Influence of fiber type,fiber mat orientation,and process time on the properties of a wood fiber/polymer composite

摘要

A rapid press consolidation technique was used to produce composites from two types of air-laid wood fiber mat,incorporating either mechanically refined or bleached chemithermomechanically refined Norway Spruce [Picea abies (L.)Karst] and a bicomponent polymer fiber.The manufacturing technique involved pre-compression,contact hating to the porcess temperatue under vacuum and then rapid transfer to the press for consolidation and cooling.Composites were tested to determine response to water or water vapor,porosity,fiber volume fraction and tensile properties.The composites absorbed waterrapidly and showed changes in thickness with flucturations in relative humidity.Porosity was higher in composites containing mechanically refined (MDF)fibers thanin composites containing bleached chemi-thermomechanically refined (CTMP) fibers.Tensile test results suggested that fiber wetting by the polymer matrix had been maximized within a five-minute heating time.Results also indicated that porosity was not the key determinant of tensile properties in the composites.