TECNOLOGÍA 2º ESO A/B/C

Hardwoods come from trees that have broad and open leaves and there seeds are contained in the fruit that they bear.Most hardwoods trees are classified as deciduous, which means that they loose their leaves during the winter months. Hardwoods are slow growing and can take up to 100 years before they reach full maturity. 

Beech, Oak and Ash are commonly found hardwoods but not all hardwood is hard for example Balsa wood is quite soft and easy to work with but because derives from a deciduous trees it technically an hardwood.

                                                                                               Oak tree just prior to shedding it leaves- autumn

Hardwoods are much heavier than softwoods, they are denser, which means that there is more material per volume. This characteristic makes hardwood harder than softwood in most cases. 

Growth

The energy in sunlight is combined with water, minerals and CO2 provide the food that tress use to grow. Each year a new layer of growth occurs just below the bark, the rough outer casing or skin of the tree, producing something called an annual ring in the cross section of the trunk. The new wood cells  that grows are called sapwood because of the hight moisture content and as this ages and moves towards the centre of the tree become less moist and harder and is known as heartwood.

Cross section through a tree trunk                                                     Grain structure- beech

Grain is the direction of cell growth within the trunk of the tree and is seen as a distinctive pattern that varies from from species of tree to another.

Hardwoods- types and characteristics

Beech toys                       Oak drawers                                   Ash ladders                   Mahogany furniture