General Motors lifted the curtain last month to give a peek into the product development and manufacturing process for the CarbonPro Pickup Box, which will be available on the new 2019 GMC Sierra Pickup. In tours of partner Teijin’s Continental Structural Plastics (CSP) facility and GM’s Fort Wayne Assembly Plant in Indiana, the company revealed details about the strong and lightweight pickup bed interior that will available exclusively on Denali and AT4 models of the Sierra, the first time that a bed built from carbon fiber has been fitted to a truck at the factory level.
What Is Carbon Fiber?
Carbon fiber is an amazing material. Pound-for-pound, it is lighter, stronger and stiffer than steel. Depending on how It is made, it can be five times stronger and twice as stiff as steel.
Carbon fiber, a man-made material, was invented in 1958, and a process was developed in 1963 to take advantage of its unique characteristics. It is a polymer — basically, a material composed of a long chain of molecules. The raw material of 90% of carbon fiber is polyacrylonitrile (PAN), though some manufacturing processes begin with common plastic and a wood byproduct. The carbon fibers are much thinner than a human hair when first produced, and are then spun into yarn. At this point, the carbon fiber yarn is often woven into fabric, or set into resin — either in a fixed pattern, or chopped into smaller strands and set into resin at random, similar to oriented strand board (OSB), a common wood product used in construction. These carbon fiber sheets are thin, light and rigid, ready to be cut, pressed and formed into usable parts. Off-cuts and scrap can be recycled with a high degree of efficiency and very little waste.
The process of manufacturing carbon fiber is slow and energy-intensive, requiring multiple steps and large machinery. As such, carbon fiber is expensive, and is used sparingly in applications where it will have the most impact. It is used in the aerospace industry, where strength and weight-saving are essential. Specialty race cars make extensive use of carbon fiber. Supercar makers use more with every iteration of their vehicles. McLaren’s lineup is built around carbon fiber monocoque frames, and Lamborghini offers a special carbon fiber interior trim package. Carbon fiber hoods, roofs and other components show up on high end street cars. Carbon fiber motorcycle helmet shells and gloves with carbon fiber knuckle guards have proliferated in the past few years, smart uses of the material. Scientists, engineers and designers continue to push toward wider use of carbon fiber, which is leading to faster, improved manufacturing techniques and lower costs.
General Motors uses carbon fiber in the chassis of the C7 Chevrolet Corvette — some of it developed and manufactured by CSP.
Developing the CarbonPro Box
The CarbonPro Box is the result of a nearly 10-year collaboration between CSP and GM. Before a box could be built, the material had to be developed and tested extensively. Engineers tested for tensile, compression, flex, impact, fatigue and creep characteristics at different temperatures and humidities. The material was exposed to UV light to test for degradation and fading, and to a wide range of weathers and temperatures. It was tested in contact with various metals for galvanic corrosion, as it would be in contact with aluminum, steel and iron in its use as a pickup bed. The carbon fiber was exposed to a wide range of chemicals to test for reaction.
When the developers finally arrived at a successful material composition, they then had to figure out what form the bed would take. Like a traditional steel pickup bed, the CarbonPro Box has a corrugated floor. Developers were able to achieve a 6-time improvement in impact performance compared to the steel bed thanks to the material’s properties and the corrugation. The surfaces of the protruding ridges have a subtle, non-skid grain, while the valleys between are smoother, which provides sure footing in the bed, with easy cleanup.
The head of the bed has a raised GMC logo and three tire pockets. Motorcyclists will appreciate the attention to detail here. The tire pockets will help to secure a big bike, like a Harley-Davidson Electra Glide, in the center position, or a pair of smaller dirt bikes in the outer positions. The bed side panels are molded for tier loading and to hold dividers, and are pre-punched for cargo lamps and a 110-volt power outlet. Fourteen cargo tie-down hooks are positioned throughout the bed. The CarbonPro bed shape delivers 1.81 cu ft. (2.37 cu yards) greater cargo capacity than the standard steel bed, mostly thanks to space gained on the side walls.
Building the CarbonPro Box
The platform, bed head and side walls are formed of multiple sheets of carbon fiber, which are laminated together and formed with heat in a gigantic 3,600-ton press. Secondary components, like the headboard reinforcement, cross sills, D-pillars and stake pockets, are formed in a 1,000-ton press. After being trimmed and after required holes and slots are routed with a water jet, parts are placed into assembly jigs, where they are bonded with adhesives supplemented by mechanical fasteners and peel stoppers.
The resulting CarbonPro Box is 62 pounds lighter than the equivalent steel box, or about 100 pounds lighter than the steel box with a bed liner. It does not require a liner or paint. It is dent-, scratch- and crack-resistant. Outer walls of the bed are steel, the cross-members and frame rails that the bed mounts on are steel, the tailgate has an aluminum outer skin and a glass-fiber composite inner skin, and the bed rail caps are plastic. Unless CarbonPro Box-equipped trucks come with body decals or badging (no word on that from GMC yet), the only way to visually identify them will be to look in the box.
Availability of the CarbonPro Box
GM and CSP are still fine-tuning the manufacturing process of the CarbonPro Box at CSP’s facility. Later this year, the boxes will begin to shuttle to Fort Wayne Assembly, where they will join the line to get installed in Sierra pickups, which are assembled on the same line as the Chevrolet Silverado.
The CarbonPro Pickup Box will initially be available on the 2019 GMC Sierra AT4 CarbonPro Edition (starting at $66,635) and Denali CarbonPro Edition (staring at $70,020), in short box (69-inch) configuration only. Pricing and availability for the CarbonPro Box on 2020 models has not yet been announced. Find a GMC Sierra for sale