Extrusion of plastics

FIELD: process engineering.

SUBSTANCE: invention relates to extrusion of plastics. In compliance with this method, auger elements are used for multiple shaft auger machines with auger shafts running in pairs in one direction and cleaning each other in pairs by scraping. Said shafts feature two (or more) auger strokes with preset axle base and OD.

EFFECT: higher quality of extrusion.

17 cl, 13 dwg, 1 tbl, 4 ex

The invention concerns a method for the extrusion of plastic materials, in particular polymer melts and mixtures of such melts, first of all thermoplastics and elastomers, particularly preferably polycarbonate and mixtures of polycarbonates with outcrosses of other substances, such as solids, liquids, gases, or other polymers, or other mixtures of polymers with improved external properties using a multi-shaft extruder with special geometrical parameters of the augers.

Extrusion is a well - known process used in the manufacture, preparation and processing of polymers. Under the mean extrusion processing of the substance or mixture of substances in a twin-screw or multi-shaft extruder rotating in the same direction, which is described in detail in [1] ([1]: Kohlgrüber. Der gleichläufige Doppelschneckenextruder, HanserVerlag, München, 2007).

Actions with the plastic mass during extrusion include one or more of the following operations: move (transportation), melting, dispersing, mixing, extrusion liquid components, degassing and pressure increase.

In the manufacture of polymer extrusion is used, for example, for the removal of polymer volatile components such as residual monomers or solvent ([1], str-212), for carrying out reactions polyaddition and polycondensation, as well as the need for houses is Alenia and the packing of the polymers and, perhaps mixing the additives with the polymer.

In the preparation of polymers using extrusion is made primarily of a mixture of polymers with additives or additives or reinforcing substances and dyes, and in addition, mixtures of different polymers, which differ from each other, for example, by chemical composition, molecular weight or structure of the molecules (see, for example, [1] p.59-93). This method, also known as compounding, is to prepare for the production of finished plastic molding material (compound) with the use of plastic raw material, which is usually plastificator, adding and mixing with the polymer fillers and/or reinforcing agents, softeners, amplifiers clutch means to facilitate sliding, stabilizers, dyes, etc. Preparation often includes the removal of volatile components, such as air and water. Preparation can also include a chemical reaction, such as vaccination, modified functional groups or modification of molecular weight through targeted its increase or decrease.

As is widely known and described, for example, in [1], pages 169-190, the mixture can be divided into distributive and dispersive mixing. Under the distribution (distribution) mixing implies uniform R is Opredelenie various components in a given volume. Distributive mixing occurs, for example, by mixing a homogeneous polymers. When dispersive mixing first distribute the solid particles, liquid droplets or gas bubbles. In the distribution, you must make considerable efforts shift to overcome, for example, the surface tension at the interface between the molten polymer and the additive. Under mixing below always refers to a distributive and dispersive mixing.

In the publication [1], starting on page 73, describes the movement of the melt and the pressure increases. Zone transportation of the melt are designed to move product from one working area to another, and also to enter into it the fillers. Zone transportation melt filled, as a rule, in part, as, for example, during transportation of the product from one working area to another due to degassing, as well as in the areas of exposure.

When processing polymers latter is usually translated in the form of prefabricated, ready-to-use product or part. Processing can be performed, for example, methods of injection molding, extrusion, blow film extrusion film or molded fiber. When processing is also possible, mixing of polymers with fillers and additives and additives as well as chemical modification, such as, for example, vulcanization.

Double-shaft or if you need multi-shaft machine with phase rotation, the rotors of which are mutually cleaned each other exact scraping, has been known (German patent DE 862668). In the manufacture, preparation and processing of polymers screw machines, which are based on the principle of profiles with exact gearing and cleaned by scraping, find a wide variety of applications. Such screw machines have, as you know, high efficiency mixing, high efficiency degassing and melt the polymer. Advantages as produced with the help of these machines products due to the fact that the polymer melts stick to surfaces, and ambient temperature processing they eventually decompose, which prevents self-cleaning screw-scraping. The rules for generating screw profile with precise cleaning by scraping shown, for example, in the book Klemens Kohlgrüber. Der gleichläufige Doppelschneckenextruder, Hanser Verlag, München, 2007, S.96 ff [1]. It describes the design of single, two and three profiles.

The specialist is known that in the region of the crests of the screw is subjected to dissipation in the melt a particularly large amount of energy, which leads to strong local overheating of the product is the same. It is presented for example in [1], starting with str. This local overheating can damage the product, for example, can change its smell, color, chemical composition or molecular weight or may cause a violation of homogeneity, for example, gel-like inclusions or crapin. Especially harmful in the high inclination of the helical line.

Modern twin-screw extruders is built on a modular principle, in which the main shaft can be worn various screw elements. This specialist can set twin screw extruder at a specific process with a specific task. As a rule, currently using screw elements with two-way or three-way profiles, because due to the large angle of the helix energopotreblenie when using a single screw profile is very high.

