Environment-friendly mobility

How reinforced composites contribute to lightweight design
Heinrich Strunz GmbH has been producing fiber reinforced composites and daylight systems made of plastic, glass and aluminum under the LAMILUX brand name for more than 50 years. This medium-sized company is a European market leader with its technologically outstanding continuous production process in its LAMILUXplan Fiber Reinforced Composites Division.
In an interview to MOTORINDIA, Mr. Stefan Bachstein, Technical Director of the LAMILUXplan Fiber Reinforced Composites Division at LAMILUX Heinrich Strunz GmbH, said that LAMILUXplan supplies customers around the globe in a wide range of sectors such as the automotive and recreational vehicle industries, refrigerated store and refrigerated cell manufacturing and the construction industry. Headquartered in Rehau, Bavaria, the company with a workforce of 400, achieved a turnover of 111 million euros in 2008.

Excerpts from the interview:

Question: Energy efficiency and reducing CO2 emissions have quickly become hot topics within the commercial vehicle industry. The keyword here is “lightweight design”. In this respect, the transport and logistics sector primarily expect manufacturers to reduce the tare or unladen weight of vehicles. How can fiber reinforced composites make a difference?

Answer: They are an ideal material to incorporate into different sections of truck bodies and trailers. They can be used both as surface layer in sandwich elements for side walls and roof structures as well as for flooring surfaces. We are talking about extremely sturdy, yet very lightweight materials which result in reduced overall vehicle body weight due to their light structure, which, in turn, leads to fewer emissions.

Q: What makes the material so light and so strong?

A: This is due to its basic structure. The composite material is a so-called laminate consisting of fibers and resin. The two components are brought together in a continuous production process. The two main parameters which determine the material’s physical and chemical characteristics are the type of fiber and fiber arrangement it features, such as woven fabric or multiaxial fabric, and the kind of resin formulae used in production.

Q: What kind of characteristics do you mean exactly?

A: Many of them, and we can present them all as real advantages when comparing the product with conventional materials such as aluminum or sheet metal. First of all, strength and durability, characteristics which I mentioned earlier. The material firmly resists hail storms and even major mechanical impacts without any damage. If damage should still occur, even on a large scale, it is easily remedied. Moreover, fiber-reinforced composites are noncorrosive, weatherproof and UV resistant, all of which results in a long-lasting, pleasing appearance and ensures their equally attractive value is not impaired with age. The material is also food-safe, which means it is highly recommendable for use at all stages in controlled refrigerated transportation.
Q: What advantages can the commercial vehicle industry now gain from fiber reinforced composites?

A: A vehicle’s tare or unladen weight can be reduced dramatically. Let me give you a few figures with regard to surface layers typically used in sandwich elements:

Whereas steel 0.6 millimeter thick has an absolute weight of 4.7 kilograms per square meter, our 2.0 millimeter-thick fiber reinforced composite features just 2.7 kilograms.

With its 3.2 kilograms, aluminum 1.2 millimeters thick is also clearly heavier. This means with composites there can be a 40 per cent reduction in body weight compared to steel and a 15 per cent reduction in comparison to aluminum. What’s more, due to the strong reinforcing effect in fiber reinforced composites, sandwich elements can feature a thinner design. The reduction in weight offers a direct benefit due to a higher loading capacity, i.e., a greater payload and, consequently, lower transport costs as well as a decrease in fuel consumption.

Q: How versatile is the material in adapting to its future use?

A: Our fiber-reinforced composites are a customizable material, which are tailor-made to specified requirements. We are thus well experienced in supplying the ideal material for all trailer components, such as different interior and exterior surface sheets for side walls and roof structures and extremely firm, anti-slip coverings for floors. We can manufacture special variations for each of these sections, which are ideally matched to the loads and requirements of specific transport and logistics sectors. Along with excellent physical and chemical properties, this versatility also includes being able to incorporate the color directly into the upper gelcoat layer. Colors can be chosen from the RAL and NCS systems, or customized according to clients’ requirements.

Q: What is the advantage of a solid-colored gelcoat layer?

A: This surface coating consisting of extremely high-grade pure resin makes subsequent painting completely unnecessary. As this layer has been chemically bonded with the fiber-reinforced composite material, it won’t chip like conventional paintwork. Surfaces don’t require immediate repainting even in the event of slight damage such as scratches or stone chipping as our fiber reinforced composites won’t corrode whatever happens. This is highly relevant when it comes to “durable surface appearance” and “maintaining value”. Q: Are there any other uses for your material in day-to-day goods transportation?

A: Yes. Our material can be produced with a pore-free surface. This means it is very easy to clean, so it fulfils other hygiene requirements for food transportation or vending trucks, in addition to those for food application certification. Moreover, when combined with PU or XPS foam in sandwich elements, our composites make good use of excellent heat insulation properties and truly excel in terms of low thermal conductivity when compared to materials such as steel or aluminum. Our material enables refrigerated truck bodies or trailers to be built in such a way that the risk of thermal bridges in the joints between walls and floors is reduced significantly.

Q: How do you ensure that fiber reinforced composites maintain the qualities you mentioned earlier on a long-term basis?


A: First of all, at the research and development stage, we carry out a whole series of very intensive material checks, such as a salt spray test in accordance with DIN EN ISO 9227 to verify corrosion resistance, or a Xenotest to check UV resistance and color fastness. Then, in the production stage, our self-developed continuous production system, where fiber reinforced composites are manufactured in an automated continuous infeed process, enables us to manufacture composites featuring a consistent quality which can be reproduced at any time.