Glulam Solutions, will prepare CADCAM and general arrangement design drawings. Glulam Solutions Ltd are moving towards a fully developed ISO 9001 Quality Assured manufacturing process that utilises the most sophisticated CNC machinery including large bed (40 x 4m) CNC machining technology using laser eye sensors, to position and accurately produce the desired shapes, notches, and penetrations. Multi-tool magazines ensure tool changes are quick, eliminating downtime and maximising production. The latest production techniques achieve unparalleled precision in the manufacture of Glulam engineered components, and, by utilising state-of-the-art software; new cross sectional shapes can be achieved, offering limitless potential for design innovation.
To get a rough overview we summarize the production process of glulam as follows:
The timber is kiln-dried to a moisture content of 10+2% for maximum bond-strength and glulam stability. The softwood boards are first carefully dried in modern drying kilns and the planed. By drying the lamellas individually before gluing it is possible to guarantee that the wood in glulam with even the largest of cross-sections has been dried to a standard wood moisture content of appox. 12%. In addition, since the lamellas have already been dried before gluing, the amount of internal stress generated by later dying is considerable reduced and with it the propensity for cracking.
The dried boards are sorted by machine according to strength and visual appearance. Grading is on the basis of DIN 4047, which already meets the requirements made by EN 14081 for German grading regulations. For the higher surface qualities the facing lamellas for the construction elements are also subject to other grading criteria not just the strength criteria, therefore we use a Woodeye-Scanner. Any sections of board with growth defects discovers during grading which could reduce the strength of the timber or look unattractive, eg. Large knots, resin galls and ingrown bark can be cut out, subject to the strength class and surface quality class. The timbers are sorted unto four strength classes based on amount of knots, bulk-density and bending E-Module.
In order to produce highly effective beams the individual lamellas can be chosen from different strength classes, to suit the load requirement of the beam. The graded lamellas now go through the finger jointing machine. Their appearance defects are cut off and the finger joints of the laminates are moulded and glued together under pressure to form an “endless” board. After the lamellas are planed to the required thickness and cut to the necessary lengths. It is possible to produce individual cross-sections with heights of up to 3m and lengths of up to 65m.
Adhesive mix is applied to the faces of the laminates and the glulam is placed into the hydraulic jigs. There the shape is formed by several jigs side by side. The glues used for glulam are high-performance glues. Since the glue joints are extremely thin (approx. 0.3mm) they are hardly even noticeable, especially with the light coloured glues normally used. Measurements have confirmed that the formaldehyde emissions of the glues used are well within the limits of the forthcoming European EN14080 standard on glulam (E1 class, i.e. formaldehyde emissions of less than 0.1 ppm in a pre-defined test). Standard glulam also easily also easily meets the requirements of emission class F0.
After gluing the beams are planed to get smooth surface. We use CNC-machines for machining the glulam member for setting the templates for metalwork, fixings and connections. Curved and big beams are machined on a 40m long and 4 to 6m wide frame, which can rotate through five axis and automatically choose the required tools. Works as drilling, milling, sawing etc. can be executed in the factory to a very high degree of precision as the electronic CAM-working file is automatically generated out of the CAD-Construction information designed by Glulam Solutions Ltd. A final surface can be pre-coated in the production process if agreed and fitting of connectors such as steel parts can be fitted in the factory to simplify erection on site on specific connections.