Many types of timber are used in commercial truck bodywork today, and it is used in a variety of different forms ranging from sections for framing, chipboard for partitions, to faced plywood for decorative panels. Manufactured timber panels are also used in conjunction with other materials such as aluminum and plastics to produce panels for special purposes which include heat and sound insulation and to improve resistance to general wear and the weather.
Some timbers are more suitable for vehicle bodywork than others because of their superior strength, resistance to wear, decay and fire, or appearance.
Although timber is used in many forms, it is all obtained from either soft wood trees or temperate or tropical hardwoods. wooden teether
There are a large number of softwood trees, which include many varieties of pine, fur, and spruce which make up about 90 per cent of all timbers used generally in the U.S.A and Europe. These trees are normally found in the northern hemisphere; most of them are cone bearing and evergreen, but there are some exceptions. In fact some types of softwoods are harder than hardwoods.
There is a good supply of softwoods and since less time is required to mature and they are easier to work they are generally cheaper than hardwoods. Softwoods are uses for the sides and floors of mineral carrying vehicles, since it is cheaper and easier to replace. It is also used for manufactured panels for other commercial vehicle bodies.
These are obtained from broad leaf trees, and there are over 2000 varieties including such well known types as oak, ash, teak and mahogany. All basal wood, which is much softer than softwoods, is in fact a hardwood, since it is the structure that decides the group not the texture.
Because the hardwoods take much longer to mature, are more difficult to obtain and work, and take much longer to season they are considerably more expensive. However, they are generally much stronger, more durable and have far more uses than softwoods.
Hardwoods are divided into two groups:-
1. Tropical. These are from trees found in Central Africa, India and South America and include the many different types of teak, mahogany and ebony.
2. Temperate. The varieties found in this group are oak, walnut, and ash are some of the temperate hardwoods found in U.S.A, Europe, Japan and Australia.
Hardwoods are used for framing and in some forms of veneer on panels for interior finishing. Also hardwoods such as ash are very suitable for curved framing members.
Plywood, block-board, chipboard, MDF and hardboard panels are often used instead of solid timber panels, and have many advantages. They can be obtained in larger sizes, are often stronger and are more stable, which means labor costs can be reduced when compared with other methods of covering large areas with equivalent tongue and groove jointed timber.