WOOD: A NATURAL RAW MATERIAL

There are more than 5.000 tree species in the world, with different densities and other distinct properties in mechanical, thermal, acoustic and biochemical terms.

Arbor has selected the most suitable wood species according to their density, mechanical strength, stability ve fungus resistance. There is a correlation between density and strength as well as shrinkage. The ideal density of wood material to be used for window manufacturing wood be 0,50 - 0,70 g/cm3 for hardwood and 0,35 - 0,50 g/cm3 for softwood. Stability is the behaviour of swelling and shrinking that wood shows with regards to changing climatic conditions. The related parameters are changing rate of humidity, swelling rate and the ration between tagential swelling and/or shrinkage to the radial one. Those trees with greatly disoriented fibers cannot be used in Arbor products due to their extreme deformations with changing temperature and humidity.

Resistance to biological threats is another criterion. Selection is made with regards to sap wood. The major biological factors threating wood are fungi, bacteria and pests. Unlike humans, some fungi and bacteria can digest the cellulose in wood. Therefore wood, which contains more than 50 % carbon, is the ideal food for these creatures. Nevertheless they need favorable humidity and temperature to make use of this. If the raw moisture content of 20 - 35 %  based on the tree species, comes down to 3 %, the operation of most fungi and bacteria nearly stops. Therefore wood material in interior spaces rarely decays.

Arbor treats the surface of its kiln dried material with proper substances against biological threats. The moisture in Arbor products which are painted with special paints are kept in limits against exterior conditions. These are the measures that Arbor takes against decaying.

Most fungi develops in wood over 20 % moisture. The wood material that arrives at Arbor are kept in control for the sake of biological resistance and physical stability.The whole production site is under control of temperature and humidity for this purpose.

We prefer spruce among conifers, dark red meranti among tropicals and oak among traditional wood species. Premium quality, 3 layers laminated wood scantlings, under 12 % moisture content are used in 68 mm thickness for window and 42 mm thickness for door production. All three wood species are stable in terms of deformation against temperature and humidity fluctuations. They provide excellent surface and are suitable for industrial processing.

Meranti, unlike many tropical species is a product of sustainable forestry and is available in standard properties. Spruce is surprisingly versatile, behaving like high density woods despite its low density. Oak is traditionally the most luxurious joinery material. Arbor processes the best american oak in the best way.