Useful output of lumber. Determining the yield of lumber when sawing wood, in particular, round timber How to calculate the yield of lumber from round timber

Yield rates for lumber from roundwood

Tags and keywords

Lumber is obtained by cutting logs (blanks). In essence, this is sawn timber of a certain size with two plane-parallel sides (layers). Sawing can be either radial or tangential.

On fig. 1 presented different kinds lumber - from the plate to the edged board.

Figure 1. Types of lumber: a - plate; b - double beam; in - not edged board; g- quarter; d - four-edged timber with a wane; e - semi-edged board with wane; g - clean-edged timber; h - croaker; and - edged board; k - planed tongue-and-groove boards; 1- face; 2 - edge; 3 - rib; 4 - butt; 5 - wane

In lumber, the following elements are distinguished: layer, edges, ribs, ends. Plast - the longitudinal wide side of the lumber, as well as any side of the square section lumber. In the best layer of lumber, the least number of defects, best quality processing. The layer of lumber facing the core is called the inner, and the one facing the sapwood is called the outer. Edge - the longitudinal narrow side of the lumber. Rib - the line of intersection of two adjacent sides of lumber. Butt - the end transverse side of the lumber. Wane is not obligatory element lumber, this, so to speak, is an element of defective edged boards due to the non-conformity of the source material (logs or blanks).

Lumber is manufactured according to GOST 8486-86E:

1) from coniferous wood - pine, spruce, larch, cedar and fir;

2) hardwood - beech, birch, alder, linden, aspen and poplar.

The following are used: boards with a thickness of 100 mm or less with a ratio of width to thickness of 2 or less; bars with a thickness of more than 100 mm (four-edged and two-edged).

The length of lumber: softwood - no more than 6.5 m, hardwood - no more than 5 m. Lumber up to 9 m long, made by special order, can be used for special structures. The thickness and width of lumber are determined by the assortment (Tables 1, 2, 3).

Table 1

Note:

1) With an increase in the grade of roundwood to the 1st standard for the output of sawn timber increases by 3%.

2) When the grade of roundwood is reduced to the 3rd grade, the lumber output standard is reduced by 2%, to the 4th grade - by 7%.

3) In case of a mixed supply of large and medium logs, the lumber yield rate is taken as the arithmetic average between medium and large logs.

Table 2. Thickness and width of sawn softwood in mm

Table 3. Thickness and width of sawn hardwood in mm

The ends of lumber and draft blanks must be sawn off at a right angle to the longitudinal axis. Wane bars (with a partial absence of a cut in the edge) with a section of 120 x 120 mm or more must have a cut width at the thin end of at least one third of the side of the bar.

The highest permissible moisture content of lumber for load-bearing structures- 25%, for glued structures - 15%.

The use of sawn hardwood is allowed for rafter parts, interior stairs, inner skins walls and partitions, filing ceilings, rollovers, gables, internal architectural details, joinery and clean floors.

It is not allowed to use birch, linden and poplar wood for rafters; linden, alder, aspen and poplar for treads wooden stairs; linden and poplar for clean floors.

SAWN WORK OUTPUT BASED ON FIR ROUNDWOOD VOLUME TABLES

Koptev Artem Sergeevich 1 , Weiss Andrey Andreevich 2
1 Siberian State Technological University, Bachelor in Forestry
2 Siberian State Technological University, Doctor of Agricultural Sciences, Associate Professor of the Department of Forest Inventory, Forest Inventory and Geodesy

OUT OF LUMBER BASED ON THE TABLES OF VOLUMES OF ROUNDWOOD FIR

Koptev Artem Sergeevich 1 , Weis Andrey Andreevich 2
1 Siberian state technological university, bachelor in "Forestry business"
2 Siberian state technological university, doctor of agricultural sciences, assistant professor of forest inventory, forest management and geodesy

As far back as the second half of the twentieth century, in forest inventory, it was considered expedient to determine volumes for practical purposes using special tables. Of all the tables compiled, the tables of A.A. Kründer, common to all breeds, have found the greatest use in our country, without taking into account the location of the harvested assortments on the trunks. These tables were subsequently recalculated by G.M. Tursky into the metric system, supplemented by N.P. Anuchins and approved as GOST 2708-44.

Other tables were also used in practice earlier. For example, Provatorov's table, which was compiled without any basic taxation material, purely mathematically calculated the volumes of logs, assuming one constant run for logs of all species and categories.

