Recycling and recycling of polymer materials. Category “Recycled polymers” Use of secondary polymer in bfs technology

Removal, processing and disposal of waste from hazard classes 1 to 5

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In Russia, the level of production and consumption of polymer materials is relatively low when compared with other developed countries of the world. Polymer processing is carried out on only 30% of the total volume of material. This is very little, considering the total volume of waste of this type.

A little about polymer products

Almost half of all polymers come from packaging containers. This use of polymer materials is determined not only by the aesthetic appearance of the product, but also by the safety of the product in the packaging. Polymer waste is generated in significant quantities - about 3.3 million tons. Every year this number increases by about 5%.

The main types of polymer waste are represented by the following materials:

• Polyethylene materials – 34%
• PET – 20%
• Laminated paper – 17%
• PVC – 14%. Polystyrene – 8%
• Polypropylene – 7%

Disposal of the bulk of plastic involves burial in the soil or incineration. However, such methods are unacceptable from an environmental point of view. When materials are buried, soil poisoning occurs due to the presence of harmful substances in the composition. Also, when burned, toxic substances are released into the atmosphere, which all living things subsequently breathe.

The processing of polymer materials using new technologies is developing poorly for the following reasons:

1. The state lacks the necessary regulatory and technical conditions and production facilities for the creation of high-quality secondary raw materials. For this reason, secondary polymer raw materials created from waste are characterized by low quality.
2. The resulting products have low competitiveness.
3. High cost of recycling plastics - a price assessment for this activity showed that approximately 8 times more processing costs are required than for household waste.
4. Low level of collection and processing of such material due to the lack of economic conditions and legislative support.
5. Lack of information base regarding the issue of recycling and separate waste collection. Few people are aware that polymer recycling is an excellent alternative to oil in production.

Classification

There are 3 main types of polymer waste:

1. Technological – include two groups: removable and irremovable. The first type is represented by defective products, which are subsequently immediately processed into another product. The second type represents all kinds of waste during the production of polymers; they are also eliminated through recycling and the manufacture of new products.
2. Public waste is all waste related to people's daily lives that is usually thrown away with food waste. Introducing the habit of collecting garbage in separate bags and throwing it away separately could greatly facilitate the solution to the recycling problem.
3. Industrial consumption waste - this type contains secondary polymers, suitable for recycling due to the low level of contamination. These include all packaging products, bags, tires, etc. - all of this is written off due to deformation or failure. They are readily accepted by processing enterprises.

Chain of extraction and processing of recyclable materials

Extraction and processing of polymer waste is carried out according to the specified technological chain:

1. Organization of points that accept secondary polymer raw materials. At these points, primary sorting and pressing of raw materials are performed.
2. Collection of material from landfills, legally or illegally, by companies involved in the processing of secondary raw materials.
3. The release of raw materials to the market after preliminary sorting at special waste processing stations.
4. Processing companies purchase material from large shopping malls. Such recyclables are less contaminated and subject to minor sorting.
5. Collection of recyclable materials thanks to the implementation of a program necessary for separate waste collection. The program is being implemented at a low level due to the lack of citizen activity. People without a fixed place of residence carry out acts of vandalism, which involve breaking containers intended for separate waste collection.
6. Pre-processing of polymer waste.

Polymer processing begins in the processing plant. It consists of a number of actions:

• Performing rough sorting for mixed waste.
• Further grinding of recyclable materials.
• Perform separation of mixed waste.
• Washing.
• Drying.
• Granulation process.

Not all residents of the Russian Federation are aware of the benefits of recycling. Polymer materials will not only bring a small income if they are regularly handed over to recycling plants, but will also save the environment from hazardous substances released during the decomposition of polymer materials.

Equipment for processing polymer waste

The entire complex for processing the necessary raw materials includes:

1. Washing line.
2. Extruder.
3. Necessary conveyor belts.
4. Shredders – crush almost all types of polymer products and belong to the first stage.
5. Crusher - they are classified as the second stage of shredders and are used after using a shredder.
6. Mixers and dispensers.
7. Agglomerators.
8. Screen substitutes.
9. Granulation lines or granulators.
10. Post-processing machine for finished products.
11. Dryer.
12. Dosing device.
13. Refrigerators.
14. Press.
15. Sink.

Currently, the production of crushed polymer materials, so-called “flakes,” is especially important. For their production, a modern installation is used - a polymer crusher. Most entrepreneurs do not even think about purchasing processing equipment, considering this service to be expensive. However, in reality it pays for itself in about 2-3 years of use.

Recycling technology

The most common technology for processing polymer waste is extrusion. This method consists of continuously pressing molten raw materials through a special forming head. Using the output channel, the profile of the future product is determined.

Thanks to processing using this method, the following is obtained from recycled materials:

• Hoses.
• Pipes.
• Siding.
• Insulation for wires.
• Capillaries.
• Multi-layer moldings.

Through extrusion, polymer raw materials are recycled, as well as granulation. Polymer granulation makes it possible to effectively use secondary raw materials in various fields of human activity. Polymer waste contributes to the entry into the market of a large number of new products made through the recycling of recyclable materials. To carry out the extrusion process, special equipment is used - a screw extruder.

The technology for processing waste polymers is as follows:

• Melting of the polymer material in the extruder.
• Plasticization.
• Injection into the head.
• Exit through the forming head.

To process plastics in production, different types of extrusion equipment are used:

1. Screwless. The mass is pressed into the head using a specially shaped disk.
2. Disk. Used when it is necessary to achieve improved mixing of the constituent components of the mixture.
3. Combined extruders. The working device combines the screw and disk parts of the mechanism. Used to create products that require high accuracy geometric dimensions.

The use of waste polymer materials as secondary raw materials helps not only to reduce the volume of waste stored in landfills, but also to significantly reduce the amount of electricity consumed and petroleum products used to manufacture polymer products.

For effective solution On this issue, the authorities need to inform citizens about the benefits of separate waste collection and recycling of all types in order to further produce products necessary for various purposes, including household ones.

The penetration of polymer materials into a wide variety of applications, including our daily life, is now taken for granted throughout the world. And this despite the fact that their victorious march began relatively late - in the 1950s, when their production volumes were only about 1 million tons per year. However, with the growth of production and consumption of plastics, the problems of recycling used plastic products have gradually become more acute and have now become extremely urgent. This review discusses the experience of solving these problems in Europe, where Germany is leading in this regard.

Due to their many advantages (in particular, high strength, chemical resistance, the ability to be molded into any shape and any color, low density), they quickly penetrated into all areas of application, including construction, automotive, aerospace, packaging, household products, toys , medical and pharmaceutical products.

