The truck body uses a wide variety of wood and is used in various shapes for frames, chipboard and plywood. Decorative panels. Manufactured wood blocks are used in conjunction with other materials such as aluminum and plastics to produce panels for special purposes that improve heat and sound insulation, as well as general wear and weather resistance
Some woods are more suitable for wear, decomposition and Despite the fire or appearance
Although wood is used in many forms, both soft woods and temperate or tropical hardwoods
Woods are generally in the US and Europe. These trees are usually found in the northern hemisphere; Most of them are tapered and evergreen, but there are exceptions. In fact, certain types of softwoods are harder than hardwood.
Puff trees are of good quality, and since less time is needed for maturity and easier to work, they are usually cheaper than hardwood. Luminous wood refers to the side and floor of the mineral-driven vehicles as it is cheaper and easier to exchange.
These are derived from large leaf trees and have more than 2000 varieties, Known types: oak, ash, teak And mahogany. Each base tree, which is much softer than softwood, is actually hardwood, since this structure determines the group rather than the texture.
As hardwood matures for a much longer time, And work and it takes a lot longer time in the season are much more expensive. However, they are usually much stronger, more durable and have a lot more use than softwood.
Hardwood is divided into two groups: –
1. Tropical. Trees in Central Africa, India and South America include many types of teak, mahogany and ebony
. Moderate. The varieties of this group are oak, walnut and ash found in some of the moderate hardwoods found in the USA, Europe, Japan and Australia.
The hardwoods are framed, final. Hardwood such as ash is very suitable for curved framing elements.
Plywood, masonry, chipboard, Solid wood panels, and many advantages. Larger sizes are available, often stronger and more stable, which means that labor costs can be reduced by comparing other methods for covering areas with large, equivalent tongues and grooved saws.
The veneer sheet is made by gluing layers of veneer at right angles to each other. This prevents splitting and significantly increases the panel strength. Arched elements can also be manufactured by placing veneers in a suitable form or shape prior to gluing
Used to produce birch, ash, pine and pine plywood, but many other varieties are used in decorative panels . Plywood can be obtained in several thicknesses and sizes from which one body can be made from one body.
From solid wood trunks. One of them is the block block, which is joined by soft wood and faced with wood veneers such as birch and mahogany. Thicknesses up to about 2 inches in thickness are produced and used between floor and partition walls
Particleboard is made of graded wood chips, Pressured with synthetic resins and adhesives Produce strong panels of 0.5 inch-1 inch thickness. They can be faced with many different materials to get painted, plastic or veneered surfaces. It replaces solid wood for a wide variety of purposes and is a useful utility vehicle due to its size.
Medium Density Fiberboard (MDF)
Adhesive, heat and pressure bonded with wood fibers. This is a very adaptable material, but it can only be used for internal bodywork. It should be sealed / painted as it gradually releases urea-formaldehyde, which is known to be carcinogenic and eye, throat and lung irritant. Appropriate security procedures should always be used to work with this material in any way.
This is another useful material which, due to its smaller thickness, is very suitable for interior trim. It is made from pressed wood fibers and usually has a smooth side and the back is rough or mesh. Identification of woods
Wood is used in bodywork, it is possible to identify more common ones such as oak and teak. Most types have distinct features and properties and when samples are thoroughly examined, it is often possible to identify a particular type. The following characteristics shall be taken into account: –
1. General appearance
- i) Color – red, brown, yellow, white
- (ii) Cereal – close or open, straight or twisted
- iii) texture – hard or soft, rough or smooth
- Figure iv – Grain shape
Sample measurement is not reliable because weight depends on moisture content and The weight of the samples may also vary. Use a handwheel
Examination of surface and end-pieces can reveal distinctive properties
4. Use a microscope. Using a microscope allows a much narrower examination of a thin part.
This allows for microscopic examination of the shape and size of cells and fibers
It should not be forgotten that characteristics and colors may be affected Origin, Growth Rate, Timber Treatment, and many other factors.
One of the major drawbacks of wood is that errors can occur or develop later. Some of these can be handled satisfactorily, others may require replacement of the part. Some mistakes can be avoided by careful grubbing, transformation, and seasoning, but knowing errors will make it possible to make the most of the tree that can be slightly lower.
Knots. These are not always serious mistakes, as they often cover wood with paint, panels, or other disguises and in wood such as knotty pine, they are treated to improve appearance. On the other hand, knots may not be present in frame, some decorative panels, or in other situations where they can affect strength or appearance. Knots are almost always present, and wood is often divided by the distribution and number of knots present. Some woods are more than others, so careful selection is usually worthwhile.
Shocks appear in different shapes and are not always obvious until wood is cut and sawn. Shocking of the heart and cup is no problem, but other types, such as the ring and the shaking of the stars, can make valuable wood unusable. During drying or seasoning, moisture will leave the tree faster than the sides as the sides. If this is too fast, other splits may occur.
Various types of wood are affected by various insects, and chemical treatment can be effective. The alternative is removing and burning the infected part and inserting a new piece
Wood stored in wet or ventilated conditions Lowers strength and becomes soft and spongy . If this happens, the wood must be destroyed.
This is a common mistake and is caused by uneven shrinkage during seasoning. The softwood is more prone to this because the softwood contains moisture like hardwood. The drift can be reduced by radial and not tapering the rods. If you look at the end of the planks, you can decide how they were cut off from the log. (19459003)
The causes of the faults of the tree (i) storm damage.
