Federal-Mogul Maximizes Durability and Performance with Innovative Protection Products

Federal-Mogul Maximizes Durability and Performance with Innovative Protection Products

 

Federal-Mogul Maximizes Durability and Performance with Innovative Protection Products

Federal-Mogul Corporation is an innovative and diversified global supplier of quality products, trusted brands and creative solutions to the automotive, light commercial, heavy-duty truck, off-highway, agricultural, marine, rail and industrial markets.   Our 45,000 employees and our globally-networked engineering and technical centers in North America, Europe and Asia enable us to bring our customers breakthroughs in advanced technology and innovation.

Product innovation is a hallmark of Federal-Mogul Systems Protection (SP).  One of the world’s foremost suppliers of protective solutions for the heavy-duty, agricultural and industrial vehicle markets, Federal-Mogul SP’s products are designed to protect wire harnesses, hoses, cable assemblies and exhaust systems against the impact of abrasion, high temperatures and electromagnetic interference. This high level of protection helps to safeguard the performance and reliability of commercial vehicle applications, while reducing maintenance costs.

The following is an overview of thermal management, flexible heat shield and abrasion solutions that are frequently called upon during the design, maintenance and repair of off-highway vehicle applications:

Thermal Management
• Operating temperatures up to 1000°C
• Protects components against reflective, convective or conductive heat
• Constructed with aluminum, polyester, fiberglass, silica or basalt
• Self-wrapping, tubular and adhesive designs available
• Die-cut or custom configurations available

Flexible Heat Shields
• Custom configurations designed to fit your application
• Solutions available for sensors, connectors and blow-molded plastic components
• Available with standard or customized attachments

Abrasion & Bundling
• Operating temperatures up to 200ºC
• Excellent abrasion and cut-through protection
• Self-wrapping, expandable and flat profile designs available

The ability to simulate customer specific scenarios on-site, utilize predictive modeling and conduct extensive testing, enables Federal-Mogul SP to deliver superior protection for your application. Additionally, the company’s advanced research and development facilities, located worldwide, explore and design innovative products to anticipate and meet customer requirements.

Most recently, Federal-Mogul SP’s efforts led to the creation of a new thermal solution constructed of silica and fiberglass installed directly on the exhaust pipe for maximum thermal protection.

ThermFlex® 1223

The combination of silica and fiberglass creates an innovative product designed to insulate exhaust systems with operating temperatures up to 1000°C. This high degree of insulation enables exhaust gas to maintain temperature as it moves through the exhaust system, ensuring complete conversion of exhaust gas and particulates. Complete conversion is necessary to meet the increasingly strict emissions regulations set in place by government mandate.

ThermFlex 1223 is a dual wall knit sleeve used for insulation of high temperature exhaust systems. The sleeve is made with an inner layer of silica yarn, which can withstand temperatures up to 1000°C, and an outer layer of fiberglass yarn, which can withstand temperatures up to 420°C.  Materials are strategically placed during fabrication to create a cost-effective sleeve without sacrificing insulation performance. Knitting the sleeve allows for fabrication of finished edges and it also enables stretch in the circumference of the product. This allows the sleeve to accommodate changes in diameter along the length of an exhaust pipe.    
     
In 2003, a major automotive manufacturer decided to use a crossover pipe that ran from the engine manifold directly into the turbocharger. The final design specified a crossover pipe that varied in diameter along its length and also incorporated a bend. Flanges were required at both ends. Upon initial testing of the system, it was determined that the temperature of the crossover pipe was high enough that measures had to be taken to protect the surrounding components.

In keeping with industry standard practice, the customer’s first idea was to use a metal shield to protect the surrounding components.  Engine and pipe configuration, however, did not allow enough clearance to use a shield.

The next attempt involved another industry standard -- the use of a braided fiberglass sleeve. Braided fiberglass sleeves initially achieved popularity in the 1990s as it was the product of choice for exhaust gas recirculation (EGR) tubes. Braided fiberglass sleeving used on EGR tubes is usually coated or saturated with a resin to reduce loose fiberglass fibers, add stability to the product and color the sleeving black. Although the resin accomplishes these items, it also limits the expansion and flexibility of the product.