In prior art [1] (see, for example, p.101) the geometrical characteristics of screw elements with precise cleaning by scraping asked, indicating the following independent variables: the number of turns of Z, the distance between the axis and the diameter corresponds to the diameter of the contour precision cleaning by scraping DE). The number of turns is the number of arcs of a circle each item that cleans the outer wall. The angle of such a circular arc relative to the center of rotation is called the angular the inclination of the helical line (hereinafter also referred to as "the angle of the ridge") KWO. The outer radius of the profile in the angle of the ridge is equal to the radius of the housing. At the present technical level, the KWO is not a value variable depending on the task, as determined by equation 1 (Ur)

$$KW0=\frac{\pi }{Z}-2\arccos \left(\frac{A}{DE}\right)(Yp.1)$$

where KW0 is the angle of the ridge profile with precise cleaning by scraping in arc measure) and π is the ratio of a circles circumference to its diameter (π ≈3,14159). The sum of the angles of comb pairs of elements with a dense mesh SKWO is automatically

The specialist knows that the screw profiles with a direct clean by scraping cannot be directly inserted into twin screw extruder, on the contrary, between the screw elements and the housing and/or between the augers must be a gap (gap, gap). Geometrical parameters made augers specialist receives on the basis of the contour of the screw with the exact cleaned by scraping, using known methods, as described, for example, in [1]. In the book [1], starting with page 28, describes the different possible strategies for working with feed elements. When you use described in this text the longitudinal or spatial equidistants angles crest KWAO screws made in reality as it is, for example, presented in [1] on p.100, decrease compared to the corner KW0. In particular, to reduction of KWAO leads to a significant gap between the screws. There is a big gap between the screws, designed to reduce the angle of the ridge, however, is disadvantageous because it reduces the effect of the mutual cleaning augers, and length of stay of materials on the surface of the screw elements increases, which leads to local damage to the product and therefore, to them the structure of its quality. In addition, the specialist is known that the increase of the gap negatively affects the efficiency of the screw elements in the transportation plan and the formation pressure, so if you need to perform some specific technological problem, the gaps should not be done too large.

So there was a task to find the way the extrusion of polymers, combining the benefits of reduced gelation effect of self-cleaning and benefits at a low temperature.

In an unexpected way this problem can be solved by applying simultaneous degassing extruder with a tight engagement with the screw elements having a particular geometric parameters.

Therefore, the object of the invention is a method of processing plastic materials, in particular polymer melts and mixtures of polymer melts, especially thermoplastics and elastomers, particularly preferably polycarbonate and mixtures of polycarbonates with outcrosses of other substances, such as solids, liquids, gases, or other polymers, or other mixtures of polymers using simultaneous degassing extruder with a tight engagement with the use of pairs of rotating in one direction and pairs just cleaning each other by scraping auger shaft with two (or more) of the turn of the screw, otlichayuschihsya, that the sum of the angles of the ridge (SKW) pairs of elements can be chosen randomly, and it is greater than 0 and less than

$$2\pi -4Z\arccos \left(\frac{A}{DE}\right)$$

where Z is the number of coils (turns screw), And the distance between the axes of two screw elements, a DE is the external diameter of the screw elements. In screw elements according to the invention geometrical parameters of the push and pull of the lateral sides can according to need to adjust separately, and the edges bounding ridges, to round out also on demand.

While the invention is not limited to a screw elements normal now modular design, consisting of screw elements and the Central shaft, and is applicable also to Sneem solid construction. Therefore, the term "screw elements include solid augers.

The number of turns of the Z screw elements according to the invention is preferably 2, 3, 4, 5, 6, 7 or 8; a particularly preferred meaning, from 2 to 4.

Outer radius of the profile of the screw is RE=DE/2, inner diameter DK and an inner radius RK=DKl2. Therefore, it is always true A=RE+RK.

Creating and created profiles of screw elements according to the invention ("profiles auger", "screw profiles")are formed of arcs of a circle, which pass into each other on a tangent (tangentially). Creating and created a profile of a screw element according to the invention in each case consist of at least 6*Z arcs of a circle.

The size of the circular arc is defined by its Central angle and radius. Further, the Central angle of the circular arc for short, is called the angle of the arc of a circle. The position of the circular arc is defined by the position of its center and the position of both its endpoints.

The profile of a screw element according to the invention differs in that the radius of one or more arcs of a circle can have a value of zero. In this case, the profile has one or more bends.

Predefined profile screw on the first shaft-rotating twin screw extruder ("form") uniquely identifies the profile of the screw on the adjacent second shaft ("generated"). Accordingly, the profile of the screw on the first shaft-rotating twin screw extruder referred to as forming the profile of the screw, while the profile of the screw on the adjacent second shaft-rotating twin screw extruder call generated by the profile of the screw. Multi-shaft extruder forming the profile of the screw and formed the profile of the screw is always applied on adjacent shafts alternately.

Profiles of screws according to the invention is always closed and convex. The sum of the angles of the individual arcs of a circle the La of each element is always 2π.

