Explain artificial seasoning of timber

Types of defects in timber as a construction material. Woodworking when wood is used as a construction material, whether as a structural. The defects occurring in the timber are grouped into the following five divisions. Seasoning is the process of removing the moisture content from wood to minimize structural problems when used in construction or to provide less smoke and more uniform combustion when used as. During the process of converting timber to commercial form, the following defects may occur. What are advantages and disadvantages of artificial. One of the best of these is to immerse the timber in water as soon as it is cut down, and after it has remained about a fortnight in water, but not more, to take it out, and dry it in.

Seasoning of timber is also achieved by boiling it in water for 3 to 4 hours. Seasoning is the reduction of moisture content of timber to that of thesurrounding air sydney area approx. Seasoning by boiling wood logs in hot water is called seasoning by boiling. In this process timber is seasoned under controlled temperature and humidity condition with proper air circulation and ventilation system. Others method may be used but for the carpenters work, natural seasoning should be the preference. In this technique timber is seasoned in a chamber with, controlled humidity, regulated heat and correct air circulation. Different ways of seasoning wood home guides sf gate. Seasoning of timber various method natural and aartificial. Free unfinished flashcards about seasoning of timber. It takes more than six months for timber to season in moderate climates. In this method of seasoning, the logs of timber are subjected to the high frequency of alternating currents. This video includes following defects in timber due to natural forces 0. This prevents changes in the dimensions and shape of the articles, eliminates wood rot.

The popular method of artificial seasoning is kiln seasoning. Its subject to defects from the time it emerges as a seedling to the last stages of seasoning. Artificial seasoning of timber seasoning by boiling. Methods of seasoning natural seasoning is a slow process and the reduction in moisture content to the desired level may not be attainable by air seasoning alone. In a perfect seasoning process, stress is kept minimum by controlling the shrinkage. This process of drying is known as the seasoning of timber and the moisture should be extracted during seasoning under controlled conditions as nearly as possible at a uniform rate from all parts of the timber. Felling, conversion and seasoning of wood engineers. The water is to be removed before the timber can be used for any engineering purpose. Air drying airdrying is the drying of timber by exposing it to the air. Water seasoning on account of the time required to season timber in the natural way, various methods have been tried to effect the same purpose in a shorter time. Wood seasoning article about wood seasoning by the free. Natural and artificial flavors are defined for the consumer in the code of federal regulations. Cupping is when the timber dries out in a curved shape.

Before the timber can be used a large part of the moisture must be removed. Artificial method of seasoning or kiln seasoning speeds up the seasoning process. Timber is seasoned to dry out the timber to bring it to a usable and workable condition. There are multiple advantages to having wood artificially seasoned that relate to the quality, strength and cost of the wood. Natural and artificial seasoning of timber explained mcqs. The defects in timber are caused by the nature of the soil on which the tree is grown, the fertility it gained, and changes occurred in the environment during its growth. This is simply the weight of water contained in a piece of timber compared with the weight of actual woody substance in the same piece. Bowing is a warp along the length of the face of the wood. Timber stacked on trolley with stickers between planks for air circulation. In case of chemical seasoning, timber is stored in suitable salt solution. The curvature of a piece of sawn timber in the direction of its length, cf.

For a large amount of wood, it is done in an enclosed place where hot steam is passed. Artificial seasoning kiln seasoning compartment progressive explain what happens during the kiln seasoning process. We need to reduce the mc of timber for the following reasons. If seasoning is not uniform, the converted timber may warp and twist in various. Kiln drying of lumber is perhaps the most effective and economical method available. Air seasoning the easiest way, but not the most effective method of seasoning timber, is to stack it outside. The rise in temperature should be such that the timber retains originals strength and elastic properties. In this method timber is subjected to hot air in air. What is timber and what are various uses of timber. In the air seasoning or natural seasoning or natural drying, seasoning of timber, timber is dried by direct action of air, wind and sun. Lumber or timber, a wood which is capable of yielding the minimum size of a dimension, is generally produced from growing woods. Seasoning of timber artificial and natural methods. Artificial kiln seasoning wood and timber seasoning. What is the difference between artificial and natural.

After artificial seasoning the wood becomes harder, whereas in natural seasoning the wood becomes soft. Seasoning of timber from day to day, most people have some contact with seasoned timber. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Twisting, cupping, bowing are defects caused by defective seasoning and conversion.

What are the different types of seasoning timber answers. Artificial seasoning is the process by which lumber is dried using manmade devices such as a kiln. Artificial methods of seasoning of wood air seasoning the traditional method of seasoning timber was to stack it in air and let the heat of the atmosphere and the natural air movement around the stacked timber remove the moisture. Seasoning of timber seasoning is the name given to the methods of drying timber there are two methods by which timber can be dried. The timber is laid out as seen in the diagram below. It is also extensively used in the production of beams and planks. Artificial or kiln seasoning is a quicker method of seasoning timber t the desired moisture content under highly controlled conditions. Twisting occurs when constriction causes the edges of a piece of timber to move out of parallel. It is normally placed in a hut building, with two sides open to allow air to circulate. Length of drying time is also greatly reduced and is predictable so that dry lumber inventories can often be reduced.

Electrical seasoning is the type of artificial seasoning in which electricity is used for reducing the moisture content. When a tree is newly felled, it contains about 50% or more of its own weight as water. During seasoning of timber, exterior or surface layer of the timber dries before the interior surface. Faulty method of seasoning causes serious defects in woods. The purpose of seasoning is to reduce the moisture content in the wood to a level appropriate to the use of the articles made from the wood. Timber is the most important element used for making furniture. Seasoning definition, salt or an herb, spice, or the like, for heightening or improving the flavor of food. When the converted timber is stored for longer time, some timber planks may have curve along its length which is known as bow. Types of defects in timber are grouped into the following divisions. In this technique timber is immersed in water and then water is boiled for 3 to 4 hours. When the drying is done in a kiln, the product is known as kilndried timber or lumber, whereas air drying is the more traditional method there are two main reasons for drying wood. This document has been scanned from hardcopy archives for.

The roof and two other sides keep the timber relatively dry. Definition of seasoning of timber natural seasonin. When the moisture content in the timber is more than 25%, some types of fungi attacks the sap wood and makes it discolored. Drying rates in a kiln can be carefully controlled and defect losses reduced to a minimum. The various types of defects under each category will now be briefly discussed. The following are a list of the most common wood defects.

Wood seasoning the process of inducing evaporation of the moisture contained in wood. So, stress is developed due to the difference in shrinkage. Timber is far from being a stable and consistent material. Seasoning is the controlled process of reducing the moisture content mc of the timber so that it is suitable for the environment and intended use. Kiln seasoning is an important type of artificial seasoning in which the timber is seasoned by the use of a forced draught of warm air in which brings about a rapid reduction in moisture content. Methods of natural air seasoning of wood timber how to. The technique of airdrying consists mainly of making a stack.

Its mainly used for building a structure or for other reasons. This process of drying of timber is known as the seasoning of. This type of defect is due to excessive compression in the tree when it was young. Pdf introduction to timber as an engineering material. The seasoning by this method generally takes four to five days under normal conditions. More than half the weight of freshly cut timber consists of moisture or sap.