TarProm LLC is a supplier of cardboard boxes, corrugated boxes and high quality packaging cardboard. The prices for the boxes presented in the “price” section will delight you and make you our regular customer. We are ready to accommodate every buyer, so we will be happy to discuss any of your proposals for purchasing boxes by phone provided on the website.

If you need to make a wholesale or retail purchase of corrugated boxes, then you will not find a better option than cooperation with TarProm LLC! The quality of our packaging remains consistently high, satisfying the requirements of the most demanding customers. We can always offer you a wide selection of corrugated packaging and various types of boxes.

We are ready to deliver our products (corrugated cardboard, corrugated boxes, trays, gratings, gaskets, cardboard, chipboard, fiberboard, MDF, FSF, etc.) directly from the manufacturing plant to the customer’s warehouses, which allows us to significantly reduce cash costs on the client’s part, making it easier buy. Today TarProm LLC occupies a strong position in the market and continues to develop, offering very favorable conditions on the market. We care about our reputation and are ready to take into account any wishes of the client. We will do everything to save your time and money. Buying boxes and corrugated boxes from Tarprom is simple and profitable!

Buy boxes and corrugated boxes from Tarprom

Corrugated box

Corrugated packaging is actively used for packaging goods of various groups: food products, household chemicals, shoes, medicines and many others. A corrugated box, consisting of several layers, is able to reliably protect goods from exposure to sunlight, temperature changes, and mechanical damage during transportation.

Products packed in corrugated boxes are always convenient to transport and store in such a way that they occupy minimal space in the warehouse. Corrugated boxes have special advantages over other types of packaging. It is always more convenient to buy goods in a good eco-friendly box, on which you can also apply the necessary logos and labels.

Introduction

Types and brands of materials and products

Characteristics of starting raw materials

Description of production processes

Characteristics of main equipment

5. Production process control and product control

Conclusion

Bibliography

Introduction

Fiberboard is a sheet material made by hot pressing or drying a carpet from wood fibers with the introduction, if necessary, of binders and special additives. Fiberboards are used in construction for heat and sound insulation, the manufacture of interfloor ceilings, walls, for finishing rooms, etc. For the production of fiberboard, wood waste is used in the form of technological chips, lump waste and non-commercial wood. You can also use only wood chips. Making fiberboards is one of the most promising ways to use wood waste.

Fiberboards (fibreboards) are widely used in the furniture industry, the production of building materials and other industries, as a substitute for plywood. Fiberboard is a sheet material made from wood ground to fiber. The fibers are formed into a carpet using a wet or dry method.

In wet forming, fibers suspended in water are fed onto a mesh, the water flows down through the mesh, and a fibrous carpet remains on the mesh.

In dry forming, fibers suspended in air are fed onto the mesh. A vacuum is created under the mesh, due to which the fibers, deposited on the mesh, form a dry carpet.

After the carpet is formed, it is pressed in a hot press, and the pressing can be wet or dry. During wet pressing, the remaining water and steam released from the carpet require a mesh under the carpet to escape. After pressing, one layer of the slab is smooth, the other with mesh imprints.

During dry pressing, there is little moisture in the carpet and a small amount of steam is formed, which manages to escape through the edges of the slab. With this method, a mesh is not required; both sides of the slab are smooth. Thus, depending on the technology used, there may be methods for producing fiberboard: wet, dry, semi-dry, wet-dry.

1. Types and brands of materials and products

According to GOST 4598-74, the following grades of slabs are manufactured:

soft M-4 (density up to 150 kg/m3); M-12, M-20 (up to 350 kg/m3);

semi-solid PT-100 (400-800 kg/m3);

solid T-350, T-400 (>850 kg/m3);

superhard ST-500 (>950 kg/m3). According to TU 13-444-79, the following grades of slabs are produced using the dry method: semi-solid PTs-220 (density > 600 kg/m3);

solid Ts-300, Ts-350 (> 800 kg/m3), Ts-400 (> 850 kg/m3); Ts-450 (> 900 kg/m3); STs-500 (> 950 kg/m3).

In all the indicated brands of slabs, the numbers after the dash characterize the tensile strength of the slab during static bending (kgf/cm2). Slab dimensions: thickness 2.5-25 mm, length up to 5.5 m, width up to 1.83 m.

Fiberboard (fiberboard) of the wet production method:

Fiberboard: GOST 4598-86, TU 5536-024-06279163-94

Fiberboard T gr. A, gr. B

Format, mm: 2745*1700, 2745*1220

Thickness, mm: 3.2; 2.5

Emission class: E1

Manufacturer: Kotlas PPM, Sukhonsky PPM, Nelidovsky DOK, Arkhangelsk PPM.

Advantages: an excellent cladding material for cladding frame partitions, walls, ceilings, floors of residential buildings, for the manufacture of doors, parts of built-in wardrobes, furniture production, laminated parquet, packaging production.

Fiberboard (Fibreboard) dry continuous production method:

Fiberboard: TU 5536-001-49602733-2001, TSN-30, TSN-40

Format, mm: 2440*1220, 2620*1220, 2440*1830, 2440*2050

Thickness, mm: 3.2 -6.0

Emission class: E1

Manufacturer: KDP Novaya Vyatka, Sheksninsky KDP, Kronoshpan, Plitspichprom, JSC "Yug".

Advantages: used for cladding interior walls, making bases for parquet, linoleum, and carpet.

Fiberboards are used in the production of furniture, door panels, office partitions, and exhibition stands.