- (ii) exposed cultivation conditions
- iii) Inexperienced mowing
- iv) Incorrect conversion
- (vi) Wrong Storage Conditions
(V) bad seasoning.
%, And because this is too high for trees when cut- Should be cold or dry until the moisture content is reduced. The thickness of the vehicle structure is 12% – 15%. If the moisture content is too high, the wood will continue to dry and shrink after use. If it is too low, the wood absorbs moisture from the atmosphere and may swell. To find the moisture content, measure a wood sample in normal condition and dry thoroughly. The moisture content shall be calculated as follows: –
Moisture Content of the wood (MC%), taking wet weight, extracting the dry mass and separating the response by dry mass,
Wood moisture content is in practice superfluous as electric devices are used for immediate reading. There are several reasons why the wood should be properly treated (Seasoned): –
- I much stronger than unwooded wood.
- II) Less insect destruction and attack
- III) Painting, dyeing and other finishing methods can be successfully performed in the experienced wood.
It should be remembered that the cells in a piece of wood are like wooden buckets. There is a large amount of water in the cavities and walls, so it is important that the wood is properly seasoned. Once the trees are cut, the logs are transported to the sawmill where they are converted, or sawn on planks or other sections. As this creates a larger surface in the atmosphere, seasoning time is reduced. The method used for sawing or converting wood affects the shrinkage, deformation or other woods discussed earlier.
Sawn wood With sticks or pieces of wood that separate the individual layers. This allows the air to circulate freely around each piece. The top of the bundle must be protected from sun and rain, and as moisture dries faster at the ends of the boards, they are sometimes protected against blockage of the ends. The air drying method leads to cheap and often high quality wood, but this is a slow method that lasts several years. Wood is stained and insect repellent, and moisture is rarely less than the surrounding area.
This is a much faster method, which results in wood with tighter moisture content. The wood is placed in arms and placed in an oven where the temperature and humidity are controlled. Air flow can be forced by a natural sketch or electric fans. The artificially seasoned wood may become brittle and other defects may occur, but reduced time is a great advantage. Some woods are air dried for some time before the oven is dried.
Storage of Wood
Seasoning of wood may take several years, before use. To safeguard good condition, certain precautions must be observed: – (i) The prevention of wood must be protected from chemicals and other foreign substances, eg. nail.
Wood preservatives used before painting This kind of preservative is generally low viscosity and usually applicable to a coach or decorative enamelling and dyeing process. It can be applied by brush, spraying or rubbing and usually dries over the night before applying the above-mentioned dye systems. This promotes good adhesion and helps to reduce the problems of wood and rot.
Before using this type of product, it is essential to ensure that it does not contain waxes or silicone additives ]
It is important to check that the wood is clean, dry and oil-free before the wood is drained. The wood should be carefully dressed with appropriate glassware and degreased with a "lint-free" cloth wetted with white liquor or with a suitable solvent.
The primer is then a suitable primer. It is essential that all areas are properly grounded. This includes tree structures, tongue and grooves, where areas must be fitted with metal structures or body parts. This is because it prevents moisture from entering, resulting in paint waste.
II. The tree should be rubbed thoroughly and degreased as described above.
The lumber containing the knots should be treated before priming as follows: –
III. Each knot should be treated with one or two layers. (19459002)
These are non-pigmented surfaces. These include wax polishes, closures, long and short oil varnishes, alkyd varnishes, yacht varnishes, unpacked polyurethanes and teak oil. All of these are suitable for branding. For spraying only, use: cellulose lacquers, two-component polyurethanes, two-packed catalyst varnishes and one and two pack epoxides. The requirements for wood painting are as follows: – i) elasticity of color
- (ii) Builds.
- iii) Life expectancy
- iv) Acid or Alkaline Resistance
Sealers and wax polishes
Waxes – These are petroleum based. One example is chilled wax, which dries fairly quickly, gives little stain to the wood and results in a good average
Waxes – Silicone based. These waxes dry very quickly and provide a hard waterproof surface. Before use, the wood must be closed and it is more cloudy.
Waxes – beeswax. It is a natural product from honey, made from white spirit drinks. It can be removed with a brush or cloth and creates a good surface that can be re-cleaved.
Long oil varnishes
These contain more oil than resin formulations. The resin used is usually an alkyd or a fossil resin. Long oil varnishes are flexible due to the amount of oil and are ideal for outdoor use due to their good durability. It's also fairly clean to finish. Polyurethanes are used for woods that remain under exposed conditions, but are more suitable for internal use. Life expectancy is two and a half years and a four layer system is recommended, ie a very thin coat should be applied and then three full coats should be injected Short oily lacquers
] These lacquers are quick to dry, but are more fragile. They are hard dry and are more suitable for internal use, as they do not have flexible external use.
These are clear for quick dryers for indoor and outdoor use. The caravan is popular as a lacquer and is also used as a four layer system.
This oil is easy to apply but Liberal coatings are required to restore natural wood's color
French Polishing This structure is for shellac And is based on methylated spirits. Quickly dries and the wood sank. It is made of a pillow, wool or gauze pad that is wrung to a cotton fabric. However, water and white spirit drinks are fragile and can easily be damaged. It is mainly used in antique furniture.
These varnishes are of two types, pre-catalyzed and nitro-urethanes. They include amino and polyurethane resins.
There is no doubt about the benefits of using wood for commercial truck bodies. Of course, other materials are and will come to try to replace it, but due to its versatility and availability it is still unparalleled and will come a long time.
Know what wood is and how to care for them Maximum lifetime of truck or commercial vehicle