Screw elements according to the invention are characterized in that in each case a circular arc of the generated profile of the screw matches the arc of a circle creating a profile of the screw. The term "match" means that the

the angles corresponding arcs have equal value,

- the sum of the respective radii of the arcs is equal to the distance between the axes,

in each case one of the lines connecting the center of the arc of a circle creating a profile of the screw with its endpoints, runs parallel to one of the lines connecting the center of the circular arc of the generated profile of the screw with its end points,

- directions at the endpoints of an arc of a circle creating a profile of the screw from the center of the arc of a circle in each case opposite directions at the endpoints of the corresponding circular arc of the generated profile of the screw from the center of the arc of a circle,

- the center of the arc of a circle creating a profile of the screw is from the center of the circular arc of the generated profile of the screw at this distance, which corresponds to the distance between the axes,

the line connecting the center of the arc of a circle creating a profile of the screw with the center of the circular arc of the generated profile of the screw parallel to the line connecting the center of rotation creates a profile of the screw with the center of rotation is saveimage profile auger

- the direction in which it is necessary to shift the center of the arc of a circle creating a profile of the screw, to cover the center of the corresponding arc of the generated profile of the screw, is identical to that in which it is necessary to shift the center of rotation creates a profile of the screw, to cover the center of rotation of the generated profile of the screw.

Figure 1 shows an example of two corresponding arcs of a circle. The center of rotation of the generating screw - DR, and the center of rotation of the generated screw - DL. This figure is an arc of a circle 1 - creating, as an arc of a circle 1' is created.

In creating a profile of the screw of a screw element according to the invention Z arcs of a circle radii equal to RE and the centers coincide with the center of rotation ("arc ridge").

In creating a profile of the screw of a screw element according to the invention Z arcs of a circle radii equal to RK, and the centers coincide with the center of rotation ("arc groove"). The corresponding generated profile of the screw is also Z-arc ridge and Z arc groove.

The sum of the angles of the arcs of the ridge and arc groove in creating the profile of the screw according to the invention can be chosen randomly, it is greater than 0 and less.

$$2\pi -4Z\arccos \left(\frac{A}{DE}\right)$$

The sum of the angles of all arcs of the ridge created and create a profile of the screw is equal to the sum of the angles of the ridge and groove creating a profile screw according to the invention it is greater than 0 and less than

$$2\pi -4Z\arccos \left(\frac{A}{DE}\right)$$

In a preferred embodiment, the screw elements used in the implementation of the method according to the invention, the arc of the ridge and arc groove is located so that when driving around the profile they appear alternately, i.e. in a circular motion for each arc of the ridge follows the arc of the groove, and for each arc groove - arc ridge. In the case of the created profile of the auger from this necessity, it follows that the arc of the ridge and arc groove is located so that when driving around the profile they appear alternately, i.e. in a circular motion for each arc of the ridge follows the arc of the groove, and for each arc groove - arc ridge.

In a preferred form of execution of the screw elements used according to the invention, have the same profile on both shafts except for rotation relative to the corresponding center of rotation of the profile π/Z odd-Z.

In another preferred form of execution of the screw elements used according to the invention have a point (Central) symmetry relative to the center of rotation of this profile, but not axial symmetry.

In another preferred form of execution of the augers is e elements, used according to the invention, symmetric with respect to the line passing through the center of the arcs of the ridge and arc groove. Accordingly, the screw element with the number of moves Z has 2*Z axes of symmetry.

Screw elements are preferably used as the conveying elements. The transport element, as is known, differs (see, for example, [1], str-248)that the profile of the screw is continuously rotated in the axial direction and continues like a screw. While the transport element can be right or left. Step conveying element is preferably in the range from 0.1 to 10 values axle spacing, with a mean step length along the axis required for a complete revolution of the profile of the screw, and the length along the axis of the conveying element is preferably in the range from 0.1 to 10 units of the diameter of the screw.

In screw profiles of screw elements according to the invention possible gaps that make up a value ranging from 0.1 to 0.001, relative to the diameter profile of the screw, preferably from 0.002 to 0.05, and particularly preferably from 0.004 to 0.02. As is known to the specialist, the gaps between the auger and the housing may differ from the clearances between the screws or can be the same. Gaps can also be constant or to vary within specified limits. You can also sdigital auger within the gaps. Specialist known methods, designed to bring the profile of the screw with a gap of a given profile of the screw with the exact cleaned by scraping. Possible methods for these purposes are, for example, described in [1], starting on page 28, the possibility of increasing the axle spacing, equidistant longitudinal sectional or spatial equidistant, all of which are known to the specialist. With increasing axle spacing design the profile of the screw with a smaller diameter and widen the gap between the screws. In the method with equidistant longitudinal sectional curve profile in longitudinal section (parallel to the axis of rotation of this element) shift on half of the gap between the screws perpendicular to the curve profile inside in the direction of the axis of rotation. In the method using the spatial equidistant from the spatial curve, which caused the screw elements, the screw element is reduced to half of the size of the gap between the two screws in the direction perpendicular to the planes of the profiles with the exact cleaned by scraping. It is preferable to apply equidistants longitudinal section and spatial equidistants, particularly preferably spatial equidistants.

