as well as three additional types:
Scheme of types of log cutting
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). Wood boards radial cut fairly 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.The main products of sawmill production are sawn materials. Minor – sawdust and wood chips, which are used for the manufacture of particle boards, fuel pallets, etc.
If you follow the “letter” of GOST 18288-77, the materials that are produced at the sawmill include:
Lumber– wood blanks with two plane-parallel layers and certain dimensions specified in the standards.
Blanks– edged lumber with wane and edges that are sawn perpendicular to the facets in whole or in part. These include plates (half sections of logs) and quarters;
Lagging– material with an internal sawn and an external unsawed (or only partially sawn) face. Plank obapol - with a convex part sawn half or more, used for the production of fence pickets and in the construction of formwork, scaffolding, strengthening mine workings;
Gorbyl– the outermost parts of the log that remain during sawing. The croaker differs from the obapole in that certain ratios of thickness, width and minimum length requirements are not established for it. Most often used as an environmentally friendly fuel or for the production of wood chips.
Plast– wide longitudinal surfaces of the sawn log and any side of the lumber square section. The inner surfaces are those closest to the core of the log, and the outer surfaces are the surfaces that are farthest from the core.
Edges– narrow surfaces, the processing method of which determines the division of lumber into edged, partially edged and unedged;
Edge– the intersection of adjacent two sides of lumber;
Ends– surfaces perpendicular to the edges.
Depending on the location of the layers to the annual layers, lumber is divided into:
A radial cut is a cut in which the cut passes through the core of the log, at right angles to the rings. In this case, the surface of the layers is uniform in texture and color, and the distances between the annual rings are minimal.
Boards made by radial sawing have excellent quality indicators (swelling coefficient 0.2%, shrinkage coefficient 0.19%). Therefore, radial lumber is in demand for the manufacture of parquet, timber, lining, block house - the finished products have practically no gaps, in comparison with similar tangentially cut products.
Lumber made by radial sawing is the most durable and expensive. They are used in construction, in the production of massive panels and window beams. The yield of a radial board is usually small (30% is already a good indicator), and depends on the method chosen for cutting the log. Optimal scheme cutting to obtain radial and semi-radial boards is considered as follows.
When cutting a log tangentially, the saw passes tangentially to the annual layers of the trunk without touching the core of the tree. Such lumber has a wavy pattern, which clearly shows the patterns of annual rings and beautiful wood structure.
For tangential boards, the coefficient of shrinkage and swelling is at least twice as high as that of radial material, so their cost is more affordable and the quality of the products is lower. Such boards are not used for the main building elements - the wood can be deformed and the product will “lead”. But, nevertheless, due to its high aesthetic qualities and low price, the demand for tangential wood is high - it is used for decorative finishing furniture, doors, building elements.
For many centuries, humanity has been using wood as a building material and, despite the constant emergence of new ones, modern materials, the popularity of natural wood is not decreasing at all.
How to choose the right lumber from a huge assortment? What causes the differences in price and quality?
Quality finished materials made from wood depends on many parameters - the type of wood and the quality of the original timber, the professionalism of the machine operators, compliance with the technology of drying lumber and the production of finished products. Another factor that has a significant impact on the quality and appearance lumber, as well as their mechanical properties, is the method of cutting wood that determines the texture of the board.
There are several types of wood cutting - tangential, radial, rustic and transverse, of which the first two are most widespread. To understand the difference between types of cuts, you need to have a good knowledge of the structure of wood and understand the technology of sawing wood.
In cross-cutting, wood is cut across the grain. The method is used in production artistic parquet. A rustic cut is any cut made under acute angle to the direction of the fibers. The method is used in the production of lumber for rustic flooring - the most heterogeneous and original in pattern and shade.
With a tangential cut, 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.
Radial cut boards have good resistance to external influences, have greater resistance to deformation and wear resistance than tangential 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 finished products ( parquet board, floor board, block house, imitation timber, lining) from radial cut lumber on front surface almost no gaps are observed, 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. The microprocessor control and optimization system UP-700 is important, which is used by technologists to determine the percentage of yield of radial cut boards based on the criteria for optimizing the maximum yield finished products, as well as the conditions of radial and semi-radial cutting.
Comparing radial and tangential types of cuts, several conclusions can be drawn:
Wood is a valuable natural product created by nature and it is very important to learn how to use it correctly. After all, just as no person has the same fingerprint, there is no similar tree in a forest area. For many centuries now, humanity has been using wood for various needs: building houses, assembling furniture, skillfully creating decorative interior items and using it for industrial purposes. That's why correct processing cutting down a tree is a very important task facing the masters of their craft. As they say: “If you cut down a tree, then only to create a masterpiece!”