For Klimashevsky's tables, as well as Provatorov's tables, it was characteristic that the volumes of logs are calculated purely mathematically, assuming their division into five classes, respectively, in 1/8, 1/4, 3/8, 1/3 and 5 / 8 tops for a sazhen.

Tables of Tour, Arnold, Tursky, Rudzsky - were characterized by the compilation of the volume of logs based on numerous observations on the run and volume of logs of different species, and it was recognized that it was possible to give one general table for logs of all classes and species.

However, these tables had certain disadvantages. For example, the tables of Tur, Arnold, Tursky, Rudzkiy were not adapted to the normal taxation of logs separately and acceptablely determined the volume, only with joint taxation more logs when smoothing of extremes in the average result should be expected.

Also, it was not provided in the tables that the accuracy of the evaluation of logs is affected by the degree of fractionation of the thickness steps for the diameters of the logs and the total length of the logs. When taking a very large step for log diameters of 4 cm, tables for single logs or for a small number of them should give large errors due to the rounding of the diameters.

In modern forestry practice, the relationship between the characteristics of the entire forest stand and the parameters of individual trees in this forest stand is known. For example, according to studies, the density of the grown forest stand affects the quality of the timber. To improve the quality of the timber, a large stand density is needed in the early phase of rotation to reduce the growth of branches in the lower part of the trunk, their accelerated death and self-cleaning of the trunks. In the late phase of felling rotation, a relatively sparse stand is desirable for clearing branches and accelerated overgrowth of nodes. As you know, the greater the density, the less runoff and vice versa, the lower the density, the greater the runoff, which, in turn, as it is already clear from the material presented, greatly affects the accuracy of determining the volume of assortments.

It is also necessary to take into account the impact of cuttings on the characteristics of the renewed subsequent forest stand. It is known that thinning contributed to a significant increase in the diameter of the trunk at chest level, increase in height, ratio of crown and trunk sizes, crown width, but led to a decrease in the height of the trunk to the diameter at chest height. The stem run also increased significantly, and therefore the determination of the timber stock turned out to be overestimated by 2-15%, especially for trees in thinned stands.

The international timber trade is developing very dynamically. According to the FAO, the volume of world exports of roundwood over the past decade has increased in quantitative terms by 8 million m 3 . This was facilitated by the constant growth in the global consumption of sawn timber in various sectors of the economy and the growing importance of wood as a natural, environmentally friendly universal material. The international trade in raw wood today is developing in the face of growing volumes of its consumption. The leading exporters of roundwood in the world are Russia, New Zealand, USA, and the main importers of raw wood are China, Austria, Germany. The main driver of the growth in international trade is currently the growing consumption of wood in the world, and this trend in the world market will continue in the next few years .

Experimental studies. The studies were carried out in the Biryusinsky district forestry of the educational and experimental forestry of the SibGTU. In the lower warehouse, measurements of Siberian fir roundwood were made. In the future, the volumes of round timber were established different ways. We determined the output of cubic meters of lumber from a log, you can use the following table 1.

Table 1 - Determining the output of lumber

Note: With an increase in the grade of roundwood to the 1st standard for the output of sawn timber increases by 3%. When the grade of roundwood is reduced to the 3rd grade, the lumber output standard is reduced by 2%, to the 4th grade - by 7%. With a mixed supply of large and medium logs, the lumber yield standard is taken as the arithmetic average between medium and large logs.

As can be seen from the table, lumber comes out approximately 50% of the volume of the entire log. It is worth noting that coniferous lumber yield is higher than that of hardwood.

Below is a table showing how many cubic meters of lumber, wood waste and sawdust come out when using the results of the calculation using the truncated cone formula and tabular data (table 2), as well as the median section formula (table 3). The volumes are found for one log and for a hundred logs. The difference between the two lumber yields is also shown as a percentage. For 100%, the yield of lumber is taken, obtained by calculating the truncated cone formula for the first table and the middle section formula for the second.

Additionally, the cost of lumber obtained from 100 logs was calculated, the volume of which was determined from the tabular data and the truncated cone formula (Table 3), as well as from the tabular data and the median section formula (Table 4). In addition, the difference between the cost of lumber was established.

Conclusions. Comparative analysis showed that the standard values ​​in most cases underestimate the volume of logs in terms of thickness in comparison with the truncated cone formula (-33.2-+6.4%). In the thick part of the logs, this difference stabilizes and amounts to about 10%. At the same time, in relation to the formula of the middle section, the tabular values ​​of fir logs in most cases overestimate the actual volume of round timber. In terms of value for 100 logs, the difference can be (step 36 cm) up to 60,000 rubles.