Figure 2 depicts a cross-sectional profiles of the two-way screw elements, known what's in the prior art. Center distance is 48 mm, the outer diameter profile of the screw 58 mm, inner diameter, respectively, equal to 38 mm, and the angle of the ridge KW0 in radians 0,3788 (corresponds to 21.7°). The sum of all angles of the ridge SKW0 in radians is of 1.5152.

On figa and 3b schematically presents examples of the cross-section of part of the profile X creates the profile of the screw and the corresponding part of the profile Y generated profile two-way screw elements used according to the invention. Part of the profile X is formed by circular arcs 1, 2, 3, 4, 5 and 6. Part of the profile Y formed from respective arcs of the plot arcs X 1', 2', 3', 4', 5' and 6'. Each arc is uniquely determined by its centers M1, M2, ..., M6 and M1', M2', ..., M6', angles and radii (see Figa).

In this example, the center distance is 48 mm, the outer diameter profile of the screw 58 mm and an inner diameter of 38 mm, a circular arc 1 - arc ridge part of creating a profile and a circular arc 6 - arc groove. The radius of the arc 2 is equal to zero, i.e. creating the profile has an inflection point on the arc of the ridge.

For clarity on fig.3b denote arcs and centers are not available. Part of the profile X and Y are identical to the parts of the profile shown in figa.

In Fig. 4 schematically shows a cross-section of the screw elements used according to the invention with point-symmetrical profile of the screw, resulting from the under figa or 3b, if compliance with point symmetry to continue part of the profile, shown in figa and 3b. All corners of the crest is identical and equal 0,17454 (10°). In the example shown, the angle of the ridge KW. The sum of all angles of the ridge SKW is 0,698, less than half of that value, which is characterized by the element of the present technical level. This is an obvious advantage compared to the current technical level. This profile auger has also the advantage that when rotating clockwise pushing side forms a substantially greater angle with the body than the pull side, when partial filling again means less energopac. Also the direction of rotation may be reversed, causing increased tension on the crest.

Figure 5 is a schematic cross-section of the screw elements used according to the invention, the profile of which has a point and mirror symmetry. In this example, the center distance is 48 mm, the outer diameter profile of the screw 58 mm, an inner diameter of 38 mm, respectively, and each of the corners of the ridge 0,175 (10°). In the example shown, the angle of the ridge KW. The sum of all angles of the ridge SKW is 0,69813, less than half the sum of the angles of the ridge, which is characterized by the element of the present technical level. In this case, the advantage is to reduce the military energy dissipation.

On figa shows two related to each other part of the profile XI (creating a profile of the screw) and Y1 (created profile auger) examples of screw elements according to the invention, having a point and mirror symmetry. Part of the profile X1 formed by circular arcs 1, 2 and 3. Part of the profile formed Y1 corresponding circular arcs 1', 2' and 3'. The distance between the centers of rotation are normalized to 1. An arc of a circle 3 relates to the direct FP. Table 1 shows the radii, angles, the starting point and the centers of arcs of a circle.

On fig.9b shows the profile with the exact cleaned by scraping, derived from that of figa through reflection, extension, and rotation according to the invention. The angle of the ridge KW contour of the screw with the exact cleaning by scraping is 0,1598. The sum of all angles of the ridge SKW equal 0,3196. At the present technical level, the angle of the ridge contour with precise cleaning by scraping KW0 equals 0,399, and the sum of all angles of the ridge SKW0 0,799.

Figs profile is constructed based on the profile with the exact cleaned by scraping, presented at fig.9b, according to the method of spatial equidistants. Case diameter is 0.61, and the clearances between the casing and auger δ and between different screws s in each case equal to 0.02. Step 1.2.

Made the angle of the crest of the profile KWA=0,208. The sum of all the angles crest SKWA equal 0,319.

On fig.9d shows the profile with the same gap and the same step that figs corresponding to the current technical level. Made the angle of the crest of the profile KWA0 equal 0,329, and the sum of all angles of the ridge - 0,658.

Plastic mass, which can be the about with high efficiency and at the same time with gentle respect to the product to ekstradiroval according to the invention, is, for example, suspensions, pastes, glass, ceramic material, metal in the form of a melt, plastics, melts plastic, polymer solutions, elastomer and rubber mass.

It is preferable to use plastics and polymer solutions, particularly preferably thermoplastic polymers. As thermoplastic polymer, it is preferable to apply at least one polymer from the following group: polycarbonate, polyamide, complex polyester, in particular polybutylene terephthalate and polyethylene terephthalate, polylactide, a simple polyester, thermoplastic polyurethane, Polyacetal, photopolymer, in particular polyvinylidene fluoride, polyethersulfone, polyolefin, in particular polyethylene and polypropylene, polyimide, polyacrylate, in particular poly(methyl)methacrylate, Polyphenylene oxyde, polyster, polyetherketone, polyaryletherketones, polymerizati styrene, in particular polystyrene, copolymers of styrene, in particular a copolymer of styrene and Acrylonitrile, copolymers of Acrylonitrile, butadiene and styrene, and polyvinyl chloride. Equal the same manner preferably used so-called "blend" (a mixture of) the plastic, under which term specialist involves the combination of two or more plastics. Particularly preferred polycarbonate and mixtures containing polycarbonate, it is preferred gender is a carbonate, for example, obtained by the method with the phase boundary or the method of transesterification in the melt.

