A packet of sawn timber is loaded into a tipping machine that is designed to slowly release individual lengths of timber.
An operative visually grades the sawn timber as it is released onto a driven roller table. This involves marking defects in the timber with a fluorescent crayon. The roller table is the start of the principal piece of machinery required for glulam production – the finger jointing line.
Once defects are marked, the pieces of timber are carried through a chopsaw, which recognises the marks and automatically chops out the marked defects.
After defects are chopped out the remaining pieces of timber (lengths vary from 1m to 4.8m) are conveyed to the finger joint cutter. This machine cuts a ‘zigzag’ pattern in both ends of all timber pieces.
The timber pieces then enter the finger joint press. This machine applies glue to the ends of each piece and clamps them together. From the finger joint press onwards the timber is transformed into a continuous piece.
The finger-jointed timber is then fed through a two sided planer and on to an automated stacking table. A chopsaw after the planer cuts the continuous stream of finger-jointed timber into lengths according to whatever beam length is specified.
The whole process, from the marking of timber for defects to the stacking table is automated and only requires one operative.
The finger-jointed timber is then transferred to the glue line. Each stack will contain the timber required to make one beam and is transferred by forklift. The glue line rolls each piece of timber through a glue spreader at a set speed to maintain a consistent coverage of glue.
On exit of the glue line, the timber is stacked by hand into mechanical clamps. The clamps are tightened using a torque wrench. The clamps can be arranged to produce curved or straight beams. The beams must be cured for about 8 hours at 25°C. A movable shroud is used to allow the clamping area to be heated to 25°C.
After curing, the beams are removed from the clamps, placed on a roller table then put through a 4-sided planer.
The beams are then required to be stored for a further 24hrs before being released for use.