Dry-process fiberboard (fibreboard):

MDF (Medium Density Fiberboard): TU 5536-007-44779728-03 Fiberboard (SP) - medium density (MDF)

Format, mm: 1830, 2050, 2100, 2250, 2750, 2800, 2850, 3050, 3500*1650

Thickness, mm: 6.0-24.0

Emission class: E1

Manufacturer: Zheshartsky plywood mill, Sheksninsky KDP, Kronoshpan, Plitspichprom, OJSC "Lesplitinvest"

Advantages: solid pressed MDF boards are used for the manufacture of decorative furniture facades, the production of wall panels, profiles, countertops, skirting boards, doors and moldings.

2. Characteristics of starting raw materials

Chips must meet the following basic requirements: length - 25 (10-35) mm, thickness - up to 5 mm, clean cuts without crumpled edges, contamination with bark - up to 15%, rot - up to 5%, mineral impurities - up to 1%, relative chip moisture content is at least 29%. In the production of fiberboard, the use of deciduous and coniferous wood is allowed.

Synthetic resins used for the preparation of waterproofing and anti-corrosion materials and compositions in construction conditions, epoxy resins must be viscous-liquid. In the production of fiberboard, hydrophobic (water-repellent) substances and strengthening additives are used. Fiberboard, MDF as a wood-based sheet material have a porous structure and absorb moisture from the air or when immersed in water. Therefore, in their manufacture, hydrophobic substances are used to maintain dimensional stability during changes in humidity. These viscous substances (petroleum refining products), when melted, close the pores on the surface of the material and prevent moisture from penetrating inside. Hydrophobic substances include paraffin, distillate slack, ceresin and its compositions, which are introduced into the wood-fiber mass in the form of alkaline emulsions diluted with hot water and deposited on the fibers with aqueous solutions of sulfuric acid or aluminum sulfate.

Strengthening additives are used to ensure the strength characteristics of fiberboard when the boards contain more than 30% hardwood fibers or the presence of shortened fibers in the composition. Phenol-formaldehyde resin is used as additives.

3. Description of production processes

Production of fiberboard using the wet method. The technology for producing fiberboard using this method consists of the following operations: washing the chips; grinding wood chips; sizing; carpet shedding; pressing plates; impregnation of slabs with oil; thermal and moisture treatment; cutting slabs. Washing of wood chips is carried out to remove solid inclusions from it - sand, dirt, metal particles, which, when grinding wood chips into fibers, cause accelerated wear of the grinding mechanisms. The wood chips are washed in baths using drums with blades, which mix the wood chips with water and wash them. The chips are taken from the bath by a screw conveyor, water and impurities are sucked off from the bottom of the bath and sent to settling tanks, from where purified water flows back into the bath.

Grinding of process chips- the most critical operation in the production of fiberboard. The quality of the slabs depends on the quality and degree of grinding. Since no binders are used in the production of fiberboard, the strength of the boards is ensured by their interfiber bonds, which should be similar to the types of bonds between the fibers of natural wood. In the process of grinding wood into fibers, wood fiber mass is obtained - pulp. Pulp is a suspension of fiber in water of varying concentrations. Grinding wood chips into fibers is carried out in two stages. After primary grinding, the concentration of the mass is 33%; before secondary grinding, the mass is diluted with water to a concentration of 3-12%, at low tide 0.9-1.8%. The average fiber thickness is 0.04 mm, length 1.5-2 mm. At the first stage, grinding of wood chips is carried out using defibrator mills UGR-03, UGR-02. The chips first enter the steaming chamber of the defibrator, where they heat up and become more plastic, then they are fed into the grinding chamber by a screw conveyor. The grinding chamber consists of two disks - one stationary and one rotating. The distance between the disks is 0.1 mm or more. Grinding sectors with teeth are fixed on the disks, the size of which decreases in the direction from the center.

The chips are first captured by large teeth, abraded and, as they move towards the edge of the disk, ground into small fibers.

The ground mass is fed into the outlet, where, after passing through a system of two valves that maintain a certain steam pressure in the mill, it is discharged into the collection. The productivity of the UGR-03 defibrator is 25-35 tons, UGR-02 is 50 tons of dry fiber per day. Mixing of the mass is carried out in mills - refiners.The design of refiners is similar to that of defibrators. The distance between the discs is 0.05-0.15 mm. After the defibrator and refiner, the fibrous mass is stored in collectors and basins equipped with mixers, which maintain a uniform concentration of the mass, preventing the fiber from settling to the bottom.

Sizing- this is the introduction of various additives into the mass: hydrophobic to increase water resistance, fire retardant, bioresistant and adhesive. Paraffin is introduced as a hydrophobic additive, which, in addition, prevents fibers from sticking to meshes and slabs when pressing the carpet and adds shine to the slab. To mix with water, paraffin is emulsified (an emulsion is created), which mixes well in water. To increase the strength of the boards, glue or oil is introduced into the mass in the form of an emulsion. To precipitate fatty emulsions (paraffin, oil) from water onto fiber, precipitants are used - additives that promote deposition. Sizing compounds are introduced before casting the mass. Carpet casting is done at a wood fiber mass concentration of 0.9-1.8% using casting machines. This operation consists of applying the paste to the forming mesh of the machine, filtering water through the mesh, sucking out the water using a vacuum, mechanically squeezing out the water, trimming the side edges and cutting the endless carpet into sheets of a certain length. The filling box evenly pours the mixture onto a continuously moving mesh. The mesh is supported by rollers through which water flows freely. In the path of the carpet movement there is installed a device for compacting (tamping) the mass and a filling box for pouring refining compounds onto the mass. Next, the carpet approaches three rotabelt vacuum mechanisms that suck water out of it. A leveling roller is installed in front of the second rotabelt, which rolls and levels the thickness of the carpet.

