Foamed Products

Initial situation Foamed materials made of fossil raw materials are a burden for our environment. One alternative which is already available on the market in the field of packaging technology is foamed starch. New developments in the plastics technology show that the profile extrusion tends to foamed structures too. Fine pores provide lower densities while strength properties stay almost the same. Contents and objectives Goal is to develop an environmentally friendly substitute consisting for the most part of renewable resources. Possible applications are transport packaging, thermal insulation, technical parts (e.g. motor vehicle interiors) and profile extrusion The preparation and deodorizing of the raw material are additional objectives because of the bad smelling by-products contained in the initial mixture for the assembly of the foamed products. Additionally to the thermal insulation properties and water resistance there is also a demand on compressive strength in many cases. Therefore the achievement of an optimum tamped density of the foamed product is an important objective too. Methods Getting suitable raw material based on natural origin and defining quality characteristics (e.g. grain size distribution, humidity and protein content) are main tasks. If necessary, adequate preparation has to be made. (e.g. sieving, grinding and drying of the natural materials) The deodorizing is managed by the removal respectively adsorption of the organic amines which cause a bad smell. The optimum tamped density of the foamed material can be reached by adding different additives. Suitable supplements are inorganic fillers which are already used in the plastics industry. To minimize the water absorption of the employed natural materials hydrophobizing agents are applied. The main focus rests on the realization of densities as low as possible and a consistent pore structure of the extrudates. The density and allocation of the pores is analyzed by an microscope (reflected-light method) and the appropriate analysis software. Expected results To replace products of the industry comparable properties (e.g. density, thermic insulation, water absorption) have to be obtained. In the field of the bulk goods production these are EPS (extended polystyrol ¿ ¿Styropor¿) and porous materials from nature. At the development of foamed profiles advantages over conventional plastics extrusion should be achieved by the lower weight.