Thermo-hygro rheological behavior of materials used in the manufacture of wood-based composites

Thermo-hygro-rheology of wood-adhesive systems plays an important role during the hot pressing process of wood based composites. The principal objective of this research is to quantitatively study the thermo-hygro rheological characteristics of wood-adhesive systems used in such composites. This is with a view to providing material characteristics which may be used in simulation models of industrial hot pressing operations.For this purpose, a specially designed miniature hot press system mounted on a servo-hydraulic testing machine was used to compress pre-formed fiber networks. The environment for each test was maintained uniform throughout the specimen by pre-treating it inside the system until the desired conditions of temperature and moisture were achieved.Experiments have been conducted under a range of test conditions of load (1 to 6 MPa), temperature (25Each element has been nonlinearly related to prevailing density (rather than stress) of the material. Over almost all of the investigated combinations of temperature and MC, increasing temperature and moisture leads to increased elastic, viscous, delayed elastic and plastic-fractural deformations at given load levels.The results may aid in the optimization of existing products and the development of new ones.