Further extraction of water and pre-pressing of the carpet is carried out by three press rollers. This is followed by three pairs of press shafts, which squeeze out the water and compress the pile driver with a force of 1500 N/m. The saws cut the longitudinal edges, the saw cuts the blade from the endless belt, and conveyor 12 carries away the raw blade, the moisture content of which is about 60-80%.

Pressing plates- an operation in which a raw material is formed under the influence of temperature and pressure into a solid fiberboard. Pressing is carried out in a 25-story PR-10 press. Loading and unloading is carried out by loading and unloading shelves. The pressing cycle consists of three phases: Phase I - water extraction; Phase II - drying; Phase III - hardening. The temperature of the press plates is 180-200 °C.

Phase I- the pressure is gradually increased to 2-4 MPa, maintained at this pressure for 30 s; The humidity of the slabs drops to 45%.

II phase- the pressure is reduced to 0.8-1 MPa and the slabs are maintained at this pressure until their humidity drops to 8% (usually 3.5-7 minutes).

III phase- the pressure is increased to the previous value or to a slightly lower value. The slabs are maintained at this pressure until the humidity decreases to 0.5-1.5%. Thus, the plate is hardened, i.e. increasing its mechanical properties. The duration of the last phase is 2-3 minutes. Slabs are impregnated with oil to increase their strength and moisture resistance. The slabs are impregnated in baths with linseed or tall oil heated to 120°C. Hot slabs come from the press for impregnation. Oil consumption is 8-10% of the mass of the slabs. Only special-purpose slabs are subjected to impregnation.

Thermal and moisture treatmentplates consists of two operations - heating and humidification. The plates are heated to 160-170°C and kept at this temperature for 3.5 hours. Heat treatment increases the physical and mechanical properties of the plates and reduces their hygroscopicity. It is performed in chambers in which hot air circulates at a speed of 5-6 m/min. Heat treatment of oil-impregnated boards is carried out at an initial temperature of 120°C, which then increases due to the exothermic reaction of the oil.

The slabs are moistened to give them moisture corresponding to the equilibrium humidity. If you do not specifically moisten the slab, then, by adsorbing vapors from the surrounding air, it may become unevenly moistened, which will lead to warping. Humidification chambers are used to moisten the slabs.

Plates on trolleys are installed in chambers so that each sheet has free access to the moisturizing agent. The chamber is supplied with air at a temperature of 65°C and a humidity of 95-98%. Fans circulate air in the chamber. The duration of exposure in the chamber is 6-8 hours. Cutting is done to obtain slabs of a given format. For cutting slabs, special format circular saws are used. Fiberboard contains 91% fiber, 7% moisture, 2% sizing additives. Rehearsal

Production of fiberboard using the dry method.The main operations of fiberboard production are as follows: washing of chips; steaming wood chips; grinding wood chips into fibers; mixing fiber with a binder and other additives (sizing); fiber drying; carpet formation; pre-pressing of canvases; pressing; hydration; cutting Many operations of the technological process for the production of fibreboard using the dry method are similar to the operations for producing fibreboard using the wet method, so we will only consider the distinctive features of the operations of the dry method for producing fibreboard.

Steamingchips are used for partial hydrolysis of wood. With the dry method, the water-soluble products that make up the wood remain in the fiber and participate in the technological process. The wood chips are steamed in steaming cylinders at a steam pressure of up to 1.2 MPa (190°C). The chips from one end of the cylinder are moved gradually to the output end using a screw shaft rotating at a speed of 3-10 rpm. To maintain a given pressure in the apparatus, chips enter and exit through locking valves. Chip processing time 6 min.

Chip grindingThey are produced dry in defibrators, and regrinded in refiners. With the dry method of producing fibreboards, thermosetting resins are introduced into the fiber to increase the adhesion between the fibers. Paraffin is introduced in molten form.

Carpet pre-pressingperformed to increase its transportability and the possibility of loading the carpet into the gaps of the press, since the poured carpet to obtain a 6 mm thick slab has a thickness of 200 mm. Pre-pressing is carried out using continuous belt presses, where the carpet is compacted 3-5 times between two belts, compressed by rollers at a pressure of 1800 N/cm 2. After pressing, the carpet is cut lengthwise and cut crosswise into sheets. When producing thick fiberboard (> 6 mm), the thickness of the web after pre-pressing on belt presses remains greater than permissible (> 120 mm), which makes it difficult to load it into the gaps of a multi-story press. Such canvases are additionally pressed in a single-story slab forepress of periodic action at a specific pressure of 2.5 MPa. Pressing is carried out in the same presses as for the wet method of fiberboard production. Pressing time is reduced to 1 minute per 1 mm of finished slab thickness. Plate temperature 220-250°C, pressure 6.5-7 MPa. Fibreboard produced by the dry process contains 89% fiber, 6% moisture, 2.5% resin, 2.5% paraffin. Based on dry fiber, it is possible to press not only slabs, but also various parts and components in the production of containers, furniture, and building materials.

Features of fiberboard production using wet-dry and semi-dry methods.With the wet-dry method of fiberboard production, preparation of the fiber, its transportation, and casting of the carpet are carried out as with the wet method of fiberboard production. However, no binding components are added to the mass, and good adhesion of the fibers is ensured by thoroughly grinding the wood chips into fibers due to its preliminary thermochemical treatment. Before pressing, the canvas is dried to an almost completely dry state (2-3%) in a multi-story dryer. The slabs are pressed without a mesh, both sides are smooth. Press plate temperature 240°C, pressure 6 MPa. After pressing, the slabs are moistened to 6-9%. With the semi-dry method of fiberboard production, the raw material - wood fiber mass, to which a binder is added, is dried to a moisture content of 10 - 15%. A carpet is formed from dry fiber, compacted, and cut into sheets. Before pressing, the canvases are moistened to 18-25% and pressed in a multi-story press on a pallet with a mesh. This is followed by thermal and moisture treatment.

