Equipment for the production of foamed polyethylene insulation. Foamed polyethylene: properties, types, application

Foamed polyethylene is a modern building material that perfectly retains heat by 70%, insulates from noise and moisture, and tolerates vibrations and mechanical shocks. The minimum service life and wear resistance is from 50 to 80 years, due to its durability and composition it is not subject to rotting. Used in many areas of construction and repair.

This unique material has good value and excellent qualities, and is safe for human health and life. Foamed polyethylene is successfully used in construction, medicine, mechanical engineering, and in the manufacture of leather haberdashery and footwear.

Where to buy foamed polyethylene? Here is one recommendation - we recommend buying polyethylene foam from manufacturers or trusted sellers. For example, at http://www.tecsound.com.ua/products_category/vspenenyi-polietilen-i-lenty/, representative offices of the Spanish company “TEXSA” in Ukraine.

Technical characteristics of foamed PE:

1. Foamed polyethylene has the properties of flammability and melting at temperatures exceeding + 102 0 C.
2. When the air temperature drops to - 60 0 C, foamed PE will retain its strength and elasticity.
3. The material has low thermal conductivity, which enhances thermal insulation many times over.
4. Even when burning, the product is non-toxic.
5. It does not require much effort in transportation and installation, and is light in weight.
6. The material has good load resistance.
7. Minimum amount of waste during production.
8. Environmentally friendly material, without a specific odor.

Polyethylene foam production technologies at different enterprises differ little and have similar operating characteristics.

Methods for producing foamed polyethylene

The production process of foamed polyethylene occurs by injection molding or extrusion. During production, the same qualities of various ethylene polymers remain the same - water resistance, resistance to temperature changes, plasticity, non-toxicity

Production technologies for foamed PE:

1. The production of non-crosslinked polyethylene foam in the process of physical foaming does not require a chemical reaction to preserve the molecular structure of the primary substance - foamed polyethylene. The process is divided into two stages: the first, when the raw material is melted into granules. The second is that isobutane, propane or freon gas is supplied to the chamber where the mass of the polymer substance is mixed.
2. Chemically cross-linked polyethylene foam using chemical reagents. The structure of polyethylene changed at the molecular level becomes a network type. To start the reaction, granules plus mixing and foaming reagents, special additives and pigments are mixed. Afterwards, to give the desired shape, the molten mass passes through an extruder (melting and foaming).
3. Physically cross-linked foamed PE during production requires modification of the structure at the molecular level. The production process technology involves foaming additives and radiation. The heated molten mass of polyethylene moves through an electron accelerator.

A significant drawback is that the material is highly flammable; fire retardants are added during manufacturing.

The production of cross-linked foam polyethylene has a more complex technology, and therefore has advantages over non-cross-linked polyethylene:

1. The microbiological endurance of the material is stronger.
2. Withstands temperature changes and mechanical stress.
3. Resistance to chemical solvents.
4. It withstands vibration well and is resistant to deformation.
5. More than 30% has a dense structure that increases insulation.
6. Heat retention is 20% greater than non-crosslinked PE foam.
7. Due to its high strength it has a long service life.

The advantage of non-crosslinked polyethylene foam is the low price of the material. Unscrupulous sellers often exaggerate the positive qualities of the material when they recommend it as a good soundproofing material used in construction. They are also used as various non-toxic packaging for products and goods.

Application of non-crosslinked polyethylene foam

1. Non-crosslinked polyethylene foam is convenient for packaging and, if necessary, softens pressure during loading. Has an unlimited shelf life. It cannot spoil and is beneficial when packing valuable goods and cargo. In the packaging market, NPE has no equal competitors, and occupies 90% of applications.
2. Used as packaging material for electrical equipment, dishes, furniture, glass products. Perfectly protects the surface from dust and technical debris.
3. NPE is excellent for insulating from moisture, water, steam, condensation and mechanical noise.
4. Subject to minimum quality requirements, it is used in construction as thermal insulation and mechanical engineering. Not suitable for use when there are powerful loads or the air temperature is too hot.
5. It is well used to reduce energy costs while saving heat in the house - thanks to reflective insulation. Widely used to level the surface, put under parquet, laminate, linoleum.
6. It has a variety of release forms - in polyethylene mesh, in rolls, in sheets of different thicknesses. With a laminated or foil base, non-crosslinked polyethylene foam will perform protective functions depending on the requirements and the task at hand.
7. In the European Union, there is a restriction on the use of NPE; it is used only for packaging.

