Plywood production workshop

Wood preparation for plywood production

High quality wood is used for plywood production. The presence of significant defects - knotty, cross-layering and especially the presence of cracks of various origins greatly reduce the quality of the veneer and its yield. Logs used for plywood production are cut into pieces called blocks. Cutting is performed on circular saws or manually with electric saws. Sawing removes some of the defective wood. The length of the blocks is equal to the length of the veneer to be obtained. The bark and bast are removed from the churaks. This process is called debarking.

To give the wood softness, in order to reduce damage to the veneer when cutting it, it is soaked in special basins with hot water or heated in autoclaves. Production pools can be indoor and outdoor. In outdoor pools, churaks are cooked in cycles. In covered containers, raw materials are processed continuously (through-type processing). Also, for steaming wood, cooking pits are sometimes used, where hot steam is supplied.

Investment in plywood business

Of course, this will vary in each specific situation. However, let's try to calculate the approximate investment.

Consider the option of organizing the production of FC plywood:

• For the manufacture of cubic meters. we need 1.5-1.8 cubic meters of such material. birch.
• The cost of raw materials will be about 2,000 rubles.
• With a minimum recruitment of personnel and equipment, our workshop will produce 45-50 cubic meters. plywood for a month.
• In this case, monthly investments will be:

So, we examined in detail the production of plywood: manufacturing stages, requirements for raw materials and products, and also compiled an approximate price list for the cost of equipment.

In general, with an average workload of production, the payback of such an enterprise is at least 1.5 years.
... Do not forget that funds to start production of the material can be obtained from an interested sponsor. The main thing is to provide him with a clear financial plan for the development of the enterprise, drawn up with a professional economist.

What types of plywood are there?

The entrepreneur will have to decide what type of building material he will produce:

Plywood applications

It is a versatile material that finds application both in professional environments and in households. Perhaps the largest volumes of plywood are consumed in construction and furniture production.At home, such sheets can be used in interior decoration, interior decoration and household needs. Industrial production of plywood with improved technical and physical qualities allows us to offer decent products for automobile and railroad car building. Again, the popularity of this material is due to its low cost and decent performance properties. Plywood is not so strong compared to metal and fiberglass, but it is more attractive against the background of wood-based products. The only serious limitation on the use of such sheets is the presence of chemically unsafe adhesive mixtures in the structure. That is, we are not talking about environmental cleanliness either.

Plywood production

Plywood is a high-quality building material that has many layers, it is also called in another way - wood-laminated board.

Plywood is made of veneer, the number of layers of which is often not even, that is, from three or more layers.

In order to create a very durable material, veneer layers are superimposed on each other strictly perpendicularly, so that the layers of wood adhere to each other as much as possible.

Applications:

• in construction;
• for insulating products in electrical engineering;
• in various aviation industries;
• for the production of furniture (chipboard);
• in shipbuilding.

Equipment for the production of plywood

The production of raw materials, like the plywood itself, is a high-tech process. And the equipment used in such a production must be of very high quality and high-tech. It should also be noted that specialists and workers of such a complex production must be qualified specialists.

High-quality plywood production equipment can provide the ability, manufacture and manufacture of high-quality and durable products that meet the consumer demand in the building materials market.

Speaking more precisely about the necessary equipment for production, it is worth noting here that the number of equipment for production is very large and varied.

The required equipment includes:

• various machines, both for veneer processing and for the final processing of plywood sheets;
• equipment for applying glue and gluing finished veneer sheets;
• equipment for initially foaming the adhesive suspension;
• gluing machine;
• mechanism for clear and correct stacking of sheets;
• a mechanism for feeding veneer and plywood sheets to the processing line;
• near-press mechanism;
• grinding machines;
• crushing machine;
• waste machine.

As a result, it should be said that even the manufacture of this equipment is a rather difficult process, and the manufacture of veneer and plywood is even more so.

Plywood production technology

Initially, the logs obtained are divided into blocks. The length of the blocks is usually approximately equal to the length of the future veneer, from which the plywood sheets are folded.

Churaks are cut on special machines, and steamed in special containers with hot water collected for this, in order to give the churaks elasticity and softness.

Hot water is used to prevent the wood from half-crumbling and crumbling.

To make high-quality plywood, veneer is used with a moisture content of no more than 6%. To obtain a veneer of such moisture, it is well dried in various special devices, and then divided into different varieties, according to the principle of the presence of knots, processes that were not removed during processing and other various defects.

