New paradigm for strength grading of structural timber

Purpose and goal

The purpose has been to develop and implement a new method for strength grading of structural timber. Two objectives have been fully reached; the method is today commercially imlemented to such an extent that a certification process can be initiated, and the dissemination of results through scientific publications exceed the project plan. The third objective concerns grading accuracy. The new method will result in more accurate grading than what is achived by market leading methods of today. By further development, stipulated accuracy objectives will be reached.

Results and expected effects

A high-efficient method for strength grading of timber has been developed an implemented in an industry environment. Market introduction within a year is foreseen. The method, which can also be used for quality optimization through e.g. finger-jointing, means that the academy will move forward its position within the present field of research, and new business opportunities will emerge for the WoodEye-scanner manufacturer. The project has resulted in closer cooperation between academy and industry, and two of the partner companies have signed an agreement of cooperation.

Approach and implementation

The project can be divided into three parts; 1. development of devices for dynamic excitation and density determination in lengthwise board feeding, 2. transfer of MATLAB-algorithms to machine code, and 3. verification by three test series. Lengthwise excitation and density determination had to be replaced by measurements carried out in transverse feeding. To transfer algorithms to machine code adapted to sawmill applications was however fairly simple. The test series have in total involved over 2000 boards of which about 420 have been tested to failure. About 500 such tests remain.