Polymeric materials: technology, types, production and application. Products made of polymeric materials

Most often, everyday life products are made from polymeric material. Their application is quite diverse - containers for storing food, liquids, various packaging, forms for concrete, etc. The direction is chosen depending on the availability and capacity of the appropriate equipment on which polymer products will be produced.

Where to begin

The main task of any businessman is the choice of the range of products offered and the search for customers. According to experts, the most popular products from polymer materials- dishes and other containers in contact with food, packaging film for small and large.

Conclusion of contracts with sellers or manufacturers of building materials, household appliances, hardware and ordinary stores will allow you to quickly build up a base of wholesale buyers. In the future, it will be possible to start manufacturing products under the order. A small profitability (about 15%) is offset by large sales volumes.

The initial stage of creating a business is registration. Depending on the expected production volumes, you can choose IP, LLC. To run a small plant of polymer products is enough. However, when planning large-scale activities with a wide range of products, it is better to register entity. The level of trust in organizations is higher both on the part of partners and customers.

When registering, you must specify the type of activity. The production of plastic products has the OKVED code 22 (subclass 2). The choice of subsection depends on the product.

Room search

The next task for a novice businessman is to find and rent suitable premises. At least 400 sq.m. m. You can rent hangars, garage buildings or any one-story building. Workshops, warehouses and utility rooms must meet such requirements - the availability of communications (ventilation, water supply, the possibility of using high-voltage lines under 380V) and free space for workers in accordance with the volume of production. General standards for production premises:

1. Ceiling height from 3.5 meters.
2. Non-combustible materials should be used in wall decoration.
3. Floors must be concrete or tiled.

If the production of polymer products is planned in major city(Moscow, St. Petersburg), then the rent per square meter is up to 5,000 rubles. in year. Therefore, at least 2,000,000 rubles must be included in the expenditure part of the business plan.

Procurement of equipment and materials

The cycles of the production process are complete and incomplete. This determines the cost of purchasing equipment for the production of polymer products.

The full cycle provides for the melting of granules, the formation of a film and the creation of finished product. Mandatory equipment includes:

• granulator;
• extruder (apparatus for producing film from feedstock);
• crushing units.

For additional processing of polymer products in Russia, a special printer for applying drawings and inscriptions, a device for folding edges, and a packaging machine may be required. Partial cycle - work with the finished film. To complete the lines, it will be necessary to purchase special presses for shaping, stacking and packaging machines. Approximate equipment costs for a plant producing polymer products with a full cycle:

Equipment costs will amount to at least 300,000 rubles. The cost of setting up the production line is not included here. The main raw material for a variety of household products is plastic granules. They are made from recycled plastic. It is unprofitable to purchase your own plant for the processing of feedstock. Most factories buy ready-made pellets. The cost of 1 ton of material is about 15,000 rubles.

Recruitment

There are craftsmen who are able to make polymer products with their own hands, without outside help. For example, in the garage or basement of the house.

However high income can only be obtained with large-scale production. The quality of products depends on the professionalism of employees and financial results. The employee must have experience and know the production technology. To start the line, you can limit yourself to the following vacancies:

• laborers (2 people with a salary of 25,000 rubles);
• technologist (40,000–50,000 rubles);
• machine control specialist (from 35,000 rubles);
• loader (20,000–30,000 rubles).

Monthly expenses for the payment of wages will amount to 150,000 rubles.

Sales organization procedure

Polymer film is used everywhere - from the packaging of goods to the creation of greenhouses and greenhouses. Large trading and always need such materials. They can be contracted for wholesale supply films, offering more profitable terms than competitors.

One of the most popular areas is the production of polymer molds for concrete. On the basis of the plant, it is possible to produce polymer-sand products(paving slabs, tiles, facing stone). In this case, simple compositions are used - polymer, sand, dye. This production decides environmental problem cities. Household waste (plastic, bags, bottles) is used as raw material.

By offering the city administration a waste disposal plan, your ideas and products, you can get good orders and form a positive image.

An approximate estimate of the profitability of a project for the production of polymeric materials is from 50,000 to 100,000 rubles. per month. You can reach full payback within a year.

It is amazing how diverse the objects around us and the materials from which they are made. Previously, around the 15th-16th centuries, metals and wood were the main materials, a little later glass, and almost at all times porcelain and faience. But today's century is the time of polymers, which will be discussed further.

The concept of polymers

Polymer. What it is? You can answer with different points vision. On the one hand, it is a modern material used for the manufacture of many household and technical items.

On the other hand, it can be said that this is a specially synthesized synthetic substance obtained with predetermined properties for use in a wide range of specializations.

Each of these definitions is correct, only the first from the point of view of household, and the second - from the point of view of the chemical. Another chemical definition is the following. Polymers are compounds based on short sections of the chain of a molecule - monomers. They are repeated many times, forming a polymer macrochain. Monomers can be both organic and inorganic compounds.

Therefore, the question is: "polymer - what is it?" - requires a detailed answer and consideration of all the properties and areas of application of these substances.

Types of polymers

There are many classifications of polymers according to various criteria (chemical nature, heat resistance, chain structure, and so on). In the table below, we briefly review the main types of polymers.