Areas of application of cross-linked polyethylene foam

The material is widely used in various spheres of life: construction, sports, tourism, medicine, mechanical engineering, in the production of children's toys, automobile factories, household items, sanitary products. It has enhanced strength, heat resistance, and a high level of rigidity.

Construction

1. It is used for heating and water supply systems, has good insulation of heat, water, steam and noise. Resistant to high temperatures from -60 0 to +110 0 C, begins to melt at t 0 115-130 degrees C.
2. Used to insulate ceilings, floors, and ceilings between floors. As a reflective heat insulation for heating systems.
3. The material is easy to install and acts as a high-quality, modern sound insulating layer in a “floating floor” device.
4. Insulation from moisture, water for foundations, partitions. Arrangement of basements, warehouses, garages, balconies and loggias. Insulation of electrical cables.
5. Protection for public utility systems and engineering structures.

Medicine

1. Widely used in the manufacture of orthopedic medical products. Insoles for specialized shoes made of cross-linked polyethylene foam.
2. In the production of internal organ prostheses.
3. Elastic elements that are used in medicine and medical equipment.

Package

1. Various types of containers - containers, vessels, canisters, bottles, tanks.
2. Various inserts to prevent product deformation. Padded material for the preservation and transportation of food and industrial goods.

Sports and tourism

1. Punching bags, gloves, pads, helmets.
2. Devices that do not sink in water and act as a fence or marking. Swimming boards, life jackets and safety vests.
3. Rugs and mats for tourism, yoga, fitness and other sports areas.

Mechanical engineering

1. The material is used to install a heat reflector. As a mounting tape, sealant, protection of elements during vibration isolation.
2. Noise and heat insulation of isothermal cabinets of air conditioners and refrigerators.

Automotive industry

1. Covering most parts of a car dealership to insulate heat and noise. Various seals, gaskets.
2. Buffer gaskets for car components and parts.

As a result, all types of polyethylene foam are resilient and elastic materials that have a closed-cell structure and are available in rolls, sheets or as a finished product. They have high properties of resistance to moisture and aggressive environments - alkalis, acids, oils, petroleum products. Easy installation in any structure, environmentally safe when used. The main disadvantages include poor resistance to direct sunlight and ease of ignition. When choosing, you need to know whether the material has the technical characteristics necessary for your case. What are your goals? To avoid unnecessary costs and the purchase of cheap unnecessary material.

The production technology of foamed polyethylene is based on the polymerization of ethylene, which occurs under the influence of high temperatures and pressure. High-density polyethylene is the most popular, as this type of material has increased water resistance.

Technological process

Raw materials are selected based on the final purpose of the product produced from this material. Low-density granular material with different pigments is widely used; cross-linking and foaming agents are additionally used. The function of a combustion retardant is performed by a mixture including decabromodiphenyl and antimony trioxide. The raw materials used are placed in an extruder where the mixture is heated and then extruded to create a mother sheet.
The sheet is sent to a chamber where the process of foaming takes place at the required temperature. The next stage is chemical cross-linking, during which a porous closed structure is formed under the influence of a mixture of gases. The result of the work is sheet material that undergoes a cooling process and subsequent cutting.

Types and characteristics of equipment

To establish the technological process, you need to buy equipment for the production of foamed polyethylene.
The following types of units will be needed:

• agglomerators – process film waste suitable for reuse. The result of the work is the production of agglomerate in the form of film pieces, sintered into balls under thermal influence;
• granulators - a production line consisting of several elements: an extruder, a cooling unit, a hopper, a strand head, and a device for cutting granules. It is this line that is used for processing plastic and household polymers in order to obtain raw materials suitable for the production of polyethylene;
• crushers – crush waste, which is subsequently sent to the extrusion line. Plastic pipes, polymer sheets and ingots, including those with a high level of impact strength, are subjected to crushing;
• Extruders are the main type of equipment that allows the production of various products: sheets, film, pipes.

Production of foamed polyethylene from recycled materials is an efficient process that requires the use of all the units necessary for processing and manufacturing the final product.

