Subtleties and nuances of the manufacturing process of interior door systems. Production of MDF doors - factory of painted damp doors Main types of interior doors

Veneered interior doors, manufactured by the Vladimir Door Factory (VFD), have a well-deserved reputation as an elite product, which is due, first of all, to the materials and production technology.

Veneered doors are made from natural high-quality wood, MDF (medium density wood fiber), restructured wood veneer and finishing materials- glue, varnish, paints. All materials undergo strict and careful selection and are checked for compliance with quality standards and environmental regulations.

Veneered door design

The door may consist of a solid (solid, unglazed) panel or contain decorative elements and glass inserts, but, in general, it is a frame structure.

Glazed door panels consist of:

External frame made of softwood timber;

The elements filling it are strips of special cardboard, combined with each other in the form of a structure reminiscent of a honeycomb;

Inserts made of bars for inserting a lock;

Internal frame necessary for subsequent installation of glass filling of the glazed door;

Cladding made of MDF wrapped in veneer.

Blind door leaves have a similar structure, with the exception of internal frame under glazing.

Materials for door production

The raw material used to create the frame is pine wood, which has a strictly defined moisture level: no more than 7±1%.

To achieve a given moisture content, the manufacturer uses a special process cycle in which the wood passes through a system of four front-loading drying chambers, each of which holds up to 50 cubic meters. m. raw materials. The chambers are equipped with reversible fans, humidification, cleaning and air conditioning systems. The process is automated; The accuracy of the specified indicators is achieved thanks to a system of sensor-controllers.

At the end of the drying process, the wood is moved to the cooling room, where it remains for the next 48 hours. This stage ensures the elimination of internal stresses in the lumber, due to which products made from it are reliable and have an extremely long service life.

MDF (medium density fibreboard), used to cover the base frame, is made from harder, hardwood wood. The board is produced in a highly environmentally friendly way - by hot dry pressing, with the addition of special binders that meet safety standards. This not only removes the presence of the material harmful substances and components that are usually contained in MDF - phenol and epoxy resins- but also guarantees its increased density (850 kg/m3)

Produced like this MDF method maintains density, strength, strength and unchanged geometry for a very long time.

Honeycomb elements filling the inside of the door frame between the skins give the structure the required degree of rigidity, a hundred or more times greater than the rigidity guaranteed by other fillers. This is a high-tech material that provides super-strength and, at the same time, super-lightness of the structure.

Doors with such a filler are not only extremely durable and light weight (which reduces the load on the hinges), but also have excellent heat and sound insulation qualities.

The next design element is natural veneer. This is a thinly cut layer of wood that preserves its rich natural texture and color, which cannot be imitated by any technical techniques or tricks. Securely bonded to the fiberboard base, this highly environmentally friendly and durable material does not exfoliate, does not dry out and does not crack.

The application of veneer, as well as the assembly of the door frame, occurs using the previously mentioned method - hot pressing. Then the door leaf is formed in accordance with the specified dimensions and the ends are veneered.

Bringing it to perfection

The finished door leaf is milled along the contour specified by the template depending on the desired type of door leaf. Each type has its own special milling method. It is then sanded by hand.

To make the latter as effective as possible, VFD specialists have developed a technology for step-by-step surface treatment, in which tools with different grain sizes are used in a certain sequence.

Finishing involves applying paint and varnish materials. They are applied strictly by hand, and by the craftsmen themselves. high category, real pros. The coating used is Swedish two-component acrylic composition based on organic components "Becker Acroma".

The varnish forms a thin but hard film on the surface of the door leaf, which has a high covering characteristic. It protects the tree from changes in humidity, preventing the wood from swelling or, conversely, drying out. In addition, a layer of varnish fully reveals the richness of the color and texture of the wood, giving the doors a finished look.

Glazed doors are equipped with frosted Bronze glass, installed using six flexible gaskets that securely fix the glass and eliminate even the smallest vibrations. At the same time, the process of removing a glass unit, if the need arises, is very simple and does not present any difficulties.

The manufacturer has introduced a system for identifying performers, which makes it possible to detect “defect makers” and eliminate them from production operations. Thus, the maximum possible control over all manufacturing technologies is achieved. The marking of the performers is placed at the top or bottom - at the end of the door leaf.

The doors are packed in corrugated cardboard, wrapped on top with plastic film. Each door has a passport containing a description of the model, a warranty section, and recommendations for use.