The cost of fiberboard made using the dry method is approximately 10% less than fiberboard made using the wet method. However, the dry method of fiberboard production requires a large amount of adhesive materials (22-70 kg per 1 ton of boards); 10 times higher air flow (22.1 m3 instead of 2 m3). The positive fact is that there is less (4.5 times) need for water and less (almost 2 times) labor costs. It should be noted that the dry method of fiberboard production at the fiber drying site is especially dangerous in terms of fire.

fibreboard raw material technological

4. Characteristics of main equipment

Selection of chipping machine

Raw materials are supplied to production in the form of conditioned chips. Preparation of raw materials for the production of boards, which consists of preparing conditioned chips, includes the following operations: cutting wood into sizes corresponding to the receiving cartridge of the chipper; cutting wood into chips; sorting of chips to select the required size with additional grinding of the coarse fraction and removal of fines; removing metal objects from wood chips; washing the wood chips to clean them from dirt and foreign matter.

To prepare wood chips we use a drum chipper DRB-2. The productivity of the device is 4 - 5 m 3/h, drum diameter 1160 mm and number of cutting knives - 4

Selection of sorting machine

The resulting chips after chipping machines are sorted, as a result of which process chips are selected that meet the requirements for them.

To sort process chips, we use a gyratory type sorting machine, model SShch-1M, the technical characteristics of which are given in Table. 1.

Table 1

Technical characteristics of the sorting machine

IndicatorsValueProductivity, bulk m 3/h60 Number of sieves3 Tilt of sieves, deg3Electric motor power, kW3Weight, t1.3

Selection of disintegrator

Hammer disintegrators are used to crush large chips. We select a disintegrator of the DZN-1 type, the technical characteristics of which are given in table. 2.

table 2

Technical characteristics of the disintegrator DZN-1

IndicatorsValueProductivity, bulk m3/h18 Overall dimensions, mmlength2300width1620height825Weight, kg2248Electric motor power, kW11.4

Selection of consumable bins for conditioned chips

The conditioned chips are sent to stock bins or supply bins in the grinding department. According to their plan configuration, stock bins are of two types: rectangular and round. We use rectangular bins, placing them in the building of the wood chip preparation department. For small stocks, wood chips can be stored in vertical bins. We use a DBO-60 type bunker, the technical characteristics of which are given in table. 3.

Table 3

Technical characteristics of the vertical bunker DBO-60

IndicatorsValuesHopper capacity, m360Number of unloading screw conveyors3Performance of one screw conveyor, m3/h3.8-40Installed engine power, kW21.9Height of supports, m4Total height of the hopper, m11.75Total weight of the hopper,t18.5

Selection of steaming unit

From the feeder hopper, the chips are fed by a screw dispenser into a low-pressure drum feeder, from which it is sent to the heater, where it is heated with saturated steam at a temperature of 160°C. A nozzle is mounted in the output section of the heater, through which paraffin is introduced into it in a molten state, sprayed with compressed air with a pressure of 0.4 MPa. From the heater, paraffin-impregnated wood chips enter directly into the hydrodynamic treatment apparatus. Fiberboard factories use continuous operating devices of various systems.

We install the Bauer-418 steaming and grinding system, which has the following characteristics:

Steaming boiler horizontal, tubular type, diameter 763 mm

9.15 m long, designed for pressure up to 1 MPa

.The productivity of the steaming unit is up to 5 t/h.

Selection of grinding equipment

In the production of fiberboards, defibrators and refiners are used to grind wood chips. To obtain high-quality slabs when grinding wood chips using defibrators, equipment for secondary grinding (refiners) is used. In the dry production method, refiners with two discs rotating in opposite directions are used for primary grinding.

We select a defibrator brand RT-70, with a capacity of up to 70 tons/day, and install two machines. Technical characteristics of the device are given in table. 4.

Table 4

Technical characteristics of the defibrator brand RT-70

IndicatorsValueProductivity of dry fiber, t/day70Diameter of grinding discs, mm1000Type of feederscrewPower of the electric motor driving the grinding disc, kW500-580Total weight without electric motors,t20

Selection of mixers for water-repellent additives

At most operating enterprises, water-repellent additives are introduced through special nozzles into steaming units before grinding the wood chips into fibers.

Paraffin arrives at the enterprise in a railway tank, which is installed near the finished product warehouse. From the tank, paraffin flows through a pipeline into a storage tank with a capacity of 60 m 3, from where it is supplied through a special paraffin pipeline to a paraffin supply tank installed in the workshop on a pedestal. The paraffin is drained by gravity through a measuring tank into the paraffin emulsion preparation tank.

Various types of equipment are used to prepare sizing compositions. The most common devices for preparing emulsions are cylindrical tanks equipped with stirrers.

The finished emulsion is pumped into a special container (tank) for storage. Preparation of the working composition of phenol-formaldehyde resin SFZh-3014 consists of diluting it to a working concentration of 25%. The dissolution of precipitants is carried out in a special tank, which is similar in design to the tank for preparing the emulsion.

The technical characteristics of the mixing tank are given in table. 5.

Table 5

Technical characteristics of the mixer

IndicatorsValueCapacity, m31Outer diameter, mm1206Height, mm909Overall height, mm1834Mixer diameter, mm150Electric motor power, kW1.1Total weight, kg267

Selection of drying units

The moisture content of wood fiber before pressing the boards using the dry production method should be 6-8%. The choice of drying method for shredded wood is largely determined by the size and uniformity of the material. Fiberboard factories use two-stage drying units with partial recirculation of the drying agent.

