Wood is valuable natural material which was created by nature itself. People have been using this wonderful raw material for many centuries to build houses, create furniture, decorative items interior, and also used for industrial purposes. For these reasons, proper processing of a felled trunk is an extremely important task. Sawing and planing wood are the most important operations with wood. In this article we will talk about what wood sawing is and what types of sawing exist.
Log sawing is the process of converting valuable natural raw materials into lumber. When sawing wood various methods lumber can be obtained in various sizes. To obtain high-quality products, you need to choose high-quality, even logs that are not damaged by pests.
Types of wood cutting
The quality of the final product depends on a large number of factors - the type of wood and the quality of the raw materials, the professionalism of the workers, and proper drying. However, there is another important aspect - this is the method of cutting timber.
There are the following cutting methods:
- tangential
- radial
- rustic
- longitudinal
- transverse.
Rustic is a cut that is performed under acute angle to the direction of the fibers. This method is used in the manufacture of lumber for rustic flooring, which can be called the most heterogeneous and original in pattern and shade.
During tangential cutting, the cutting plane lies tangentially to the annual layers of the material at a certain distance from the core. Since wood fibers are most often located in different directions, a natural pattern in the form of fancy “arches”, “curls”, “rings” is obtained on the surface. The structure of the board with this cutting option is heterogeneous; wood pores may be present. At the end of the tangential cut, the boards are characterized by an increased coefficient of shrinkage and swelling. Also, this log sawing scheme makes it possible to increase the useful yield coefficient, which causes a reduction in the cost of the final product.
Sawing wood blanks using the radial method is carried out perpendicular to the annual rings. Thus, a homogeneous board is obtained with the smallest gaps between annual layers. This creates an attractive pattern and also increases the strength of the lumber. Radial materials are characterized by high resistance to deformation and wear resistance. Also, such boards have lower rates of shrinkage and swelling compared to tangentially cut lumber. Therefore, finished products, for example, parquet boards, floorboards, block houses, linings, practically do not crack on the front part, but tangentially sawn materials are susceptible to such phenomena. Glued laminated timber is created only from radial and semi-radial cut boards, because the mechanical and geometric parameters are directly dependent on the resistance of the fibers. This resistance increases during gluing of layers with multidirectional annual rings at an inclination angle of no more than 45°.
From solid log only 10-15% of radial boards can be obtained. Therefore they have a high cost. The most best performance demonstrates material having an angle between the growth layers and the cutting plane from 80 to 90 degrees.
Sawing wood across the grain
The technology of sawing wood across the grain is the most common method of processing timber in carpentry. At the same time, such sawing can be called the simplest. Longitudinal sawing wood requires much more effort and certain skills.
Tools for cross cut Timber products are selected depending on the required precision, the amount of work and the conditions available in each individual workshop. You can use:
- electric circular saw. She makes neat and fast cuts. For household use A model with a 1000 W motor and a disk cross-section of 180 mm is perfect. Most of circular saws have a combined blade included, which can be used to implement the most various works. The teeth of this blade are something between the teeth of a transverse and longitudinal saw. For long-term work, it is better to take a blade that is coated with carbide. Its cost is higher, but it takes 10 times longer to dull
- miter box and tenon saw. They are used for finishing. These tools can be used to make the most precise cuts.
- circular saw
- cross saw. When purchasing, please note that the teeth of such a tool should be alternately positioned to the left and to the right of the blade itself. They must be well sharpened and beveled. The most popular is a saw with 10 teeth per 25 mm blade. With 8 teeth, the saw will cut faster, but will create rough cuts.
The range of lumber offered is quite wide; woodworking products vary in quality, cost, as well as types of wood cutting. Let's take a closer look at what types of wood cutting exist, and for this we first look at general outline what exactly is the technology of cutting wood?
Forest cutting
First of all, the log is unraveled on a belt or disk sawmill, turning into a gun carriage. If all sides are sawn, then the output will be edged material, which is divided into timber, small timber and edged boards. Planed patronage is called lining, floorboard, platbands and baseboards. Glued products include, for example, furniture panels.
There are two main types of cutting wood (logs) into boards (lumber):
- radial;
- tangential,
as well as three additional types:
- mixed;
- semi-radial (rustic);
- central.