Related door elements

No matter how good the door is, for its installation and successful long-term use such elements as a frame and trim are needed. Their production technology also has its own characteristics, which make it possible to achieve excellent quality characteristics of the product.

Box timber

The basis for the door frame is dry lumber (moisture content - no more than 8±1%); , ten-millimeter MDF and natural veneer.

The raw materials are connected by end splicing. To ensure successful registration, any defects exceeding the tolerance limits are removed. The lumber gets rid of knots, cracks, rot, etc. the workpieces are glued together and then brought to the established dimensions on four-sided planing machines.

MDF sheets are cut into blanks the right size, ideally corresponding to the specified parameters. Such precision was made possible thanks to the use of a special format-cutting machine.

Next, using hot melt adhesive, the MDF is fixed to the prepared lumber. This happens in a special workshop, on an automated line for lining molded products. The finished rough product is again processed with a four-sided planer, after which it again enters the cladding lines, but for wrapping with veneer.

The veneered timber is sent to paint shop, in which finishing processing takes place - grinding, priming, varnishing.

Platbands and additional strip

Platbands and additional elements are made of profiled fiberboard, veneered and coated with varnish similar to the paint coating on door leaf. To prevent damage, products are packaged in several layers of polyethylene.

Interior doors are mandatory element in the interior, which helps in isolating rooms, distributing odors and noises. High-quality doors cost a lot, so those who are familiar with the technology of making interior doors with their own hands are especially lucky, as this will make it possible to significantly save their money.

How to make a door with your own hands?

Species

Before we begin describing the manufacturing process, it is worth considering possible options doors. Plywood products are easy to make, but glass and wood are more difficult. This will require special equipment, as well as experience in carrying out the work. The main types of canvases for dividing rooms today are:

Paneled interior doors are distinguished by excellent sound insulation and light weight. Making them with your own hands is not easy, since they have enough complex design and the technology for their creation is not very simple - they consist of:

frames into which glass is inserted;
and a panel, which is a shield, as shown in the photo.

Panel interior doors can be called universal, as they are perfect both as entrance doors and for dividing rooms. They are made of panels lined with plastic or plywood. This type is a simple design, and is characterized by excellent quality and reasonable cost.

Types of coatings

Doors can be covered with the following types of coatings:

lamination;
coloring;
veneering;
and toning.

The simplest of them are painting and tinting.

For painting you will need one, and sometimes several layers of paint. Moreover, the quality of work directly depends on the types of paint used and the equipment used.

As for tinting, in this case a transparent or translucent varnish is used for coating. This method will help to perfectly convey the texture of the wooden base, as can be seen in the photo. But for soft wood This type of coating is undesirable, as it can leave small dents and scratches on the surface.

The lamination process consists of applying a plastic or paper film by pressing.

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Veneering consists of applying a film of wood, the thickness of which is 1 mm, to the door leaf.

Tools and materials

To begin the production of paneled interior doors, you will need not only special knowledge, but also relevant experience. But there is such a type of product, for the manufacture of which you will need:

screwdriver;
kitchen knife;
hacksaw;
roulette;
Coarser sandpaper.

As for materials, you will need to purchase:

three boards 50 millimeters thick;
5 slats for the frame (2 longer and 3 short);
Fiberboard, the amount of which depends on the size of the canvas;
glue and screws;
finishing materials, which are selected depending on the design of the future product;
accessories to choose from.

Main stages

The least cost will be needed when reconstructing the paintings located in your premises. To do this:

remove them from the hinges and lay them flat on a surface, for example, a table;
then remove all existing fittings, namely handles, hinges and, if there is a lock;
Before starting the main work, you should decide what result you want to achieve and what product you will get as a result of your work. This may be a product with a solid door leaf, or it may be with a window frame, as shown in the photo;

Having decided on what you will strive for, you can begin the main work. To begin with, in both the first and second options you need to remove all old paint, guided by the video. Sandpaper or sandpaper is suitable for this. grinder. Putty is perfect for removing defects such as cracks, crevices and holes. You should also lubricate the surface with an antiseptic, which will help with further coating of the canvas with one of the liquid materials.

