Bending quality of three Brazilian hardwoods modified by different hydrothermal treatments

ABSTRACT

Background:

Boiling, steaming, and microwave radiation treatments were used for softening and then manufacturing curved samples using three Brazilian hardwoods. Solid wood samples from Carya illinoinensis, Luehea divaricata and Platanus x acerifolia were characterized for bending quality, bending defects, minimum radius of bending, spring-back and moisture content.

Results:

Among the studied woods, Carya illinoinensis wood was the most suitable to conform curved samples since 96.7% of these wood samples reached a perfect curved shape. On the other hand, Luehea divaricata wood presented the worst behaviour, which was marked by only 36.7% of samples achieving a perfect shape. In general, the studied hydrothermal treatments and exposure times induced similar softening behaviours.

Conclusion:

In this sense, microwave heating seems to be a good option when compared to the other pathways, since it is known that this method require low consumptions of both time and energy.

Keywords:
Mechanical properties; wood bending; wood softening; microwave treatment; steam bending

HIGHLIGHTS

Boiling, steaming and microwave are appropriated for manufacturing curved samples;

Microwave seems to be the best since it requires less time and energy;

Among the studied woods, C. illinoinensis was the most suitable wood to conform curved samples, reaching 96.7% of perfectly shaped curved samples;

L. divaricata presented the worst behaviour, with only 36% of samples with perfect curved shape.