Thus, the use of the truncated cone formula makes it possible to significantly reduce the error in determining the volume of fir logs in relation to the local East Sayan mountain taiga region.

Table 2 - Yield of lumber

Continuation of table 2

Table 3 - Yield of lumber

Table 4 - The cost of lumber

1. "European Agreement concerning the International Carriage of Dangerous Goods by Road" (ADR/ADR) (Concluded in Geneva on 09/30/1957) .
2. Orlov M.M. Taxation of various assortments of commercial wood // Forest taxation. 1932. ch.14. With. 74-75.
3. Sawn timber properties of Scots pine affected by initial stand density, Thinning and pruning: A simulation based approach: Report. / IkonenVeli-Pekka, Kellomoki Seppo, Peltola Heli // Silva fenn. 2009. 43. No. 3. p. 411-431.
4. Long-term effects of precommercial thinning on the stem dimensions, form and branch characteristics of red spruce and balsam fir crop trees in Maine, USA: Report_ / Weiskittel Aaron R., Kenefic Laura S,. Seymour Robert S., Phillips Leah M. // Silva fenn. 2009. 43. No. 3. p. 397-409.
5. Varivodina I.N. , Kuznetsova E.V. , Perelygina O.G. Features of determining the volume of round timber in Russia and abroad // EUROPEAN STUDENT SCIENTIFIC JOURNAL. 2014. No. 1.

The ratio of the volume of produced lumber V n to the volume of sawn raw materials Vc as a percentage is called volume output R, %:

This is the main indicator of the rationality of the use of raw materials, because. in the cost of sawn products, the cost of raw materials is 80% of all costs for its production. The volume output is proportional to the diameter (for example, when sawing logs with a diameter of 16 cm and a length of 6.5 m into collapse, it is about 55%, with a diameter of 32 cm - 61.5%, with a diameter of 40 cm - over 63%) and is inversely proportional to its length (for example, for every 0.5 m reduction in the length of logs from 6.5 m, it increases by an average of 0.65%). The curvature of logs in 1% reduces the yield by 8...12%. When sawing with a bar, the output is 2.5 % higher than collapse. An increase in saw blade thickness by 0.2 mm in a 7-saw set leads to an increase in wood loss and a decrease in product yield by 0.3 ... 0.5%. The volumetric yield of sawn products is influenced by the organization of labor, the qualifications of workers and engineers, technical supervision of equipment, and technological discipline at all production sites.

The output of lumber by grade as a percentage of the volume of sawn raw materials is called sorted output:

The total yield of all varieties gives volume output lumber

Yield distribution by varieties and assortments in % total volume of lumber C, = 100 V ni – V n% - there is a variety composition of products. The qualitative composition of sawn products is evaluated grade factor Ks, depending on the type of wood, purpose and grade. As basic assortment (K with= 1) edged softwood lumber 2 ... 6.5 m long grade 3 (GOST 8486-86 *), (for selected grade K c = 2). The percentage ratio of the volume of specification lumber to their total volume is called specification output:

In order to stimulate sawmills for the integrated rational use of raw materials, the so-called coefficient of integrated use of raw materials- the ratio of the total volume of lumber ( V n), other sawn products (obapol, tare plank - V DP), technological chips (V SH), technological sawdust (Von) sold to the waste side (VP) and waste used for the production of steam and energy ( Vn/e) to the volume of sawn raw materials:

In this regard, equipment for the aggregate processing of raw materials appeared. Indicators of the degree and rationality of the use of sawn raw materials R, Rs, Rep, Kisp, divided into planned and reporting.

Postav

The scheme for cutting a log or a group of logs into sawn products of the required dimensions, which establishes the order and place of cuts, the thickness, and sometimes the width of the materials obtained, is called set up, (in contrast to the so-called "saw set" - a set of saws installed in multi-saw machines at a certain distance from one another to obtain boards and beams of certain sizes from logs). Postavy are symmetrical And asymmetrical. (rarely used, for example, when sawing sleepers), even And odd. In even symmetrical settings, the core falls into the central cut and ends up in two central boards, in odd settings - into the core board. Breakup and beam postavay given parameters are called settlement: a set that provides the highest volumetric yield of lumber is called maximum, and the setting that provides the highest yield of sawn timber of a given specification - optimal. Sets are recorded according to the nominal dimensions of lumber (without shrinkage allowances taken into account when calculating the sets). An even symmetrical breakup is written in different ways, for example,

19-25-50-50-25-19 or 50/2-25/2-19/2 or:

2 boards 50 mm

2 boards 25 mm

2 boards 19 mm.