Classification of polymers

Principle	Kinds	Definition	Examples
By origin (origin)	Natural (natural)	Those that occur naturally, in nature. Created by nature.	DNA, RNA, proteins, starch, amber, silk, cellulose, natural rubber
	Synthetic	Obtained in the laboratory by man, are not related to nature.	PVC, polyethylene, polypropylene, polyurethane and others
	artificial	Created by man in the laboratory, but based on	Celluloid, cellulose acetate, nitrocellulose
From the point of view of the chemical nature	organic nature	Most of all known polymers. Based on the monomer of organic matter (consists of C atoms, it is possible to include N, S, O, P and others atoms).	All synthetic polymers
	inorganic nature	The basis is made up of such elements as Si, Ge, O, P, S, H and others. Properties of polymers: they are not elastic, they do not form macrochains.	Polysilanes, polydichlorophosphazene, polygermanes, polysilicic acids
	organoelement nature	Blend of organic and inorganic polymers. The main chain is inorganic, the side chains are organic.	Polysiloxanes, polycarboxylates, polyorganocyclophosphazenes.
Main chain difference	Homochain	The main chain is either carbon or silicon.	Polysilanes, polystyrene, polyethylene and others.
	heterochain	The main frame is made up of different atoms.	Examples of polymers are polyamides, proteins, ethylene glycol.

Polymers of a linear, network and branched structure are also distinguished. The basis of polymers allows them to be thermoplastic or thermoset. They also have differences in their ability to deform under normal conditions.

Physical properties of polymeric materials

The main two states of aggregation characteristic of polymers are:

• amorphous;
• crystalline.

Each is characterized by its own set of properties and is of great practical importance. For example, if a polymer exists in an amorphous state, then it can be both a viscous liquid, a glassy substance, and a highly elastic compound (rubbers). It finds wide application in chemical industries, construction, engineering, industrial goods manufacturing.

The crystalline state of the polymers is rather conditional. In fact, this state is interspersed with amorphous sections of the chain, and in general the whole molecule turns out to be very convenient for obtaining elastic, but at the same time high-strength and hard fibers.

Melting points for polymers are different. Many amorphous melt at room temperature, and some synthetic crystalline can withstand fairly high temperatures (plexiglass, fiberglass, polyurethane, polypropylene).

Polymers can be dyed in a variety of colors, without restrictions. Due to their structure, they are able to absorb paint and acquire the brightest and most unusual shades.

Chemical properties of polymers

The chemical properties of polymers differ from those of low molecular weight substances. This is explained by the size of the molecule, the presence of various functional groups in its composition, and the total reserve of activation energy.

In general, there are several main types of reactions characteristic of polymers:

1. Reactions to be determined by the functional group. That is, if the polymer contains an OH group, which is characteristic of alcohols, then the reactions in which they will enter will be identical to those of oxidation, reduction, dehydrogenation, and so on).
2. Interaction with NMS (low molecular weight compounds).
3. Reactions of polymers with each other with the formation of cross-linked networks of macromolecules (network polymers, branched).
4. Reactions between functional groups within one polymer macromolecule.
5. Decay of a macromolecule into monomers (chain destruction).

All of the above reactions have in practice great importance to obtain polymers with predetermined and human-friendly properties. The chemistry of polymers makes it possible to create heat-resistant, acid- and alkali-resistant materials, which at the same time have sufficient elasticity and stability.

The use of polymers in everyday life

The use of these compounds is ubiquitous. Few areas of industry can be recalled, National economy, science and technology, which would not need a polymer. What is it - polymer economy and widespread use, and what is it limited to?

1. Chemical industry (production of plastics, tannins, synthesis of the most important organic compounds).
2. Mechanical engineering, aircraft building, oil refineries.
3. Medicine and pharmacology.
4. Obtaining dyes and pesticides and herbicides, agricultural insecticides.
5. Construction industry (steel alloying, sound and heat insulation structures, building materials).
6. Manufacture of toys, dishes, pipes, windows, household items and household utensils.

The chemistry of polymers makes it possible to obtain more and more new, completely universal materials in their properties, which have no equal either among metals, or among wood or glass.

Examples of products made of polymeric materials

Before naming specific products made of polymers (it is impossible to list them all, their diversity is too great), first you need to figure out what a polymer gives. The material that is obtained from the Navy will be the basis for future products.

The main materials made from polymers are:

• plastics;
• polypropylenes;
• polyurethanes;
• polystyrenes;
• polyacrylates;
• phenol-formaldehyde resins;
• epoxy resins;
• caprons;
• viscose;
• nylons;
• adhesives;
• films;
• tannins and others.

This is only a small list of the variety that modern chemistry offers. Well, here it already becomes clear what objects and products are made of polymers - almost any household items, medicine and other areas ( plastic windows, pipes, dishes, tools, furniture, toys, films, etc.).

Polymers in various branches of science and technology

We have already touched on the question of the areas in which polymers are used. Examples showing their importance in science and technology can be given as follows:

• antistatic coatings;
• electromagnetic screens;
• cases of almost all household appliances;
• transistors;
• LEDs and so on.

There are no limits to the imagination on the use of polymeric materials in the modern world.

Polymer production

Polymer. What it is? It is practically everything that surrounds us. Where are they produced?

1. Petrochemical (petroleum refining) industry.
2. Special plants for the production of polymeric materials and products from them.

These are the main bases on the basis of which polymeric materials are obtained (synthesized).