We make markings guided by the video. To do this, take a ruler and a square, as well as a marker or pencil. It is necessary to make certain indentations on all sides of the canvas: more than 160 millimeters on top, more than 500 mm on the bottom, 105 mm on the sides;
Now you need a drill. It is necessary to make 5-7 holes in the markings in the corners, taking into account a step of 3-5 mm. We cut with a hacksaw, making sure that the cut points are straight;
After cutting, remove the resulting fragment and insert wooden slats coated with wood glue between the plywood. If the cardboard ribs get in the way, try breaking them out a little using pliers. You should not expect the glue to dry completely; immediately take a hammer and small nails and attach all the slats;
Decorative elements will help give the canvas an original look. If you have stencils and contrasting paints, now is the time to use them. Vinyl stickers are also a great help; they can be regularly replaced with new ones, thereby updating the design;
If the doors are made of PVC, then new look They will be given a colored self-adhesive film. You can also simply paint them with acrylic paint, sold in cans. But before you start painting, it’s worth doing a test on the end;
A glass door can be decorated using stained glass film, or painted with your own hands. For the second option, you can order a stencil according to your sketch and make a drawing on the glass. It is worth paying attention to the glazing beads that support the glass, as they periodically become loose and can lead to glass falling out.

In this article:

The popularity of interior doors among the population is comparable only to plastic windows. For both the former and the latter, demand is stable even during the economic crisis. But since interior doors serve not only a functional purpose (to open/close access to the room), but also an aesthetic one - they should look impressive and please buyers.

Even if you make doors from environmentally friendly materials (for example, solid wood), but do not give the model a presentation appearance- the business will most likely be doomed to failure.

What does the consumer like? Selection criteria

Product range– a critical decision for future production. And it should be determined taking into account consumer preferences.

Main types of interior doors:

From the array

The door leaf is made of wood lamellas (solid different breeds- from soft ones, such as pine, to hard oak and more valuable ones). The bars are spliced using glue and exposure under pressure, the canvas is sanded, calibrated and varnished or coated decorative finishing(for example, veneer of expensive species).

For premium doors, more complex technology: partial tinting, mosaic splicing, inlay are used, thanks to which the door leaf turns into a real work of art.

Wooden with veneer finishing

Doors of the middle price segment. The base is usually inexpensive wood in the form of boards, fastened into a frame, covered with veneer on the outside.

Various fillers are used for voids, for example, corrugated cardboard.

Laminated

When laminating, a film of various colors and textures is applied to a base frame made of chipboard or MDF. This production technology makes it possible to imitate various materials(and not only wood), but the wear resistance of such doors is the lowest among all types;

Plastic, aluminum and their various combinations

A combination of materials such as plastic and aluminum is used to equip non-residential premises(offices, medical, government, educational institutions).

According to manufacturers, trends in consumer demand can be characterized as follows: “from cheap to expensive.” Today, veneered doors are most in demand, but with a base not made of chipboard, as was the case a couple of years ago, but made of solid wood. Why?

The reasons are obvious:

reliability – interior doors are subject to quite a large load (especially if there is a child in the house). And a solid array always wins over frame structure, and veneer from hard rocks the tree will be protected by the canvas better than laminate and other film materials;
veneer is homogeneous in structure (compared to furniture panels), so it is easy to choose the most similar doors for different rooms;
naturalness of the material;
price – the cost of doors made of inexpensive wood, lined with veneer, “fits” into the category of the middle price segment (about $250), but they will last much longer than frame products. And if necessary, such doors can be restored.

Organizational form and sales channels

The legal form for a business should be chosen after first assessing the potential buyer.

Here are the options:

large wholesale - construction companies and state-owned enterprises (usually, there is a tender basis, which is quite difficult for a new player in the market to win);
concluding agreements with networks of construction markets and specialized stores;
sales through own retail outlets;
dealer network.

In practice, an enterprise engaged in the production of interior doors is rarely limited to one sales option - to increase sales, all available “channels” should be developed.

Therefore, the optimal organizational form would be legal entity– LLC (many construction companies and supermarkets simply do not cooperate with individual entrepreneurs).

The following codes must be indicated in the types of activities:

20.30.1 Production of wood building structures and carpentry;
51.53.24 Wholesale trade of other construction materials.

A license for the production of interior doors is not required. But if you plan to provide installation as an additional service, please note that without special permission, installation of door panels is only allowed in place of existing openings. If the project involves expansion or any other change in the opening, then an appropriate construction license is required.