Other preferred materials are rubbers. As rubber is preferably used at least one of the materials belonging to the group comprising styrene-butadiene rubber, natural rubber, butadiene rubber, isoprene rubber, ethylene-propylene-diene rubber, ethylene-propylene rubber, butadiene-Acrylonitrile rubber, hydrogenated nitrile rubber, butyl rubber, halobutyl rubber, chloroprene rubber, ethylene-vinyl acetate rubber, polyurethane rubber, thermoplastic polyurethane, gutta-percha, ariety rubber, fluorine rubber, silicone rubber, sulfide rubber, chlorosulfonyl-plastic rubber. Of course, also possible is the combination of two or more of these rubbers, or a combination of one or more rubber with one or more plastics.

These thermoplastics and elastomers can be used in pure form or as mixtures with fillers and reinforcing substances, in particular glass, in the form of mixtures with one another or with other polymers or as mixtures with conventional additives to polymers.

In a preferred form of execution to a plastic masses, especially to the melts of polymers and polymer mixtures of races the lava, add additives. They can be administered together with the polymer in the extruder in the form of solids, liquids or solutions, or at least part of the additives (additives) or all of the additive is introduced into the extruder via a side stream.

Supplements can give the polymer a variety of properties. This can be, for example, dyes, pigments, tools that facilitate the processing, fillers, antioxidants, reinforcing agents, UV absorbers radiation and light stabilizers, metal deactivators, traps peroxides, the main stabilizers, seed, benzofuranyl and indolinone acting as stabilizers and antioxidants, helping to separation from the form, the additive which prevents burning, anti-static devices, tools, painting and stabilizers melts. Examples are carbon black, fiberglass, clay, mica, graphite fibers, titanium dioxide, carbon fiber, carbon nanotube, ionic liquids and natural fibers.

The advantages obtained by use of the process for different polymers, different depending on the type of extrusion process and the form of plastic masses.

If during extrusion of polyethylene and copolymers of polyethylene, the temperature is too high, then increase the molecular weight, degree of branching and cross-linking. In addition, politi the Yong and copolymers of polyethylene react with oxygen in the well-known specialist-oxidation cycle ([2] Hepperle, J.: Schädigungsmechanismen bei Polymeren. Polymeraufbereitung 2002, VDI-K, VDI-Verlag GmbH, [3] Zweifel, H.: Stabilization of Polymeric Materials. Berlin, Springer, M. 1997, [4] Schwarzenbach, K. et al.: Antioxidants., in the book Zweifel, H. (Hrsg.): Plastics Additives Handbook. München, Hanser, 2001, [5] Cheng, H.N., Schilling, F.C., Bovey, F.A.: 13C Nuclear Magnetic Resonance Observation of the Oxidation of Polyethylene, Macromolecules 9 (1976) S.363-365) with the formation of intensely smelling and so omegaomega low-molecular components, such as ketones, aldehydes, carboxylic acids and alcohols.

During extrusion of copolymers based on polyethylene and vinyl acetate in the case of too high temperature additionally formed intensively smelling and causing corrosion of acetic acid.

If during extrusion of polypropylene and copolymers of polypropylene, the temperature is too high, it increases the molecular weight. In addition, polypropylene and copolymers of polypropylene react with oxygen in the cycle of oxidation with the formation of intensely smelling and so omegaomega low-molecular components, such as ketones, aldehydes, carboxylic acids and alcohols.

During extrusion of polyvinyl chloride in the case of too high temperature polyvinyl chloride emits corrosive gaseous hydrogen chloride, and hydrochloric acid, in turn, catalyzes the further removal of the hydrochloric acid.

During extrusion of polystyrene in the case of excessively you the Oka temperatures are harmful for the health of styrene, as well as dimers and trimers of styrene, and the molecular weight is reduced and accordingly deteriorate the mechanical properties.

During extrusion of the copolymer of polystyrene and Acrylonitrile (SAN) product thermal load tends to yellowing, which leads to a reduction in the transparency, the formation of carcinogenic monomer Acrylonitrile and styrene, molecular weight decreases and accordingly deteriorate the mechanical properties.

During extrusion of aromatic polycarbonates product in case of excessive thermal loads, in particular, under the influence of oxygen tends to yellowing, which leads to deterioration of transparency and demonstrates the decrease of molecular weight, especially under the influence of water. In addition, at elevated temperature hatshepsuts monomers such as bisphenol A.