Already in 1989, polymer materials overtook such traditional materials as steel in terms of production volumes (we mean volumes, not weight). At that time, their annual production was about 100 million tons. In 2002, the production of polymer materials exceeded the level of 200 million tons, and now almost 300 million tons are produced annually throughout the world. If we consider the issue from a regional perspective, then Over the past decades, there has been a gradual shift in capacity for the production of polymer materials towards the East.

As a result, Asia has now become the most powerful region, where 44% of all world power is concentrated. Polyolefins, the most widely used group of plastics, account for 56% of total production; Polyvinyl chloride ranks second, followed by other traditional polymers such as polystyrene and polyethylene terephthalate (PET). Only 15% of all polymers produced are expensive materials for technical purposes used in special areas. According to forecasts of the European association of polymer producers PlasticsEurope (Brussels), the volume of production of polymeric materials per capita will continue to increase in the future at a rate of about 4% per year. Simultaneously with such success in the market, the volumes of used polymer materials and products increased. If in the period from the 1960s to the 1980s. Although the plastics industry may not have yet paid much attention to the issues of efficient recycling and reuse of used products, these issues later (especially after the German packaging regulation came into force in 1991) became an important topic. At that time, Germany took on the role of pioneer. It became the first country in which standards for the disposal and recycling of polymer waste were developed and implemented on the market. Currently, many other European countries have joined in solving this problem and have developed very successful concepts for the collection and recycling of polymers.

According to the PlasticsEurope association, in 2011, about 27 million tons of polymer materials were used in 27 EU countries, as well as Switzerland and Norway, of which 40% were for short-term use products and 60% for long-term use products. In the same year, about 25 million tons of used polymer materials were collected. Of these, 40% were landfilled, and 60% were sent for recycling. More than 60% of polymer waste came from waste packaging collection systems. In smaller quantities, post-consumer polymer products were sourced from the construction, automotive and electronics sectors.

Exemplary waste collection systems exist in nine European countries - Switzerland, Germany, Austria, Belgium, Sweden, Denmark, Norway, Holland and Luxembourg (listed in descending order). The share of collected used polymer products in these countries ranges from 92 to 99%. In addition, six of the nine countries listed provide the most high level recycling of this waste in Europe: according to this indicator (from 26% to 35% of the volume of collected waste), Norway, Sweden, Germany, Holland, Belgium and Austria are far ahead of other countries. The remaining amount of collected waste is subjected to energy recycling.

One cannot help but rejoice at the fact that over the past five years, not only the amount of waste collected, but also the share of waste recycled has significantly increased. Thanks to this, the volume of waste being disposed of has decreased. Despite this, the polymer materials recycling sector still has enormous potential for further development. To a large extent, this applies to countries with low levels of their recycling.

Experts critically consider the possibilities of energy recycling of polymer materials, namely their combustion, which many consider to be an appropriate way to recycle them. In Germany, 95% of all incinerators are waste recyclers and are therefore approved for energy recovery. Assessing this situation, Michael Scriba, commercial director of mtm plastics (Nidergebra), a company specializing in the processing of polymer materials, notes that from an environmental point of view, the energy recycling of waste is undoubtedly worse than the material one.

Within the plastics industry, recycling costs last years has become an important economic sector. Another important issue hindering the development of the recycling sector in Europe is the export of polymer waste, mainly to Far East. For this reason, there remains a relatively small amount of waste that can be reasonably recycled in Europe; This contributes to a significant increase in competition and higher costs.

Powerful industry supported by associations and companies

Since the 1990s. as initiators of intensification of recycling plastic waste In Germany, several companies and associations have come forward that have dedicated their activities specifically to these problems and are currently active on a European scale.

First of all, we are talking about the company Der Gruene Punkt – Duales System Deutschland GmbH (DSD) (Cologne), which was founded in 1990 as the first dual system and today is a leader in offering waste return systems. These include, along with household collection and recycling of commercial packaging, environmentally friendly and cost-effective recycling of plastic elements of electrical appliances and electronic equipment, as well as transport packaging, waste removal from enterprises and organizations, and cleaning of used containers.

In 1992, RIGK GmbH was founded in Wiesbaden, which, as a certified specialized company for servicing companies (bottling, distribution, trading and importing) that are the owners of trademarks, takes back used and cleared packaging from its German warehouses. partners and sends these packages for recycling.

An important player in the market is also the company BKV, which was founded in 1993 with the aim of ensuring guaranteed recycling of polymer packaging collected with dual systems. Currently, BKV serves as a kind of base platform for the recycling of polymer materials, dealing with the most significant and pressing problems in this area.

In 1993, another important association was founded - Bundesverband Sekundärrohstoffe und Entsorgung e. V. (bvse) (Bonn), whose origins are associated with the association Altpapierverband e. V. In the polymer materials sector, it provides German companies with professional and politically determined assistance in the collection and recycling of polymer waste. Along with the company BKV, which is part of the association GKV Gesamtverband Kunststoffverarbeitende Industrie e.V. (Bad Homburg), there are other associations and organizations involved in the recycling of polymer materials. These include, inter alia, tecpol Technologieentwicklungs GmbH, which specializes in environmentally efficient recycling of plastic waste, and the specialized compounding and recycling group at TecPart e. V., which is the base association of the GKV association. In 2002, leading German manufacturers of plastic profiles united into the initiative group Rewindo Fenster-RecyclingService GmbH (Bonn). The main goal was to increase the proportion of dismantled polymer windows, doors and roller shutters that are recycled (see photo at the title of the article), which would contribute to increasing the stability and degree of responsibility when carrying out economic activity.

It goes without saying that the large plastics recycling industry associations, which have their own working groups for plastics recycling and have successfully proven themselves in practice for decades, such as PlasticsEurope and IK Industrieverband Kunststoffverpackungen e, got involved in solving the problems. V. (Frankfurt).

Successful proven recycling technologies

Precise information on plastic recycling in Germany is provided by analysis results, which are published every two years on behalf of the VDMA member companies and associations - BKV, PlasticsEurope Deutschland e. V., bvse, Fachverband Kunststoff und Gummimaschinen, as well as the union IK. According to these data, in Germany in 2011, about 5 million tons of plastic waste were generated, the most most of(82%) of which are consumer waste. Of the remaining 18%, representing industrial waste, the proportion of recyclable materials can reach 90%. As has already been tested in practice, sorted industrial waste can be successfully subjected to in-plant recycling directly at the enterprises where it was generated (photo 1).

