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Over time, availability of trees is diminishing, which has led the lumber industries to cut pieces of lumber needed for construction selectively. For manufacturing lumber, one must follow some steps.
The processing of wood products is a billion-dollar industry in the world of today. It turned into a must-have knowledge for those who are into these works: of how the whole procedure goes and the most efficient way to get beautiful pieces of lumber.
Here, I am going to tell you how to cut logs into lumber and get the least amount of waste from it.
What Is Lumber?
The generic meaning of the term “lumber” is different lengths of wood which are used as construction materials. Chunks of lumber are cut according to the desired lengths from the logs of trees.
Previously, lumbers were produced having various dimensions depending on the need of customers.
Lately, there are some specific types of lumbers based on standard dimensions.
Types Of Lumber
Cutting logs in different ways will generate different kinds of lumbers. Besides, the orientation of your blade to the wood will also determine the type of cut. Based on that, there are three types of primary lumbers that you must know.
The plain sawn is the most common type of lumber cut. Since it is pretty economical, many people like manufacturing lumber with plain sawn. It provides you with extensive boards with small amount of log waste.
First, the log will be quartered; then you will saw it perpendicularly with the annual growth rings of the wood. This method of cutting logs is expensive, and it creates more log waste.
This method is pretty much similar to that of quarter sawn. In this process, before cutting the log in the quarter, it is slightly turned perpendicularly. As it produces a lot of waste, it became the most expensive type of planks.
Required Raw Materials
The trees from which lumbers are produced are classified into two groups: hardwood and softwood. Woods are comparatively more expensive than softwoods and are mostly used for panelling, cabinetry, doors, etc.
Both hardwood and softwood lumber pieces are graded based on the size and number of flaws in the wood. The higher grades are known as select grades.
These grades have few defects. Besides, the lower classes are known as common grades and are utilized for general construction.
After the trees have reached a proper size, you need to cut them down and later on, transport them to a lumber mill where they need to be cut into different sizes of lumber. The sequence of the whole procedure is mentioned below:
For visual inspection, test the trees, whether they are ready to be cut down or not. Most of the falling of trees have to be done with chain saws, which are powered by gasoline.
Make a single cut on each side and two near the base. This process will help you to have control over the direction of the falling of the tree.
Use diesel-powered tractors to drag fallen tree parts to a cleared area. Then load them and send them to the mill.
2.Bucking And Debarking
Pick up the logs from the deck and place them on a chain conveyor to bring them into the mill.
Sometimes, the outer bark of the log needs to be removed, and that removed bark is pulverized and often used as a fuel. Stop logs momentarily in the chainsaw mill and use a circular saw to cut them into exact lengths.
This process is known as bucking, and the saw used here is called bucking saw.
3. Headrick Sawing Of Large Logs
Clamp logs of diameter more than 2-3 feet onto a move-able carriage after tipping off the conveyor. Use optical sensors to scan the log which determines the width at every end, defects, and length.
Based on these, a computer calculates a preferable cutting pattern to maximize the number of pieces of lumber that can be obtained from the log.
The sawyer needs to review the suggested cutting pattern, but he will mostly rely on his personal experience. Make the very first cut along the side that is closest to the operator and remove the slab. The sawyer keeps on monitoring the log for internal defects and modifies the cutting pattern accordingly.
4. Bandsawing Small Logs
Pass the logs that have smaller diameter through a series of bandsaws which cut those into thick pieces in each turn.
Lay flat the large pieces that came from the Headrick saw and move them by a chain conveyor. This machine cuts them into required widths and trims the edges.
Sometimes, the pieces which come from smaller logs can be passed through bandsaws to cut them along their width.
Pieces of lumber that have been cut and trimmed are to be placed somewhere for seasoning. It prevents decay and helps the wood to shrink.
Some lumber can be air-dried depending on the preferred moisture content of the piece. Then store the kiln-dried lumbers in an enclosed area while 44-82 degree Celsius air circulates through the stack.
Pass the dried pieces of lumber through planers that trim the pieces, round the edges, and smoothen all the surfaces.
8.Banding And Grade Stamping
Visually or mechanically inspect each piece of lumber and grade based on the number of defects present in it.
Stamp the class on each piece. Also, put information about moisture content and related stuff. The bundle of lumber needs to be secured with steel bands.
It is pretty much evident that you will not get perfect pieces of lumber very often. Great care should be taken to minimize defects as much as possible while sawing the wood to its required sizes. The number of errors mostly determine the grade of the lumber.
So, you must ensure the quality of the lumber both during manufacturing and purchasing.