Production technology of interior doors

Let's consider the full technological cycle for the production of interior doors made of solid wood with veneer cladding.

1. Production cycle begins with sawing wood (logs) on high-precision band sawmills, which ensures a minimum level of waste.

2. Afterwards, the boards go to a special place - a drying complex, equipped with chambers with mechanized loading. The drying process is completed by controlling the moisture content of the material.

3. Then the board is dissolved into separate bars (lamellas) of the required section. All defects are removed from the slats - material with knots, irregularities, which can affect the quality of the future door.

4. On a special splicing line, defect-free blanks are glued lengthwise into a furniture panel. The strength of the door leaf is ensured by the adhesive tenon connection individual blanks. Glued beams are processed on four sides milling machines to the required section.

5. Gluing of lamellas along the width for the production of panels and individual door elements is carried out in vertical presses. At the stage of this operation, the perpendicular arrangement of fibers in adjacent beams is strictly controlled, which guarantees high resistance of future doors to various deformations during operation.

6. To give load-bearing structures doors of high rigidity and stability of shape, the door leaf is covered with veneer, the production of which takes place on a separate production line.

7. To produce veneer, whole logs are used, which are pre-steamed (in a steam chamber for 3 days), and then centered and sanded on a bark trimming machine to remove the bark and bast layer.

8. Next stage - circular trimming. The log is constantly rotating, and the machine removes a thin layer of veneer from it, only 0.6 cm thick. An average log produces about 134 linear meters of veneer.

9. The veneer is then unrolled and cut into sheets. Sheets with the same fiber pattern are stacked. From these, parts are subsequently selected for the external cladding of the door.

10. To give the door special wear resistance, three layers of veneer are used (in the economical version, they are replaced with MDF or chipboard with one layer of veneer).

To do this, glue is applied on both sides to the middle layer of the veneer sheet and sent under a hot press. Here, at temperatures above 100 C, the middle sheet sticks tightly to the other two. After a minute and a half, the glue hardens, forming a high-strength top layer - plywood for the door leaf. This finish is made from a variety of wood species (birch, oak, beech, ash and others).

11. Veneered plywood is applied to the door leaf glued together from lamellas, and placed under a cold press for 30-40 minutes until the glue dries. Next, all components of the door structure are polished and checked for compliance in order to eliminate the presence of unacceptable gaps or differences in further assembly.

12. Next, the length/width of the product is measured. The door is sent to a machine that chamfers and cuts the edges to the specified dimensions. On the next machine, the grooves for the hinges are hollowed out.

13. A hole is cut for the door handle.

14. Then, the product is sanded and varnished and dried. All parts of the structure are assembled into one whole, equipped with fittings, packaged and sent to the warehouse.

Regulatory documents and certification of interior structures

Interior doors are not subject to mandatory certification by law, but the presence of a document confirming the quality mark and compliance with standards significantly raises the level of the manufacturer in the eyes of the buyer and creates a positive image of the company.

And in order for the doors to pass all tests, you must adhere to the recommendations and requirements specified in:

GOST 475-78 – Wooden doors. General technical specifications;
GOST 28786-90 - Wooden doors. Method for determining resistance to climatic factors;
GOST 26602.3-99 — Window and door blocks. Method for determining sound insulation;
GOST 26602.2-99 — Window and door blocks. Methods for determining air and water permeability;
GOST 26602.1-99 — Window and door blocks. Methods for determining heat transfer resistance;
ST SEV 3285-81 - Wooden doors. Reliability testing methods;
ST SEV 4181-83 - Wooden doors. Method for determining flatness;
ST SEV 4180-83 - Wooden doors. Impact test method

Raw materials for the manufacture of interior doors

In the production of interior wooden doors can be used ready materials(furniture board, plywood, MDF, veneer) or blanks (edged boards, solid logs). The first option greatly simplifies the technology. The second one reduces costs and increases profits, but requires large capital investments. Therefore, only large factories focused on mass production of interior doors can afford a full technological cycle.

Medium and small businesses prefer to increase their capacity using ready-made materials as raw materials. And after the initial investment has been repaid and, if expansion is possible, open a separate production workshop furniture board, veneer and other materials in the immediate vicinity of the logging site.

Premises for the production of interior doors

Basic requirements for production workshop – dryness (a prerequisite for storing materials, products and working with wood), the presence of heating and all necessary communications, a three-phase network, access roads for transport.