The processing process is preceded by the choice of material for the manufacture of each product, based on the analysis of its operating conditions, the design of the product, the choice of the molding method and equipment, the creation of technologies. equipment and determination of optimal. parameters of the molding process. At the same time, the issue of recycling production waste should be addressed.

Technol. the recycling process includes quality control of the source material or its components, prepare. operations, in some cases, the formation of the workpiece of the product, the actual molding of the product, subsequent fur. and diff. types of processing, providing improvement or stabilization of properties in the material or product, coating on the product, quality control of the finished product and its packaging.

Main parameters of processing processes-t-ra, and time. Heating leads to an increase in the compliance of the material during molding by transferring it to a viscous or elastic state, to acceleration of diffusion and relaxation. processes, and for - to the last. material. provides compaction of the material and the creation of products of the required configuration, provides resistance to internal. forces arising in the material during molding due to temperature gradients and gradients, contributes to the release of volatile products. The time parameters of the processing process are selected taking into account the physical processes occurring in the material. and chem. processes. Optimal parameters are calculated or selected according to the results of the analysis of technol. sv-in semi-finished products and products, physical. molding model, taking into account the accumulated statistical. experience.

Processing is based on their ability to load. above the glass transition temperature, it changes into elastic, and above the yield point and melting point, and solidifies upon cooling below the glass transition temperature and temperature. During processing, chem. interaction between (resp. and) with the formation of a new, high-molten. a material that is in a thermostable state and practically does not have p-growth and fusibility (see, and also). In some cases (chap. arr. during processing), to facilitate with the ingredients and further molding of products, a pre-treatment is carried out. .

Deformation in the elastic state and during flow is accompanied by the orientation of supramolecular formations, and after the cessation of deformation and flow, the opposite process occurs - disorientation. The degree of orientation preservation in the product material depends on the rates of both processes. In the direction of orientation, some physical-mechanical. material characteristics ( , ) increase; in this case, the structure of the material turns out to be non-equilibrium and stressed, which leads to a decrease in the dimensional stability of the product, especially with increased. t-re. Duration the impact of increased t-ry, and in the case and means. the release of heat accompanying can lead to thermal oxidization. destruction of the material, and high flow rates of the material lead to its mechanical destruction. a number of p-tion is accompanied by the release of low-mol. products that cause blisters and cracks in manufactured parts.

Cooling crystallizing is accompanied by the formation, the growth rate, size and structure of which depend on the intensity of cooling of the material. By adjusting the degree of crystallinity and morphology, it is possible to directionally change the exploitation. product characteristics.

Semi-finished products (or components) intended for molding, m.b. in the form (compounds based on monomers and, solutions and dispersions and), (, based on polyester and epoxy), (filled and unfilled, solid resins and), granules (unfilled, resins, or, filled with dispersed particles or reinforced with short fibers), films, sheets, plates, blocks (and), loose-fiber compositions (materials impregnated with mats), based on continuous fibrous materials (threads, tows, tapes, impregnated mats, veneer). By technol. unfilled, particulate-filled or fiber-reinforced are identical in their capabilities and are processed into products using the same methods.

Methods for forming products from unfilled and filled molding under . Direct pressing is used to manufacture products of various shapes, sizes and thicknesses. from, produced in the form of, granules, layered blanks from reinforced, as well as blanks from. before pressing, they are subjected to preparation (, pre-heating), which improves their technology. Holy Island and the quality of the products obtained. Prepared materials are usually dosed before pressing. The specified amount of the semi-finished product to be processed is placed in a heated mold installed on the press, the configuration of the forming cavity corresponds to the configuration of the part (Fig. 1). The mold is closed. The material heats up, passes into, under 7-50 MPa fills the forming cavity and compacts. In the mold, the material is kept under until complete or raw, which ensures the fixation of the configuration given to the material. The finished product is pushed out or removed from the mold, as a rule, at the pressing temperature.

Rice. 1. Manufacture of products by pressing: a-loading the press material into a heated mold; b-pressing; in- ejection of the product; 1-punch; 2-matrix; 3 - ejector; 4-press material; 5- ready product.

In the process of pressing, to improve the quality of products, pre-pressing is used ( alternating supply and removal) and feed delay. Pre-pressures help remove volatile(products of the district, adsorbed. moisture, residues of the solution-supporters). The same goal is achieved in advance. evacuation of the material in the forming cavity of the mold (pressing with vacuum). The feed delay is used to reduce the fluidity of those having a very low molding temperature in order to prevent them from flowing through the mold gaps during the compaction process.

During processing, pressing is used to manufacture parts with a thickness of> 10-15 mm, if the material has too high a processing temperature, and also if the yield temperature is close to its destruction temperature.

Molding (transfer) pressing apply hl. arr. for processing . Molding is carried out in molds, the forming cavity of which is separated from the loading chamber and connected to it by gate channels (Fig. 2). In the process of pressing, the material placed in the loading chamber of the heated mold passes into and under 60-200 MPa flows through the gating channel into the forming cavity of the mold, where the material is additionally heated and cured.

Rice. 2. Production of products by injection molding: a-mold is heated and closed; b-transferring the melt. material into the forming cavity and it; in-mould connector; 1-punch; 2-matrix; 3-ejector; 4-press material; 5-finished product; 6-loading chamber; 7 - the rest of the press material, drilled in the injection channel of the mold; 8-casting punch.