Organization of production in Russia

You can open your own production by registering as an LLC, for which you will need to collect a package of documents: charter of the organization; minutes of the founding meeting, application, receipt for payment of state duty. You will need to obtain OKVED codes from Rosstat. Here we must take into account that the specific code will be determined by the type of production process. If you plan to open your own production of foamed polyethylene in Russia, related to the production of semi-finished products, for example, mother sheets, then the codes will be as follows: 24.16. If, however, it is intended to produce packaging plastic products from foamed polyethylene, then the codes are as follows: 25.22. You must submit an application to the tax office, order the production of a stamp, after which you are allowed to purchase equipment, hire personnel, and rent premises. The production of foamed polyethylene for packaging will be much more profitable, since the final product is more expensive than semi-finished products, which are actually a type of raw material. When opening a company, you need to establish quality control.

• Subtleties of starting a business

Foamed polyethylene in industry

Foamed polyethylene (polyethylene foam) finds its application in many industries and construction. In the construction industry it is used as a good heat insulator; in furniture production it is used as packaging that protects items from abrasion and shock during transportation. Motorists use “foam” as a material for sound insulation. Homeowners use it as an underlay for parquet, laminate or linoleum.

Foamed polyethylene production technology

Polyethylene foam is made from high-density polyethylene (less commonly, low-density polyethylene). During the production process, fire extinguishing additives are added to the desired raw material, making the material resistant to fire. The production technology involves performing two main stages: melting polyethylene granules and combining the raw materials with liquefied gas, which is a good reagent. The gas forms the foamed structure of the future product. The production of polyethylene foam can take place using different foaming technologies:

• Non-crosslinked - extrusion + physical blowing agent (propane-butane, isobutane);
• Chemically cross-linked - mixing + azodicarbonamide, extrusion, forming and cross-linking with foaming under heat;
• Physically cross-linked - cross-linking by firing a stream of fast electrons and foaming.

Subtleties of starting a business

Consider the fact that the production of polyethylene foam is not a completely environmentally friendly process. Heating polyethylene to high temperatures involves the release of dangerous poisons that destroy the nervous system and cause cancer. No, the product itself turns out to be harmless, but its production... For this reason, it will not be possible to open a workshop in close proximity to the residential sector. The minimum distance is 500 m (or even more).

What equipment to choose for production

Some difficulties may arise with the selection of equipment. In our country there are almost no manufacturers of ready-made lines for the production of VP sheets. The only well-known manufacturer is Polyprom Kuznetsk LLC. Therefore, most likely, you will have to purchase either used. u. equipment (which suffers from frequent breakdowns), or purchase it in a new form from Chinese manufacturers. The approximate composition of the line includes: a raw material loader, an operator platform, a talc injection system, an extruder, a high-pressure pump, an anti-shrinkage unit, an extrusion head, an air ring with a blowing fan, a cooling element, a pulling device, a two-station winder, and a line control system. Estimated price of the line: from $150,000. The choice of equipment and technology for production also depends on what density of polyethylene is needed. Thus, the gas method is considered more expensive, while the chemical method is cheaper.

How much can you earn on foamed polyethylene?

Average productivity of modern lines: from 50 to 300 kg of finished products per hour or 400 to 2400 kg per shift. With a selling price of 40 rubles/kg. this means a monthly turnover of 352,000 - 2,112,000 rubles. There are still not many producers of “foam” in our country, while the demand is high. By opening such an enterprise, even with small capacities, you can count on a so-called monopoly in your region.

Step-by-step plan for opening a business for the production of foamed polyethylene

1. Analysis of the polyethylene market.
2. Renting premises.
3. Purchase of equipment.
4. Conducting an advertising campaign.
5. Organization of sales and waste disposal.

After organizational issues are completed, it is necessary to obtain permits issued by the local administration, SES, and environmental service. Also, at the initial stage of launching production, it is worth solving the problem of waste disposal: start the production of garbage bags or enter into an agreement with a company that uses such waste in its production.

How much money do you need to start a business?

• Registration of permits - from 5000 rubles.
• Technological line with machine settings - from 1.5 million rubles.
• Warehouse equipment - from 60,000 rubles.
• Raw materials - from 100,000 rubles.
• Other costs - more than 25,000 rubles.

To start a business you will need about 2 million rubles. Payback of activities occurs within 1-2 years.

Which OKVID should I indicate when registering?

• 22 - production of plastic products for packaging.
• 47 - sales of other consumer non-food products.

What documents are needed to register a business?

To register a business, you will need to legalize your activities as an LLC. To register a company, you must submit an application to the tax service, a photocopy of your passport, birth certificate, and a receipt for payment of state duty. Registration of an LLC occurs in the same way as an individual entrepreneur, but provides more opportunities for business development.

Which tax system to choose when registering?