After grinding, the fiber is fed into the pipeline of the drying unit, where it is mixed with air heated in the heater, the temperature of which at the entrance to the dryer is 160-190°C. The fiber temperature at the outlet of the first stage dryer is about 70°C. After the first stage, the moisture content of the wood fiber mass is reduced to approximately 65-67%. It is most effective to use the work of combined dryers: aerofountain - drum.

Selection of the first stage dryer

To carry out the first stage of drying, it is advisable to use an air fountain dryer. In an aero-fountain dryer, due to the speed of the drying agent, the fiber fountains repeatedly, then is removed from the drying space after it has dried to the required (specified) humidity. The drying agent is hot air, which is heated in a plate steam heater to 160°C.

The air and fiber are moved by a centrifugal fan. The same fan transports the fiber sorted in the separator to the cyclone - air separator.

Technical characteristics of the dryer are given in table. 6.

Table 6

Technical characteristics of the air fountain dryer

ParameterValue Capacity (based on evaporated moisture), kg/h1000 Air temperature after the heater, °С up to 160 Air temperature at the outlet of the dryer, °С up to 70 Air speed in the inner pipe, m/s15 -20 Air speed in the outer pipe, m/s3 - 4 Inner pipe diameter, mm400 Height dryers, m15.2 Width, m7.4 Total length of pipes, m46

Selection of drying unit for the second drying stage

The second stage of drying occurs in drum dryers. The second stage dryer uses the principle of low temperature with a large volume of drying agent. In table 9 shows the technical data of drum dryers.

Table 7

Technical characteristics of the drum dryer

IndicatorsValueProductivity (for evaporated moisture), kg/h2886 Air temperature at the dryer inlet, °С180 - 205 Air temperature at the dryer outlet, °С50 Pressure drop in the dryer, Pa2820 Fan capacity, m3/h61200 Transfer valve diameter, m0.95 Air speed, m/s19 Air volume passing through the dryer, reduced to a standard temperature of 21°C, m3/h52500 Electric motor power, kW75

Selection of auxiliary equipment at the drying stage

In aerial fountain dryers, air and fiber are moved by a centrifugal fan with a capacity of 21,000 m3 3/h at a pressure of 22 MPa. The amount and speed of air are regulated by a rotating device at its inlet. The same fan transports the dried and sorted fiber in the separator to the cyclone - air separator.

We select a high-pressure centrifugal fan in accordance with GOST 5976-90. The technical characteristics of the fan are given in table. 8.

Table 8

Technical characteristics of the centrifugal fan

BrandQ, m3/сρgH, Pan, s-1ŋn Electric motor type Nn, kWŋdvV-Ts14-46-8K-026.39182016.150.73AO2-71-6170.9

Cyclones are selected based on performance. The gas speed in the inlet pipe can be 12, 15 and 18 m/s, and the cyclone productivity can change accordingly. So for w input = 18 m/s cyclone productivity will be 6000 m 3/h, and at w input = 12 m/s - 4000 m 3/h, i.e. cyclone performance at any input speed compared to w 18can be recalculated using the formula:

i =w whi /w 18 m 3/h (15)

In an air fountain dryer, air (drying agent) moves at a speed of 18 -20 m/s. Thus, the productivity of the cyclone will be 6000 m 3/h. We select the cyclone OST 26-14-1385-76 with the following technical characteristics presented in table. 9

Technical characteristics of the cyclone

Cyclone standard sizeCross-sectional area of ​​the cylindrical part of the body, m2Capacity, m3/hWorking volume of the hopper, m3Weight, kgTsN-15-800P0.50263250.56825

The air entering the dryer is preheated to the required temperature when it passes through steam heaters. Single-pass steel plate heaters are used.

5. Production process control and product control

Requirements for the quality of fiberboard surfaces

Control methods

Selection and preparation of samples, determination of physical and mechanical properties of slabs are carried out in accordance with GOST 19592 and in accordance with the requirements of this standard.

Dimensional control is carried out according to GOST 27680.

Determination of water absorption by the front surface

After conditioning and weighing the samples intended to determine water absorption in accordance with GOST 19592, their edges and non-facial surfaces are waterproofed, as well as the samples are re-weighed before soaking.

Waterproofing is carried out by immersing samples in molten paraffin according to GOST 23683 at a temperature of (85±5)°C on the edges and the non-facial side. When applying paraffin to the edges, the sample is immersed in turn with each edge to a line spaced 3 mm from it.

Testing of slabs is in accordance with GOST 19592. The humidity of slabs moistened in humidifying machines is determined no earlier than 24 hours after they leave production. The color tone and degree of grinding of the wood of the face layer are assessed visually when compared with standard samples measuring 200-300 mm.

Deviation from the straightness of the edges is determined according to GOST 27680 or using a straight edge (according to GOST 8026) with a length of 1000 mm not lower than the second accuracy class and a set of styli No. 4 according to TU 2-034-225. Measurements are carried out in at least three places along the length of two adjacent edges with an error of no more than 0.1 mm.

Deviation from the squareness of the edges is determined according to GOST 27680 or using test squares according to GOST 3749 of at least the second accuracy class with a length of one side of 1000 mm and a set of probes No. 4 according to TU 2-034-225. The measurement is carried out at each corner of the slab with an error of no more than 0.1 mm.

The tensile strength perpendicular to the plate plate is determined according to GOST 26988.

