Abstract
When producing (pressing) flax/PP composite panels, several processing parameters have to be considered. This paper describes how these parameters affect some properties of the resulting panel. The multidirectional flax/PP composite panels were made from needle-punched hybrid nonwovens. First the most appropriate process times and temperatures were determined, using unmodified flax/PP nonwovens. Once these parameters were optimized, also panels consisting of modified flax/PP (boiled and bleached flax) were pressed. Degree of needling and test direction were other parameters that were considered. Density, thickness, relative surface weight and flexural properties were determined. Extra needling only seemed useful at low process temperatures while test direction had no clear effect on results. Flax treatments did not lead to the expected property improvements but it is believed that combining a mild flax treatment with modified PP might lead to improved results, and possibly to a reduction in the odor that is released during and after production.