The whole timber process and the core of our business starts in the picturesque mountains of Tzaneen and Magoebaskloof. Here we harvest SA pine trees that had been well looked after and well managed for 18 to 25 years. As sad as it is to witness the harvesting of 25 year-old trees, it is truly one of the few 100% renewable products on the market and is thus the reason we have implemented our ‘Green’ harvesting methods. Once the tree is in the ground, log cleaning takes place to determine the best possible length to be cut. These logs are transported from the various plantations to our De Hoek Sawmill’s log yard.
Our policy of Maximum Timber Recovery is at the core of our entire process, and this starts in the yard where the logs from the plantations are sorted into different sizes and lengths for maximum saw recovery and ease of production.
De Hoek has two sawing lines to accommodate both the small logs (90 – 300mm diameter) and the larger logs (diameter > 300mm) where both lines work on the same principle and sawing methods. Logs up to 600mm in diameter can be cut with relative ease at around 6m per minute. One can only stand in awe along with a touch of fear when watching a 600mm log being cut into more than 11 timber boards.
To ensure maximum timber recovery, whilst ensuring the safety of our staff at all times, we have upgraded the old sawmilling methods to make use of the latest industry best practises and machinery. The timber boards are prepared and stacked on trolleys according to their relative lengths and thicknesses, where they will be kiln dried until the correct specified SABS moisture content is reached.
Here at De Hoek, we generate steam to produce the energy necessary to dry our timber in specialized timber drying kilns. All waste timber, which consists of sawdust, cut-to-length offcuts, knot offcuts and any other form of timber which is not sellable, is transferred through our waste transport network to one location, named the “Fuel Bin”. From here we fire up a boiler system which we keep at 6Kpa at all times which then produces the steam necessary to dry the timber. Wet timber goes into the kiln at around 900kg/m3 and after about 36 to 48 hours, depending on the size of timber, it has lost almost half its weight and comes out at around 450kg/m3.
After the boards have cooled down sufficiently, they are moved to the de-stacker where they are offloaded line by line into an industrial planer, where they are planed to the required 38mm or 50mm thickness. The boards are then sent off to the automatic rip saw where laser technology is used to determine the best cutting method to be used, thus ensuring maximum board utilisation and minimum wastage. At this point, the boards have been planed and cut to various sizes, and all that remains is to cut each board to the longest possible stock length according to the SATAS specifications. The boards are cut to lengths from 900mm to 6600mm, generally in 300mm increments. After all the cuts had been made the timber is visually and/or stress graded and stamped to SATAS specification, then bundled and strapped by size and length, and finally the timber is safely transported to the proud new owner. Selati sells and distributes timber all over Southern Africa.
This, in a nutshell is and overview of the De Hoek Sawmill’s SATAS construction timber production process.