The area of ​​spots on the surface of the slab is determined with an accuracy of 0.25 cm2, using a grid with square cells with sides of 5 mm, applied on a transparent sheet material. Deviations from the accuracy of drawing grid lines are no more than 0.5 mm. When calculating the number of cells overlapped by a spot, cells with an overlap of more than half of their area are counted as whole, and cells with an overlap of less than half are not taken into account.

The depth of dents and the height of bulges are determined using a dial indicator of the ICh-10 brand according to GOST 577, fixed in a metal U-shaped bracket with cylindrical supporting surfaces with a radius of (5±1) mm and a span between supports of 60-100 mm.

The indicator scale is set to the zero position when installing the bracket on a straight edge in accordance with GOST 8026 or a calibration plate in accordance with GOST 10905.

The stroke of the indicator rod in both directions from the reference plane must be at least 2 mm. The linear dimensions of defects are determined using a metal ruler according to GOST 427.

The amount of chemical substances released from finished slabs, as well as the frequency of monitoring, are determined by sanitary inspection authorities in accordance with current guidelines approved by the USSR Ministry of Health.

Table 10

Permissible defects in finished material

Name of defect Norm for slabs, grade I, grade II Depressions (protrusions) on the front surface Not allowed Not allowed with a depth (height) greater than maximum deviations in thickness Depressions (protrusions) on the non-face surface Not allowed more than 1 pc. area of ​​25 cm2 per 1 m2 depth (height) more than maximum deviations in thickness Not standardized Scratches on the front surface Not allowed per 1 m2 with a total length of more than 100 mm in an amount of more than 2 pcs. Not standardized Variation of shades of the front surface Not allowed for an area of ​​more than 5% of the surface of the slab Not standardized Water stains on the front surface surfaces Not allowed per 1 m2 with a total area of ​​more than 5 cm2 Not standardized Stains of an industrial nature, incl. from oil and paraffin on the front surface More than one spot per 1 m2 with a diameter of more than 8 mm is not allowed. Not allowed per 1 m2 with a total area of ​​more than 10 cm2. Chips, local damage to the edges are not allowed (single ones with a depth along the face of 2 mm or less, an extension along the edge of 15 mm or less not taken into account) Not allowed for 1 m of length with a width of more than 5 mm

Conclusion

Fiberboard (Fiberboard) is a promising material. It is widely used in furniture production and finishing work in the form of laminate. Fiberboard is now widely used, and I think the demand will only increase. This is also due to its low price relative to other similar materials.

Its prospect is also explained by the fact that wood is currently widely used. When producing certain building materials from wood, residues remain that can also be used in the production of fiberboard. And in the future, fiberboard will be widely used in construction due to the fact that it is also an environmentally friendly material. Currently, the issue of ecology in construction and finishing is acute, and fiberboard is produced without the addition of harmful chemicals.

Bibliography

1. Gorchakov G.I. Bazhenov Yu.M. Construction materials: Textbook for universities. - M: Stroyizdat, 1986.
   

Fiberboards are made from non-commercial wood, waste from the sawmill and woodworking industries. To increase the strength, durability and fire resistance of fiberboards, special additives are used: aqueous emulsions of synthetic resins; paraffin emulsions; rosin; bitumen; antiseptics and fire retardants; as well as asbestos, alumina, gypsum, etc.;

Description: plant materials are crushed in various units in the presence of a large amount of water, which facilitates the separation of wood into individual fibers, and mixed with special additives; then the liquid fibrous mass is transferred to a casting machine consisting of an endless metal mesh and a vacuum installation; here the mass is dehydrated, compacted and cut into individual slabs of a given size, which are then pressed and dried;

Technical characteristics: density of wood-fiber insulating and insulating-finishing boards 850...1100 kg/cub.m; thermal conductivity 0.046...0.093 W/mK; bending strength of at least 0.4...2.0 MPa; Size: 2745x1700x3.2 mm; 2745x1220x3.2 mm; 2500x1220x3.2 mm; 2440x1220x3.2 mm, etc. Humidity%, lower limit 4 upper limit 10; Water absorption of the front surface for 24 hours, upper limit: 11; Fiberboard (fibreboard) production technology Fiberboard (fibreboard) is a sheet material produced through the process of hot pressing of a mass of wood fibers formed into a carpet. These fibers are obtained by steaming and grinding wood raw materials. They are individual tissue cells, their fragments or groups of wood cells (wood dust). The raw materials are sawmill and woodworking waste, industrial chips and firewood. To improve the performance properties, strengthening substances (for example, synthetic resins), water repellents (paraffin, ceresin), antiseptics, etc. are added to the mass. The formation of a carpet can be carried out in an aqueous environment to obtain slabs of one-sided smoothness (wet production method) or in an air environment to obtain slabs of double-sided smoothness (dry method). When making boards using the wet pressing method, the “wrong side” of fiberboard has a texture reminiscent of the surface of cottage cheese with a “mesh”, like wet gauze. And that’s why fiberboard slabs are never thick – technology doesn’t allow it. Usually one side of the fiberboard remains this way, and the other is sometimes covered with a film (laminated or laminated). Industrial production of fiberboard was first started in the USA in 1922.

