Effects of physical parameters on the temperature and vapor-pressure behavior of bamboo scrimber during hot-pressing

Abstract

ABSTRACT Bamboo scrimber was made by “hot in-cold out” hot-pressing with hot parameters of 5 MPa, 150°C and 40–180 min. The variation of temperature and vapor pressure were investigated during hot-pressing of bamboo slabs with various initial moisture content (IMC; 5, 10, 15, and 20%), slab target density (TD; 0.9, 1.0, 1.1, and 1.2 g/cm3), slab target thickness (TT; 15, 30, 45, and 60 mm) using thermocouple sensors and a self-made press-monitoring system. The results showed obvious stages in the temperature and vapor pressure behavior of bamboo slabs during hot-pressing. IMC showed a limited effect on temperature but an obvious increase in vapor pressure. TD and target TT exhibited good linear relationships with the time to reach 120°C in the core layer, suggesting this can be used as an indicator of hot-pressing time. However, both TD and TT correlate less well with the vapor pressure, which might reflect differences in the size or fluffing degree of bamboo bundles.