To conduct business, different taxation systems can be used: simplified tax system, UTII, OSNO. Most often, novice businessmen use the simplified tax system, because the system allows the manufacturer to work in the most lenient tax conditions.

Do I need permission to open a production facility?

The production of foamed polyethylene is a harmful process. Therefore, when starting a business, you will need to obtain a certificate for the production of polyethylene and obtain permits. To successfully sell products, you will need to undergo certification for compliance with GOST 10354-82. There are also requirements for the room in which the film will be produced.

When describing polyethylene foam, regardless of the methods of its production, two definitions are used: “cross-linked” and “non-cross-linked”.

“Cross-linked” PPE is foamed polyethylene, during the production process of which the molecular structure is modified through various methods, and as a result of cross-linking, a so-called cross-linked or network molecular structure is formed. According to manufacturing technology, three types of “cross-linked” polyethylene foam are distinguished: radiation-cross-linked, chemically foamed (both materials are produced by extrusion) and material produced under pressure.

Non-crosslinked PPE is produced by extrusion using a physical blowing agent, which can be freon, propane-butane and isobutane gases. The main difference between this material and cross-linked material is that during its production the molecular structure of the polyethylene itself does not change.
The material obtained from polyethylene foam using a blowing agent is a good heat insulator, waterproofer, and noise absorber; products made from such materials are easy to bend and cut, and are also able to hold a given shape. The material is compatible with almost any building materials - wood, concrete, cement, gypsum, lime, etc.
An important positive property of polyethylene foam is that the material is chemically inert and environmentally friendly. Due to its structure, it has a low moisture absorption coefficient (less than 2%) and is resistant to rotting (the estimated service life of the material is 25 years).
The material is used primarily in construction, however, due to the above qualities, its consumers are enterprises in many other industries, in particular, mechanical engineering, automotive, medicine, the hardware and footwear industries, as well as industries where it is used as packaging.

There are various technologies for producing cross-linked PPE. Let's consider one of them.

The production process can be divided into 4 main steps:
- mixing
- extrusion
- stitching
- foaming

Mixing

raw materials

At this stage, the main components are mixed. These are polyethylene or polypropylene, a nitrogen-based foaming agent (nitrocarbonate), pigments, crosslinkers and various specific additives.

Extrusion

Extrusion is a generally accepted approach for producing products that are not finished (pipes, sheets, profiles, etc.).
The pre-mixed composition is poured into an extruder containing one or two screws. The mixed, heated under pressure substance exits the extruder already containing all the necessary components to carry out the transformation of the solid mass into a flexible foam by subsequent foaming processes.

Stitching
"Cross-linking" means changing the bonds between polymer chains. On the one hand, this improves the physical properties of the polymers themselves (for example, it imparts heat resistance), on the other hand, it becomes necessary to heat the polymer to a sufficient temperature to prevent the destruction of the material during expansion.

Physical "stitching"
Physical cross-linking is a method of obtaining a substance using the electron-radiation method, without the involvement of any chemical additives. The extruded substance is passed through an electronic processing system, where electronic influence is applied on both sides.

Foaming

Three types of foaming are used: horizontal, vertical and block. Let's look at each of these methods.

Horizontal foaming

Horizontal foaming is used in the production of many materials. In the case of chemically cross-linked materials, the polymer is cross-linked at the beginning of the foaming process; physically cross-linked - the material is pre-cross-linked, as described above.

As the oven temperature increases, bubbles form in the polymer matrix and the gas increases pressure, which converts the bubbles into a connected network of cells.

Vertical foaming

Vertical foaming is only used when the polymer has previously been physically cross-linked. After passing through the horizontal section, where the substance is preheated, it enters an almost “free” fall phase, where it foams as the temperature increases. After this, the sheet of foam is cooled and “rolled” into a roll.

Foam sheets coming out of a vertical oven

Block foaming

To produce blocks, a continuous foaming process is required. After passing through the extruder, the material is “cut” into sheets and manually inserted into formers where they are chemically cross-linked. The sheets are then placed under "foaming presses" where the final foaming step takes place.

Being one of the many modifications of polyethylene, light, thin and environmentally friendly polyethylene foam has become a part of our lives. Its production was established relatively recently - in the 70-80s. 20th century, but during its existence the material managed to prove itself well in everyday life and in industry. This unique product is distinguished by its outstanding chemical and physical properties, as well as its low cost, which makes its scope of application almost limitless.

