SawsOptimization is designed for sawmill technologists and planners and is a tool for optimizing sawmilling and maximizing yield. The program has convenient and flexible settings and an intuitive interface, which greatly facilitates the development of the program and further work with it.
The initial data for the program are:
log dimensions
· Required dimensions of lumber and their cost.
· Characteristics of sawmill equipment.
The basic functionality of the program is the calculation of optimal deliveries based on these data. The program gives deliveries that can be implemented on this equipment and provide maximum yield or maximum cost of products, allows you to calculate the amount of ash content of boards, volume and cost finished products.
By registering on our website, you can download a demo version of the program in the "Documentation and support" section.
What's new in version 3.0
The SawsOptimization program of the previous version 2.3 is well known to many sawmillers and has gained wide popularity in Russia. Users of SawsOptimization2.3 will find the following improvements in the new version of the program:
· advanced options for customizing sawing profiles and equipment settings, including: additional settings for saws, profiling machines, saws and milling cutters, additional equipment profiles (Carousel, Linck, SAB, sawing in 3 passes), dependence of the width of the saws on the thickness of the cut.
· Special sawing modes: coreless board, sawing with a fixed thickness of the outer side boards, sawing material with a false core.
· Improved optimization engine gives better results in some cases.
· extended options for operations with staves: manual creation and editing, saving-reading, application of an arbitrary stave to a log of arbitrary sizes, selection of the optimal diameter for a stave.
· Automatic calculation of the saw sizes depending on final humidity in accordance with GOST 6782-1.75
In addition to the basic version, there is version 3.0 Professional, designed to optimize the sawmill cycle from log sorting in large enterprises and, in addition to the above, has the following additional functionality:
· Planner functionality: group optimization for logs of different diameters, general specification of output for the entire volume of the sawlog, planning and optimization to obtain the desired output by section.
Optimization for curvature
optimization of sorting logs by delivery to obtain maximum output products.
integration with OptiGrade log sorting optimization software
Brief description of the program features Saws Optimization Professional:
- Batch optimization for all diameters, with the calculation of the optimal sets for each diameter, the total yield of sawn timber and the yield by section.
- Possibility of optimization to achieve the required cross-sectional yield.
Example: it is required to optimally obtain an output of section 32x150 of at least 10%. We achieve this, while the overall yield drops from 52.24% to 51.83%.
- Automatic optimization of sort group boundaries, as well as the ability to change the boundaries manually and see how changing the boundaries affects the output.
Example: changing the boundaries of the variety groups increased the yield to 52.66%
- The ability to choose an alternative set for any variety group and see how a change in set will affect the overall yield.
- Accounting for the availability of a cutting optimization system for an edge trimmer. Different widths of side boards in one set.
Distribution of raw materials by diameters: the ability to either set the remaining raw materials in stock by diameters in pieces, or use statistical distribution according to log sorting data. Consideration of all dimensional factors (diameter, runoff) when calculating the total output.
- Detailed configuration of equipment profiles, the ability to specify different profiles for different diameters.
All photos from the article
In this article we will talk about how cutting logs is performed on a band sawmill. In addition, we will consider what are the criteria for selecting one or another method of wood processing and how this affects the characteristics of finished lumber.
Methods for cutting logs to obtain various lumber have been developed and improved for a long time, since this is the only way to get an edged board, timber and other categories of similar products from a solid tree trunk.
For a long time to this day, wood processing methods have evolved, and in addition, new, more productive equipment has appeared that allows you to get the necessary lumber quickly and with the minimum amount industrial waste.
Features of wood processing
The instruction for processing raw materials and obtaining sawn products consists of a number of technological operations, including longitudinal cutting of logs, sawn timber trimming and cutting to width, sorting by standard sizes, sorting by workmanship quality, drying and storage.
Each of these stages is important in terms of the quality of the finished product. But, it is cutting that is the most time-consuming and responsible stage, during which the main characteristics of finished lumber are formed.
Drawing up a plan for cutting logs into lumber (the choice of a suitable processing method) depends on the type of wood, on the standard sizes of raw materials, on the degree of humidity, on density and hardness, and on many other factors. Of course, the method of processing raw materials is largely determined based on the level of technical equipment of the enterprise.
Consider what equipment is used for industrial sawing of wood and what methods are relevant for each category of this equipment.
Equipment for cutting and features of its application
The following categories of equipment are used for longitudinal cutting of logs:
- Single band saws or circular (circular) saws are a traditional solution that has been used for a long time.