Types of board cuts
Radial cut- this is a cut in which the axis of the cut passes through the core of the log and, as a result, the lines of annual rings in the section of the board form an angle of 76 - 90 degrees. with its faces (two main planes of the board). The wood of radial cut boards is quite uniform in color and texture. Such boards practically do not deform when dried and do not swell when moistened, because the change in wood dimensions occurs mainly along the line of the rings (across the grain), and for radial cut boards they are located along the thickness. Radial cut lumber has the highest performance indicators compared to lumber of other types of cut.
Tangential cut- This is a cut that is made along tangents to the lines of the annual rings of the trunk at some distance from its core. The surfaces of such boards have a pronounced texture and a bright wave-like pattern of annual rings. For tangentially cut boards, the coefficients of shrinkage and swelling due to moisture are twice as high as for radially cut boards, which causes their significant deformation when the humidity state changes. For this reason, tangential cut boards are less preferable for use in wet conditions than radial cut boards.
Rustic (semi-radial) and mixed cuts- these are cuts with signs of two main types of cuts at the same time: radial and tangential and, as a result, have indicators averaged between them. In a rustic cut, the lines of annual rings have the form of straight lines located at angles of 46 - 75 degrees. to the layers, and in a mixed cut these lines change from straight at the edges (along the width) of the board to arched in the middle.
Central cut- This is a cut made directly in the center of the trunk and including its core. Considering that the core of the trunk consists of the least durable wood, center-cut lumber has the most heterogeneous structure in terms of strength of all the types considered.
Features of the main types of cutting
At tangential cutting the cut plane runs tangentially to the annual layers of the tree at some distance from the core. Since wood fibers, as a rule, do not have a single direction, they create natural patterns on the surface of the board in the form of fancy “arches”, “curls”, “rings”. The texture of the resulting tangential cut board is uneven and may contain wood pores. Some of the dry boards may develop delaminations on the surface after finishing planing. After tangential cutting, boards are characterized by higher coefficients of shrinkage and swelling; moreover, such a scheme for sawing logs allows an increase in the useful yield, which in turn leads to a reduction in the cost of the board.
For radial cutting of wood, the cutting plane is located perpendicular to the annual rings. With this method, the texture of the board is quite uniform with minimum distance between annual layers. This not only creates beautiful drawing, but also helps to increase the strength of lumber.
Boards radial cut They are distinguished by good resistance to external influences, have greater resistance to deformation and wear resistance than tangentially cut boards.
The shrinkage and swelling coefficients of radially cut lumber are 0.18% and 0.2%, respectively, which is almost two times better than that of tangentially cut lumber. The reason for this phenomenon is that for radial cut boards, shrinkage and swelling occur along the thickness of the material, in contrast to tangential cut boards, in which dimensional changes occur along the width of the board. This explains the fact that in finished products (parquet boards, floor boards, block houses, imitation timber, lining) made from radially cut lumber, there are almost no gaps on the front surface, which is not excluded in products made from tangentially cut lumber. To obtain laminated veneer lumber by splicing wood without knots, blanks and boards of radial and semi-radial cuts are used, since the mechanical and geometric characteristics of the timber depend on the resistance of the fibers, which increases when gluing layers with multidirectional annual rings with an inclination angle of up to 45°.
The average useful yield of radial cut boards is only 10-15%. This explains their high cost. Radial cutting includes lamellas in which the angle between the annual rings and the blade is 60-90°. If the specified angle is in the range of 45-60°, such boards are classified as semi-radial cut. The best performance properties are found in lumber in which the angle between the annual layers and the cutting plane is 80-90 degrees. Taking into account semi-radial cut boards, the useful yield coefficient can reach 30%.
Typically, when radial sawing, the log is initially sawn into quarters, and then from each quarter, boards are sawn off alternately from two layers. For sawing logs in a radial way, for example, UP-700 longitudinal sawing machines can be used. Of great importance is the UP-700 microprocessor control and optimization system, which is used by technologists to determine the percentage of yield of radial cut boards based on the criteria for optimizing the maximum yield of the finished product, as well as the conditions of radial and semi-radial cutting.
Comparing radial and tangential types of cuts, several conclusions can be drawn:
- Radial lumber has best properties shrinkage and swelling.
- Radial cut boards have better mechanical characteristics and dimensional stability.
- The wood of radial cut boards has a uniform shade and uniform texture, which gives a special decorative value to finished wood products.
- Due to its characteristics, radial boards are more widely used, although they are more expensive.