In the case of consumer waste, the share of material (that is, without incineration and landfill) recycling is only 30–35%. In this area, there are also already practical methods for recycling waste sorted by type. Examples include the experience of processing polyvinyl chloride (PVC) and PET. As a result of its 10 years of activity, Rewindo, using its own technology for recycling used PVC windows and doors, has gained a strong position in the market.

In recent years, the volume of recycled PVC produced from collected used products by companies specializing in this field Toensmeier Kunststoffe GmbH & Co. KG (Hechter) and Veka Umwelttechnik GmbH (Herselberg-Hainich) was maintained at a level of about 22 thousand tons with an increasing trend.

PET bottles are also collected and recycled after proper sorting. The range of new products made from recycled materials ranges from fibers and films to new bottles. Various companies, such as the Austrian companies Erema GmbH (Ansfelden), Starlinger & Co. GmbH (Vienna) and NGR GmbH (Feldkirchen) have created special production lines for PET recycling. Recently, the European Food Safety Authority EFSA published a positive opinion on the recoSTAR PET iV+ technology for the production of recycled PET suitable for food packaging (developed by Starlinger).

The EFSA opinion serves as the basis for certification of such technologies European Commission and member states of the European Union.

To achieve such a result, the interested company must prove that the technology and equipment it has developed for processing polymer waste reduces the degree of contamination of the corresponding PM to a level that is safe for human health.

The standard scenario of the so-called “challenge-test” for the efficiency of cleaning recycled PET, usually obtained from waste in the form of used bottles, involves the use of five control “pollutants” - toluene, chloroform, phenylcyclohexane, benzophenone and lindane, differing in chemical composition , molecular weight and, therefore, migration ability. The tests themselves are carried out in several stages.

First, the recycled PET flakes are washed, after which they are “contaminated” with a control substance with a given concentration (3 ppm) and washed again. Then these re-washed PET flakes are processed using the tested technology into PET regranulate and the residual concentration of the “polluting” medium is determined, from which the degree of purification of recycled PET is calculated. In conclusion, both indicators are compared with the maximum permissible values ​​for them and conclusions are drawn about the effectiveness of cleaning.

In addition to the standard tests, Starlinger independently decided to tighten up the test scenario by conducting them under so-called “worst-case” conditions for the material (Worst-Case-Szenario), in which PET flakes were processed that were not washed after they were contaminated with model environments. Previously, before each type of test - to ensure the purity of the experiment and stable conditions for its conduct - 80-100 kg of transparent virgin PET were processed on the recoSTAR PET 165 iV+ installation (photo 2) in order to clean the working parts of the installation from the remnants of the previous batch of material. The tested PET flakes were colored blue; therefore, the output from the same installation of PET regranulate is only of blue color testified that during the processing process there was no mixing of it with pure PET and the FIFO (first-in, first-out) principle was maintained. Test results using a standard scenario showed that the recoSTAR PET iV process cleans rPET so effectively that it is well above the EFSA threshold (see table). Even in the case of lindane (a non-volatile non-polar substance), the purification rate was more than 99.9%, although the threshold value is 89.67%. Almost the same results were shown by tests conducted according to the “tightened” scenario, with the exception of benzophenone and lindane. But even in these cases, the degree of PET purification met EFSA requirements. The abbreviated name of the company NGR stands for quite ambitiously - as “Next Generation Recycling Maschinen”. And having become 100% owner of BRITAS Recycling Anlagen GmbH (Hanau, Germany) in May of this year, NGR has significantly strengthened its position in the European and other regional markets of the world. The fact is that BRITAS is known as a developer and manufacturer of filter systems for melts of heavily contaminated polymer materials, including consumer packaging waste (photo 3).

In turn, NGR develops and produces equipment for the recycling of both industrial and consumer polymer waste, having an extensive market for its products.

Both engineering companies are confident in the positive synergistic effect of the merger. Gneuss Kunststofftechnik GmbH (Bad Oeynhausen) has reached the market great success thanks to its MRS extruder (photo 4), the use of which is even approved by the FDA (Food and Drug Administration) - the US Department of Commerce for Food, Drugs and Cosmetics. In addition, machine manufacturers offer various drying systems, such as the infrared rotary tube from Kreyenborg Plant Technology GmbH (Senden), as well as special filtration systems for PET recycling or crystallization technologies, such as the Crystall-Cut process from Automatik Plastics Machinery (Senden). Grosstheim). Closed loop systems such as the PETcycle system have been successfully used to make new bottles from used bottles.

Summarizing all of the above, it can be stated that the PET recycling system with an annual volume of about 1 million tons is successfully implemented in Europe. A similar situation is observed in the field of processing sorted polyolefin waste, the sorting of which is carried out without any special complications using appropriate separation technologies. In Germany alone, there are ten large and many small preparation plants specializing in the production of recycled granulate suitable for injection molding from household and industrial polyolefin waste. This granulate can be further used for the production of pallets, bathtubs, buckets, pipes and other types of products (photo 5).

Recycling Challenges

Additional challenges for recycling come from polymer products made from several different materials that cannot be separated from each other at a reasonable cost, as well as polymer packaging that cannot be completely emptied. Waste in the form of used consumer film is also problematic for recycling due to significant surface contamination, which requires significant processing costs.

According to Scribe, although there are experienced recycling experts in this area, there are no real markets of European importance. Additional complications also arise when handling the wide variety of PET bottles produced that are not intended for beverages; this significantly limits the volume of their recycling. To date, waste from the automotive and electronics industries has been difficult to recycle.

In such problematic cases, processors and machine builders require special technical solutions (photo 6). In particular, one such solution regarding the recycling of consumer film waste supplied by DSD was recently provided by Herbold Meckesheim GmbH to the waste management company WRZ-Hoerger GmbH & Co. KG (Sontheim). The turnkey production plant, consisting of a system for separating foreign substances, a wet grinding stage and a compaction device, makes it possible to process 7 thousand tons of waste annually into a bulk agglomerate with a high bulk density, suitable for the manufacture of products using injection molding technology (photo 7 ).

In general, the supply program of the Herbold Meckesheim company, which is also known on the Russian market, includes a variety of equipment for processing both heavily contaminated and mixed waste, both solid and hard-to-recycle soft plastic waste - washing plants and dryers, shredders, agglomerators, mills for fine grinding.