- The group of frame saws is a more advanced solution that allows you to significantly increase the productivity of raw material processing without compromising the quality of the finished product.
Let us consider in more detail the features of the use of the listed categories of equipment.
- Individual sawing is a method in which single saws are used. In this case, only one cut can be obtained in one pass of the saw. Therefore, the entire tree trunk can be cut in several passes.
Important: The advantage of individual sawing is the independence of each subsequent cut from the previous one.
That is, sawing can be carried out in different planes.
As a result, it becomes possible to use certain properties more rationally. different parts logs.
At the same time, this method is inefficient, and therefore not suitable for use in large woodworking enterprises.
- Group sawing- This technological process, during which a group of frame saws is used.
The advantage of this method is that the log is cut completely in one pass. This saves time and, as a result, reduces the cost of production. But you need to remember that group sawing is performed in one plane.
To date, the following categories of equipment for group sawing are most widely used:
- narrow-clear vertical frames, machines with circular saws, milling saws (diameter of processed raw materials from 14 to 22 cm).
- medium-light vertical frames (diameter from 24 to 48 cm)
- wide-clear vertical frames, double and quadruple units band saw type(diameter of processed raw materials over 50 cm).
To obtain a high percentage of lumber from round logs at the output, several different technologies are used, including certain cycles of actions. The time of sawing round wood and the labor intensity of the process varies, depending on the chosen processing method, the place of work, the season. So, some enterprises build shops for the primary processing of raw materials near the place of logging and save on this.
Not only trunks are processed, but also large branches. Roundwood is sorted by size and bark. Trunks that have not passed sorting are used in the future for rough work (manufacturing scaffolding and etc.). When accepting raw materials from the supplier, not only the cubic capacity is checked, but also the presence of damage, rot, knots - such materials do not comply specifications. Flaws in wood reduce the percentage of finished products at the output, and knots can damage equipment.
Before sawing, trunks are often debarked (removal of bark on a special machine) - this process is optional, but considered economical:
- due to the absence of stuck pebbles and sand in the bark, the saw is preserved from premature wear;
- improves the quality of chip material;
- some enterprises do not accept slabs from unbarked logs for processing;
- the error of the results when sorting the forest with the help of electronics is reduced.
Types of wood cutting
First of all, you need to decide on the type of cut - there are several of them. Tangential - the cut goes tangentially to the growth rings, the surface is obtained with patterns in the form of rings, arches. Boards obtained in this way are cheaper, but have high percentages of shrinkage and swelling.
Radial - a cut along the radius, perpendicular to the annual rings, the pattern is uniform, the output of the board is small, but it is of high quality and greater strength.
Rustic - carried out at any angle, defects, knots, sapwood, etc. are visible.
Cutting methods
For each specific case, a cutting method is selected.
Vrazval - the most economical, almost no waste, a high percentage of finished timber. The output is not edged boards and two croakers.
With a bar - first they get a two-edged bar, unedged boards, two slabs. Then the beam is sawn perpendicular to the saw cut into edged boards, two unedged boards and two slabs are obtained along the edges.
Sector - first, the log is sawn into 4-8 sectors, and then each of them into radial or tangential materials. Sometimes several unedged boards are sawn in the center.
Split-segment - with such a cut, two or more unedged boards are cut in the center of the trunk, and edged one-sided boards are sawn from the segments on the sides.
Beam-segment - similar to break-segment, only in the middle of the log a two-edged beam is cut, which is then sawn into edged boards. The yield of lumber is high.
Circular - after sawing off one or more unedged boards, the log turns 90 0 and the next boards are sawn off. This method is used when a large log is affected by heart rot in the center. With its help, healthy wood is separated from low-quality wood.
Aggregate - with the use of milling tools and circular saws, along with high-quality lumber, technological chips are obtained at the output (instead of slabs and slats). Such complex processing of the forest allows rational use of raw materials and labor costs. It turns out non-waste production finished lumber.
Required Tool
The choice of tools depends on the quantity of the planned finished product, its quality and the size of the products. Most often, the cut is performed with a circular saw. At certain stages of production, the use of special machines is required.
Circular saw makes precise cuts in any direction, perfectly copes with any size log, suitable for professional and home use.
It is used for home use when it is necessary to prepare a small amount of lumber. It is easier to do more difficult work with a chainsaw than to buy expensive equipment. It will only need a special nozzle, a fixative for the trunk and cutting guides.