During extrusion of esters, as, for example, polyethylene terephthalate, polybutylene terephthalate and polytrimethylene or polylactide, in case of too high temperature and water effects are observed decrease in molecular weight and the shift of end groups in the molecule. The problem it is primarily for recycling of polyethylene terephthalate. At high temperature from polyethylene terephthalate cleaved acetic aldehyde, which may, for example, lead to changes in what about the taste of the contents of bottles for beverages.

In the extrusion of thermoplastics, modified for toughness with diene rubbers, in particular through butadiene rubber, particularly in the extrusion of polystyrene modified for toughness type (HIPS) and modified for toughness SAN (Acrylonitrile-butadiene-styrene, ABS), in case of too high temperature hatshepsuts carcinogenic butadiene, as well as the poisonous vinylcyclohexane. In addition, in the diene rubber are formed cross-linkage, so that deteriorate the mechanical properties of the product.

During extrusion of Polyoxymethylene in case of too high temperature cleaved toxic formaldehyde.

During extrusion of polyamides, such as polyamide 6, polyamide 6,6, polyamide 4,6, polyamide 11 and polyamide 12, the temperature is too high leads to staining of the product and to reduce the molecular weight and the separation of monomers and dimers and hence to a deterioration of the mechanical properties, especially in the presence of water.

In the extrusion of thermoplastic polyurethanes too high a temperature leads to a change in the structure of the molecules due to periureteral, and in the presence of water to reduce molecular weight. Both processes are undesirable influence on the properties of thermoplastic polyurethane.

During extrusion of polymethylmethacrylate if over ergicheskoi load cleaved methyl methacrylate with a decrease in molecular weight, what causes an unpleasant odor and deterioration of mechanical properties.

During extrusion of polyster too high temperature causes the removal of sulfur-containing organic and inorganic compounds, which has an unpleasant odor and can cause corrosion in the extrusion tools. In addition, the formation of low molecular weight oligomers and monomers and reduced molecular weight, which impairs the mechanical properties of polyster.

During extrusion of polyphenylsulfone in case of too high temperature hatshepsuts organic compounds, especially in the presence of water. Also reduced molecular weight, which deteriorates the mechanical properties.

When extrusion polyphenylenether in case of excessive temperature hatshepsuts low molecular weight organic compounds, thus reducing the molecular weight. This leads to deterioration of the mechanical properties of the product.

During extrusion of butadiene rubbers, such as polybutadiene (BR), natural rubber (NR) and synthetic polyisoprene (IR), butyl rubber (IIR), chlorbutanol rubber (CIIR), bromatologia rubber (BIIR), styrene-butadiene rubber (SBR), polychloroprene (CR), butadiene-Acrylonitrile rubber (NBR), partially hydrogenated butadien-Acrylonitrile rubber (HNBR), and also copolymers of these is s, propylene and dienes (EPDM) in the case of too high temperature due to cross-linkage is formed gel, which leads to deterioration of mechanical properties made of it parts. In chlorbutanol and bambucicola the rubber at elevated temperature is possible the removal of corrosive gases of hydrogen chloride or bromoiodide respectively, which in turn again catalyze further decomposition of the polymer.

During extrusion of the rubber mixtures containing the presses, such as sulfur or peroxides, due to too high temperatures are premature vulcanization. Because of this of these mixtures of rubbers already nothing to make.

During extrusion of mixtures of one or more polymers in the case of too high temperatures shortcomings extrusion of each individual polymer.

Single phase degassing of polymers in their manufacture is carried out on the so-called degassing extruders. Degassing extruders, in principle, known to the expert and are described, for example, in [1]. For degassing extruder is characteristic of the so-called degassing dome. This section with holes through which may deviate formed pairs. It is known that the possible operation of various degassing caps (domes) at different pressures, if between the domes and Eesa "congestion" of the product, so between zones of different pressure seal is formed division.

Screw elements according to the invention, it is preferable to use partially filled zones, and particularly preferably in the degassing zones.

Degassing extruder according to the invention can be filled with a product in different ways depending on the state in which receive the polymer. In a preferred embodiment, the extruder serves the liquid phase, which, in addition to the polymer may contain another solvent and possibly residual monomers. States that receive the polymer after the reaction and, if necessary, pre-evaporation, well-known specialist. Examples the following:

- polystyrene with residual styrene and, possibly, ethylbenzene, toluene, xylene, butanone or other solvent;

the copolymer of styrene and Acrylonitrile with a residual styrene residual Acrylonitrile and, possibly, ethylbenzene, toluene, xylene, butanone or other solvent;

linear polyethylene of low or high density, branched polyethylene with a solvent, such as hexane, technical hexane, propane, isobutane and monomers, such as propylene, butene-1, hexene-1,4-methylpentene-1, octene-1 (processes with suspensions is: process SH company Mitsui Chemicals (hexane), the Hostalen process company Basell (hexa is), Chevron Philips USA (isobutane), the process of firm Borealis Borstar (propane), Belgium, and DSM use hexane in the process with the solvent), more details are given in [6] (Comparative Analysis of Various Polyethylene Production Technologies, Chem. And Petroleum Eng. Vol.44, Nos.7-8, 2008);

- polycarbonate with a solvent, for example chlorobenzene and methylene chloride;

- polymethyl methacrylate with a monomer, i.e. methacrylate.