The main stated priorities in the development of equipment are its compactness, increased productivity and energy efficiency. At the K-2013 exhibition, the company will demonstrate a number of new products, including:

New mechanical dryer model HVT with a vertical rotor, saving production space, easy to maintain and consuming significantly less energy when drying PET flakes (photo 8);
shredder model SML SB with forced screw feed of waste into the cutting unit, which makes it possible to compact the supplied material and thereby increase processing productivity (Fig. 1);
a machine for grinding large-sized solid waste in the form of, for example, slabs or pipes, which are considered the most difficult objects to process. Especially for the processing of mixed fractions, Erema together with Coperion GmbH & Co. KG (Stuttgart) has developed a combined Corema plant for waste recycling and compounding (photo 9). Characteristic feature of this plant is its suitability for processing a wide range of materials. According to commercial director Erema company Manfred Hackl), we are talking here about an optimal solution for the processing of economically generated mixed waste, in particular for the production of a compound containing 20% ​​talc from waste polypropylene non-woven materials, or for the processing of waste in the form of a mixture of PE and PET with additives. Another successful example of several partners joining forces to solve recycling problems is the production line for the recycling of used agricultural films, the recycling of which is difficult and expensive due to their thinness, softness and contamination. The problem was solved by combining in one line a specially optimized grinder model Power Universo 2800 (manufactured by Lindner reSource) and an extrusion plant for recycling polymer materials model 1716 TVEplus manufactured by Erema), which made it possible to obtain high-quality regranulate.

Equipment that is universal in terms of the form of waste processed into regranulate (films, fibers, flakes of PET bottles, waste of foamed polymer materials) is offered by the Austrian company ARTEC Machinery. The impetus for further development and expansion of production capabilities was its 100% entry in 2010 into the “family” group GAW Technology, of which ECON is also a member, complementing the supply program with appropriate extrusion lines for processing crushed waste into regranulate. Due to the design and technological modernization of manufactured equipment over the years, it was possible to increase its productivity by an average of 25%. The modular principle that ARTEC professes when designing its installations allows, as if from cubes, to assemble and install equipment for a specific application, which is currently produced with a capacity of 150 to 1600 kg per hour (Fig. 2).

A specific extrusion plant with an MRS type extruder (see photo 4), designed for processing crushed waste from PA11 polyamide, was also supplied by Gneuss to the British company K2 Polymer.

The source material is obtained by crushing deep-sea oil pipelines, which become unnecessary after the source of oil dries up and must be recovered on land.

The MRS (Multi Rotation System) extruder allows, without the use of chemical cleaning, to provide one-stage purification and processing of these high-quality, but highly contaminated polymer wastes due to many years of contact with oil. This list could be supplemented with many other examples. In conclusion, the recycling sector has become an important area of ​​economic activity in recent years. Although many technologies have already been successfully tested in practice, there remains great potential for further development in the field of recycling. Solving existing problems must begin with the development and production of polymer products that are as recyclable as possible.

Certain opportunities for progress also remain in the development of optimized technological solutions and the creation of appropriate equipment for the processing of complex waste.

To a certain extent, progress in this area can also be facilitated by policy measures that should ensure the wider implementation of optimal waste collection and recycling concepts in each country.

New and proven solutions in the field of recycling of polymer materials will be widely presented from October 16 to 23, 2013 at the International Exhibition “K” in Dusseldorf.

Prepared by Ph.D. V. N. Mymrin
using press materials from the exhibition company Messe Duesseldorf
Recycling of Plastics in Europe:
New and Proven Solutions The penetration of plastics in a v ariety of
applications, including our daily lives, are now seen worldwide as a matter of course. And this
despite the fact that their winning streak started relatively late – 60 years ago, when their output
accounted for only about 1 million tons per year.

However, with the growth of production and consumption of plastics gradually sharpened
and has now become a critical problem disposing of used plastic products. Although many
processes hav e alr eady become established, recycling still has plenty of potential for
improvement. A first step could be the recyclable design of plastics items that should be examined
closely with a view to later r covery. Suitable recycling processes and machine solutions for the
processing of problematical wastes offer a good deal of scope for further dev elopment. This
review discusses the experience of solving these problems in Europe, wher e the leading in this
respect is Germany.

Thermoplastics are plastics that, once molded into a product, remain recyclable. They can repeatedly soften when heated and harden when cooled without losing their properties. This is precisely why huge interest to the recycling of thermoplastic waste - both domestic and industrial.

The composition of municipal solid waste (MSW) in the capital differs markedly from the Russian average. Every year about 110 thousand tons of solid household waste are generated in Moscow. Of these, 8-10% are polymer, and in commercial waste from large enterprises this figure reaches 25%.

Plastic bottles should be highlighted separately in the structure of solid waste. Every year in Moscow alone, about 50 thousand tons of them are thrown away. According to the results of the International scientific-practical conference“Packaging and the Environment”, 30% of all polymer waste consists of polyethylene and polyvinyl chloride bottles. However, at present, according to the State Unitary Enterprise Promotkhody, in Moscow and the region no more than 9 thousand tons of polymer waste separated from solid waste are processed annually. And half of them are in the Moscow region. What are the reasons for such little recycling of thermoplastic waste?

Organizing the collection

Today, several channels for collecting plastic waste are used.

The first and main one is the collection and removal of waste from large shopping complexes. These raw materials are predominantly used packaging and are considered the “cleanest” and best suited for further use.

The second way is selective garbage collection. In the southwest of Moscow, the city administration, together with the State Unitary Enterprise Promotkhody, is conducting such an experiment. Special German Euro containers have been installed in the courtyards of several residential buildings. Container lids with holes: round - for PET bottles, large slot - for paper. Containers are locked and constantly monitored. In two years, 12 tons of plastic bottles were collected. Today the project includes only 19 residential buildings. According to experts, when covering a territory with more than 1 million inhabitants, the benefits of such a system become obvious.

The third option is the sorting of solid waste at specialized enterprises (experimental industrial waste sorting center "Kotlyakovo", private enterprise MSK-1, other waste sorting complexes). It is still quite difficult to accurately determine the volume of sorted waste, but the share of this source of secondary raw materials is already noticeable. Some commercial organizations under the control of municipal authorities, they organize their own collection points for secondary raw materials (including polymer waste) from the population. Primary sorting and pressing usually take place there. However, there are very few such points in the city.

A significant share of secondary raw materials used for processing is collected illegally at landfills. This is done by private companies, and sometimes by the management of the landfills themselves. Collected and sorted materials are sold to resellers or directly to manufacturers.

