Effect Of Processing Parameters, Resin, and wax Loading On Water Vapor Sorption of Wood Strands

Abstract

The outdoor use of oriented strandboard (OSB) is undesirable if exposed to atmospheric vapor or rain; however, increasing resin and wax content can mitigate adverse sorption behavior of panels under such negative conditions. The objective of this study was to investigate the effect of resin loading, emulsion wax loading, and pressing parameters on the water vapor sorption behavior of loblolly pine strands. Pure earlywood of loblolly pine (Pinus taeda) strands were cut and oven-dried at 50°C. The phenol-formaldehyde resin or wax was sprayed on the wood strands, which were oven-dried at 50°C for 900 s. All specimens were equilibrated at 11% relative humidity (RH) over a saturated salt solution. After equilibration, specimens were placed in a conditioning chamber with the RH increasing from 11-80%. The mass change was continuously recorded by a dynamic contact angle analyzer. The results show that platen temperature, wax loading, compression ratio, and resin loading were influential, in decreasing order, on sorption behavior.