Main dimensions of lumber
There are standard dimensions of lumber. For example, the cross-section of a beam can be 10x10, 10x15 or 15x15 cm, and the length is 6 m. Deviation from these standards will require a special order and will also be associated with additional financial costs. The most expensive is profiled timber, manufactured in-house high class cleanliness.
The edged board can be 2.5 cm, 4 cm or 5 cm thick, 10 cm, 15 cm wide, and a standard length of 6 m. The length of small timber, in addition to the standard value of 6 m, can also be 3 m Its cross-section will be 4x4 cm or 5x5 cm. A by-product of the production of these lumber is a slab, on one side of which there is a face, and on the opposite side there is untreated wood.
Criteria for choosing lumber
Before you choose good lumber, the first step is to find out the type of wood being offered. It can vary from 4 to 0 depending on the number of knots and their quality. It is imperative to check the length of the lumber and the cross-sectional dimensions. If bends or rotational deformations are visible, then it is better to refrain from purchasing such products. You can check the evenness of the lumber by applying a stretched cord.
Interested in the rules for industrial cutting of wood, as well as the differences and characteristics of wood in different ways sawing. So, if anyone is interested, read on. The knowledge will be useful when purchasing building materials and building a country house.
There is a radial cut, in which the cutting plane passes through the core of the trunk. The wood of such boards is quite uniform in color and texture, the inter-ring dimensions are minimal. Radial cut boards-2 are resistant to external influences, are practically not subject to deformation and have high wear resistance. The radial cut board has a shrinkage coefficient = 0.19% and a swelling coefficient = 0.2%. These indicators for radially cut lumber are twice as good as for tangentially cut boards. For a radial cut board, the process of shrinkage and swelling occurs along the width of the fibers - the thickness of the board, and for a tangential cut along the width of the board, because the fibers at the "tangent" are located along the width. Accordingly, at the floorboard, parquet board, imitation timber, block house, lining - radial cut - there are practically no gaps compared to similar tangential cut products. design features:
Since the yield of radial cut boards is 10–15% of the total volume, their cost is quite high. Sawing scheme for maximum production of boards with radial-2 and semi-radial cutting-3.
Tangential-1 is a cut in which the cutting plane passes at a distance from the core, tangentially to the annual layer of the trunk. Such boards have a pronounced texture and a rich wave-like pattern of annual rings. Tangential cut boards - 1 have more high odds shrinkage and swelling, but are more affordable.
Radial sawing-2 wood is a method of cutting a log in which all the fibers in the board run along the direction of the annual rings. When radially cut, lumber has the best physical and mechanical properties. The strength and hardness of wood with radial cutting is higher than with tangential cutting.
The yield of radial saw-2 boards is usually small (does not exceed 30%). On the UP-700 longitudinal sawing machines, the yield of radial cut boards reaches 60%. This high rate is achieved thanks to the cutting optimization system. By choosing among the optimization criteria the maximum yield of a radial cut board, the conditions of radial and semi-radial-3 cuts, the technologist determines the percentage of yield of the radial board.
Building materials made from hardwood and softwood have a wide range of applications; they are used for the construction and cladding of houses, paving paths, interior design building. The lumber on the market is divided according to the cutting method; it can be tangential, radial, longitudinal, disk or mixed. Depending on the presence of edges, boards are classified into edged, semi-edged and unedged.
Mechanical processing of logs can be carried out using special machines or electrical appliances by cutting or splitting. Distinguish following methods cutting wood: planing, turning, drilling, grinding, they all involve removing chips. There are three types of cutting - longitudinal, transverse and straight. The first involves cutting along the fibers, the second and third – perpendicularly. Sawing is the main stage in the manufacture of all lumber; the operational and aesthetic characteristics of the finished product depend on the quality of the procedure.
Tangential sawing
This method of processing logs is considered one of the most popular. With a tangential cut, the plane of the cutter passes at a certain distance from the core of the trunk, tangentially to the growth rings. The result is practical and durable boards that are resistant to shrinkage and swelling. Such lumber has an attractive texture - the graceful wave-like pattern of annual rings is clearly visible on them. Boards obtained by tangential cutting can be used for exterior decoration of buildings and creating a cozy interior.