When processing thermoplastics, the uniformity of the polymers used, the degree of contamination, color and type (film, bottles, scrap), and the form of the supplied waste (compressed, packaging, etc.) are very important. Depending on these and a number of other parameters, the degree of suitability of a particular batch for further processing (and, consequently, its market value) may vary significantly. Waste paper is the most expensive.

Sorting, crushing and compaction can be carried out by numerous intermediaries, waste sorting complexes, processors themselves, and structures of the State Unitary Enterprise "Industrial Waste".

In most cases, manual sorting is used, since the appropriate equipment is expensive and not always effective.

Polymer processing

Collected and sorted waste can be processed into secondary granulate or directly used for the production of new products (shopping bags and packages, disposable tableware, cases for video cassettes, country furniture, polymer pipes, wood-polymer boards, etc.).

Only NII PM OJSC is engaged in the processing of polymer household waste on an industrial scale in Moscow (production of products for the needs of the municipal economy as part of the program for separate waste collection in the South-Western Autonomous District and by order of the capital's mayor's office). State Unitary Enterprise "Promotkhody" carries out crushing, washing and drying, then the flakes at a price of $400 per ton are transported for further processing to the Research Institute of PM.

Other processors of secondary raw materials are either too small (capacity up to 20 tons per month), or under the guise of processing they are engaged in crushing and further resale; at best, they add crushed raw materials to their products. Almost no one is engaged in large-scale production of secondary granulate and agglomerate in Moscow.

According to other information (N.M. Chalaya, NPO "Plastik"), many small companies are engaged in processing polymers contained in Moscow waste, for which this activity is not their main activity. They try not to advertise it, since it is generally accepted that the use of recyclable materials in the production of products worsens its quality.

A typical company for this market is the Vtorpolymer production cooperative, which works directly with the city landfill. The homeless people who live at the landfill collect everything plastic there: bottles, toys, broken buckets, film, etc. For a certain fee, the “product” is handed over to intermediaries, and they deliver it to Vtorpolymer. Here, worn-out items are washed and sent for recycling. They are sorted by color, crushed and added to plastic, which is used to make installation pipes (they are used in the construction of new houses to insulate electrical wiring). The purchase price of dirty plastic scrap is 1 thousand rubles. per ton, clean - 1.5 thousand. Smaller lots are accepted at prices of 1 and 1.5 rubles. per-kg respectively.

Sorting of polymer waste is carried out manually. The main selection criterion is appearance products or corresponding markings. Without markings, packaging made of polystyrene, polyvinyl chloride or polypropylene cannot be visually distinguished. Bottles are most often considered PET, film - polyethylene (the specific type of PE is usually not determined), although it may well turn out to be PP or PVC. Linoleum is mainly PVC, foamed polystyrene (foam) is easily identified visually, nylon fibers and technical products (spools, bushings) are usually made of polyamide. The probability of matches with this sorting is about 80%.

An analysis of the activities of companies operating in the secondary materials market allows us to draw the following conclusions:

1) prices of recycled materials on the market are determined by the degree of their preparation for processing. If we take the cost of primary low-density polyethylene granulate as 100%, then the price of pure crushed polyethylene film prepared for processing ranges from 8 to 13% of the cost of the primary polymer. The price of polyethylene agglomerate is from 20 to 30% of the cost of the primary polymer;

2) the price of most granular secondary polymers, averaged by composition, ranges from 45 to 70% of the price of primary polymers;

3) the price of secondary polymers strongly depends on their color, that is, on the quality of preliminary sorting of polymer waste by color. The difference in the price of secondary polymers of pure and mixed colors can reach 10-20%;

4) prices for products made from primary and secondary polymers are, as a rule, almost the same, which makes the use of secondary polymers in production extremely profitable.

On average, the price of polymer waste separated from solid waste, depending on the degree of preparedness, batch and type, ranges from 1 to 8 rubles/kg. Purchase prices from processors depending on the batch and level of contamination are shown in Table 1.

The price of clean MSW waste is usually equal to the price of industrial and commercial waste.

The market price for the purchase by a processor of polymer waste from solid waste consists of the price of purchase by an intermediary from the population (approximately 25% of the cost), fees for the formation of large-scale batches of waste, sorting, pressing and even washing for the most expensive (clean) raw materials.

Prices for products such as agglomerate and granulate average 12-24 rubles/kg (polyamide is more expensive than others - 35-50 rubles/kg, PET - from 20 rubles/kg). Further processing increases the added value depending on the type of product by 30-200 %.

Investment attractiveness

According to most experts, investing in the processing of polymer waste is profitable, but only if supported by government support and legislative framework, focused on the interests of processors of secondary raw materials.

Today, the Moscow market consists of 20-30 small companies engaged in processing polymer waste, mainly of industrial origin. The market as a whole is characterized by informal connections between processors and suppliers, a large share of companies for which this business is a side business, as well as low processing volumes (12-17 thousand tons per year). It can be assumed that if there is a stable demand for such waste from processors, the supply volumes will increase.

It should be noted that the amount of polymer waste that is actually recycled today constitutes a very small part of urban solid waste. And this despite the fact that the demand for polymers and products made from them is constantly increasing, and the problem of waste disposal is increasingly worrying city authorities.

A limiting factor in the construction of new processing plants is the underdevelopment of the waste collection system and the lack of serious suppliers. The coincidence of interests of private business and the state in this area should inevitably lead to the adoption of laws that meet the interests of recyclers.

Present and future

1. The annual volume of PET processing in the capital is 4-5 thousand tons per year. The plans of the Moscow authorities include the organization of a system by 2003 selective collection PET containers and the creation of two production complexes for its processing with a capacity of 3 thousand tons per year. Currently, the construction of two private PET processing plants with a total capacity of six thousand tons annually is being completed.

In the coming months, the Moscow government should adopt regulations regulating the activities of polymer processors (their exact content is not yet known). Existing and under construction capacities are sufficient to meet market needs. The possibility of state support for the projects of the State Unitary Enterprise "Promotkhody" and the company "Inteko" (potential processing capacity - 7-8 thousand tons per year) is being considered.

2. The volume of PP recycling in Moscow is 4-5 thousand tons per year, although about 50-60 thousand tons are thrown away annually in the city - mainly film and big bags. After processing, PP in the form of granules is added to primary raw materials or is entirely used for the production of plastic dishes, shopping bags, etc.).

The absence of large-scale projects for the recycling of this polymer (as is the case with PET) opens up wide opportunities for investment. The most profitable at this stage is the processing of recyclable materials into granulate, since in the field of production of consumer goods the competition is much tougher.