In a preferred embodiment, in a degassing extruder liquid feed product is served with a so-called reverse degassing. In this case, the solution of polymer, optionally preheated, is introduced into the twin screw extruder and foamed therein. Then divert gases by one co-rotating twin screw extruder back to the degassing dome. Generally, this reverse degassing refers to the current technical level and are described, for example, in [1] on str-195. The concentration of the polycarbonate in the solution in this case is from 55 wt.-% to 95 wt.-%, particularly preferably from 65 wt.-% up to 90 wt.-%.

In a preferred embodiment, the product flow in a degassing extruder with a liquid inlet in the extruder is instantaneous evaporation, preferably instant evaporation directly above the extruder, so that the partially degassed melt was falling directly on the screw shafts. Pairs formed by evaporation, preferably away from the tank-separator, also on th the th above the extruder, using one or more steam lines. The temperature of the polymer solution is preferably in the range from 180°C to 300°C., particularly preferably from 200°C to 250°C. the Instantaneous evaporation is preferably carried out in the pressure range from 0.3 bar to 6 bar (abs.), particularly preferably from 0.5 bar to 2 bar (abs.)

In another preferred embodiment, the product flow in a degassing extruder with a liquid, this process takes place in the heat exchanger in the form of a bundle of tubes at the entrance to the extruder, located on its shaft, so that coming out of the pipes partially degassed solution of polymer may fall directly on the shafts. Between the exit of the heat exchanger in the form of a bundle of pipes and shafts of the extruder is another tank separator, in which a pair and the polymer solution is separated from each other and which has at least one outlet for vapors. The polymer solution is injected through an inlet opening in the upper end of the evaporator standpipe and through the distribution plate serves many tubes, which are heated from the outside. Heating is preferably performed using condensed water vapor, condensed organic fluid or liquid organic carrier. Through the inner surface of the pipe thermal energy for evaporation of the solvent enters the melt polycarbonate this component, the solvent evaporates and forms a two-phase gas-liquid mixture. Thus, it is possible to avoid overheating of the polymer melt. The exhaust vapor of the solvent provides a constant mixing of the polymer melt and update its surface, which means the effective increase of its concentration. Due to this evaporation extruder is melt polycarbonate much higher concentrations so as Energotech, and the duration of stay of polycarbonate melt in the extruder can be reduced while providing the same or even a higher degree of degassing of the polycarbonate melt. Preferably, the inlet of the heat exchanger in the form of a bundle of tubes, the concentration of the polymer solution ranged from 50 to 80 wt.%. The temperature of the heating pipes is from 240°C to 360°C, preferably from 250°to 340°C., and very preferably from 260°C to 300°C. At the entrance to the extruder, the polymer concentration is from 80 to 99 wt.%, preferably from 90 to 99 wt.%. The pressure in the tank separator is preferably from 0.3 bar to 6 bar (abs.), particularly preferably from 0.5 bar to 2 bar (abs.)

Another preferred version of the product flow in a degassing extruder with a liquid is to use a foaming evaporator described for polycarbonate, for example, in European patent EP 1740638. Foaming evaporator may consist of, nab is emer, of the tube bundle or plate with nozzles. Of holes foaming evaporator is foam polymer melt and the solvent leaves it remains only a small residual content.

This foaming evaporator is preferably fitted over the shafts of the extruder so that the speaker of the pipes of the polymer solution can flow directly to the shafts. Between the exit of the heat exchanger in the form of a bundle of pipes and shafts of the extruder is another tank separator, in which a pair and the polymer solution is separated from each other and which has at least one outlet for vapors.

Particularly preferably used as a solution of the polymer solution of polycarbonate.

In this case, the concentration of the solution of the polycarbonate at the entrance foaming in the evaporator is from 90 wt.% to 99.95 wt.%. As an option in the solution of the polycarbonate also add a blowing agent such as nitrogen, CO₂. The vapor pressure of the blowing agent in conjunction with a residual solvent is from 0.1 to 100 bar, preferably from 0.5 to 60 bar, and particularly preferably from 1 to 40 bar. Passing through the holes foaming evaporator, the polymer solution is divided into separate flows under pressure from 0.1 to 20 mbar. The temperature of the polymer solution is from 250°to 340°C. the pressure in the tank separator preferably there is camping at the level of from 0.1 to 20 mbar.

Figure 6 shows a degassing extruder according to the invention. In zone a through the pipe instantaneous evaporation of 1 in the extruder submit a solution of polycarbonate. The pair is separated from the solution of the polycarbonate in the tank degassing 2. Zone C, E, G, J and L is the degassing zone. Released there pair divert through the degassing dome 3. Zone b, D, F and H are areas of sludge, in which "zaprygivayem" element creates a tube of the product, allowing you to generate various pressure adjacent to each other areas. In the area To impose additional selective displacer to improve the efficiency of the degassing zone L. In zone M, the polymer is mixed with a side stream containing additives, and increase the pressure to filter and nozzles located behind the extruder.