In 1931, Asplundr's Swedish patent marked the beginning of the introduction of a new technology for the production of fibreboards. Equipment for it was supplied by Defibrator. This fiberboard manufacturing technology has become most widespread in the world. A significant number of factories in many countries still operate according to it. The total production volume of fibreboards (hard, semi-hard, soft) is, excluding MDF, about 20 million cubic meters per year, and there is a downward trend. The share of solid slabs is approximately 4 billion square meters (they are calculated by area per square meter and thickness 3.2 mm)

In furniture production, solid fiberboard with a thickness of 3.2-5.0 mm with a density of 800-1000 kg/m3 is used. Structural elements of furniture, back walls and shelves of cabinets and cabinets, bottom shelves of sofas, drawers, headboards, and partitions are made from fiberboard. They are also used in the manufacture of bent-glued parts with outer layers of sliced ​​veneer of valuable species. In practice, hard fiberboard is sometimes called hardboard (i.e., “organic stone”), but such a term is hardly acceptable, given the ability of hard fiberboard to swell when immersed in water and absorb up to 20-30% of water per day. A separate group consists of soft boards with a density 100-400 kg/m3, produced by drying the carpet without hot pressing. They are characterized by high porosity and low thermal conductivity, but low strength limits their scope of use - they are used only in construction as a thermal insulation material. Sawmill waste is the raw material for the production of fibreboards (fibreboard). Fiberboard is in great demand both on the Russian market and abroad.

Fiberboard (hardboard), produced at the enterprise using the wet method, is an environmentally friendly product. In addition to regular fibreboard, laminated boards are produced. Laminated fiberboard is produced by applying paper-resin and synthetic films to fiberboard (hardboard) by hot pressing using glue based on urea-formaldehyde resins. Fiberboard (Fibreboard) is a sheet material that is made by hot pressing or drying wood fibers with the addition of binders and special additives, depending on the required parameters. There are two methods for producing fibreboards: - wet - without the addition of a binder; - dry, requiring the introduction of synthetic resin into the crushed wood.

Fiberboards are used in construction for heat and sound insulation, the manufacture of interfloor ceilings, walls, for interior decoration, etc. Fiberboard has become widespread in standard house construction, and in the production of furniture and containers. Making fiberboards is one of the most promising ways to use wood waste. Fiberboard of wet production method. Density of fibreboard (fibreboard) is 850...1000 kg/cubic meter, thermal conductivity 35-40 (m*C). Bending strength is not less than 0.13...0.15 W/mPa.

The advantage of fiberboard slabs is their large size (length up to 5.5 meters), as this helps to simplify and reduce the cost of construction and installation work. The physical and mechanical properties of fiberboard comply with GOST 4598-86. Fiberboard slabs allow their use for heat and sound insulation of walls, ceilings, partitions and floors, roof insulation (especially in wooden housing construction), acoustic finishing of special premises (radio studios, concert halls, etc. .) Standard fiberboard insulation boards are used for additional insulation of walls, ceilings and floors. They can be used for interior coating of walls, floors and ceilings before final finishing. The slabs are used for “floating” flooring under parquet and laminate. Fiberboard evens out uneven surfaces under parquet. Fiberboard of the dry continuous production method TSN 40. The tensile strength of fiberboard in bending is 40 mPa, density is 850-950 kg/m3. The boards are intended for use in furniture and building structures, protected from moisture.

Decorated (laminated) fiberboard TSN 40. Fibreboards are intended for the production of furniture, wall panels, door panels. Not so long ago, a new material appeared on the consumer market that combines the properties of wood and chipboards. These are fiberboard slabs of special density. They are already used in the furniture industry. This material can also be useful for the home craftsman. Soft fiberboards are the result of efforts to overcome the negative properties of wood, which swells and shrinks, bends and warps. As a result of counteracting this, one can consider the appearance of plywood, joinery and chipboards, that is, materials that behave more “peacefully” than wood. But they also have negative properties that need to be taken into account.

In the new fiberboard slabs, the source material - wood - is not only processed by cutting, but it is literally “soaked” into individual fibers. Thus, after the cut wood pulp passes through the grinding discs, fibers with a thickness of only 0.1 mm appear. They are mixed with glue, then pressed and hardened at high temperatures. At the end, the surface of the slabs is sanded or, in the case of their special application, a coating is applied to the surface that imitates the texture of wood.

Soft fiberboard of special density is produced in the same thickness as multilayer chipboard, namely from 16 to 29 mm. Uncut slabs have lengths of 262, 366, 410 and 524 cm and widths from 183 to 207 cm. If you look at the cut of a chipboard slab, you can see that the adhesion of the chips in the surface layer is quite tight. In the middle the structure is very loose. Fiberboard boards, on the contrary, have a uniformly dense structure. If you move a saw with a thin blade and fine teeth with measured, leisurely movements, you will get an even cut that only needs to be sanded. Therefore, visible sections of cuts on workpieces do not require additional labor-intensive processing. You can forget about the overlay, which you still need to try to cut correctly or shape with a milling cutter.

When coating fiber boards with varnish, you do not need to putty either the surface or the edges. Only reduce the suction power of the fibrous material with a suitable primer so that the varnish dries evenly. Uniformly dense structure throughout the entire thickness of the slab: even a nail or screw inserted from the end holds tightly. The dense structure of fiberboard boards has certain design advantages: they hold nails and screws tightly, which cannot be said about chipboard boards. Another very valuable property: fiberboard slabs can be milled just as well as solid wood. For example, the edges of the slabs can be made profiled. And it will be an impeccably smooth and clear profile.

In the market of materials for construction and furniture making, one of the most popular materials is wood fiber boards (DFB). The Redkov company has its own production and, through its online store, offers to buy fiberboard panels at the price of a direct manufacturer, without markups, which allows you to save significantly.

Fibreboard manufacturing technology

Fiberboard panels (hardboard) are made by pressing wood fibers at high temperatures. The composition also includes filler, glue and modifiers. Environmental friendliness and harmlessness are important qualities of this material.

Fibreboard production is carried out using two methods:

• Wet pressing – for sheets with a one-sided smooth surface.
• When dry pressing, the slab has two smooth sides.

