Today, finger-jointed components are being increasingly used in the joinery, construction and furniture sectors. Timber manufacturers are therefore investing more in finger-jointing equipment, and are realising the many benefits of improving timber quality, increasing yield and bigger profit margins – in addition to the known environmental benefits of conservation.
The market growth for finger-jointed and laminated timber has been considerable. In Europe, demand for laminated timber has grown by 310% since 1989 and in 2002, production stood at 2.1 million m3. Constructional finger-jointed timber in Europe in 2002 stood at 3.4 million m3.
Finger-jointed material provides many advantages over natural timber because it is defect free. It can be provided in longer lengths; is stronger and straighter; it’s more durable and stable; and it gives a higher performance – commanding a higher value. If tested to breaking point, the finger-joint is the last section to break. Finger-jointed structures also have a better fire rating than steel.
UK manufacturers have been slower to take up finger-jointing than their European counterparts but, today, more UK timber manufacturers are using finger-jointing to add value to softwoods and there is also a niche in the recycling of used hardwoods, where short pieces are being finger-jointed into longer lengths and sold profitably. The home-grown timber sector too is a growth market for finger-jointing.
Versatile machines
UK companies in the finger-jointing field include Magnet Ltd, Dale Joinery, Chris Sharp and James Jones & Sons Ltd. To date, most of the manufacturers tend to be larger companies with large throughputs but this is likely to change as new and more versatile finger-jointing machines are introduced.
It is important that the technology is not judged on finger-jointing techniques and machinery used in the early days of the process. Today, there is a world of difference. The tooling for cutting finger profiles is now much more precise, with the latest cutters made by specialist companies to very close tolerances, providing a perfect closed joint. When the material is planed all round, the joint is hardly detectable.
Improved adhesives
Furthermore, glue manufacturers have improved adhesives. Even wet timbers can be finger-jointed now, with the moisture in the timber activating the glue, hence the increasing use of finger-jointing for glulam beams for main building structures, laminated timber in window scantlings, panels and, more recently, decking. In furniture too, more finger-jointed products can be seen in furniture stores like IKEA. And finger-jointed decorative timber is widely used in shopfitting and garden products.
There are two types of finger-joint – vertical and horizontal. Vertical joints are mainly for high strength applications – constructional timbers, glulam beams, window scantlings and large cross-section material. Horizontal joints apply mainly to glued panels for furniture production, interior décor and flooring.
Critically, today finger-jointing is also accessible to a much wider range of companies, with machine makers like Weinig subsidiary GreCon producing a much wider range of finger-jointers suited to a broader spread of throughputs and budgets.
Two machines unveiled by GreCon at Ligna illustrate this trend. The new ProfiJoint is designed for the small- and medium-sized company and can produce finger-jointed material for a wide range of potential applications. It is targeted at manufacturers entering the finger-jointing market and can accept off-cuts as short as 15cm. The automatic glue spreader is a new patented design which applies the minimum of glue needed. This ensures a clean joint, minimum glue consumption and a low level of maintenance.
At the other end of the scale is GreCon’s HS 120 Plus. Capable of operating at 180 component parts per minute, it is claimed to be the fastest horizontal finger-jointing system available.
