Machine strength grading with Precigrader enables precise estimates of E-modulus and density to sort your wood products into defined timber or lumber grades.
Machine strength grading of timber or lumber can be done according to several product standards. Common commercial grades in Europe are the grades C18, C24 and C30 and in North America the MSR grades such as 1650 and 2100.
Precise estimates of E-modules and density
The use of the dynamic E-modules as indicating parameter results in precise estimate of the static E-modulus (MOE) and enables reliable prediction of strength. A good estimate of density is derived in the process, and is delivered together with the grade and E-modules to the mill control system.
Easy and efficient strength grading for cross conveyor lines
The Precigrader equipment for on-line strength grading of structural timber and glulam laminations is easily installed in cross conveyor lines. This enables efficient grading directly in a sorting mill or in a planer mill. Less than two meters of an existing cross conveyor line have to be allocated for the operation. The maximun capacity of 180 pieces per minute will meet the requirements of most prospective clients. Patent related to the technique has been granted.
Proven technology – simple and reliable working principle
The dynamic working principle is based on the Dynagrade experience. Since many years, numerous Dynagrade units are in use for machine-grading structural timber and glulam laminations for the markets in Europe, Japan, Canada and the USA.
A spring-loaded impact mechanism at the main unit is activated by the transverse movement of the timber. The vibration from a small impact on the timber end is captured by microphones. Simultaneously, the length is measured by the laser-based length measurement unit and the density is measured. The timber piece is supported by sliding units during measurement. The use of dynamic parameters for the grading process is the key to the good repeatability.
The Precigrader is designed for strength grading according to various standards, such as EN 14081 (grades C24, C30, etc) enabling CE-marking, as well as for MSR production for North America (grades 1650Fb*, 2100Fb*, etc.), and for the production of JAS laminations for the Japanese market (grades L125, L140, etc). The Precigrader may also be used for production control, where the E-modulus and/or the density are in focus rather than strength grading.
Precigrader is based on the proven Dynagrade technology.