The advantage of injection molding is the ability to manufacture products complex shapes with deep through holes of small diameter or with low-strength ext.(external) fittings. Products obtained by this method are characterized by less stress than with direct pressing, because. the process in the forming cavity proceeds simultaneously throughout the entire volume of the part, and when filling the mold, conditions are created that ensure the removal of volatile products from the material.

Centrifugal molding is used to manufacture products that have the shape of bodies of revolution (bushings, pipes, hollow spheres, etc.), under the action of centrifugal forces. In this way, viscous thermosetting compounds are processed, both unfilled and containing powdered and fibrous compounds. In centrifugal molding, either a thermosetting compound is poured into a heated mold fixed on a shaft, which is rotated. Under the action of centrifugal forces, the processed material is distributed in a uniform layer over the forming surface of the mold and compacted. After the mold has cooled, it is stopped and the finished product is removed. For the manufacture of low bushings and products having the geometry of a paraboloid of revolution, a mold with a vertical axis of rotation is used; long pipes are produced in molds with a horizontal axis of rotation, hollow spheres are produced at the same time. rotation of the form around two mutually perpendicular axes. The value of forming during the molding process is determined by the frequency of rotation of the mold and the radius of its forming cavity and reaches 0.3-0.5 MPa. This method usually produces thin-walled and thick-walled products, the production of which is difficult or impossible by other methods.

Rolling is used to mix raw and plastic components. masses at the stage of their preparation or improvement of technol. sv-in the material before molding products, as well as for the manufacture of semi-finished products (sheets, films). Rolling is carried out in the gap between the rolls (cooled or heated), rotating towards each other with decomp. speed. Depending on the instrumentation of the method, the material can be removed from the rollers in the form of a sheet or a narrow continuous tape.

Calendering is used for continuous molding decomp. film or sheet, application to the surface sheet materials embossed pattern, duplication of preformed tape blanks, reinforcement or mesh at a temperature higher than the yield point or temperature. Carried out on units of continuous action, DOS. part of which is multiroll (Fig. 6). The polymer or rubber composition is continuously supplied to the feed rollers or . In contrast to rolling, in calendering the material passes through the gap between the rolls only once. To obtain a sheet of a given thickness and with a smooth surface, they are made multi-roll, which makes it possible to sequentially pass the material through two or three gaps. different sizes. In the process of calendering in the gap between the rolls is subjected to intense shear, it develops in the direction of movement means. elastic, to-rye are fixed in the product after. cooling. Longitudinal orientation determines the meaning. sv-in the material (calender effect).

Calender aggregates m. b. equipped with additional devices for one- or two-axis film orientation.

Rice. 6. Manufacture of products by calendering: 1 - mixer; 2 - rollers; 3 - detector; 4-5-shaped inclined; 5 - cooling; 6-thickness gauge; 7-device for trimming edges; 8-sealer.

Rolling is used to process sheet thermoplastic semi-finished products in order to give them the required dimensions. cross section or increase fur. sv-in in the direction of rolling. Unlike calendering, it is carried out on roll machines, the rolls of which rotate towards each other at the same speed, at temperatures not exceeding the vitrification temperatures and temperatures. In the gap between the rolls, the material is compacted and oriented in the direction of rolling due to the forced elastic forces developing in the material.

For molding monolithic thin-walled products from blanks (sheets, pipes, etc.), stamping (stamping) and its varieties (mechano-pneumatic molding, vacuum molding, etc.) are used.

Stamping is used preim. for molding large-sized volumetric products from blanks obtained by casting, pressing, or extrusion and transferred by heating into an elastic state. The heated billet under the action changes its shape, filling the forming cavity of the stamp, which has a temperature below the glass transition temperature. To fix the resulting configuration, the molded product is cooled under . When stamping, it is possible to combine the operation of manufacturing a workpiece and obtaining a product from it. In this case, the workpiece is obtained either by extrusion and, without allowing it to cool below the glass transition temperature, is subjected to stamping. Depending on the design of the equipment and tooling used, the shape and size of the workpiece and products, various types are used. types of stamping.

Parts with walls of variable thickness or with a relief on the surface are made from relatively thick-walled blanks in rigid dies that have a punch and are mounted on hydraulics. or pneumatic. presses (Fig. 7). Of all types of stamping, this method is the most expensive, because requires paired punches and .

Rice. 7. Stamping with a rigid stamp having a punch and: 1 - camera; 2 - ; 3 - blank; 4-clamping ring; 5-punch.

Fur. stamping with a punch (Fig. 8, a) through a stretching ring and mechano-pneumatic molding (Fig. 8, b) are used to manufacture products with a pronounced thickness difference, for example, if the bottom of the product should be much thicker than the walls. Upon receipt of products, on one of the surfaces to which it is necessary to apply a drawing with small elements, Ch. arr. stamping in an elastic punch made of sponge or soft monolithic.

Rice. 8. Stamping with a punch: a-through a stretching ring; b-mechanopneumoforming; 1 - camera; 2-blank; 3-drawing ring; 4-clamping ring; 5-punch.