The size of the workshop varies depending on the volume of production and the completeness of the technological cycle. If for an enterprise manufacturing doors from edged boards an area of at least 400 m2 will be required, then for small production from ready-made furniture panels, 100-120 m2 will be sufficient.

heated warehouse for primary drying of wood;
production workshop;
separate room for applying paint and varnish;
a place for assembly and storage of finished products.

Estimated business plan

1. Renting premises

For the production of interior doors from natural wood(oak, pine) with veneer of various types of wood by the enterprise (LLC on common system taxation) rented production premises with an area of 450 m 2.

2. Plans for production volumes

Planned production output: 800 l.m/year

Ways of implementation:

through our own warehouse store;
through a network of construction supermarkets;
on a contractual basis with construction contractors.

3. Capital costs

Equipment for the production of solid wood doors:

drying chamber – 35 thousand rubles;
band sawmill – 110 thousand rubles (Fig. 15);
tenon cutting machine for trimming lamellas and cutting tenon joints – 170 thousand rubles;
cross-cutting press – 220 thousand rubles (Fig. 16);
pneumatic press for forming a shield – 180 thousand rubles (Fig. 17);
format-cutting machine for sawing lumber – 200 thousand rubles;
milling and copying machine – 90 thousand rubles (Fig. 18);
grinding machine – 100 thousand rubles (Fig. 19);
auxiliary equipment (construction equipment) – 50 thousand rubles.

Total: 1,155,000 rub.

4. Material costs for raw materials

Material costs to start production:

sawn oak – 50 m 3 * 6,500 rubles = 325,000 rubles;
glue – 500 kg * 110 rubles = 55,000 rubles;
fittings (handles, hinges, latches) – RUB 30,000.

Total: 410,000 rub.

5. Salary

To support production activities, it is planned to hire the following staff:

director,
accountant,
sales manager,
5 workers to service machines and assemble doors.

Payroll – 120 thousand rubles/month.

Payroll taxes (37.5%) – 45,000 rubles/month.

6. Calculation of the actual cost of production

Fixed costs (rub/year):

salary – 1,440,000;
taxes – 540,000;
rent – 500,000;
utilities – 60,000;
advertising – 120,000;
depreciation of fixed assets – 52,750
reserve fund – 54,255.

Total: RUB 2,767,005/year.

Material costs per 1 m.p. products:

edged board - 1/8 m 3 * 6500 rubles = 812.5 rubles;
glue - 0.4 kg/m 3 * 110 rub/kg = 44 rub;
frosted decorative glass – 0.3 m 2 * 1300 rubles = 390 rubles;
accessories (handles, hinges, screws, screws) – 300 rubles;
natural oak veneer 8 m 2 * 64 rubles = 512 rubles;
paint and varnish products 0.75l * 180 rubles = 135 rubles.

Total: RUB 2193.50

Product cost for 1 year of operation = (Fixed costs: Planned annual production) + Material costs for production

RUB 2,767,005/year: 800 m.p. + (RUB 2,193.5 * 800 m.p.) = RUB 1,758,258.76

7. Selling price, profit

At a cost of 1 m.p. doors at 2197.82, we calculate the selling price as follows: 2197.82 + (2197.82 * 25%) = 2747.28 rubles. Of course, the selling price is set taking into account market value and competition is the minimum level below which an enterprise should not fall in order not to incur losses. Annual revenue: RUB 2,747.28 * 800 m.p. = 2,197,820 rub.

Profit: 2,197,820 - 1,758,258.76 = 439,561.24 rubles/year.

8. Profitability

Product profitability = (Profit: Cost) * 100% (RUB 439,561.24: RUB 1,758,258.76) * 100% = 25%

Project payback: 3 years, 4 months.

Interior doors are a necessary part of residential, industrial and office premises. When choosing door leaves and additional elements, you need to know how and according to what rules they are made, as well as understand the advantages and disadvantages of the materials used in the production of doors. Modern manufacturers use high-tech equipment that allows them to produce large number products high quality with different types of coating and modern design.

Manufacturing technology of interior doors

Doors serve to separate different functional parts of the room and provide sound insulation, protection from foreign odors and excess moisture. Methods for manufacturing door leaves and additional elements depend on the materials used in production. The most popular doors are those made from solid wood or prefabricated on a wooden frame. Glass inserts make the canvas partially permeable to light and visually expand the space of rooms or corridors.

