Innovative, fibre-based products

In the field of innovative, fibre-based products, we are investigating new application possibilities for paper fibre material at PMV.

Paper, in particular, offers outstanding potential for biobased applications in the construction sector. It can be produced at low cost, consists mainly of renewable raw materials, offers very good strength properties based on its weight, can be produced as a flat material but also with high porosity or even as foam and is relatively easy to functionalize chemically. For applications such as facade elements with high thermal insulation or as shell structural elements, however, today's products lack three-dimensional formability, compressive strength, weather resistance, long-term resistance, and other properties. The LOEWE focus aims to eliminate the remaining deficits concerning the basic principles, to exploit synergies from the disciplines involved and to develop a systematic development methodology along the material processing chain. This requires new design approaches for industrial production and individualizable shaping, familiar material properties must be adapted to the new requirements and further developed, suitable characterization methods developed and material data generated. This will make it possible to use scientifically proven methods to design new paper structures that are suitable for materials, production, and use.

In recent years, more and more composites based on natural fibers have been researched and used on an industrial scale. Thermoplastics reinforced with hemp, flax, jute or sisal fibers can now be found in many cars. Wood is hardly used, since it has considerably shorter fibers than the first-mentioned plants, only for printed circuit boards wood fibers in the form of paper have been used in composite materials for about 100 years, here however in connection with thermosets. In printed circuit boards, the papers are only used for low-quality products, since glass fibers have been used for higher strengths since the 1950s and 1960s. A few research projects in recent years have brought the paperback into focus as a reinforcing fiber for thermosets, as wood fibers are available in much higher quantities than other natural fibers. Their quality is also no worse: their properties scatter less strongly and their strengths are comparable to hemp and flax. Besides, fiber and network properties of no other natural fiber can be influenced as specifically as by the processes used in paper production. Nevertheless, fundamental knowledge of the influence of paper and fiber properties on the properties of the composite is still lacking. This gap between the potential of mechanical pulp and cellulose fibers and their application in composites is to be reduced by research at PMV.

In addition to classical composite materials, we are involved in several projects with vulcanized fibers. In the field of natural products, vulcanized fiber is one of the high-strength fiber materials. Vulcanized fiber is a material that can be produced from cellulose in the form of several layers of a special paper, by the action of concentrated zinc chloride solution or concentrated sulphuric acid. Low molecular weight components dissolve and gels are formed which act as cement between the individual fibers and between the paper layers. The properties of the paper webs are changed considerably. Vulcanized fiber is characterized by high impact resistance, hardness, low thermal conductivity, and low density, but still consists of 100% of renewable raw materials and can be further processed by various manufacturing processes (e.g. cutting, forming). Unfortunately, scientific research into this multifaceted material has almost ceased in favor of plastics. Due to the increasing awareness of using sustainable materials, this material could experience a renaissance. Since the material is composed of multi-layer paper webs, the aim of further investigations should be to find out which paper properties can influence the later vulcanized fiber properties.

Deep drawing of paper is an established forming process which is used, for example, for the production of paper plates, cheese boxes, and French fries trays. These products have been manufactured in an almost unchanged manner for decades. As a rule, they have low degrees of deformation and simple geometries. Recent investigations show, however, that the forming of paper has a much greater potential. The aim of our work in cooperation with the Institute for Production Technology and Forming Machines of the TU Darmstadt (PtU) is, therefore, further development of deep drawing of paper towards model-based development methods, more complex components, and adapted materials. This could lead to new market opportunities and applications for the process. Optimized deep-drawn paper packaging would benefit, for example, from the fact that sustainability and ecological considerations are increasingly influencing the choice of packaging and are being used specifically for marketing purposes. New areas of application for paper with its excellent recycling possibilities and good lightweight construction properties could also emerge in automotive engineering, the furniture industry, and architecture.