Vacuum forming through a stretching ring (Fig. 9, a) from sheet blanks produces products that have the shape of bodies of revolution. The workpiece is pinched between the clamping and lingering ring, fixed at the end of the sealed container, in which a vacuum is created. Under the influence of atm. the workpiece is deformed inside the container, and when created in the container overpressure-in reverse side. The shape and dimensions of the resulting product are determined by the configuration in terms of the stretching ring and the degree (depth) of drawing of the workpiece, which is characterized by the ratio of the height of the product to its width. Vacuum molding in (Fig. 9,b) with molding up to 0.09 MPa produces products from thin-walled blanks. If this is not enough for the design of products, they are used in the matrixtsu (Fig. 10). This method also makes it possible to obtain products of a more complex configuration.

Fig.9. Vacuum forming: a-through the stretching ring; b-c; 1-camera; 2-blank; 3-drawing ring; 4-clamping ring; 5-matrix.

Rice. 10. in: 1-chamber; 2-blank; 3-clamping ring; 4-matrix.

In the process of punching-cutting, flat products are manufactured decomp. configurations having holes in the plane of the detail decomp. diameter. Punching of products is carried out in dies equipped with cutting elements (to separate the product from the workpiece along the contour), a clamp holding the workpiece in the required position, a punch and punching holes in the workpiece.

Forming without . In this case, the compaction of the material and the molding of the product is carried out under the action of gravity and forces.

By casting, products are made from curable compounds based on monomers, resins, polymer-monomer compositions or having a viscous consistency. Compound at normal or high t-re is poured into the technol. tooling (form) in which it or hardening takes place. To ensure the removal of the product from the mold, the walls of the mold are covered with a layer of anti-adhesive, for example. curing silicone grease. Casting produce sheets, plates, blocks, decomp. kind of mechanical engineering. details (gears, pulleys, cams, templates), technol. tooling for stamping, and other molding methods.

Will prepare. operations include preparation (, various types of energy and chemical processing to improve combination with), shaping and shaping tooling and equipment, and in some cases - preparation and its application to. The structure and shape of the reinforcing material used largely determine the choice of method for manufacturing the workpiece.

Obtaining a product blank by the selected method is carried out by laying the reinforcing material in a given sequence on a tooling that determines the shape of the future part. At the same time, the orientation of the fibrous material is maintained in accordance with the stress diagram, which provides the required St. in the material in the product.

The manufacture of a workpiece can be carried out using - pre-impregnated, dried or confirmed (the so-called dry method of winding, laying out), with impregnation during its laying out or winding (the so-called. wet way winding, laying out), with alternating layers of unimpregnated or partially impregnated with layers in the form of a fusible film or using, in which reinforcing fibers alternate with fibers of the matrix material (fiber technology).

Obtaining a workpiece of a product from, reinforced with continuous fibrous (ch. arr. threads, tows, rovings, tapes, knitted materials), is carried out by the methods of layer-by-layer laying out, winding, weaving or weaving, as well as combining. method.

Using the method of layer-by-layer laying out of continuous fibers, blanks of sheets, slabs, sheathing, as well as products of relatively simple geomes are made. forms. In layer-by-layer laying out, layers or unimpregnated reinforcing material are sequentially, observing a given orientation, assembled on a rigid form (punch), repeating the shape of the product, into a package to the required thickness. In the process of laying out, layer-by-layer compaction of the package is carried out using a roller or other tool. In serial production, special is used. laying out installations or complexes using robotics and program control.

The winding method is widely used for the manufacture of workpieces in the form of bodies of revolution. When using unidirectional continuous reinforcing in the form of threads, bundles, tapes, rovingsapply circumferential, longitudinal, spiral (helicoidal) or combined. winding.

Spiral winding is used for the manufacture of shells together with bottoms, conical parts. forms, products of variable section. When combined winding combine in any case spiral, longitudinal or circumferential winding to achieve the required material strength. The simplest type of combination winding-longitudinally-transverse. The use of multi-axis winding machines with program management allows you to automate the winding process and make it highly productive.

When using reinforcing in the form of canvases, tapes with a cross arrangement of fibers, circumferential winding with rolling is used, for example. at pipe manufacturing, cylinders, conical shells forms. If the compaction of the material due to tension or rolling is sufficient to provide the required density of the material during the last. products, then winding is also a molding method.

Combined methods for creating blanks for products include several. dec. methods when assembling one part, for example. combination of layering and winding.

The above methods allow you to orient the product in one or two planes. If it is necessary to obtain volumetric reinforcement in three or more planes, the method of weaving or weaving a workpiece from bundles or threads is used. The direction of reinforcement and the content in each of the directions are determined by the operating conditions of the part. The weaving method is also used to create multilayer parts blanks, in which the layers are mechanically interconnected.

The manufacture of a workpiece of a part reinforced with short fibers is carried out by the method of layer-by-layer laying out using rolled in the form of mats, canvases, felt, both pre-impregnated and impregnated during the manufacture of the workpiece, as well as spraying, suction and chopped fibers. In the manufacture of product blanks by spraying, segments of bundles (30-60 mm) are used as quality, to-rye with the help of special. installations are sprayed with a stream together with the mold until the required thickness is reached. This method produces large-sized products, for example. hulls of boats and boats, elements of cars and trucks, decomp. destinations, swim. swimming pools, floor coverings, facings of concrete structures.