The most complex and multi-link process occurs during the manufacture of doors using wooden elements. The fact is that timber that has not gone through a full cycle of pre-drying and processing is susceptible to warping and cracking. To avoid losses in the quality of the final product, it is necessary to pay great attention to the preliminary preparation of wood using certain technological techniques. The manufacturing process of interior doors includes the following steps:

Timber (round timber) of pine species is sawn into blanks using band saws with automatic feeding logs
Logs are sawn into pieces of the required thickness
Workpieces are processed high temperature and steam in drying chambers to avoid uneven drying and warping of wood. At the end of the drying process, mandatory humidity control is carried out.
Drying of lumber is carried out under the influence of steam and high temperature
The dried blanks are cut into bars of technological cross-section and defective fragments (chips, knots, cracked and rotten areas) that can affect the quality of the door frame and leaf are removed from them.
Defective areas are cut out from the workpiece cut into timber.
Then the blanks are spliced using tenons, glue and a vertical press into a shield, from which, after drying and cutting, a door leaf is obtained.
Using a vertical press, a door panel blank is produced
After sanding, the canvas is covered with three-layer veneer or MDF panels with one layer of veneer and placed in a press for gluing.
At the next stage, shaped decorative elements, panels or openings for glazing are cut out using a milling and engraving machine, and after assembly, the door panels are coated with three layers of varnish with intermediate and final sanding.
During final assembly, paneled elements or glazing are installed
After final drying, the products are packaged, supplied with accessories if necessary, and sent to the consumer.

The technological sequence for manufacturing doors may be different and this depends on the material, equipment and design of the product. For example, expensive doors made from solid wood do not typically use veneer and are made using complex CNC machines, while budget doors often use corrugated cardboard inserts and cheap lamination film.

It is important to note that in the factory, fittings on doors with symmetrical decor are usually not installed, since when installed at the consumer’s site, the product can open either to the left or to the right; accordingly, hinges and handles are installed by installers locally.

Video: making solid wood doors

Rules and regulations for the production of interior doors

Door blocks are manufactured using equipment located in large production areas. These premises have certain requirements, as do industrial facilities, which include timber warehouses, dryers, a processing shop, a paint and varnish department and a finished product warehouse. Each production site is equipped according to the rules and regulations, in accordance with the technical conditions for a specific task. The main requirements for industrial premises for the production of doors are the following criteria:

availability of free access roads;
buildings must ensure stable temperature, humidity, natural and artificial lighting;
electricity supply, heating, ventilation, water supply and sewerage must be provided;
premises must be equipped fire alarm, fire extinguishing means and emergency exits;
workplaces require provision safe conditions labor;
paint areas must be isolated from other rooms and provided with fresh ventilation.

Personnel are required to undergo professional training and education in labor protection, fire and electrical safety standards, as well as undergo unscheduled, repeated and initial briefings in the workplace.

The production facility must be equipped in accordance with standards

The main standard for the production process is technological documentation, which is based on Technical conditions for production TU 5361−001−58037723−2015 “INTERIOR DOORS, PARTITIONS AND MODELED PRODUCTS FOR THEM.” This document sets out the requirements for the design of interior doors, the quality of material and coating of the front surface, as well as environmental requirements. The standards specify the procedure for acceptance of finished products, certification and installation warranty period operation.

It is important for the buyer to have a certificate, a warranty period and compliance of the door, frame and additional elements with the requirements of technical specifications, since this confirms the quality of the product and allows one to count on a long service life.

Current GOST standards for the production of interior doors

The technical characteristics of doors are determined by standards that set general technical conditions or methods for determining the physical parameters and dimensions of the finished product. Many manufacturers create products based on non-standard sizes, but with strict adherence to quality requirements. The consumer may be interested in the list of regulatory standards by which manufacturers of interior doors operate, namely:

General requirements for wooden doors with a list of regulatory documents are established by GOST 6629–88, and the requirements for wood products are set out in GOST 475–78.
Design options for interior doors, their types and sizes are specified in GOST 24698–81.
Requirements for accessories, fasteners and hinges are prescribed by GOST 538–88.
Methods for determining sound insulation, heat transfer resistance and air permeability are regulated by GOST 26602.
Determination of the flatness of the door leaf is carried out according to the standard ST SEV 4181–83.
The methodology for testing reliability is set out in ST SEV 3285–81.
Impact load resistance is carried out according to the method specified in ST SEV 4180–83.