The beam setting is recorded in two passes, for example:

a) 1st pass - 16-16-175-16-16, 2nd pass - 16-16-50-50-50-16-16;

b) 1st pass - 175/2 - 16/2 - 16/2, 2nd pass - 50/1 - 50/2 - 16/2 - 16/2;

c) 1st pass - 1 beam 175 mm, 2nd pass - 1 board 50 mm

2 boards 16mm 2 boards 50mm

2 boards 16 mm, 2 boards 16 mm

2 boards 16 mm.

There are other types of recording settings.

The thickness of the intersaw spacer is equal to the sum of the values ​​of the nominal thickness of the board, the allowance for shrinkage along its thickness and the bilateral broadening of the saw teeth by flattening or setting.

When drawing up and calculating the sets, it is necessary to know the consumption of the width of the set A, mm - the distance between the symmetrical outer surfaces of the extreme side boards in the set, consisting of the sum of the nominal thickness of the boards, shrinkage allowances and the width of the cuts e(at P boards in the setting):

Drawing up sets for a given specification of lumber with a known diameter of logs consists in determining the number of boards and in sequential selection (fitting) of their thicknesses in a given diameter of logs. First, the most favorable log diameter is selected to obtain a beam of a certain size, and then the board thicknesses are selected for the first and second passes. Rules for compiling deliveries the following:

a) in case of mass sawing of raw materials, the deliveries must be symmetrical;

b) the preparation of postavs should start from the axis of the log;

c) the number of sections cut from a log should be minimal - no more than 1-2 thicknesses of thick lumber and two thicknesses of thin lumber should be obtained from a log;

d) should not be included in the supply of boards of adjacent thicknesses with a difference of less than 5 mm, because they are difficult to sort;

e) do not cut the central boards from logs with a thickness of 36 ... 62 cm and more, and the core ones are not thinner than 40 ... 100 mm, and from logs with a diameter of 14 ... .50 mm;

f) avoid multi-saw "heavy" sets: with log diameters from 14 ... 16 to 30 ... 32, the number of boards in the set should be from 4 ... 7 to 8 ... 12;

g) take the height of the beam within 0.6 ... 0.8 of the top diameter of the log (Fig. 3.17);

h) receive side boards on the 1st in the 2nd pass of the same thickness;

i) the width of the set must be equal to or close to the maximum coverage of the diameter of the log by the set, depending on the minimum width bmin board length lmin(assumed 1.5 m), from the diameters and length of the log D And L:

j) when sawing logs into collapse, the maximum and optimal thicknesses of the boards are set according to the graphs (Fig. 3.18) or according to the formulas;

l) the thickness of the edge boards, in order to avoid gaps, is recommended to be taken depending on the diameters of the logs: 16 and 19 mm with a diameter of 14-18 cm; 19 and 22 mm at 20-24 cm; 19, 22 and 25 with a diameter of 26-36 cm; 22 and 25 with a diameter of 38-42 cm; 25 and 32 with a diameter of 34-56 cm; 32 mm at
diameter 58 cm or more.

Settlement calculation- this is the definition of the width, length of the sawn boards, their volume, volumetric and graded output for each section of the boards and for the whole log. The length and width of the boards are found graphic or analytical methods. On a sheet of paper, the circles of the top and butt ends of the log are applied on a certain scale and, starting from the center, the required sections of lumber are entered, the width is measured, and the length of the boards is determined taking into account the run of the log. Sometimes they use templates made of transparent plastic. A widely used method for calculating set-ups using a quadrant chart (Fig. 3.19).

To determine the length and width of unedged and edged boards and the dimensions of the beam on the abscissa axis, find the distance from the axis of the setting to the board in question. From the obtained point, a vertical is drawn until it intersects with the calculated diameter, and the intersection point is taken down to the y-axis, where the calculated width of the board is found. The allowance for shrinkage in width is subtracted from it and the result is rounded up to the standard width of the board. As the calculated diameter of the log, the diameter of the top section can be d or the diameter of any section d x , separated from the top end at a distance x. The diameter of a log in any section is determined by the formulas:

Where b x - board width in section, cm; α - distance from the axis of the log to the layer of the board, cm;

S– log run, cm/m.

