Enhanced urea-formaldehyde adhesive spreading on plasma treated wood particles

It is assumed that improved mechanical properties of plasma treated particleboards are caused by enhanced spreading of urea-formaldehyde adhesive on wood particles. Spreading of adhesive drops was therefore microscopically evaluated based on dimensions and shape of the drops. Plasma treated wood surfaces revealed increased adhesive spreading, which resulted in more contiguous and increased adhesive areas; this was indicated by decreased drop circularity. It is concluded that the plasma treatment increases the adhesive coverage of the particles and therefore enhances the mechanical properties.