Areas of application

The excellent characteristics of foamed polyethylene allow it to be used:

In the construction industry - for insulating roofs, walls, floors, foundations; ventilation, air conditioning and sewerage systems; door and glass seals; substrates for laminate; insulation of temporary housing, etc.

Automotive industry - for insulating the car interior, including in combination with non-woven materials.

In light industry - as an element of sporting goods and recreational items (backpacks, rugs, life jackets, protective accessories, etc.)

As protective packaging when transporting various goods.

For thermal insulation of industrial and domestic refrigeration equipment.

For the needs of the defense industry - as packaging for navigation equipment and ammunition, as well as heat and sound insulation of military equipment.

In the shipbuilding industry - as an insulating material for finishing cabins.

Thermal insulation made of polyethylene foam deserves high marks, because thanks to its low thermal conductivity coefficient (0.037 - 0.038 W/mK), the material is an effective insulation material. In addition, polyethylene foam is durable - its service life is about 80-100 years without loss of its original physical and chemical properties. The properties of the product include its high vapor barrier properties. The use of polyethylene is possible at temperatures from -80 to +100 °C

The emergence of safe polyethylene foam has made it possible in most cases to abandon the use of traditional thermal insulation materials, especially in Western countries. Having a closed-cell structure, the material has excellent heat, noise and waterproofing properties, is easy to bend and cut, retains its given shape, is resistant to aggressive building materials, and also does not support combustion and is non-toxic in fire conditions. In addition, polyethylene foam can be used in combination with other building materials - concrete, cement, wood, etc. Extruded polyethylene is also used for anti-corrosion protection of pipes.

Types of foamed polyethylene

Today there are three types of foamed polyethylene:

Chemically cross-linked, with a modified molecular structure. It is obtained using chemical reagents, which contribute to the formation of a network molecular structure.

Physically cross-linked polyethylene foam also has a modified cross-linked structure, but its production is associated with exposure to radiation.

Uncrosslinked (or gas-filled), which is mainly used for packaging. For its production, physical gas generators are used (freon, propane-butane and isobutane), and the main difference from its cross-linked “brother” is the preservation of the integrity of the molecular structure of the material.

Material production technology

To produce foamed polyethylene, processed high-density polyethylene is used, which is subjected to physical foaming or direct extrusion. The material production technology includes a number of stages:

At the first stage, granules of thermoplastic low-density polyethylene are fed into the hopper of injection molding equipment, where they are melted at a temperature exceeding the melting point of polyethylene - 115°C.

After the molten mass is formed, liquefied gas (carbon dioxide or nitrogen) is supplied to the chamber. It is the very foaming agent due to which the structure of the future product is formed. The creation of a gaseous environment is carried out in two ways: chemical or physical.

Thus, chemical gas generators are various substances that are capable of releasing gas under the influence of high temperature. Depending on the type of material used and the desired properties of the resulting polyethylene, their compounds can be very different. The use of chemical foaming agents is possible on standard equipment, and no special fire safety measures are required.

Physical gas formers are liquids with low boiling points - they release gas during evaporation. Despite the fact that from an economic point of view, the use of physical additives is more profitable, the process of producing foamed polyethylene becomes explosive and fire hazardous. This, in turn, requires strict adherence to preventive measures and the use of specialized equipment.

As a result of the continuous rotation of the hopper, the polymer mass acquires a homogeneous structure, including at the molecular level. The fluidity of the melt increases almost 2 times compared to the initial indicators, while the fluidity temperature decreases. Depending on the degree of pressure and temperature in the chamber, the size of the material cells changes.

The final stage of polyethylene production involves injecting a liquid mass into an injection mold and its subsequent cooling. This avoids shrinkage and possible deformation of the finished material when removed from the molds.

Polyethylene foam is most often produced with a one-sided or double-sided coating, which is used as foil, metallized film or lavsan. Polyethylene foil foam, which is commonly used for insulation, is also called reflective insulation.

The form of production of foamed polyethylene products can be very different - sheets, plates, films, threads, tubes, etc. The density of such products ranges from 5 to 800 kg/cub.m., and the cell size ranges from 0.05 to 15 mm.

As a rule, the production of foamed polyethylene is based on the use of polyethylene waste, which reduces the cost of the work process and at the same time avoids serious environmental problems. Of course, processing of secondary raw materials imposes a number of restrictions on its use. For example, if a material created as a result of primary processing can be used as packaging for various goods, then polyethylene, which has gone through several cycles of processing, can only be used as a covering garden film.