The length of the shortened board is determined by the formula

Compilation and calculation of sets is a very important and crucial stage in planning the cutting of raw materials. It determines the rationality of using wood when cutting. After compiling and calculating each set, it is necessary to immediately determine the volume of sawn raw materials, as well as the yield of sawn timber from it, and enter them in the cutting plan sheet (form 3.1).

Graded output of lumber C t, % from different sorts of raw materials is determined according to the standards for the output of sawn timber of the grade being determined R, R 2 Rz R 4,%, from logs of I, II, III, IV grades by volume (or in quantity), respectively Q 1 , Q 2 , Q 3 , Q 4 m 3 (or pcs) and calculated by the formula

The determination of the volumetric yield of sawn timber for each assortment and for the delivery as a whole is carried out in cubic meters and as a percentage of the volume of the log.

The cutting plan is drawn up for the entire volume of raw materials intended for processing within a month or for 1,000 m 3 (while maintaining the specific ratios of the size and quality of the logs indicated in the specification for the month) (form 3.3). Based on it, a schedule for sawing raw materials is drawn up, taking into account the possibility of sorting it and the timing of delivery of sawn products to consumers.

All operations for planning the cutting of raw materials can be performed on a computer.

wood balance when cutting raw materials, this is the distribution of the entire volume of wood by type of product, waste and losses, reflecting the rationality of using wood and depending on the sawing methods, the size and quality of the raw materials, the purpose of sawn products, the settings used, the thickness of the saws and other factors. The wood balance can be planned (calculated) and reporting (actual). For example, the balance of softwood sawmill raw materials in the production of edged sawn timber in accordance with GOST 24454-80 * and 8486-86 contains: sawn products 60%, technological chips 18%, sawdust 14 %, waste (screening wood chips) 2%; shrinkage 6 %. (This does not include off-balance waste - bark 10 ... 12% and allowances for the length of logs 1%).

Table 3.3

Form 3.1. Plan for cutting raw materials into lumber

for month 20

Sawing wood is a cycle of actions using a variety of technologies aimed at obtaining lumber from round timber suitable for further use in industry. The duration and labor intensity of the process depend on the chosen method of processing round timber, as well as the time of year.

Tool and equipment

Barrels go into production and big size branches. All material is divided into groups according to the thickness and presence of bark. Often, wood processing enterprises have workshops near the harvesting site, in which machines are installed for the initial processing of wood.

Manual debarking of the forest

The forest that has not passed the stage of debarking can be used on the device of floors or as ridge beam in an appropriate interior, or as a supporting device during construction.

Industrial debarking

If another option for using the tree is planned, then sawing is carried out, resulting in the following segments:

• unedged and semi-edged (rough material from which the bases of the floor, walls or ceiling are mounted);
• edged (designed for finishing flooring).

The cut can be carried out by an outsourced organization that has all the necessary tools.

Tree sawing map

The rational use of the material is ensured by compliance with the sawing map. This allows you to reduce the cost due to waste, the percentage of which the card can significantly reduce. The used tools and types of forest processing equipment depend on the volume, desired quality and size of the finished lumber.

Most often use a circular saw and various machines:

• circular at the expense circular saw allows you to make precise cuts of various directions. Suitable for both professional and home use, perfectly copes with the diameter of the round timber above the average;
• chainsaw;
• machines for clean removal of bark;
• sawing on a band sawmill makes it possible to process dense logs, is considered the most popular, as the output gives quality material and a small amount of waste;
• disk machine: production of two-edged timber and unedged boards;
• a frame sawmill does not need a foundation, the technology with its use allows you to install equipment in close proximity to the cutting site;
• thin gauge process universal machines, the output gives high-quality building materials even from low-grade whips;
• sawing roundwood at a large woodworking enterprise should be carried out with the largest number lumber, differing from the rest in special quality and exact dimensions. For this purpose, special lines are installed for sawing.

At the sawmill, a beam and an edged board are obtained due to the cut of a log up to 7 m long and 15-80 cm in diameter along the longitudinal line. The circular saw has one or more discs, it processes different diameters of the forest according to their number.

If at home it is necessary to process a small amount of wood, then you can use a regular chainsaw.

cutting wood

Before choosing a tool, you need to decide on the type of cut, focusing on the annual rings of the log. There are several types:

• radial (along the radius);
• tangential (the cut is parallel to one radius, touches the annual rings);
• the fibers are arranged parallel to the cut being made.