High-quality parquet is also produced in this way. When cut perpendicularly, a natural pattern is visible on the boards - rings, arches, waves, curls. If the parquet is made from Siberian larch, it can be used for laying flooring in rooms with high humidity, since products made from this rock, upon contact with water and steam, not only do not collapse, but also become stronger. Wooden flooring, created as a result of tangential sawing, will last for many years without needing repairs or renovations.
It is customary to call a radial cut of a log, carried out perpendicular to the annual layers. Lumber produced by this method has a uniform texture, they are characterized by increased strength and wear resistance, and are practically not subject to deformation. Radial cut boards have minimal shrinkage and swelling coefficients, so they do not collapse due to negative influence environment and are great for external cladding buildings. With this processing method, lumber has virtually no flaws. Defects may be caused by a violation of sawing technology (displaced core, incorrect size).
Radial sawing is used for the production of edged boards, a sought-after lumber used for finishing houses, summer houses and cottages. If the cladding is made of Siberian larch, it is perfectly would be better suited for decoration of baths, saunas and bathrooms. Products from this coniferous don't need additional processing, have an attractive texture and have a long service life. Edged board widely used by interior designers, with its help you can create cozy atmosphere. Lumber from Siberian larch contains resin, when released, it spreads a pleasant aroma.
Mixed wood cutting
Semi-radial sawing is a common method of producing lumber. It involves cutting logs at an angle of 45°. This technology allows you to save raw material and reduce the cost of the finished product. The only drawback this method cutting is that the resulting board may be subject to deformation due to improper drying. Therefore, special attention must be paid to preparing wood for processing.
Semi-radial sawn timber can be made from both hardwood and softwood. Products made from Siberian larch are especially popular today; their demand is due to their strength, resistance to mechanical damage and aesthetics. Coniferous cladding reliably protects the building from exposure atmospheric phenomena, helps retain heat and create a comfortable microclimate indoors.
Equipment for cutting wood
For the production of lumber, modern high-tech equipment should be used, only in this case ready product will have a minimum of defects. The amount of waste generated when cutting wood also depends on the characteristics of the special equipment. Today, angle sawing machines are used for the production of boards, beams, and parquet; due to their special design, they make it possible to produce high-quality products and reduce the amount of waste. Using equipment for radial cutting, you can obtain not only radial, but also edged lumber. The basis for creating molded products is a log - a tree trunk freed from branches. Wood cutting can be done in various ways:
- at the sawmill;
- manually (using special sawing tools);
- on woodworking machines.
To use existing logs rationally, the craftsman needs to carefully study the sawing pattern (tangential, radial, longitudinal, mixed). Knowing how to distribute raw materials can reduce waste and significantly increase profits. Suitable for the production of wooden building materials at home manual method, which involves the use of chainsaws and hacksaws. However, homemade boards and beams, as a rule, have defects and look unaesthetic. It is advisable to buy attractive lumber from specialized companies. Large enterprises carefully control the quality of their products.
The cut of wood determines the texture of the parquet board and the row performance characteristics. There are 3 main types of cuts: tangential, radial and rustic. Less often, mainly for artistic parquet, transverse or, as it is also called, end cutting of wood is used, in which entire growth rings are preserved. In addition, there are mixed cuts - semi-radial and semi-tangential.
The radial cut is made perpendicular to the growth rings, the layers are clearly visible on the die, they are located parallel along the length, the texture of the parquet board is uniform and monochromatic.
Advantages and disadvantages of radial cut
Due to the fact that the process of shrinkage and swelling occurs along the thickness, the coefficient is only 0.18 and 0.2 accordingly: the value is 2 times higher than that of tangential cut wood, which changes dimensions along the width.
Parquet has increased strength characteristics and exceptional stability in various climatic conditions. However, you have to pay for everything: the radial cut yield does not exceed 15%, which significantly increases the cost of lumber.
Tangential cut
The tangential cut runs tangentially to the annual layers, but bypasses the core of the log. The texture is heterogeneous and variegated; natural patterns are created on the dies that convey the uniqueness of the breed.
Pros and cons of tangential cutting
However, with all the originality of the parquet texture less resistant to humidity and temperature changes. Thanks to minimum quantity defective tangential cut boards are cheaper.
Rustic cut
The cut is made in any direction at an acute angle to the wood fibers: boards are obtained with a wide variety of textures. That is why the rustic cutting method is extremely rarely used in the production of parquet: it is almost impossible to select uniform dies that are comparable in color.
The cutting method determines the texture and color of each die, and also directly affects the stability and strength of the floor covering.