Study of the influence of the temperature and pressing time on the physical and mechanic characteristics of different types of MDF when coated by pressing

Mestrado em Engenharia de Materiais Lenhocelulósicos - Instituto Superior de AgronomiaThe present work has the objective to contribute for the study of the effect of the temperature and pressing time in the physical-mechanical characteristics of three types of medium density fibreboard (MDF) commonly used for flooring, during the finishing process. The main difference between the analyzed MDF was the type of resin and the inclusion of a fire retardant agent. The first type of MDF was produced with a urea-formaldehyde resin, the second type with melamine-urea-formaldehyde resin and the third type with a melamine-urea-formaldehyde resin and a fire retardant additive. The experimental plan was developed for two different pressing times of 22 and 35 s and temperatures of 90, 180 and 210 ºC for each MDF type. The pressing time and temperature influenced significantly the properties of MDF after the finishing process, namely when coated with melamine papers. It was observed a thickness reduction, a density and swelling thickness increase, and a densification on the product faces, with the increase of the pressing time and temperature. It was also noticed, that after the physical-mechanical properties analyzes of all the tested products, the product that seems to present the higher resistance to the degradation during finishing is the MDF-MUF. The MDF-IGN seems to be the less resistant; however additional assays are necessary to confirm these trends