Among the cutting methods, the one that is most suitable for a particular case is selected:

1. Razval. Sawing wood in this way is carried out for deciduous trees with a small trunk thickness, it is considered the simplest processing. Exit: unedged elements and slabs.
2. If there is another woodworking machine, then it is possible to cut up to 65% of the material to produce edged boards of the same width. First, a two-edged timber and boards are sawn from the sides, and then a certain amount of edged lumber is obtained from the timber.
3. More specific methods are sector and segment sawing. The number of elements in the first method varies from 4 to 8, and depends on the thickness of the trunk. After separation, elements are sawn from each sector along a tangential or radial line. The second method begins with the exit of the beam from the central part, and boards are sawn from the side segments in a tangential direction.
4. For individual sawing of wood, the circular method is suitable. It is based on turning the log along the longitudinal line by 90° after each sawn board. This allows you to monitor the quality of wood and timely remove the affected areas of the trunk.

Handmade: chainsaw application

For home cutting of several trunks, it is not advisable to purchase a tool whose cost is several times higher than the price of finished products. If you have the necessary skill, then it is more efficient and cheaper to do the whole necessary work conventional chainsaw, or chain equipment powered by electricity. Of course, such work requires much more physical costs and time, but the price of the issue is significantly reduced.

Work on garden plot needs pruning fruit trees, and it also becomes possible to additionally produce material for outbuildings without resorting to the services of specialists, so that any zealous owner would prefer to buy a chainsaw. Most often prepared for the home conifers, with the cut of which this tool does an excellent job. Thanks to even trunks, it is easier to outline the cut lines, which increases the speed of work. Professionals, by the way, most often use a chainsaw, since it is more powerful than an electric one and you can use it anywhere, regardless of whether there is a cutting or sawing of power supplies at the site.

To work with a chainsaw on cutting logs, you will need such a device as a nozzle on the saw, as well as saw cut guides and base-trunk fixers. The nozzle in the form of a frame is attached to the tool so that it remains possible to adjust the distance between the chain and the frame itself. This is done to enable the output of finished lumber, different in thickness. For the role of a guide, you can take either a profile of the desired length, or a flat one. wooden plank with sufficient rigidity. A special chain is selected for the tool, designed to cut the trunk along. Its difference from the rest is in the teeth, sharpened at a certain angle.

Before starting work, it is necessary not only to prepare all the necessary tools. Regardless of whether a woodworking machine is intended for processing the trunk or hand fixture, the first step is to familiarize yourself with the cut map. This is done in order to minimize the percentage of waste, and increase the yield of useful products.

The first thing you need to worry about when ripping is the uniform density of the finished boards. To do this, a competent sawmill guides the tool with east side logs to the west, or in the opposite direction. This is due to the greater density of round timber in its northern part than in the southern.

Next, the slab is removed from both sides with a chainsaw in such a way as to obtain a two-edged beam. It, in turn, is sawn in accordance with the sawing scheme chosen at the beginning of the work. Output gives unedged board. If there is a certain percentage of defects in the trunk, then a circular cut is possible with the trunk turning at a right angle or 180 °.

Quantity of finished material, cut price

The output of useful material from coniferous and hardwood differs in percentage terms. For lumber obtained from coniferous trees, are characterized by the following indicators:

• provided that the operation is carried out by a professional, and is used circular sawmill, the percentage of finished wood will be the highest (80-85%);
• edged material, which is given by machines, averages 55-70%;
• unedged board when working with a chainsaw leaves up to 30% of waste.

The figures are given without taking into account the finished rejected wood, the amount of which can reach 30%. However, such material is used for products that allow a certain marriage.

Deciduous round timber gives 60% of the finished unedged wood and about 40% of the trimmed wood. This is due to the initial curvature of the round timber. You can increase the amount of products received: this will require woodworking machines of various kinds. A certain kind of fixture can increase the amount of lumber by 10-20%. For one cube of lumber, you will need about 10 cubes of hardwood round timber. Installation price additional equipment will pay off the cost of the finished wood. Special lines give more volume, but their use is advisable only on a large area. The average price of sawing wood at a conventional sawmill will be approximately 150-180 rubles per cubic meter of boards.

sawing map

The sawing map is a calculation of the optimal amount of finished lumber from one log. It can be calculated independently for each specific log diameter, or you can use a computer program that greatly facilitates the calculation, and the price of which is quite affordable.

Or the source can be a regular guide to sawmilling. The result is a table that is taken as a basis. The sawmill must always be oriented to its data, in order to obtain more lumber of any kind of wood.