Commercially available braided sleeving was tested on the pipe, but the braided fiberglass could not withstand the combination of the heat of the crossover pipe, the engine vibration and the engine roll. This combination degraded the sleeve to the point where integrity was lost. Installation also was a problem because the coated sleeve had difficulty expanding and recovering over the end flanges.

With back-to-back failures and no solution in sight, the customer turned to Federal-Mogul SP.  Long known for its ability to design and fabricate unique protective solutions, Federal-Mogul’s SP was already working toward the creation of a superior insulating sleeve to replace standard resin-coated EGR sleeving. The goal of creating a superior product led SP to experiment with high-temperature materials and with numerous textile technologies. Recognizing the expansion and conformability limitations of braiding, SP had recently started experimenting with knitting of high temperature materials.  

When the crossover pipe opportunity was presented, knowledge garnered from working with high-temperature fibers and knitting technology gave Federal-Mogul SP a head start in the right direction.   Temperatures associated with the crossover pipe were beyond the capabilities of fiberglass yarn but were within the operating range of silica fiber.  Used sparingly in the automotive industry because of its high price, silica is an organic yarn that can maintain structural integrity in temperatures up to 1000°C.

While acknowledging the price limitations associated with silica, Federal-Mogul SP decided to move forward with it in the initial design phase.  Silica appeared to be the only fiber capable of withstanding both the required thermal environment and the stresses of textile fabrication processes.  The challenge was to find a way to use it in a cost-effective manner.

After studying the actual crossover pipe, the design team confirmed that a knit construction offered the best combination of properties for the application.  A knit construction would allow the sleeve to expand to fit over the end flanges and then recover back to the diameter of the pipe. The inherent flexibility of the knit fabric would also allow it to accommodate the bend in the pipe.

It is important to note that knit sleeves were not new to the automotive industry, as they had seen some prior use in a very limited form.  Simple knits have been used with various materials, including fiberglass, because of its associated flexibility. These small-diameter sleeves were found largely on wire harness applications. Uses included protection against low- to medium- level thermal environments and low-level mechanical bundling and protection.

The jump in technology in the crossover pipe application involved the type of knit, diameter of the product, design of the sleeve and the uniqueness of the raw material combination.

Standard knit sleeving, as described above, is most often fabricated using a jersey knit construction. This is a basic, single-layer fabric knit construction continuously knit on a circular-knitting machine. The finished product is wound on a roll and then cut to the desired length at a later time. When a knit fabric is cut, small pieces of yarn tend to unravel and flake off. This creates several problems; it is not aesthetically pleasing and the cut edges tend to curl back on themselves causing small pieces to flake off and contaminate surrounding environments. In addition, cutting the product requires a separate manufacturing process adding cost to the product.

Federal-Mogul Looks Outside Industry for Innovation

Federal-Mogul SP chose to adapt technology from the hosiery industry.  Knitting machines used for hosiery utilize a construction with a high level of stitch expansion.   The hosiery machine also creates a finished edge which means pieces can be knit to finished length. When a sock or other piece of hosiery is knitted, it is knitted as one finished piece, from the enclosed toe to the top, eliminating the need for a separate cutting operation. After exploring this technology further, the design team decided it could be modified for use on the crossover pipe project. Once this technology was chosen, the challenge of knitting silica yarn was next.  Because silica is made from a ceramic-based material, it is not an easy material to work with and several false starts were attempted before a source of material was found that could withstand the stresses of knitting.

Once a usable yarn was received, a knit sleeve of 100 percent silica yarn was made. Subsequent testing led to the conclusion that a single layer knit sleeve could not provide enough insulation to reach the required temperature drop on the surface of the crossover pipe.   The initial thought was to install multiple sleeves, one on top of each other, onto the pipe. This approach would create an assembly capable of high levels of insulation, but it was quickly dismissed since a complex assembly process in a production environment would be too costly.

A breakthrough came when the design team came up with the idea of knitting a sleeve twice the required length and then folding the finished sleeve back onto itself.  This produced a sleeve of double thickness that was fabricated with finished edges.  As an added benefit, it also could be installed in one operation.