In the accompanying documents finished products must be present symbol door leaves, for example, U05195 VERSAL pat. 1014 dec/oro leaf D3 91x 230 L, which means the following door parameters:

article - U05195;
the trade name of a certain collection is VERSAL;
type of finish/color − pat. 1014 dec/oro;
product name - canvas;
product model - D3;
width and height of the canvas - 91x230;
opening type, left - L.

Before ordering doors, you must carefully measure doorways to select the desired size of box, canvas and the required number of additional elements. For interior doors, there are standard opening dimensions with the corresponding designation according to SNiP, and this approach makes it easier to select a door frame according to the table.

Table: relationship between the dimensions of the opening and the dimensions of the door leaf

Existing regulatory documents guarantee high level product quality, size standardization and compliance with environmental requirements, in addition, the consumer can determine the compliance of the product properties declared by the manufacturer with the quality and price level.

Material for the manufacture of interior doors

In the production of interior doors and partitions we use modern materials, which are characterized by environmental friendliness, strength, light weight and long service life. These include metal-plastic and glass doors, for which it serves as a frame aluminum profile, and the placeholder is plastic panels or tempered triplex glass with a matte finish. But traditional doors with wooden frame and inserts made of glass, MDF panels and paneled elements occupy the main niche in the market. The following materials are used in the manufacture of such products:

Pine lumber cleared of defects with a moisture content of no more than 8%, spliced into a tenon using adhesive pressing.
High density particle boards.
Natural veneer from various types of wood with a thickness of 0.6 mm.
Laminating film imitating precious wood.
Laminating film gives doors the texture of natural wood
MDF panels of various thicknesses are used for cladding door panels and creating paneled elements.
Frosted, triplex or tempered glass is used for light-diffusing and decorative inserts in the door leaf.
Corrugated cardboard is used in budget options, as soundproofing inserts into the canvas between the beams of the frame.
Corrugated cardboard is used for insulation and sound insulation of inexpensive door panels
Wax and waterproof coatings, tinting compounds and varnishes.
Glue such as "Kleyberit 303.2", MERITIN GLUE D3 and others, used for industrial gluing of fabric fragments, door frames and additional elements.

The production of inexpensive doors is based on application of chipboard, laminating film, corrugated cardboard and MDF, and more expensive products use solid wood with milled elements, panels and tempered glass inserts.

The author of the article has six years of experience in using veneered paneled doors shows their significant reliability. But in rooms with high humidity I would like to recommend various types laminated doors with an additional waterproof coating. After four years of service in the bathroom, the interior veneer panel, despite being treated with liquid wax twice a year, developed whitish stains and streaks from exposure to steam and condensation. There is a need cosmetic repairs, so I had to sand the surface of the door leaf, degrease it with a solvent, cover it with a coloring compound and waterproof varnish in two layers. To a lesser extent, the same problem appeared in the laundry room, and as for the other doors, minor damage to the veneer and scratches were eliminated by gluing and treating with hard, tinted wax of various shades. After this minor repairs canvases, boxes and extensions acquire their original appearance and serve for more than six years. In dacha conditions during summer living, wooden doors coated with waterproof varnish last more than eight years. In this case, warping and drying out do not occur under conditions of temperature changes and changes in humidity. But it should be noted that the best option For country house construction are metal-plastic doors and frames that do not change their properties and maintain their geometry under changeable weather conditions.

Equipment for the production of interior doors

The most expensive production of interior doors, in terms of the amount of equipment required, is the production of wood products. Factory products made of metal-plastic and glass require a large number of components and a small number of machines for cutting frames and processing glass panels. Processing of lumber is more saturated with machines, presses and other equipment. Let's consider the equipment that is used for the production of wooden doors:

Sawmills and band saws, used for cutting round timber.
The sawmill allows you to obtain lumber of the required thickness from round timber
Thermal chambers with steam supply for drying lumber.
Industrial drying chambers allow you to bring lumber to the required moisture level and avoid warping of the workpieces
Equipment for veneer production.
Tenon cutting machine for frame and door leaf.
Using a pneumatic press, the door leaf is glued together
Circular saws and sizing machines for cutting workpieces to size.
Copy-milling machines with program control for decorating door panels.
Using milling machines, shaped and paneled elements are produced
Grinding machines for intermediate and finishing processing of products.
Paint and varnish equipment.

