Abstract—This paper deals with the evaluation of flow properties of polymeric matrix with natural animal fillers. Technical university of Liberec cooperates on the long-term development of “green materials“ that should replace conventionally used materials (especially in automotive industry). Natural fibres (of animal and plant origin) from all over the world are collected and adapted (drying, cutting etc.) for extrusion processing. Inside the extruder these natural additives are blended with polymeric (synthetic and biodegradable - PLA) matrix and created compound is subsequently cut for pellets in the wet way. These green materials with unique recipes are then studied and their mechanical, physical and processing properties are determined. The main goal of this research is to develop new ecological materials very similar to unfilled polymers. In this article the rheological behaviour of chosen natural animal fibres is introduced considering their shape and surface that were observed with use of SEM microscopy. Keywords—Polypropylene matrix, Green polymers, Rheology, Natural animal fibres. I. INTRODUCTION LASTICS are world-wide spread materials. New processing technologies lead to new applications of polymers (PIM, injection molding of organic sheets etc.) which put high demands on these materials. The basic endeavour of this research is to get a tough material that should be light, easy processable and as „green“ as possible. These requirements come from needs of automotive industry where one of the biggest market with plastic parts exists. The aim is to reduce the weight of vehicles and that will lead to reduction of petrol consumption and the amount of combustion product released to air. Technical university of Liberec in cooperation with several organisations develops recipes of new polymeric materials with synthetic and biodegradable (PLA) matrix. The developed materials are given for interior parts of vehicles at this time but the final applications will be vast and will touch many industries. Branch of “green materials” is very extensive and the issue of implementation natural fibres into polymeric M. Seidl is with the Technical university of Liberec, Faculty of mechanical engineering, Plastic molding department, Liberec, 461 17, Czech republic (phone: +420485353333; fax: +420485353676; e-mail: martin.seidl1@tul.cz). J. Bobek is with the Technical university of Liberec, Faculty of mechanical engineering, Plastic molding department, Liberec, 461 17, Czech republic (phone: +420485353164; fax: +420485353676; e-mail: jiri.bobek@tul.cz). P. Lenfeld is with the Technical university of Liberec, Faculty of mechanical engineering, Plastic molding department, Liberec, 461 17, Czech republic (phone: +420485353350; fax: +420485353676; e-mail: petr.lenfeld@tul.cz) L. Běhálek is with the Technical university of Liberec, Faculty of mechanical engineering, Plastic molding department, Liberec, 461 17, Czech republic (phone: +420485353331; fax: +420485353676; e-mail: lubos.behalek@tul.cz) A. Ausperger is with the Technical university of Liberec, Faculty of mechanical engineering, Plastic molding department, Liberec, 461 17, Czech republic (phone: +420485353332; fax: +420485353676; e-mail: ales.ausperger@tul.cz) matrix is very complex and that is why only the rheology is mentioned in this paper. Deformation and flow behaviour under various conditions (different temperature and pressure) is studied by the rheology [1], [2], [3]. This branch of science works with fluid and solid mechanics. Deformation behaviour of ideal solid is described by the Hooke’s law. The applied stress is proportional to the resultant strain but is independent of the rate of this strain. When the stress is removed, the body gets the original shape again and accumulated deformation energy is released. The ideal behaviour of liquids is described by Newton’s law [4], [5]. The viscosity is defined as equivalent to the force needed to affect the flow of a fluid. Deformation behaviour of polymeric materials goes from combination of the viscosity of a liquid and the elasticity of a solid state. Properties of polymers are depend on surrounding occupation (temperature, pressure etc.) and get near to one or the other ideal state and that is why this materials are classified among viscoelastics (Fig. 1) [2], [6]. A lot of rheological models were created for description of complicated viscoelastic behaviour [7] but generally we can say that when small deformations are caused than the behaviour is liner and when bigger deformations are used than the behaviour is non-linear. Flow properties of polymeric materials can be observed in the state of melt (Non- Newtonian flow behaviour) or in the solid state (creep, stress relaxation etc.) [8]. Furthermore we will deal only with polymers in state of melt. The final melt behaviour is given by the molecular weight, chain branching, and molecular distributions and is also affected by used fillers [9]. Fig. 1 Liquid jets of (a) viscoelastic fluid and (b) Newtonian fluid [2] II. MATERIALS AND METHODS A. Fillers shape and size impact Various components are added to the polymeric matrix to reach required properties of the material. In the literature we can find two main groups of fillers. The first group involves M. Seidl, J. Bobek, P. Lenfeld, L. Běhálek, A. Ausperger Effect of Natural Animal Fillers on Polymer Rheology Behaviour P World Academy of Science, Engineering and Technology International Journal of Mechanical and Mechatronics Engineering Vol:5, No:10, 2011 1984 International Scholarly and Scientific Research & Innovation 5(10) 2011 scholar.waset.org/1307-6892/12155 International Science Index, Mechanical and Mechatronics Engineering Vol:5, No:10, 2011 waset.org/Publication/12155