To improve the quality of the produced and processed veneer, normalization of the veneer size is required. To do this, some veneer sheets are processed manually, that is, they cut out various defects, knots, processes, and are sealed with veneer patches that level the sheet and improve its quality and grade. All this is done by means of various machines.

After these manipulations and quality control, veneer requires processing and conditioning, and only after all this does it go to the workshop, which glues the sheets, creating plywood.

Then the finished plywood is placed in packing bags and transported.

After the plywood has been processed and glued on machines, before being packed, it is processed on circular saws, which cut off the excess parts of the finished plywood sheets to one required size.

The very best grades are ground and processed on a special grinder or other available equipment. Plywood that has lent itself to grinding has greater strength and wear resistance, as well as less susceptible to various mechanical and technical damage. Such finished plywood is called calibrated.

After all these treatments and sanding, the plywood is packaged and marked for shipment and delivery to the customer.

Plywood production in stages

<? php if (! is_single (array (1040, 14160))) {??> <? php} ??> First step
in production - this is the primary processing of wood (usually from coniferous trees), which must be measured and cut into bars. The tree is exposed to steam or placed in a pool of warm water (about 40 degrees Celsius). This increases the plasticity of the material.

Second phase
- removal of bark from wood. The bark is a by-product of the manufacturing process, but it is usually ground and pressed into particle board.

Third step
production - sawing into pieces from 1.3 to 1.6 m long. They are called "churakami".

Fourth stage
production - circular sawing of block by diameter. As a result, we get a sheet of wood, which has the name "veneer". The veneer is cut to the required size and dried in stacks under the influence of a stream of warm air.

Peeling process of birch veneer at a plywood factory.

Fifth stage
in the manufacture of material - checking the drying of veneer. This is a required step as raw wood cannot be used to make plywood. Raw sheets are disposed of or sent for re-drying with warm air. Veneers are pressed, polished and sent to the next processing stage.

Sixth step
- strips of wood are glued into sheets, which are later cut to the required size and laminated.

Final works:
sorting, edge processing and packaging.

List of requirements that must be considered when producing a material.

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The production of building materials is regulated by GOST 3916.1-96

Help

If the article is read by experts, then a deeper knowledge of the manufacture of plywood can be obtained from me if you seek advice.

In addition, I can arrange the supply of equipment and sell your equipment.

Often, plywood manufacturers set up their own production of resin cooking in their production. This allows you to reduce the cost of resin by 3 - 6 rubles. I wrote in my new book how to organize all this, gave very detailed information on how to cook the resin and what equipment is needed for this. The resin is suitable for both plywood and other wood-based panels and even sawdust beams. Read more about the book in the "BOOKS" section.

Good luck and see you soon!

Plywood manufacturing technology

As it is already clear from the above, the plywood manufacturing technology at the plant consists of several stages. Let's take a closer look at how plywood is made at the plant.

1. Initial preparation of logs. Raw materials are selected for the production of plywood. Selection standards are fixed in GOST 9462-88. The logs delivered to the woodworking plant are debarked, cut to the required length - depending on the specified width of the sheet, then soaked in hot water for some time - and hydrothermally processed.
2. Peeling. The prepared logs are cut into thin veneer sheets using a peeling machine. The thickness of the veneer plates is 1.5-1.8 mm. The principle of operation of the peeling machine is identical to that of a pencil sharpener. Only the blade in the sharpener is fixed at an angle, and in the peeling machine - straight. The blade of the machine is set tangentially to the tree rings of the log. By the way, our compatriot is also the inventor of the peeling machine. Professor Fisher invented it in 1819.
3. Cutting, sorting, repairing. The resulting veneer is cut into sheets of a certain size. Then the resulting veneer is sorted. It's not just solid veneer sheets that are involved. Plates with a width of at least 490 mm are suitable for production. Non-solid pieces are glued together and ribbed. The sheets repaired in this way are used to make the inner layers of the plywood sheet.
4. Drying. The sorted sheets are dried in a special chamber.
5. Gluing. The finished sheets are glued together, while the veneer plates are positioned so that the wood fibers of the next layer are perpendicular to the wood fibers of the previous one. This method gives strength to the plywood sheet. The number of layers depends on the specified sheet thickness. For gluing, an adhesive composition is used, the recipe of which is kept secret by each manufacturer. The veneer sheets with the applied glue are collected in packages, then the cold pressing stage takes place. After that, the sheets are still hot pressed.
6. Cropping and marking. Finished sheets are cut to size, sorted and marked depending on the grade and brand.