The suction method is used in the production of products of relatively small sizes. The manufacture of the workpiece is carried out by Ch. arr. in the suction chamber, to the top. part of the cut is supplied with chopped fiber (Fig. 12); in the bottom part of the chamber on a rotating table is mounted perforated. a form through which it is sucked through (pumped) with the help of a powerful fan. The atomized fiber, entrained by the flow, is sucked onto the mold until the required thickness is achieved. The method allows the use of both dry in the form of or fusible polymer fibers supplied together with reinforcingfiber, and liquid, applied to the pumped workpiece using guns located around the perimeter of the chamber. After suction, the workpiece is removed from the chamber and molded using one of the methods listed below. In addition, suction can be carried out from fibers in a liquid medium using paper technology (see).

Rice. 12. Production of blank parts from the suction method: 1 - bobbin with a tourniquet; 2-cutting device; 3-funnel for powder; 4 - camera; 5-gun for spraying liquid; 6-per-forir, form; 7 - rotating table; 8-fan.

After forming, the workpiece of the part is subjected to molding decomp. methods. The contact molding method is used in the manufacture of parts using polyester and epoxy cold primers. in combination with the creation of a workpiece by the calculation method. With this method of forming, the impregnated layers are compacted by pressing with a brush or rolling with a roller. material is produced without the application of a constant in the main. at t-re shop.

In the manufacture of large-sized parts, vacuum, vacuum-autoclave and press-chamber molding methods using an elastic bag (cover) are widely used. In these cases, a division is applied to the mandrel according to the shape of the product. layer (to prevent sticking of the molded part), lay out or wind the workpiece of the product, on which the perforator is sequentially laid. will divide. layer, tsulagu (

The production of polymer products includes the manufacture of various household and technical items. For example, the most hot goods are containers for liquids, molds for pouring concrete or food products, as well as various tapes for packaging goods.

Business can be directed to one specific area of ​​production or several at once, depending on the amount of technological equipment and the overall scale of capacity. The ideal option would be cooperation with an enterprise that deals with household appliances, selling building materials or small goods.

Usually their field of activity needs polymers, and specifically packaging film. As practice and analytical statistics show, it is best to start this business with film and plastic tableware, and as the business develops further, develop production. At proper organization business is quite realistic to achieve a profitability of about 15 percent.

Rent of premises for business.

For industrial production free space is required. The production complex for the production of polymer products can be equipped with 400 square meters. For this purpose, small hangars, agricultural premises, garages or any one-story buildings with a specific area are perfect.

When choosing, it is worth considering the presence of communications, namely ventilation systems, water supply, gas supply, including a high-voltage line 380V. There are no specific requirements for the working space, it all depends on the volume of production and the number of workers.

The average cost of an area in the Moscow region is at least 5,800 rubles per sq. m. m. per year, respectively, total: 400 x 5,800 = 2,320,000 rubles. After signing the contract and all related papers, it is necessary to take up the preparation of the premises for the placement of equipment, in particular, to prepare the ventilation system, fasteners, free space, etc.

Purchase of the necessary equipment.

The production of polymers is impossible without technologically sophisticated and bulky equipment. These are conveyor systems, ovens, presses, compressors and more.

The main systems and units for production:

Extrusion machine - 110,000 rubles;
- film cutting machine - 56,000 rubles;
- punching press - 40,000 rubles;
- air compressor- 12,000 rubles;
- gas stove - 70,000 rubles;
- auxiliary tools and equipment - 10,000 rubles;

The cost of each machine is calculated based on the average data of catalogs for large regions of Russia. Total equipment costs: 110,000 + 56,000 + 40,000 + 12,000 + 70,000 + 10,000 = 298,000 rubles, the price does not include the amount required for installation and configuration of systems.

Working staff and procurement of raw materials for the enterprise.

The polymer products business needs skilled workers who can maintain stable production, thereby showing the face of the company. First of all, these should be people with experience and knowledge. For the first time, a small staff of workers will come down, enough: 2 handymen, a technologist, a machine operator and a packer-loader. When choosing, it is worth carefully checking people, since the presence of stable demand and the amount of profit will depend on the quality of work.

Average salaries in Moscow and the Moscow District:

Handymen - 28,000 rubles;
- process engineer - 45,000 rubles;
- CNC manager - 38,000 rubles;
- loader-packer - 30,000 rubles;

Total salary costs for employees: 56,000 (2 people) + 45,000 + 38,000 + 30,000 = 169,000 rubles per month, for one year: 169,000 x 12 (months) = 2,028,000 rubles, without deducting bonuses, sick leave or vacation.
In terms of procurement of raw materials, a systematic supply of plastic pellets, which are made from recycled plastic, will be needed. This will significantly save production costs, since equipment for processing raw materials is not cheap enough. The purchase of ready-made granules costs about 15,000 rubles per ton, depending on the color of the material.

Production technology.

The purchased raw material in the form of multi-colored granules enters the remelting tank. Next, the tub moves to a special gas-fired oven, where it is heated to a certain temperature. The heated liquid is poured into even sheets that do not solidify, but are in the form of rubber. After heat treatment, the polymer material is suitable for punching press. This device repels a product of a certain shape.

The finished blanks are moved to the processing point, where handymen correct all possible minor defects, in the form of extra traces of plastic from the press, and so on. Processed products go to sorters who are engaged in packaging for its subsequent sale.

Business promotion and advertising.