Brainstorming the problem also led to the realization that silica was needed to survive contact with the crossover pipe, but it might not be needed on the outside layer of the sleeve. The temperature drop across the silica layer was thought to be enough to enable the fiberglass yarn to survive on the outside layer. Testing confirmed this theory and the team developed a process to switch the raw material from silica to fiberglass halfway through the knitting process. This then created a sleeve that when folded, had an inner layer of silica yarn and an outer layer of fiberglass.  On-vehicle testing showed that with an exhaust manifold temperature of 677°C, the temperature of the clamp holding the crossover pipe in place dropped to 464°C. ThermFlex 1223 created a temperature drop of 213°C, enabling surrounding components to survive.

The new sleeve was easy to install onto the assembly, had a low profile enabling it to meet the clearance limitations and met the customer’s thermal requirements. Thermflex 1223 was a leap ahead in terms of high-temperature sleeving. The use of silica yarn raised the temperature barrier and the combination of expandability/recovery, easy assembly and finished edges, were unlike anything ever seen in the marketplace.

With 100 percent of customer requirements met, ThermFlex 1223 went into production in January 2004.  As of this writing, the product is still in use on the platform on which it initially launched.

The success of ThermFlex 1223 on the initial engine launch led to the product’s consideration for numerous other programs. It was subsequently released on platforms at two commercial vehicle manufacturers and the product is currently under evaluation for use on several other platforms.

Additional interest in ThermFlex 1223 is now being driven by the increasingly strict emissions requirements set in place by government mandate. Although initial development was not driven by government regulation, ThermFlex 1223 may play an important role in meeting these regulations. In order to achieve complete conversion of CO and unburnt carbon to CO2 and Nox to NO2, gas inside exhaust pipes needs to stay as hot as possible. High-temperature exhaust gas entering the catalytic converter allows for a more complete conversion, and thus, fewer pollutants. With the insulating value of ThermFlex 1223 proven on several platforms, numerous heavy truck and commercial vehicle manufacturers are evaluating ThermFlex 1223 for use on their future systems.  Meeting “US ’07” and “US ’10” is a major force behind the increasing interest in ThermFlex 1223.

Heavy-Duty Truck and Commercial Market Interest

Further refinement of ThermFlex 1223 continues. Because of the interest from the heavy truck and commercial segment, development efforts are in place for related items such as coatings to make the product more “durable” for underbody use. Construction modifications and new technologies are continuously being evaluated.
 
The team is currently working with new types of raw material, such as basalt fiber made from volcanic rock, to improve durability.  The basalt fiber version of the sleeve, known as ThermFlex 1224, has already been released for use on the exhaust systems of motor homes. The working temperature of ThermFlex 1224 is slightly lower than ThermFlex 1223, but it does offer a higher level of durability. Evaluation of each individual application in terms of temperature and on-vehicle location helps determine which sleeve is most appropriate.

ThermFlex 1223 opened new doors for textile-based protective sleeving.  Prior to its development, the use of textile sleeving on exhaust systems was limited.

Today, the opportunities keep growing and are expected to continue for years to come. As exhaust systems get hotter, the need for ThermFlex 1223 and other innovative products will increase.

For more than a century, the global automotive industry has relied upon Federal-Mogul Corporation’s products and services for power, safety and protection.  As we move into the future, Federal-Mogul continues to build upon its past accomplishments, forging new industry benchmarks in both mature and key growth markets.

Federal-Mogul Corporation is a leading global supplier, serving the world’s foremost original equipment manufacturers of automotive, light commercial, heavy-duty, agricultural, marine, rail, off-road and industrial vehicles, as well as the worldwide aftermarket. The Company’s leading technology and innovation, lean manufacturing expertise, as well as marketing and distribution deliver world-class products, brands and services with quality excellence at a competitive cost. Federal-Mogul is focused on its global profitable growth strategy, creating value and satisfaction for its customers, employees and stakeholders. Federal-Mogul was founded in Detroit in 1899.

The Company is headquartered in Southfield, Michigan, and employs 45,000 people in 35 countries. Federal-Mogul’s aftermarket products are sold under a variety of power brands, including but not limited to, AE® engine products, ANCO® wipers, Champion® spark plugs and wipers, Fel-Pro® gaskets, Ferodo® brake pads, Glyco® bearings, Goetze® piston rings, MOOG® chassis products, National® wheel-end components, Nüral® pistons, Payen® gaskets, Sealed Power® engine products and Wagner® lighting and brake products.

For more information on this or other Federal-Mogul innovative protection products, contact Jason Rodriguez at Jason.rodriguez@federalmogul.com or call (610) 363-2600.