3. The volume of PE processing is also 4-5 thousand tons per year. The main type of raw material is film, including agricultural film. In total, about 60-70 thousand tons of polyethylene waste are thrown out in the city every year. As a rule, enterprises processing PE also deal with PP. One of large companies, through which about 2.5 thousand tons per year pass - “Plastpoliten”.

PE is characterized by high resistance to pollution. However, the existing ban on the use of recycled polymer raw materials in the manufacture of food packaging limits the possibility of sales.

Thus, the most rational option today seems to be the construction of an industrial complex for processing waste polyethylene, polypropylene and PET into granulate.

This production must include:

a) sorting (requires special training of personnel to reduce the proportion of another type of polymer, which is very important for the quality of the product);

b) washing (the largest potential volumes of raw materials are usually not sorted and washed);

c) drying, crushing, agglomeration.

It is economically most profitable to locate this complex in the near Moscow region, since prices for electricity, water, rent of land and industrial space there are significantly lower than in the capital (see Table 2).

For such production to operate effectively, government support is required. It may make sense to partially revise the existing sanitary standards for the processing of solid waste, as well as oblige manufacturers of polymer products to make contributions for the processing of polymer waste. In addition, comprehensive measures should be taken at the level of the Moscow government and individual housing and communal services aimed at developing a selective collection system and creating a network of collection points for recyclable materials.

The state's increased interest in waste disposal is already reflected in the budget: from 2002 to 2010. It is planned to spend 519.2 million rubles for these purposes. from the federal budget. The budgets of the federal subjects are expected to be allocated until 2010. 11.4 billion rubles. for the implementation of the “Diversions” program.

In 2001, Moscow spent on security environment 3.1 billion rubles To date, the cost of already implemented projects for processing household waste is 115.5 million rubles.

Andrey Golinei,

Introduction

Recycling of homogeneous polymers is a relatively simple task if their structure is preserved and there has been no significant destruction either during manufacture or during primary use (see, for example,). Of course, the process of destruction, which may result in structural and morphological changes caused by a decrease in molecular weight, the formation of branches, other chemical groups etc., leads to a significant deterioration of all physical properties. While recycled materials that retain their properties can be used in the same applications as virgin polymers, recycled materials with reduced properties can only be used in specific applications. Therefore, when mechanically recycling homogeneous polymers, the challenge is to avoid further destruction during the technological process, that is, to avoid deterioration of the properties of the final material. This can be achieved the right choice processing equipment, processing conditions (see Chapters 4 and 8) and the introduction of stabilizers (see Chapters 3 and 7).

In this chapter we will consider the relationship of the properties of homogeneous polymers with the conditions of their processing (in the order in which the properties of polymers change with increasing number of processing steps), as well as with the type of machines used; In addition, we study the dependence of properties on the initial structure.

Recycling of polyolefins and polyvinyl chloride

Introduction

Mechanical recycling of polyolefins constitutes a very important area of ​​the recycling industry. Of course, the main share here comes from raw polyolefins and, accordingly, a huge number of polyolefin products are produced, and the relative ease of their collection makes for simple and economical recycling. As with other polymers, the final properties and economic value of polyolefins depend on the degree of degradation during primary use and on the conditions of recycling. In addition, the chemical structure of polyolefins is very important in determining the properties of the recycled polymer.

Polyethylenes

The different structural types of commercial polyethylenes (PEs) greatly influence the recycling behavior of these materials. Of course, branching (short or long chains) affects the kinetics of destruction, and then the final properties of the recycled material, which has undergone several stages of processing. This behavior has special meaning for those plastics that are subject not only to thermomechanical destruction during processing, but also to other destructive influences during further use. Photo-oxidation and other types of destruction cause various structural and morphological changes, depending on the structure of the PE.

Recycling of PE is discussed in several monographs and in many articles.

The relationship between properties/processing stages will be considered both using the example of various types of commercial PE, and various types of destruction that the material experiences during its use.

High Density Polyethylene

The main sources of recovered high-density polyethylene (HDPE) are liquid containers and packaging film; In addition, the volume of recycling of automotive fuel containers is growing. In all cases, the molecular weight of these used HDPE products remains very high because the degradation experienced by this type of material in short-term use is very small. The latter circumstance assumes that the properties of the recycled material are close to those of the original polymer. In table Figure 5.1 compares HDPE samples obtained from recycled bottles and from virgin polymer. It is clearly seen that most of the properties are very close. As noted above, this is a result of the bottles being used for a short period of time and not undergoing significant degradation, although some structural change may have occurred during recycling; this is indicated by the expansion of the molecular weight distribution. In addition, the elastic modulus and elongation at break differ significantly, and the recycled material has slightly higher tensile strength.

These differences may result from subtle changes in structure and morphology. In particular, when processing PE melts, both chain scission (with a decrease in molecular weight) and branching (increase in molecular weight) can occur, against the background of which cross-linking reactions are difficult to determine from molecular weight measurements, and they can change the final properties recycled material.

Recycled polymers go through at least two to three recycling cycles, and in each cycle, melting causes additional degradation of the material. In addition, the increase in recycled polymers and the use of recycled and virgin material blends (see Chapter 6) means that a significant proportion of recovered plastics is recycled again and again. This means that the properties of such repeatedly recycled polymer materials are constantly changing with increasing number of processing cycles in the direction of their deterioration. For example, in table. Figure 5.2 shows the changes in some properties of a HDPE sample (fuel canister) after 15 cycles of injection molding recycling.

It is clearly seen that the changes in mechanical properties are relatively small, although the melt flow rate decreases significantly. The latter circumstance can be explained by the strong dependence of viscosity on molecular weight and this means that the workability of the material has changed significantly.

The result clearly shows that the properties of recovered HDPE depend not only on the properties of the recycled products, but also on the nature and number of recycling cycles. In addition, both the properties of the melts, which determine the processability of the polymer, and the properties of the solid material are influenced to some extent by recycling

Thus, it is necessary to know the relationship between properties and recycling cycles in order to be able to predict to some extent the likely characteristics of recycled plastics and therefore determine the applications available for these materials. Of course, the final properties will depend not only on the number of processing cycles, but also on the properties of the recovered materials, the nature of the processing and its conditions.