The right approach to advertising will soon promote own business. For this specific production, there are methods of advertising. However, it is impossible to do without having your own website. The web resource opens up opportunities for providing the client with more detailed information about the production. The site may contain a product catalog, contact information, reviews, and more. The creation and development of the site will cost about 120,000 rubles, this amount already includes the initial content promotion.

It is also worth paying attention to advertising in ads, for example, you can publish your ad in a popular construction or trade magazine, as well as place an ad in a local newspaper. Naturally, the cost of services of this kind depends on the specific rates of the press and the requests of the main editorial board.

Sales plan for polymer products and possible dates payback.

Polymeric products are applied practically in any sphere of production. First of all, it is a polymer film, which is used for various purposes, from food packaging to the arrangement of greenhouses and greenhouses in agriculture. It will be a big advantage to have contacts with large industries or trade enterprises who need similar products. Also, the main direction of sales will be retail and wholesale. Polymer products are a very broad concept, and can include many household and technical products, for example, polymer molds for concrete are very popular due to their ease of use and the availability of a variety of forms.

The amount of income from this business can vary from 50 to 100 thousand rubles per week, respectively, for one month the profit will be 100 x 4 (weeks) \u003d 400,000 rubles, for the year 400,000 x 12 (months) \u003d 4,800,000 rubles excluding taxes and various payments. The total costs for this business in the first year are about 4,781,000 rubles, respectively, the net income will be about 4,800,000 - 4,781,000 = 19,000 rubles per year, which is quite acceptable, since with this type of business, it can go to zero take from several months to 2-3 years. Based on the calculated data, it can be confidently stated that the business of producing polymer products will be able to pay off already in 12 - 14 months.

Polymeric materials are chemical high-molecular compounds that consist of numerous small-molecular monomers (units) of the same structure. Often, the following monomeric components are used for the manufacture of polymers: ethylene, vinyl chloride, vinyl dechloride, vinyl acetate, propylene, methyl methacrylate, tetrafluoroethylene, styrene, urea, melamine, formaldehyde, phenol. In this article, we will consider in detail what polymeric materials are, what are their chemical and physical properties, classification and types.

Types of polymers

A feature of the molecules of this material is a large one that corresponds to next value: M>5*103. Compounds with a lower level of this parameter (M=500-5000) are called oligomers. In low molecular weight compounds, the mass is less than 500. The following types of polymeric materials are distinguished: synthetic and natural. The latter include natural rubber, mica, wool, asbestos, cellulose, etc. However, the main place is occupied by synthetic polymers, which are obtained as a result of a chemical synthesis process from low-molecular-weight compounds. Depending on the method of manufacturing high-molecular materials, polymers are distinguished, which are created either by polycondensation or by an addition reaction.

Polymerization

This process is a combination of low molecular weight components into high molecular weight to obtain long chains. The polymerization level value is the number of "mers" in the molecules this composition. Most often, polymeric materials contain from a thousand to ten thousand of their units. The following commonly used compounds are obtained by polymerization: polyethylene, polypropylene, polyvinyl chloride, polytetrafluoroethylene, polystyrene, polybutadiene, etc.

Polycondensation

This process is a stepwise reaction, which consists in connecting or a large number monomers of the same type, or a pair of different groups (A and B) into polycapacitors (macromolecules) with the simultaneous formation of the following by-products: carbon dioxide, hydrogen chloride, ammonia, water, etc. Polycondensation produces silicones, polysulfones, polycarbonates, amino plastics, phenolic plastics, polyesters , polyamides and other polymeric materials.

Polyaddition

This process is understood as the formation of polymers as a result of reactions of multiple addition of monomeric components that contain limiting reaction combinations to monomers of unsaturated groups (active cycles or double bonds). In contrast to polycondensation, the polyaddition reaction proceeds without any by-products. The most important process of this technology is the curing and production of polyurethanes.

Classification of polymers

By composition, all polymeric materials are divided into inorganic, organic and organoelement. The first of them (mica, asbestos, ceramics, etc.) do not contain atomic carbon. They are based on oxides of aluminum, magnesium, silicon, etc. Organic polymers constitute the most extensive class, they contain carbon, hydrogen, nitrogen, sulfur, halogen and oxygen atoms. Organoelement polymeric materials are compounds that in the main chains have, in addition to those listed, atoms of silicon, aluminum, titanium and other elements that can combine with organic radicals. Such combinations do not occur in nature. These are exclusively synthetic polymers. Characteristic representatives of this group are compounds on an organosilicon basis, the main chain of which is built from oxygen and silicon atoms.

To obtain polymers with the required properties, technology often uses not "pure" substances, but their combinations with organic or inorganic components. good example polymer building materials are used: metal-plastics, plastics, fiberglass, polymer concrete.

Structure of polymers

The peculiarity of the properties of these materials is due to their structure, which, in turn, is divided into the following types: linear-branched, linear, spatial with large molecular groups and very specific geometric structures, as well as ladder. Let's briefly consider each of them.

Polymeric materials with a linearly branched structure, in addition to the main chain of molecules, have side branches. These polymers include polypropylene and polyisobutylene.

Materials with a linear structure have long zigzag or spiral chains. Their macromolecules are primarily characterized by repetitions of sites in one structural group of a link or chemical unit of the chain. Polymers with a linear structure are distinguished by the presence of very long macromolecules with a significant difference in the nature of bonds along the chain and between them. This refers to intermolecular and chemical bonds. The macromolecules of such materials are very flexible. And this property is the basis of polymer chains, which leads to qualitatively new characteristics: high elasticity, as well as the absence of brittleness in the hardened state.

