Lightweight construction with paper

Less weight, better energy balance and more sustainability - lightweight construction is one of the key technologies [1] in Germany and worldwide. Compared to conventional products, lightweight products also often have better product properties. The well thought-out integration of functions, the material-optimized design and the use of lighter materials promise a sparing use of resources as well as improved functionality at lower production costs. Due to its versatile characteristics and areas of application, lightweight construction is one of the cross-sectional technologies. Accordingly, networking among the sectors is crucial in order to take advantage of all the opportunities and develop others. Bayern Innovativ, together with the Bavarian Paper Associations, has made it its task to network lightweight construction with paper across sectors and to open up new growth markets for the Bavarian paper and film processing industry.

Lightweight construction as a technology of the future

Lightweight construction with paper requires a holistic and interdisciplinary approach that brings together and further develops lightweight construction solutions from different perspectives and applications. The German Federal Ministry for Economic Affairs and Energy (BMWi) promotes cross-industry knowledge and technology transfer at a higher level to further develop lightweight construction as a technology of the future. This makes an important contribution to securing Germany as an industrial location, competitiveness and jobs, expanding the culture of innovation, and promoting environmental and climate protection. [2] Prof. Rudolf Stauber, spokesman of the New Materials Cluster of Bayern Innovativ , agrees.

Further, he adds, "Future research priorities in materials include lightweight construction, energy-efficient and resource-efficient component manufacturing, CO2-optimized drive concepts and the design of tools for a sustainable circular economy. The need of the hour is therefore to anchor these new disciplines permanently in the Bavarian research landscape and to support industry through expedient political framework conditions." [3]

Strong associations for the paper industry

The Bayern Innovativ GmbH acts on behalf of the Bavarian Ministry of Economic Affairs, Regional Development and Energy and is a knowledge manager, initiator and accelerator of innovations. Among other things, the company is active in the field of paper and, together with the Bavarian Paper Associations, supports the paper industry in the Free State. Under the umbrella name BayPapier [4], the competencies of three associations are bundled: the Association of the Bavarian Paper, Board and Plastics Processing Industry e.V., the Association of Bavarian Paper Mills e.V. and the Employers' Association of Bavarian Paper Mills. Together, they are committed to the interests of the industry and its member companies. Through the initiation and management of networks, the targeted transfer of information and knowledge, strategy consulting for cooperative innovations of customer-specific project support and, last but not least, in applying for funding , the location conditions for the industry in Bavaria are to be improved. [5]

Lightweight construction in industries

Profit from cross-linking

Fiber composites have strong growth potential. A sustainable design and construction process, mastery of manufacturing technologies, and the right choice of materials are the prerequisites for successful lightweight construction - including with paper as a material. As a cross-industry topic, the bundling and networking of competencies are essential to ensure that lightweight construction, and thus the competitiveness of all those involved, develops efficiently and quickly. In addition, completely new opportunities are opening up for companies in the paper and film processing industry, as many sectors are interested in manufacturing their products using lightweight construction. For example, lightweight construction in terms of sustainable building saves enormous amounts of building material worldwide. In aviation and the automotive sector , on the other hand, people are particularly interested in reducing weight.

Aviation: welcome aboard

Lightweight construction is elementary in aerospace. For example, the first airplanes would not have been able to take off in the first place without lightweight designs. Moreover, every kilogram costs energy , as fuel consumption depends mainly on the weight and aerodynamics of the aircraft. With all the efforts to make aircraft lighter, they must of course also be kept stable, and the materials and components installed must meet the highest safety requirements. Whether heatable, electrically conductive or flame-retardant papers and films - the need for innovative materials is great. Already, flame-retardant paper as well as water vapor barriers are being used for interior cladding. [6]

Network meeting identifies needs

A network meeting planned by Bayern Innovativ envisaged cross-linking the paper and film processing industry with aviation companies. In the run-up to the meeting, discussions were held, needs and opportunities were identified and then compared with each other in the course of the preparations. This clearly revealed a need for heatable, electrically conductive and flame-retardant paper- or film-based materials, but also for new manufacturing processes for sandwich structures. Of particular interest was the question of lightweight construction with paper and similar materials, such as carbon papers. [7]