What is wood sawing? In a nutshell: it is the transformation of valuable natural resource into lumber, i.e. sawing - processing a tree trunk in any way to obtain material suitable for economic, technical and industrial needs.
To obtain a high-quality product, the raw materials for its production must also be good. If trees of the required and correct sizes, then cutting a large amount of highly productive material from it will not be difficult. The main thing to remember are three fundamental factors: resource quality, shape and volume of wood And correctly selected types of wood sawing.
A good resource is a fresh resource. It is best to start working with wood immediately after the tree has been cut down. The more knotty and curved the trunk, the more difficult it is to obtain good lumber from it; therefore, before starting sawing, you need to sort the logs according to their qualitative features, and only then use equipment for sawing wood.
There are no perfectly round trunks, so it is believed that a log has 4 sides, each of them consists of a quarter of a circle and occupies its full length. These 4 faces do not overlap one another. There is such a thing as a “clean edge”; the higher it is, the greater the value of the wood. This edge is free from various defects: cracks, scars, branches, chips, rot and damage.
Cutting tool for sawing wood V in this case- This band-saw 60 mm wide. The principle of its operation is based on sawing a stationary object, fixed between two guides with fixed movable stops, with a horizontally moving saw blade. The thickness of the resulting material is set at your discretion. If they are processed at the sawmill different breeds wood, then you need to carefully monitor the settings for a specific material. It is necessary to monitor correct installation feed speed of the workpiece so as not to break the saw. A system for regulating the supply of lubricating fluid is necessary to ensure that waste from sawing wood (sawdust) does not stick to the saw teeth and saw pulleys. This significantly extends the life of the equipment.
If you decide to start your own wood sawing business, then first you should decide on the volume of lumber production, and then you will decide what method and equipment to choose for this.
How much does it cost to cut wood?– the question is rather rhetorical, it all depends on who will carry out the work and how it will be done.
Such services can be provided by organizations for the removal of unnecessary green spaces, immediately after the removal of the tree. If the plant was small or there are a number of defects in the trunk, then such wood is used in economic activities or the trunk and large branches are sawed for firewood. When more than one object is removed, for example, for planned construction, and the tree stands are of industrial attractiveness, then we can already talk about the value of such lumber.
In order to start cooperation with a company, sometimes it is necessary to conclude a contract for sawing wood, which will indicate all the technical issues, the timing of the work and the cost of this process. You can draw up an estimate - this is a document that indicates how the work will be carried out and in what way, and also indicates the type of wood, because different types of wood are also cut and processed differently.
There are a great many types and classifications of wood: hard, very hard, soft, seasoned, resinous, with and without knots, etc. It is clear that the harder it is, the more difficult it is to process, and the more knots it contains, the more waste there will be.
When cutting a log, the location of the fibers is also taken into account. Hence, three types of sawing are distinguished:
Home sawing and planing of wood – manual method wood processing. It is used to produce single copies of products and decorative items of artistic value.
This type of sawing is allocated to a separate category not by chance, since the processing of this type of raw material occurs quite often, and according to quality characteristics differs significantly from conventional dry and fresh raw materials. Logging areas are often developed in the cold season, so the flow of frozen wood to processing points practically never dries up.
Manufacturers cutting tool produce saws specifically for working in winter conditions, accordingly, the equipment used for sawing must be configured for frozen raw materials. The fact is that such wood sawing (price and terms are specified separately) has different physical and mechanical properties than usual. Freezing moisture affects the increase in the strength of frozen trunks, therefore the design of the cutting tool must correspond to the processing mode. There may also be a decrease in machine productivity, but the resulting material is more durable, so improving processing mechanisms is the only solution to the problem.
"Arborist" offers a service such as sawing of wood with on-site visits to the customer. This is very convenient way, allowing you to solve your problems without even leaving your site. We can also buy and transport firewood, taking up space near your home. You make a profit and get rid of unnecessary wood. In addition, our specialists can carry out any work on removing unnecessary trees, as well as crowning and trimming dangerous elements using special equipment. All equipment that our specialists work with is certified and adjusted, and our employees are equipped with a license for their services. By contacting our company, you will first receive advice and answers to all questions.
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 to do this, first let's look in general terms at what the actual technology of wood cutting is.
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):
as well as three additional types:
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.
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 a minimum distance between the annual layers. This not only creates a beautiful pattern, but also increases the strength of the 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:
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 to the highest cleanliness class.
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.
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.
