CW Blog

Driven by an explosion of mobile and portable electronic devices, as well as the proliferation of drones and electric vehicles (EV), the research race is on to develop new lightweight materials for energy storage technology — specifically, materials with longer life and higher weight- and volumetric-based efficiencies. Carbon and composite materials have been integral components of energy storage systems for several decades, one notable example being graphitic carbon comprising anodes in lithium-ion batteries. The anodes generally consist of a carbon fiber composite manufactured with metal or metal oxides, coupled with polymer coating, barrier layers and some type of cathode, creating an electrical potential that causes electrons to flow through the circuit. Carbon fiber/polymer-matrix composites filled with conductive materials have also been go-to materials for electromagnetic interference (EMI) shielding used in a host of applications including aerospace, automotive and consumer electronics.

One emerging research approach in composites energy storage is minimization of the mass of batteries, fuel cells and capacitors via state-of-the-art materials, with the ultimate goal of increasing overall power densities. “One of the problems you have today is that about 50% of the weight of the battery can go to components that aren’t producing energy,” says Dr. Richard Collins, a senior technology analyst, IDTechEx (London, UK), which conducts independent market research on emerging technologies, including advanced materials.

Rare is the composites manufacturing engineer, operations director or plant manager who has looked at his or her facility and not wished for the opportunity to do things differently — to improve material flow, optimize processes and replace waste with efficiency. Most of the time, such improvements are done in-situ, working with existing space. Occasionally, however, such improvements are done with a blank slate in a new, purpose-built plant that allows for a complete reconsideration of manufacturing operations.

Such was the case for San Diego-based Meggitt when it was given the opportunity to not only move out of the smaller, older space, but to create a new manufacturing space designed specifically for the materials and processes it uses. Along the way, the company learned much about itself, as well as about how people, resins, fibers and machinery can and should be organized to make parts now and in the future.

Composites manufacturing is inherently an additive process and has always been about structural efficiency in our three-dimensional world¹. However, the 3D printing community has been slow to catch on. For more than 30 years, 3D printing has been stuck in 2.5D, building parts a layer at a time on a flat (2D) base to form a 3D structure with little strength in the third dimension. This Z direction weakness has been known since the 1980s, but little has been done to address it. However, 3D printing has caught the public's imagination and grown to a US$7 billion/year industry. This success is primarily due to incredibly resourceful young minds that have leapt over many of the hurdles presented by these early 2.5D technologies. But they neglected the third dimension.

These early rapid prototyping technologies have evolved into additive manufacturing (AM) — not just prototypes, but functional parts in real-world structural applications. The composites community has been doing this since the beginning, but we are progressing from hand layup to automatically “printing” composite structures. Automated fiber placement (AFP) was a huge step forward and is a process that is now widely used to place continuous fibers precisely where they are needed in the direction of the load paths to manufacture high-performance, three-dimensional structures. The Boeing 787, Airbus A350 and Lockheed F-35 are good examples of structures that feature composite parts produced via AFP. However, AFP with thermoset prepreg still requires a manually placed bag and an autoclave cure step, and is therefore is not considered true additive manufacturing.

Tecnofire is a family of intumescent nonwoven veil products made by Technical Fibre Products (TFP, Burneside Mills, UK and Schenectady, NY, US).  They have been used in a variety of applications, including fiberglass-reinforced plastic (FRP) wind fairings on the Whitestone Bridge in the Bronx, New York City (Fig. 3). Steel fairings that slice and deflect wind that buffets the bridge were replaced with FRP, cutting weight to reduce load on the bridge by 6,000 metric tonnes. Designed by Gurit US (Bristol, RI) and manufactured locally, the composite fairings covered 20,000 m² of the bridge’s surface. “Each fairing was faced with Tecnofire to provide fire protection,” recalls Klopfer. “It was a drop-in solution. All they had to do before installation was paint the outside.”

Klopfer sees an uptick in architectural and construction applications, especially interior wall and panel designs where the materials must stop flame propagation to allow occupants time to exit. “Traditional materials have been entrenched for so many years,” he says, “but now there is a movement to reduce weight. There are advanced FR resins, including systems from Polynt and Ashland, but we see that designers want to use a combination of fire resistance strategies — for example, an FR resin with Technofire.” TFP has shown that with Tecnofire alone, lightweight composites can pass the common building fire standards per ASTM E119 and NFPA 285/286 tests. “We also ran the ASTM E84 test on Tecnofire and got zero flame spread with very little smoke. We can lower the heat release rate by up to 40% and increase the time to ignition by 40%.”

Composites manufacturer COBRA International (Chonburi, Thailand) recently supported a 14-day campaign to clean up the Chao Phraya River in Thailand. The company donated  10 lightweight kayaks for the Kayaking for Chao Phraya River clean up mission which took place in December 2018.

The campaign involved kayaking along the Chao Phraya River in an effort to clear trash from the waters and raise awareness of environmental issues escalating in Thailand’s waters. The effort was organized by Asst. Professor Prinya Thaewanarumitkul of Thammaset University (Bangkok, Thailand). The clean up team consisted of 10 principal team members equipped with the COBRA-built kayaks, as well as an additional 30 volunteers who joined the trip.