Bark removal machines. They are quite expensive, but with regular use in an enterprise where large amounts of work are performed, they quickly pay for themselves. It is not necessary to use them, but it is desirable, because a number of economic advantages and conveniences in the production process can be obtained by doing so.
And you will also need:
- Disc machine - for obtaining unedged materials from the forest at the exit.
- The band sawmill produces high-quality lumber and a low percentage of waste.
- Frame sawmill - does not need a foundation and can be installed directly in logging sites.
- Universal machines are able to produce high-quality material even from low-grade wood.
At enterprises with mass production, entire complexes are installed to obtain ultra-precise and high-quality products. modern equipment, and sawing up the forest is carried out of any complexity.
Technological map of sawing
To calculate the optimal percentage of obtaining finished lumber from a log, a map of sawing the forest is drawn up. You can do these calculations yourself or use a special computer program. Such information can still be obtained in the usual directory, which contains information on sawmilling.
The cutting map allows you to determine how much will be the output finished products What percentage of waste will be recycled. Based on these data, you can determine the final cost of production. The result can largely depend on the type of forest. There are some measures to increase the yield of lumber.
The percentage of lumber output is ready-to-use, usable wood. Waste - raw materials for the production of MDF, chipboard, fiberboard. These volumes will depend on the diameter of the tree, the types of solid wood products manufactured, and the sawing option.
Percentage of round timber
An accurate count of each cubic meter of wood, an expensive natural raw material, is important at every woodworking enterprise. Cubic meters of roundwood are calculated in several ways.
By volume of transport. For each type of transport, its own cubic capacity of the forest is calculated and established. For example, a wagon holds 70.5 cubic meters of round wood. Then in three wagons it will be 22.5 cubic meters. This counting method speeds up the acceptance of raw materials, this is especially important when in large numbers incoming cargo. But at the same time, there is a large error in the results of calculations in this way.
Calculation for the volume of one trunk. If the entire logging consists of timber of the same size, then by counting the volume of one, you can count them all and multiply by the cubic capacity of one. This method is more accurate, but it requires a lot of time and attracting more workers to receive the goods.
Automated systems with measuring frames. These measurements give higher percentages of accuracy than those taken by humans. When the logs pass through the measuring frame, all thickening and curvature of the trunk and even knots are taken into account. In this case, you can immediately sort the trunks.
A method of calculation by multiplying the volume by a factor. The height, width, length of the stack is measured and multiplied by a factor. This calculation is fast, but with a low percentage of accuracy. It is used when it is urgent to determine the number of cubic meters.
Dependence of the final yield percentage on sawing technology
To increase the yield of finished lumber, it is necessary to optimize the sawing process itself. This is especially true when working with workpieces that have curvature, damage or other flaws:
- First, you need to select and put into production only high-quality wood.
- Then select trunks with damage at the ends (rot, cracks) and trim these places.
- With a section of the trunk with a rotten core, it is necessary to remove it, and cut the remaining wood into lumber. They will be shorter, but better quality.
- And also for obtaining a high-quality board, the circular cut method is suitable.
- Higher percentage yield when sawing timber with large diameter.
The output also depends on the quality of the log, the type of wood, the equipment used. New high-quality, well-tuned equipment allows you to process trunks almost without loss.
The efficiency of cutting the forest can be increased if special measures are taken in advance. To do this, you need to make accurate calculations through digital programs. If this is done manually, then the percentage of marriage in the output will be greater. It should be noted in advance that conifers forests, a greater percentage of the output of lumber is obtained. Because their trunks are even, large, less prone to decay and therefore almost without marriage. From deciduous, a large volume is often discarded.
For rational use wood it is better to take short logs. But in domestic production, trunks with a length of 4 m or more are usually taken for sawing. Because of their curvature, the output is a large percentage of marriage.
When sawing wood, it is important to immediately calculate what the consumption will be, as this will affect the cost of lumber. The output of finished products may be different. It all depends on the quality of the wood used, whether measures are taken to optimize cutting. There are special measures to increase the efficiency of work, make the output better, and the quality of sawing is higher. Before cutting, you must first calculate everything. It is not as difficult as it may seem, but the consumption of roundwood will be optimal, beneficial for obtaining an excellent result.
How to increase cutting efficiency
In order for the lumber yield to be significant, it is necessary to use special measures to increase the efficiency of the process:
- The calculation should be carried out only when using special programs, manually it will have low efficiency, the rejection rate will turn out to be large.
- The round timber must first be sorted so that the processing is carried out correctly.
