Lumber is a term we use for wood that has been transformed by any one of the processes during felling to drying and is used in a number of ways from the building of houses to the laying of fences. Dimensional lumber is finished lumber that has been cut to a specific thickness and length. In early sawmills, lumber was cut into varying sizes depending on a customer's specifications. Today, however lumber is treated and cut into predetermined sizes by virtue of 3 categories per the thickness of each piece. Lumber that is lees than 2 inches in diameter is classified as a board.
Lumber that has a nominal thickness of 2 inches but is less than 5 inches is considered dimensional lumber while wood that has been cut to 5 inches or greater is referred to as 'timber' and can vary from 2 to 16 feet in length. The standard sizes for dimensional lumber in the U.S. include the 2x4, the 4x4, and the 2x6. Standard lumber lengths in the states run by 6, 8, 10, 12, 14, 16, 18, 20, 22, and 24 feet. When the rough-cut pieces of lumber are dried and surfaced their finished dimensions end being less than the logs original size. Rough-cut lumber is dried and finished with a plane on all four sides, so that by the time the whole process is over the cut lumber plank is actually smaller in dimension than its original size before it was cut.
The process in which all trees are turned in to lumber and sized accordingly goes as follows: In Felling, a tree is cut down with a gas powered chainsaw in most cases and all of the limbs and branches are removed. This is done once the tree has fallen, hence the term 'felling', before the logs are transported on logging trucks to the mills. At the mill, logs are pulled from piles by forklifts and carried to with rubber-tired rollers a chain conveyor called a carriage that brings them inside the mill for debarking and bucking. In debarking, the bark is stripped from the log either by the many teeth of a set of grinding wheels, or by a high-pressure water stream. The stripped bark is then broken down into pulp that is in most cases used to heat the furnaces within the mills.
Next, a huge circular saw known as a 'bucking saw' is used to saw each of the logs into pre-measured lengths. Then, the larger logs will undergo the heading saw. Heading is done to logs that are too large to be cut with a ban saw. In the Heading process, a log is taken from the conveyor and clamped to a moveable carriage that slides lengthwise on a pair of metal rails. Optical sensors scan each log to determine the diameter of each of the log ends as well as citing whatever surface defects a log might contain such as holes, knots, or rotten wood scores.
The machine then suggests a cutting pattern to the saw operator who reads the printout from a booth near the heavy saw. The first cut is on the side of the loge that is closest to the saw operator. The wood left from the cut is known as the 'slab'. The slab's outer surface will have the trees original round shape. This piece is then taken away and chopped up for making paper pulp.
The carriage on the heading saw is then returned to its original position, which causes the log to tilt sideways for the cutting away of the selected boards. After the boards are cut they are dried and planed. The smaller logs are cut with a ban saw into nominal sizes of 1, 2, or 4 inch thickness in only one pass. All wood is then dried, or 'seasoned' to prevent decay and increase shrinkage of the wood to fit for size as it dries out. This process takes at least one year to complete. For transfer, most lumber is bundled by machine and transported to truck by crane, or mounted on wooden skids or palettes held by forklifts that carry the wood to other places within the milling yards and warehouses.
Bathroom Fan Heater Combo Reviews Martin D45 Guitar Order Lowest Price Faucet Water Purifiers
