Transformation by deformation
Mechanical woodworking - Processing operations without cutting tool

Wood is a natural composite material composed essentially of three natural polymers:

• Cellulose, composed of crystalline glucose, is the main component of wood (around 40-50% of mass). It forms the walls of wood cells. It gives wood much of its mechanical strength;

• lignin, the matrix in which cellulose is embedded. It accounts for 20 to 30% of the wood's mass;

• Hemicelluloses, whose proportions and compositions vary according to species, represent 25 to 30% of wood mass. They facilitate bonding between cellulose and lignin molecules.

Each of these three substances has its own glass transition temperature, the transition from glassy to rubbery behavior: 200 to 250°C for cellulose, 150 to 200°C for...