New materials and sandwich structures

When it comes to lightweight materials, the aerospace industry currently uses the highest proportion of carbon-fiber-reinforced plastics compared with other industries. For example, high-performance fiber-reinforced composites (FRP/CRP) are already being used successfully in Airbus and Boeing models. Paper-based composites in particular are popular for use as structural components in aircraft due to their properties. [8] Here, sandwich elements [9] are popularly used for the interior due to their high weight reduction, reduced manufacturing costs, and ease of handling and storage. They are among the most important composite structures in lightweight construction. When carbon fibers are used, honeycomb structures are mainly employed. Due to the difficult flammability of the material used and the very low density, sandwich elements are often used for parts in aircraft cabins as well as for external covers in aviation.

Automotive industry: lightweight components - heavy on the rise

Topics around lightweight construction currently represent one of the biggest challenges for the automotive industry . Automotive manufacturers and suppliers are faced with requirements that involve reducing weight in vehicles and the associated impact on fuel consumption, CO2 emissions and manufacturing costs.

The question of materials

Whether carbon, aluminum, steel, magnesium - the automotive industry is currently experimenting with many lightweight materials in order to save weight and thus reduce consumption. The key to successful lightweight construction is seen in the selection of the appropriate material for each component. [10] The industry has particularly high hopes for the use of fiber-reinforced composites (FRP/CFRP), especially for economic reasons. If manufacturing costs can be reduced further, high-performance fiber-reinforced composites (FRP/CFRP) may achieve a breakthrough, according to the unanimous opinion of industry experts.

Lighter brakes

In addition to materials, manufacturing technologies and design principles must also be included in the consideration. One example is paper-based brake pads. In order to implement this innovation, which is still very costly today, a close collaboration of manufacturing processes, process- and material-oriented design and material is necessary. The result: a lightweight product with around 50% less weight that has improved properties such as higher temperature resistance and operating temperatures compared with conventional gray cast iron brake discs. [11]

Giving components a structure

Renewable fibers are increasingly finding their way into vehicle interiors. The challenge here is to give them the right shape so that they are stable and load-bearing. One idea is molded sandwich parts, which are used as car load floors, for example. Compared to the conventional aluminum design, the weight has been reduced by about half and energy consumption has been cut by 15%. [12]

Wind energy technology: lighter construction with paper

The wind energy represents an attractive future and growth market. Appropriate lightweight solutions could decide Germany's future competitiveness in wind turbines, experts predict. Most rotor blades are currently made of GFRP or CFRP. These structures are difficult to recycle. [13] This is where paper comes into play as a reinforcing fiber in composite materials. By means of a new sheet forming technology, it is possible to produce highly oriented papers or also to combine them with recycled carbon fibers. Corresponding work is underway at the TU Darmstadt. [14]

Construction and building materials: making it easier to build

The material demand is growing, the environmental impact is increasing - which is why the construction industry is looking for alternatives to conventional building materials such as concrete or polystyrene. One of them is paper. The challenges for the material are high. On the one hand, it is a matter of adapting properties such as high strength or water resistance. On the other hand, stable and at the same time malleable structures are to be created. At a network meeting organized by Bayern Innovativ and BayPapier in January 2020, precisely these topics came up.

Research meets practice

At the meeting, Robert Götzinger of TU Darmstadt expressed great interest in meeting with the construction and building materials industry. [15] Topics raised as interesting included: Lightweight construction in the building industry, functions such as insulation, the possible substitution of glass fiber-reinforced plastic in lightweight construction with corresponding paper-based materials, and hybrid products made of wood with paper.

Lightweight construction methods in architecture

Götzinger is involved in the research project "BAMP! - Building with Paper." The aim is to create scientific and technical foundations for the use of paper in building applications and to develop new approaches to solutions. For example, the production of rod and sheet elements based on paper is to be developed as a model here. [16]