Plywood grades and brands

Plywood is made from softwood and birch. Birch plywood is more durable but also more expensive. Therefore, materials for general consumption, for example, in construction, are most often made from softwood.

There are standards for the manufacture of five grades of plywood. Grade E is elite. It does not allow the presence of defects on the front surfaces. The rest of the grades - from I to IV - admit different defects of the sheet surface: the presence of knots, including those that have fallen out, cracks, wormholes, warpage, etc.

This is how, in general terms, the process of making plywood looks like. In the video, you can learn more about how plywood is made from birch or other wood.

Drying veneer

For this procedure, a special conveyor is used, on which the lamellas are bathed in warm air currents. With the help of measuring devices such as a moisture meter, the line operator controls and sort the veneer. According to the technology, the optimum moisture coefficient of lamellas for plywood production should be 6%. Excessively wet sheets after heat treatment are either sent for final drying, or rejected. Since the lamellas have a very delicate fine structure, mechanical defects are not uncommon. But in the presence of minor damage, the veneer is not discarded. At this stage, it is possible to repair plywood sheets using artificial inserts of fragments of new veneer, which is selected according to the texture, moisture content and size. The lamellas that have successfully passed this stage are checked by a scanner and sent for daily storage.

From the depths of history

As often happens with history, from prolonged use it is overwritten, and now you can no longer see the details, and only very convex facts are visible.

The name "plywood" comes from the Dutch word "fineer", which means a thin sheet of wood, veneer. But thin wood sheets, glued together into a single three or more layer sheet, was called arborite.

Thin sheets of wood - veneer, have been known for a very long time. The most ancient product, with a veneered coating, scientists consider a casket found in one of the pharaoh's tombs. The chest is made of cedar wood, and on the front side is covered with thin plates of ebony. This was done, most likely, to reduce the cost of the product - in Egypt, its forests were, to put it mildly, not enough, and timber was imported from afar.

Mass production of veneered furniture began in France in the 16th century. This imitation of valuable wood species in furniture production has made furniture items more accessible to the mass consumer. It is precisely from the carpentry technology of veneering that the slang name for the use of plus phonograms by some performers originates: “to sing to the plywood” - to imitate for the mass consumer a valuable live performance with a pre-recorded phonogram.

But back to the material glued from several sheets of plywood - arborite. Ogneslav Stepanovich invented this technology in 1881. Kostovich. Kostovich developed a new material for the manufacture of parts for the Rossiya airship. Not only the frame of the airship was made of arborite, but also the engine parts, including the transmission shaft, which had a length of thirty meters.

Gluing lamellas

As a glue, special compositions are used, sometimes with unique recipes. Each plant strives to develop its own methods of making an adhesive mixture that will set the plywood sheet apart from the crowd of competitors. For example, some compounds already within the structure provide the effect of lamination with phenol-formaldehyde resins. But more often the production of film faced plywood with the application of a paper-resin film is practiced, which makes the material stronger and more resistant to moisture absorption.

The binder is applied on special machines using corrugated cylindrical drums. The lamellas treated with glue are sent to a set, where veneer packs are formed. Here, the sheets are cold pressed, which is a preparatory stage before the final gluing. The sheets are flattened perpendicular to each other. The basic gluing procedure uses a hydraulic hot press, provided with mechanical loading. Finished plywood sheets are aged for 24 hours in a workshop.

Equipment for the production of plywood

<? php if (! is_single (array (1040, 14160))) {??> <? php} ??> Equipment for plywood production is not cheap.

You can be convinced of this by examining the table of prices for the main components of the production line:

To work on the equipment, you need to hire several handymen, as well as a technologist who will oversee the process. Do not forget about an accountant - it will be extremely difficult to maintain without him.

Plywood production technology. What are the stages of the process?

Necessary equipment. The use of plywood.