Now let's find out what polymeric materials with a spatial structure are. These substances form, when macromolecules are combined with each other, strong chemical bonds in the transverse direction. As a result, a mesh structure is obtained, which has a non-uniform or spatial basis of the mesh. Polymers of this type have greater heat resistance and rigidity than linear ones. These materials are the basis of many structural non-metallic substances.

Molecules of polymeric materials with a ladder structure consist of a pair of chains that are connected by a chemical bond. These include organosilicon polymers, which are characterized by increased rigidity, heat resistance, in addition, they do not interact with organic solvents.

Phase composition of polymers

These materials are systems that consist of amorphous and crystalline regions. The first of them helps to reduce stiffness, makes the polymer elastic, that is, capable of large reversible deformations. The crystalline phase helps to increase their strength, hardness, elastic modulus, and other parameters, while reducing the molecular flexibility of the substance. The ratio of the volume of all such areas to the total volume is called the degree of crystallization, where the maximum level (up to 80%) has polypropylenes, fluoroplasts, high-density polyethylenes. Polyvinyl chlorides, low-density polyethylenes have a lower degree of crystallization.

Depending on how polymeric materials behave when heated, they are usually divided into thermosetting and thermoplastic.

Thermoset polymers

These materials primarily have a linear structure. When heated, they soften, but as a result of the flow in them chemical reactions the structure changes to spatial, and the substance turns into a solid. In the future, this quality is maintained. Polymer polymers are built on this principle. Their subsequent heating does not soften the substance, but only leads to its decomposition. The finished thermosetting mixture does not dissolve or melt, therefore, its reprocessing is unacceptable. This type of material includes epoxy silicone, phenol-formaldehyde and other resins.

Thermoplastic polymers

These materials, when heated, first soften and then melt, and then harden upon subsequent cooling. Thermoplastic polymers do not undergo chemical changes during this treatment. This makes the process completely reversible. Substances of this type have a linear-branched or linear structure of macromolecules, between which small forces act and there is absolutely no chemical bonds. These include polyethylenes, polyamides, polystyrenes, etc. The technology of polymeric materials of a thermoplastic type provides for their manufacture by injection molding in water-cooled molds, pressing, extrusion, blowing, and other methods.

Chemical properties

Polymers can be in the following states: solid, liquid, amorphous, crystalline phase, as well as highly elastic, viscous and glassy deformation. The widespread use of polymeric materials is due to their high resistance to various aggressive media, such as concentrated acids and alkalis. They are not affected. In addition, with an increase in their molecular weight, the solubility of the material in organic solvents decreases. And polymers with a spatial structure are generally not affected by the mentioned liquids.

Physical properties

Most polymers are dielectrics, in addition, they are non-magnetic materials. Of all the structural materials used, only they have the lowest thermal conductivity and the highest heat capacity, as well as thermal shrinkage (about twenty times more than that of metal). The reason for the loss of tightness of various sealing assemblies under low temperature conditions is the so-called glass transition of rubber, as well as the sharp difference between the expansion coefficients of metals and rubbers in the vitrified state.

Mechanical properties

Polymeric materials are distinguished by a wide range of mechanical characteristics, which strongly depend on their structure. In addition to this parameter, the mechanical properties of a substance can be greatly influenced by various external factors. These include: temperature, frequency, duration or speed of loading, type of stress state, pressure, nature of the environment, heat treatment, etc. mechanical properties polymeric materials is their relatively high strength at a very low rigidity (compared to metals).

Polymers are usually divided into solid ones, the elastic modulus of which corresponds to E=1-10 GPa (fibers, films, plastics), and soft highly elastic substances, the elastic modulus of which is E=1-10 MPa (rubbers). The regularities and mechanism of destruction of those and others are different.

Polymeric materials are characterized by a pronounced anisotropy of properties, as well as a decrease in strength, the development of creep under the condition of long-term loading. Along with this, they have a fairly high resistance to fatigue. Compared with metals, they differ in a sharper dependence of mechanical properties on temperature. One of the main characteristics of polymeric materials is deformability (pliability). According to this parameter, in a wide temperature range, it is customary to evaluate their main operational and technological properties.

Polymer flooring materials

Now consider one of the options practical application polymers, revealing the full range of these materials. These substances are widely used in construction and repair and finishing works, in particular in flooring. The huge popularity is explained by the characteristics of the substances in question: they are resistant to abrasion, have low thermal conductivity, have little water absorption, are quite strong and hard, and have high paint and varnish qualities. The production of polymeric materials can be conditionally divided into three groups: linoleums (rolled), tile products and mixtures for seamless floors. Now let's briefly look at each of them.

Linoleums are made on the basis of different types of fillers and polymers. They may also include plasticizers, processing aids and pigments. Depending on the type of polymer material, polyester (glyphthalic), polyvinyl chloride, rubber, colloxylin and other coatings are distinguished. In addition, according to the structure, they are divided into baseless and with a sound and heat insulating base, single-layer and multi-layer, with a smooth, fleecy and corrugated surface, as well as one- and multi-color.

Materials for seamless floors are the most convenient and hygienic in operation, they have high strength. These mixtures are usually divided into polymer cement, polymer concrete and polyvinyl acetate.