- For cutting, high quality equipment must be used. Otherwise, the amount of waste will be large, and the quality of the resulting lumber will become low.
- It is best to cut wide lumber first, it takes longer to process narrow lumber.
- Logs are not recommended to take long.
- Before work, you must configure the equipment.
The output of finished lumber may be different. It must be remembered that at the first stage boards are obtained, then they are sorted. As a result, the percentage decreases even more, for example, for hardwood it can be only 10-20%.
How to optimize cutting
In order to increase the output of lumber, the sawing process must be optimized. This applies primarily to those blanks that have a significant curvature. To cut a curved roundwood, you need to perform a series of actions:
- First, only suitable wood is selected for work. If the remaining logs have rot, sprouts, cracks at the ends, then it is necessary to trim some sections.
- If a rotten core is found during operation, then you can carefully remove it, and then cut the rest. This will avoid large losses, get boards with a length of 1 m with the required quality.
- It is recommended to use logs with a larger diameter so that the yield percentage is higher. The coefficient can be 1.48-2.1, but it all depends on the diameter, quality of round timber, sorting, and equipment. For frame shops, this coefficient will be 1.48-1.6, and for lines with milling equipment- 1.6 for large forest. With a round timber diameter of 12 cm or more, the coefficient may exceed 2.1.
Waste volume after sawing
In order for the finished board to come out with a large percentage, it is necessary to prepare everything correctly, work should be carried out only in accordance with the technology. The round wood of coniferous and deciduous breeds gives various output. In the latter case, the volume is smaller, even if special additional equipment is used. Needles for sawing are considered more convenient, since the trunk is straight, and the log has a larger diameter. Coniferous forest is not so prone to decay, so there is less marriage. For hardwoods, 2 cutting technologies are usually used:
- using a band sawmill at Z75, Z63;
- into collapse, when a half-beam is cut out in the core of the material, passed through a multi-blade machine.
The volume of a band sawmill is 40-50%. When using the technology in the collapse, the yield is different, it can be increased up to 70%, but the costs of such work are higher. If roundwood is sawn, the length of which is 3 m, then you can see that the percentage of rejects is quite large, and the remaining material requires processing. This applies to the bulk with boards 22x105 (110, 115) x3000 mm. There are many options for such a marriage. For example, it may be a wormhole, which is no longer suitable for most jobs.
After sorting, the volume of hardwood material that is grade 0-2 will be only 20-30% of the amount that is obtained after sawing. This means that from the total mass of harvested roundwood, the output of a normal board will be only 10-20%. The rest of the materials are mainly used for firewood. Coniferous round timber will have a different yield, but attention should be paid to what average values of the obtained volume are observed.
lumber output
In order for the lumber yield to be optimal, numerous conditions must be taken into account. For a correct calculation, you can consider the example of the output of round wood. The data was obtained on the real experience of specialists and on the performance of sawmills. This makes it possible to compare percentages and calculate optimal averages.
In conifers, the following output is possible:
- For unedged boards and other unedged materials during sawing, the yield will be 70%. This is the amount of material obtained during processing, the amount of waste will be 30%.
- For edged material, when using sawmills at 63, 65, 75, there will be a lower yield of lumber, in the region of 45%. At band sawmills the yield is usually up to 55-60% finished material. If you apply the means to improve efficiency, then you can reach 70%, although this requires a lot of experience.
- 70-75% lumber can be obtained from a sawmill, although with efficiency improvement methods it may well be 80-75%. But experience is required.
According to GOST 8486-86, for grade 0-3, the percentage of yield, excluding sorting, is approximately 70%.
Another 30% can be left for rejection of the finished material. Rejected material is not thrown away, it is used for the manufacture of other types of lumber, which allow the presence of a certain marriage.
Hardwood roundwood has a different yield percentage:
- For unedged material - 60%.
- For edged wood - up to 35-40%, since the curvature of the original hardwood forest is usually large.
The output can be increased, for this additional equipment is used. It can be a special multi-saw machine, an edge trimming machine, a slab machine. In this case, it will turn out to increase the yield of lumber by about 20%. The given percentage is given on the basis of data on the production of grade 0-4 boards. When sorting grades 0-1, the percentage of lumber production is 10%. To get a cube of finished hardwood edged material, it is necessary to cut 10 cubes of the original roundwood for sawing.
The output of lumber from roundwood can be different. It all depends on the original wood species used by the sawmill. Special measures to increase efficiency allow you to get a higher percentage than possible, but for this you need to have some work experience.