Types of fibreboards and their scope of application

In accordance with GOST 4598-86, slabs are:

• Soft: density up to 350 mg/m2, thickness up to 25 mm. Application – rough work, for sound insulation, sheathing over insulation.
• Semi-solid: density up to 850 mg/m2, thickness up to 12 mm. It is used in finishing, in the manufacture of containers, as a heat and sound insulator.
• Hard hardboard: density up to 1000 mg/m2, thickness 3–6 mm.

Solid fiberboard boards come in the following types:

• – with an untreated surface on both sides, intended for rough cladding of walls and ceilings.
• T-C slabs consist of two layers: the bottom is untreated, the front is made of wood pulp. Scope of application: interior decoration.
• The T-SP brand has an untreated bottom layer, and the front part is made of wood pulp with coloring. Used for the manufacture of interior parts of furniture and panels.
• ST are super-hard slabs with an untreated outer layer. Designed for floor lining.
• ST-S has one side - painted fine wood pulp. Application – for furniture, wall panels, partitions, doors, floor coverings.
• HDF has a PVC film glued on one side. The advantage of laminated sheets is increased moisture resistance. They are used to make furniture and panels for the kitchen.
• It has several layers of protective and decorative finishing. Application: in furniture production and finishing.

Where is it profitable to buy fiberboard

The Redkov company, as a direct manufacturer, offers to buy fiberboard wholesale and retail, as well as use the service of a professional

The production of fiberboard and chipboard is a material-intensive industry, so the production cycle begins with the preparation of the main components. All kinds of wood waste and substandard wood are used as filler for fiberboard. In addition, waste paper, hemp and flax seeds, corn stalks, as well as cotton and even bamboo can be used to make the mixture. Naturally, for factories built in Russia, the last two components are exotic and are practically not used.

After washing in vats with special drums necessary to separate foreign mineral impurities (sand, gravel, clay, etc.) and magnetic separation, the raw material goes through several stages of grinding:

1. First, processing is carried out on special chipping machines, where large fragments are turned into chips.
2. The resulting chips are fed to a vibrating separator for separation into fractions.

Then the mixture will undergo further grinding in defiberizers and refiners. The ultimate goal of this process is to obtain a homogeneous fibrous mass, which is dried to the optimal (prescribed by the recipe) degree of moisture content.

Preparing a recipe mixture

The prepared raw materials are sent by screw guides to a hopper, where they are combined with a binder. The latter can be either phenol-formaldehyde resins or less toxic urea-formaldehyde resins, as well as natural lignin.

In addition to glue, other ingredients can be added to the mass at this stage to improve some of the properties of the final product.

The production of waterproof fiberboard involves the addition of paraffin emulsions, rosin or ceresin compositions, which envelop wood fibers and make the boards hydrophobic.

In addition, the introduction of paraffin gives the finished fiberboard and chipboard sheets shine and prevents excessive sticking of the mass to the equipment for the production of fiberboard during pressing.

To increase the resistance of the finished material to rotting, manufacturers add various antiseptics to the pressing composition to prevent the development of microorganisms. Fire retardants can also be added - agents that increase the fire resistance of fibreboard.

Carpet formation and pressing

The fiberboard production technology may involve wet and dry pressing, but there are significant differences in the further processing of the resulting mass.

Wet pressing method

The production of fiberboard using the wet method involves the production of a suspension of wood fiber mass of a certain concentration. To do this, the fiber after grinding is diluted with water and collected in a pool, creating a working supply of pulp. The wet mass is fed to casting machines, which form a so-called carpet on the mesh, leveling the formed layer with a pressure roller. After formation, part of the water is sucked out by vacuum and the carpet is sent for pre-pressing.

Pressing slabs is a responsible operation on which the quality of the finished product significantly depends. Equipment for the production of fiberboard is a multi-story press, which allows you to perform a three-phase pressing cycle at a plate temperature of 180-200°C:

1. water extraction under pressure 2÷4 MPa;
2. drying under pressure 0.8÷1mPa;
3. hardening under pressure 2÷4 MPa.

The capacity of the plant depends on the productivity of the press, and its cost is about 30% of all costs for equipment for the production of fiberboard.

To improve the strength properties of the resulting slabs, they can be additionally impregnated with tall oil by placing them in chambers with circulating hot air.

Most factories in Russia operate using the wet pressing method. A distinctive feature of this fiberboard is the mesh back side of the sheet.

Dry pressing method

In the dry method, wood fibers mixed with glue are laid on a mesh through which air is sucked out in a vacuum unit and the mass is compacted. The felted carpet is sent for pressing. Due to the absence of water, the duration of the pressing stage is reduced by more than half. Using this method, it is possible to produce fiberboard up to 30 mm thick, as well as profiled fiberboard sheets.

This method is less common in Russia, since dry production has very significant disadvantages, namely:

1. high fire hazard of enterprises;
2. the formation of a large amount of wood dust and, as a consequence, production requires the purchase of expensive cyclones to capture it.

Major fiberboard manufacturers

Unfortunately, due to the fact that many handicraft mini-factories have recently appeared in which the production of fiberboard is carried out without proper laboratory control over the quality of the finished product, the market is filled with second-rate fiberboard.
In Russia, we can name several enterprises with significant experience in the production of wood-based panels:

• CJSC Izoplite (Kursk region) has been producing fiberboard sheets and parts for more than 45 years.
• One of the largest manufacturers is also the Knyazhepogost fiberboard plant (KOMI Republic).
• LPK "Poleko" (Kirov region) produces lignin-based products that meet the strict requirements of Western European standards, thanks to which they are sold not only in Russia, but also imported abroad.
• Fiberboard "SteelBoard" is positioned by the manufacturer as a material that has a coefficient of water absorption and swelling that is unique among wood boards.