Heartwood and Grain Angle On-Line

Purpose

Sorting green lumber by heartwood content and/or grain angle for processing with specially adapted drying methods can vastly reduce drying times and improve board shapes. It also enables new products based on heartwood content.

The system can be used in several ways:

• To find boards with high or low proportion of heartwood. This is important to achieve a good drying result. The heartwood of pine and spruce has lower moisture content than the sapwood. Consequently, boads with high heartwood content should preferably be dried differently to those with less heartwood content. Board with high heartwood content also have higher durability and are therefore required in some quality classes.
• To find twist prone boards with a large grain angle. Twisted boards may cause production problems and are also often downgraded, resulting in economic loss. Twist prone boards can be found and also be put in the bottom packages in the kilns to force the boards to remain straight and flat.
• To separate core boards from outer boards. Core boards and outer boards have different properties, regarding e.g. year ring orientation, knot structure and heartwood content, and can thus be of different use.

Method

Heartwood and Grain Angle On-Line are measuring systems based on laser and image processing that can detect heartwood content and grain angle, or both, in one unit during transverse feeding in the sawmill’s green sorting line. The system can work as a standalone unit or be connected to existing automatic green sorting stations, where heartwood content and grain angle are included as grading parameters.

Deliveries

Included when ordering:

• Installation and commissioning of the system Heartwood and Grain Angle On-Line
• Introduction for operators in using the system
• Software in English (or Swedish)
• Two measuring heads for double sided measuring
• High performance vision system computer
• Software licence and remote support for one (1) year