General manufacturing technology

Plywood is a type of non-uniform wood material. Thin-sheet veneer is used only as a base, which is superimposed on each other under high pressure of the press. Actually, the whole process can be divided into three main stages - wood preparation, processing and gluing. Also, in different industries, additional stages may be included that improve or modify certain qualities of blanks or finished products. For example, modern technologies for the production of plywood provide for repeated impregnation of the veneer structure in order to impart fire-resistant and frost-resistant qualities to it.

This is especially important if plywood is to be used in the future for roof construction. After the production of this material, there is also a lot of waste (mainly after peeling), which can be consumed in the process of manufacturing particle boards.

Stages of production and technological process of manufacturing plywood

With minor upgrades related to equipment and gluing components, the very technological and production process and the procedure for obtaining plywood as a finished product has remained practically unchanged since the 19th century, when it was developed.

Stages preceding the receipt of finished products:

• Logging (the initial log of the required parameters);
• Pre-treatment - removal of bark, outgrowths and knots, giving the log a rounded shape and processing the wood with steam in hot water to reduce the internal stress of the trunk;
• Veneer peeling - obtaining a thin (from 0.5 to 3 millimeters) and long tape;
• Edging, veneer repair and drying;
• Multi-layer veneer compilation with glue application on the workpiece plane.The sheets are laid in such a way that the fibers of each subsequent sheet after the first layer were perpendicular to it;
• The process of pressing, drying in chambers and final processing of plywood blanks - edging.

You can see the production of FSF film faced plywood in more detail in the video:

Technological characteristics and types of plywood sheets

Plywood production technology offers several types and grades of finished products, differing in the type of processing, moisture resistance and grades. According to water-repellent characteristics, these are:

1. FC - plywood, with low resistance to moisture and recommended for use for interior construction work and decoration;
2. FSF - plywood in which compounds based on phenol and formaldehyde were used for gluing veneer. It has the best moisture resistance in comparison with FC and can be used for outdoor work. But due to its chemical components in the adhesive composition, it is not intended for rooms with a constant presence of people in them.
3. FB - specialized plywood for climates and rooms with a very high moisture content (tropical climate, swimming pools, baths, etc.);
4. FOF - a plywood sheet laminated from 1 or 2 sides with special paper or film.

By the quality of the treated surface:

• ground on 1 side (w1).
• from 2 sides (w2).
• plywood with not sanded surfaces (nsh).

The number of grades is defined by 4 categories depending on sheet defects (knots, manufacturing defects).

Plywood production

Plywood production technology begins with the acceptance of round timber. At the receiving site, the quality of incoming raw materials is monitored, the compliance of the volumes declared by the supplier is monitored, and the correct storage and storage of wood is monitored.

The incoming raw materials are debarked and sorted. The softer the wood and the less contaminated, the longer the tool will run for both debarking and peeling. A distinctive feature of raw materials for birch plywood is first GTO (hydrothermal treatment of wood), and then debarking, while soft conifers are debarked without preliminary preparation. The bark separated during the debarking process can be used for production needs, for example, in boiler houses. Clever Japanese have come up with their own way of recycling the bark, read more here.

The next operation after sorting is cutting into blocks from which the veneer will be obtained. In the process of this operation, wood defects can be cut out from the whip, for example, a small half-meter area of ​​rot or a site on which there is a huge knot.

Further, veneer is peeled from the blocks. As mentioned above, soft conifers are allowed for this operation without steaming, harder woods must be steamed. After peeling, the veneer must be dried and then sorted.

Part of the veneer goes to the formation of plywood packages, part for repairs, where it is glued into an edge, knots are cut out of the veneer and patches are applied - this operation is called repair.

We get veneer!

In the process of peeling veneer, defects are formed, here are the main ones:

1. Uneven veneer thickness along the length of the veneer.
2. Uneven thickness across the veneer width.
3. Hairiness, mossy veneer surface.
4. Roughness of veneer.
5. Cracks.
6. Weak, crushed veneer.
7. Corrugated veneer surface.
8. Scratches and risks on the veneer.
9. Curvilinearity of veneer tape edges.

Drying, sorting, splicing and repairing veneers ...

After the veneer is repaired, it is also sent to the formation of packages. The formed packages are pressed. Plywood pressing, unlike chipboard, can be organized both on urea-formaldehyde (more about resin here) and on phenol-formaldehyde resin. The temperature of plywood pressing is from 130 to 170 degrees Celsius.

The pressed plywood is cut to size and sanded.Then, depending on the functions that the plywood will perform, it can be laminated.