne’s digital factory aims to reduce the cost of traditional composite manufacturing by 25 - 50%. In parallel, Airborne aims to introduce more radical automated technologies converting raw materials directly into end product, allowing composites into the automotive market and other transportation markets where lightweighting is important.
Soon, everyone, not just elite bikers, will be using composite materials. We will be flying in more comfortable airplanes and driving lighter, more fuel-efficient cars.