The list of production parks can be expanded due to the use of various technological and design solutions in the production process of interior doors and components, which has a positive effect on the consumer properties of the final product.

Video: production of interior doors

We reviewed some types of interior doors, production technology, as well as regulatory documents and requirements governing products of this type. For the right choice doors, you need to know the properties of the coating and the material from which they are made. High-quality equipment and adherence to production technology ensure resistance to external influences and long service life of products. A wide selection of design solutions allows you to give your living space an individual look and unique style.

When making wooden doors, you should clearly know what elements it consists of. For the production of wooden doors, the following elements are used: laminated board, panel, cladding.

Glued panels are produced from high-quality solid wood without knots or defects. It plays the role of a frame. The optimal type of wood from which laminated panels are made is pine. It is easy to process, soft and flexible, and resistant to mechanical damage.

The panel is a plate placed in the shield to give the product aesthetics. It is made from both solid wood and MDF.

The cladding is made of veneer or specially treated paper.

Thanks to this structure, a wooden door has many advantages:

environmental friendliness and naturalness;
high strength;
combined with other materials, such as metal, plastic or glass;
heat and sound insulation;
long service life, especially for doors made of solid wood.

The disadvantages of wooden doors include their high fire hazard and the possibility of changing sizes under the influence of moisture and temperature changes.

Wooden entrance structures installed in the house are divided into entrance and interior doors.

Materials for creating wooden doors

In the production of wooden doors, expensive types of wood are used: ash, beech, oak, cherry, walnut. More affordable option is solid pine or glued material. You can give such a door a more solid look using wood trim made from noble types of wood.

Despite the high cost wooden structures, they fully justify their cost, as they can last up to 50 years.

Glued material for the production of doors is very popular today, because quality indicators not much inferior to solid wood construction, but costs less. It is made from several lamellas of dried wood and glued together with special adhesives. In order for the structure of the lamellas to be strong enough, they are placed perpendicular to each other.

A wide range of doors are made from MDF - fibreboard. To obtain them, wood is subjected to deep processing. Products made from MDF actively compete in the market with structures made from natural wood and attract customers with their affordable price. Also, MDF is not subject to deformation and exposure to insects or fungi, unlike natural wood. But the service life of such a product will be shorter.

Why does defect occur during the production of a wooden door?

To get a high-quality wooden door, you should treat its production with full responsibility. Errors are unacceptable at any stage of manufacturing, otherwise the result will be a defective product. entrance structure, which will quickly become unusable.

The most common reasons for marriage are as follows:

the material is not dried enough;
poor quality of gluing of lamellas to each other or veneer to the frame.

3 main stages of door production

The production of wooden doors occurs in the following stages:

Wood preparation.
Product assembly.

How wood is prepared

The correct choice of wood is a fundamental factor influencing the obtaining quality product. During the selection process, it is important to pay attention to the presence of such defects:

rot;
cracks;
a large number of knots;
presence of traces of pest bugs;
increased amount of resin.

The timber is sawed into special equipment. Afterwards, the lumber is sorted by quality and size, and then dried in drying tanks to a moisture content of 5-10%. This is necessary so that the tree does not swell and becomes resistant to various deformations. The next stage is re-sorting in order to remove wood with a large number of knots, cracks and other defects.

Product assembly

For the production of frame panels, the most best tree, from which lamellas are then made. They are glued together in . If desired, the pillars and transverse elements can be covered with MDF 3 mm thick. Paneled parts can also be coated with 12-15 mm of this material.

The boards at the corners are rounded, and the protruding parts are cut at an angle of 45°. At the same time, standard boards should be about 2 m in length and 70-80 cm in width. After installing all the component elements, you should make sure that there are no gaps or cracks between them.

All structural processing processes are carried out on modern high-precision equipment. Using it, you can create a variety of patterns on the door leaf, which allows you to offer the consumer a wide range of products. For this, various decorative techniques are used: brushing, applying patina, etc.

If the door has not been veneered or laminated, it should be exterior finishing special compounds: acrylic paints, polyurethane varnishes, etc. Their offer on the market is very diverse. For ease of painting, it is better to use a spray bottle. Before painting, the doors should be treated with a special primer. Now you need to mount the required fittings and insert the door into the finished opening.