In Fig. Figure 5.1 shows the flow curves of a HDPE sample (canister). The data refers to samples that have gone through several processing cycles on a single-screw extruder. Viscosity decreases with increasing number of recycling cycles over the entire shear rate range. This means that during repeated extrusions, thermomechanical stresses acting on the melt cause a certain destruction of the polymer. This simple circuit, however, it is in conflict with what was observed for the same sample passing through a twin-screw extruder (Fig. 5.2). In this case, the situation is much more complicated, since a small decrease in viscosity occurs only at high shear rates, and at low rates the effect is reversed. Thermomechanical stress causes both chain scission and molecular growth, mainly due to the formation of long side branches and stitching The final molecular structure depends on the relative contribution of these two processes. In particular, increasing the processing temperature and time (on a single screw extruder) favors chain breaking, resulting in a reduced viscosity of the final melt. In addition, the nature of the competition between the two mechanisms may change with excess oxygen during processing or depending on the specific molecular structure of the HDPE sample. For example, it has been shown that high

the content of vinyl groups leads to a significant increase in melt viscosity - a decrease in molecular weight - and long-chain branching. Vlachopoulos et al. found that chain scission dominates in copolymers (as evidenced by chain branching), while cross-linking is the main degradation mechanism in homopolymers. The increase in extrusion pressure as the number of processing cycles increases for the last sample, and the decrease in the copolymer sample, occurs due to the increase and decrease in molecular weight, which is confirmed by these mechanisms. This means that it is very difficult to predict changes in the structure of recovered HDPE and therefore its rheological and mechanical properties, since this material consists of copolymer and homopolymer polymers. In addition, homopolymers may contain varying numbers of vinyl groups. The extrusion quality of the bottle recovery material tested in the same work was indeed independent of the extruder passes, indicating that both mechanisms play the same role and that the recovered material is, as already assumed, a mixture HDPE copolymer and homopolymer.

The data presented shows that the type of recycling machines and processing conditions significantly, and sometimes decisively, influence the final properties of the recycled material - in this case the HDPE sample. As an example in Fig. Figures 5.3 and 5.4 show modulus and elongation at break as a function of the number of passes through the extruder. The mechanical properties of the two samples changed completely differently.

The elastic modulus curve increases with the number of processing steps, while the elongation at break behavior shows the opposite trend. Moreover, the modulus curve of the sample processed in a single-screw extruder is higher than that of the sample extruded in a twin-screw extruder, but its elongation at break is lower. The unexpected behavior of the dependence of the modulus on the number of processing cycles was explained by an increase in crystallinity with a decrease in molecular weight. The same reason that causes a decrease in molecular weight causes a decrease in elongation at break. A more pronounced increase in modulus and a decrease in elongation at break of the sample processed on a single-screw extruder reflects the fact of more significant destruction of the melt in this machine. This is mainly due to longer processing times.

The influence of the structure on the mechanical properties of recycled HDPE becomes clearer if you look at the values ​​of crack resistance under external stress given in Table. 5.3. Data refer to homopolymer, copolymer and post-consumer samples after 0 and 4 passes through a single screw extruder.

Two initial samples demonstrate deterioration in crack resistance under external stress, but the drop in properties of the copolymer after repeated recycling is catastrophic. The crack resistance value of the recovered material after four passes through the extruder decreases by

20%, although it consists mainly of copolymer. The significant change in the crack resistance of the copolymer appears to be balanced by an improvement in the behavior of the homopolymer fraction.

The data presented clearly shows the influence of the structure of HDPE and the nature of the processing equipment on the final properties of the recycled polymer.

The main uses of recycled HDPE are in the manufacture of liquid containers (including multi-layer bottles with recycled HDPE linings), drainage pipes, granules and films for bags and trash bags.

11.08.2015 16:09

Waste classification

Waste is generated during the processing of polymers and the manufacture of products from them - this is technological waste, partially returned to the process. What remains after using plastic products - various films (greenhouse, construction, etc.), containers, household and large-scale packaging - is household and industrial waste.

Technological waste is subjected to thermal effects in the melt, and then during crushing and agglomeration - also to intense mechanical stress. In the polymer mass, processes of thermal and mechanical destruction occur intensively with the loss of a number of physical and mechanical properties and, with repeated processing, can negatively affect the properties of the product. So, when returning to the main process, as usual, 10-30 percent secondary waste, a noticeable amount of material goes through up to 5 cycles of extrusion and crushing.

Household and industrial waste is not only processed several times at high temperatures, but is also exposed to prolonged exposure to direct sunlight, oxygen and air moisture. Greenhouse films can also come into contact with toxic chemicals, pesticides, and iron ions, which contribute to the destruction of the polymer. As a result, a large number of active compounds accumulate in the polymer mass, accelerating the decomposition of polymer chains. Approach to recycling such various waste accordingly, it should be different, taking into account the history of the polymer. But first, let's look at ways to reduce the volume of waste generated.

Reducing the amount of process waste

The amount of process waste, primarily start-up waste, can be reduced by using thermal stabilizers before stopping the extruder or injection molding unit, in the form of a so-called stop concentrate, which many people forget or neglect. When equipment stops for simple material in the extruder or injection molding machine cylinder, it is quite for a long time is under the influence high temperature when cooling and then heating the cylinder. During this time, the processes of crosslinking, decomposition and burning of the polymer actively occur in the cylinder, products accumulate, which, after start-up, come out for a long time in the form of gels and colored inclusions (burnt marks). Thermal stabilizers prevent these processes, thereby facilitating and speeding up cleaning of equipment after startup. To do this, before stopping, 1-2 percent of stop concentrate is injected into the machine cylinder for 15-45 minutes. before stopping at the rate of displacement of 5-7 cylinder volumes.

Processing (extrusion) additives, which increase the manufacturability of the process, can also reduce the amount of waste. By their nature, these additives, for example, Dynamar from Dyneon, Viton from DuPont, are derivatives of fluororubbers. They are poorly compatible with basic polymers and in places of greatest shear forces (dies, sprues, etc.) they are deposited from the melt onto the metal surface, creating on it a wall lubricating layer along which the melt slides during molding. The use of a processing additive in the smallest quantities (400-600 ppm) makes it possible to solve numerous technological problems - reduce torque and pressure on the extruder head, increase productivity while reducing energy costs, eliminate defects in appearance and reduce the extrusion temperature of polymers and compositions that are sensitive to high temperatures. temperatures, increase the smoothness of products, produce thinner films. When producing large-sized or thin-walled injection molded products with complex shapes, the use of an additive can improve flowability, remove surface defects, weld lines and improve the appearance of the product. All this in itself reduces the marriage rate, i.e. amount of waste. In addition, the processing additive reduces the adhesion of carbon deposits on the die, fouling of the gates, and has a washing effect, i.e. reduces the number of stops to clean equipment, which means the amount of startup waste.

