Paper Title
Mathematical Modelling of Plastic and Wood Raw Wastes Recovery Process

Abstract
The main aim of this paper is to present the design of experiment (DOE) and evaluation methodology for this experimental plan in order to determine the mechanical properties of waste raw materials based wood-plastic composites (WPCs). One of the recovery possibilities for mentioned raw materials is production of waste raw materials based wood-plastic composites. Using a variety combination of influencing variables can be improve the quality of WPCs samples from a mechanical properties point of view. Raw material variables impact, especially (type of raw material, particle size, moisture content, etc.) can be recognized during the production of WPCs. Their impact can be seen through the quality indicators; especially mentioned variables significantly influence the mechanical properties of WPCs. In this experimental research authors would like to investigate properties, behaviour and application of WPCs based raw waste wooden and recycled plastics, instead of original (virgin) plastics. That´s why is important to determinate the mechanical properties of WPCs. This contribution discusses the analysis of experimental process, its individual steps and their subsequent DOE leading to the development of a mathematical model that will describe this process. This paper also presents the research findings regarding the recovery possibilities of plastic and wood raw wastes which were achieved during the first phase of experimental research. In this first phase the mutual interaction between mechanical properties, type of the plastic matrix used in WPC, wood/plastic concentration ratio and particle size of wood sawdust used in WPC was determined. Index Terms - Experiment, central composite design, mathematical model, WPC, waste