The use of cleaning concentrates has an additional effect. They are used when cleaning casting and film equipment for rapid transition from color to color without stopping, most often in a 1:1-1:3 ratio with the polymer. This reduces the amount of waste and time spent changing colors. The composition of cleaning concentrates produced by many domestic (including Klinol, Cleanstair from NPF Bars-2, Lastik from Stalker LLC) and foreign manufacturers (for example, Shulman - Polyklin "), usually include soft mineral fillers and surfactant detergent additives.

Reducing the amount of household and industrial waste.

There are various ways to reduce the amount of waste by increasing the service life of products, primarily films, through the use of thermal and light-stabilizing additives. By extending the service life of the greenhouse film from 1 to 3 seasons, the amount of waste to be disposed of is correspondingly reduced. To do this, it is enough to introduce small amounts of light stabilizers into the film, no more than half a percent. The costs of stabilization are low, but the effect when recycling films is significant.

The opposite way is to accelerate the decomposition of polymers by creating photo- and biodegradable materials that quickly degrade after use under the influence of sun rays and microorganisms. To obtain photodegradable films, comonomers with functional groups that promote photodestruction (vinyl ketones, carbon monoxide) are introduced into the polymer chain, or photocatalysts are introduced into the polymer as active fillers that promote the rupture of the polymer chain under the influence of sunlight. Dithiocarbamates, peroxides or oxides of transition metals (iron, nickel, cobalt, copper) are used as catalysts. The Institute of Water Chemistry of the National Academy of Sciences of Ukraine (V.N. Mishchenko) has developed experimental methods for the formation of nanosized cluster structures containing metal and oxide particles on the surface of titanium dioxide particles. The rate of film decomposition increases 10 times - from 100 to 8-10 hours.

The main directions for obtaining biodegradable polymers:

synthesis of polyesters based on hydroxycarbonic (lactic, butyric) or dicarboxylic acids, but so far they are much more expensive than traditional plastics;

plastics based on reproducible natural polymers (starch, cellulose, chitosan, protein), the raw material base of such polymers is, one might say, unlimited, but the technology and properties of the resulting polymers have not yet reached the level of basic large-scale polymers;

imparting biodegradability to industrial polymers (polyolefins primarily, as well as PET) by compounding.

The first two areas require large capital expenditures for the creation of new production facilities; the processing of such polymers will also require significant changes in technology. The simplest way is compounding. Biodegradable polymers are obtained by introducing biologically active fillers (starch, cellulose, wood flour) into the matrix. So, back in the 80s, V.I. Skripachev and V.I. Kuznetsov from ONPO Plastpolymer developed starch-filled films with accelerated aging. Unfortunately, the relevance of such material was purely theoretical at that time, and even now it is not widely used.

Recycling

You can give the polymer a second life with the help of special complex concentrates - recyclizers. Since the polymer undergoes thermal destruction at each stage of processing, photo-oxidative destruction during the operation of the product, mechanical destruction during grinding and agglomeration of waste, destruction products accumulate in the mass of the material, and contains a large number of active radicals, peroxide and carbonyl compounds that promote further decomposition and cross-linking of polymer chains. Therefore, the composition of such concentrates includes primary and secondary antioxidants, heat and light stabilizers of the phenolic and amine type, as well as phosphites or phosphonites that neutralize active radicals accumulated in the polymer and decompose peroxide compounds, as well as plasticizing and combining additives that improve the physical and mechanical properties properties of the secondary material and bring them more or less close to the level of the primary polymer.

Complex additives from Siba. The Siba company, Switzerland, offers a family of complex stabilizers for the processing of various polymers - high-density polyethylene, HDPE, PP: Recyclostab and Recyclossorb. They are tableted mixtures of various photo- and thermal stabilizers with a wide range of melting temperatures (50-180°C), suitable for introduction into processing equipment. The nature of the additives in Recyclostab is common for polymer processing - phenolic stabilizers, phosphites and processing stabilizers. The difference lies in the ratio of components and in the selection of the optimal composition in accordance with the specific task. "Recyclosorb" is used when important role light stabilization plays a role, i.e. The resulting products are used outdoors. In this case, the proportion of light stabilizers is increased. The company's recommended input levels are 0.2-0.4 percent.

"Recyclostab 421" is specially designed for processing and thermal stabilization of waste LDPE films and mixtures with a high content of LDPE.

"Recyclostab 451" is designed for processing and thermal stabilization of waste PP and mixtures with high content.

Recyclostab 811 and Recyclossorb 550 are used to extend the life of recycled products exposed to sunlight, so they contain more light stabilizers.

Stabilizers are used in the production of injection molded or film products from recycled polymers: boxes, pallets, containers, pipes, films for non-critical purposes. They are produced in granular, non-dusting form, without a polymer base, pressed granules with a melting limit of 50-180°C.

Complex concentrates from the company "Bars-2". To process secondary polymers, NPF Bars-2 produces complex polymer-based concentrates containing, in addition to stabilizers, also combining and plasticizing additives. Complex concentrates "Revtol" - for polyolefins or "Revten" - for impact-resistant polystyrene, are introduced in an amount of 2-3 percent when processing recycled plastics and, thanks to a set of special additives, prevent thermal-oxidative aging of secondary polymers. Concentrates facilitate their processing due to improved rheological characteristics of the melt (increased MFR), increase the strength characteristics of finished products (their ductility and resistance to cracking) compared to products made without their use, facilitate their processing as a result of increasing the manufacturability of the material (reduced torque and drive load). When processing mixtures of secondary polymers, “Revtol” or “Revten” improves their compatibility, so the physical and mechanical properties of the resulting products also increase. The use of Revten makes it possible to increase the properties of secondary UPM to the level of 80-90 percent of the properties of the original polystyrene, preventing the appearance of defects.

Nowadays, the development of a complex concentrate for processing recycled PET is very relevant. The main problem here is yellowing of the material, accumulation of acetaldehyde, and a decrease in melt viscosity. There are known additives from Western companies - Siby, Clarianta, which help overcome yellowing and improve the processability of the polymer. However, in the West and here we have a different approach to the use of recycled PET. If 90 percent of it is used to produce polyester fibers or technical products and additives for this purpose are well developed, our processors strive to return recycled PET to the main process - producing preforms and bottles using casting and blowing methods or producing films and sheets using flat-slit extrusion. In this case, the target properties of the polymer that need to be influenced are somewhat different - manufacturability, moldability, transparency, and the formulation of complex additives must meet the goal.