7 shows another degassing extruder according to the invention. In the zone And through the vertical pre-heater 1 in the extruder submit a solution of polycarbonate. The pair is separated from the solution of the polycarbonate in the tank degassing 2. Zone C, E, G, J and L is the degassing zone. Released there pair divert through the degassing dome 3. Zone b, D, F and H are areas of sludge, in which "zaprygivayem" element creates a tube of the product, allowing you to generate various pressure adjacent to each other areas. In the area To impose additional villages is active displacer, to improve the efficiency of the degassing zone L. In zone M, the polymer is mixed with a side stream containing additives, and increase the pressure to filter and nozzles located behind the extruder.

On Fig presents another degassing extruder according to the invention with foaming evaporator. In the zone And through the foaming evaporator 1 into the extruder submit a solution of polycarbonate. The pair is separated from the solution of the polycarbonate in the separator 2. In zones b, D, F and H are added to and dispersed selective displacer. In zones C, E, F, G, and J from the polymer is separated volatile components. In the area To the polymer is mixed with a side stream containing additives, and optionally with another polymer and increase the pressure to filter and nozzles located behind the extruder.

Double-shaft or multi-shaft extruder according to the invention in the manufacture of polymers can also be downloaded particles. In this case, the extruder according to the invention is used primarily to melt, packing and mixing with additives. States that receive the polymer after the reaction and, if necessary, after the preliminary evaporation or deposition, well-known specialist. Examples the following:

- polypropylene, when the polymer is produced in powder form after the last reaction;

- polyethylene you the Oka density of the process in the gas phase or process with pulp;

- emulsion polymerizate, as, for example, Acrylonitrile-butadiene-styrene after deposition and, if necessary, drying.

When additional processing double-shaft or multi-shaft extruder according to the invention is particularly useful in problems with degassing. Particular benefits are obtained by direct processing of secondary raw materials (polyethylene terephthalate), material for bottles, in which case the degassing occurs when the minimum temperature load.

Particularly preferable to use the method according to isoberlinia in the manufacture and compounding of polycarbonate. In this case, it has the advantages primarily in the sense of color polycarbonate, which is the color unpainted polycarbonate is measured by yellowness index (YI). A particularly preferable to apply the screw elements according to the invention in the degassing zone.

Divinely, suitable for the manufacture of polycarbonate by means of the method according to the invention, repeatedly described in the current technical level.

Proper divinely is, for example, hydroquinone, resorcinol, dihydroxydiphenyl, bis-(hydroxyphenyl)-alkanes, bis-(hydroxyphenyl)-cycloalkanes, bis-(hydroxyphenyl)-sulfides, bis-(hydroxyphenyl)-ethers, bis-(hydroxyphenyl)-ketones, bis-(hydroxyphenyl)-sulfones, bis-(hydroxyphenyl)-sulfoxidov, α,α'-the IP(hydroxyphenyl)-diisopropylbenzene, as well as their alkylated and nuclear-alkylated and nuclear-halogenated compounds.

Preferred definaly is 4,4'-dihydroxydiphenyl, 2,2-bis-(4-hydroxyphenyl)-1-phenyl-propane, 1,1-bis-(4-hydroxyphenyl)-phenyl-ethane, 2,2-bis-(4-hydroxyphenyl)propane, 2,4-bis-(4-hydroxyphenyl)-2-methylbutane, 1,3-bis-[2-(4-hydroxyphenyl)-2-propyl]benzene (bisphenol M), 2,2-bis-(3-methyl-4-hydroxyphenyl)-propane, bis-(3,5-dimethyl-4-hydroxyphenyl)-methane, 2,2-bis-(3,5-dimethyl-4-hydroxyphenyl)-propane, bis-(3,5-dimethyl-4-hydroxyphenyl)-sulfon, 2,4-bis-(3,5-dimethyl-4-hydroxyben yl)-2-methylbutane, 1,3-bis-[2-(3,5-dimethyl-4-hydroxyben yl)-2 - propyl]benzene and 1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (bisphenol TMC).

Particularly preferred definaly is 4,4'- dihydroxydiphenyl, 1,1-bis-(4-hydroxyphenyl)-phenyl-ethane, 2,2-bis-(4-hydroxyphenyl)-propane, 2,2-bis-(3,5-dimethyl-4-hydroxyphenyl)-propane, 1,1-bis-(4-hydroxyphenyl)-cyclohexane and 1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (bisphenol TMC).

In the case of homopolymerization used only one diphenol, and in the case of copolycarbonates apply several diphenols, and needless to say that the applied divinely, like all other chemicals and auxiliary substances used for the synthesis, can carry pollution caused by their own synthesis, processing and storage, although it is desirable to work with raw materials is diversified materials of the highest possible purity.

Monofunctional circuit breakers necessary to specify the molecular weight, such as phenol or ALKYLPHENOLS, especially phenol, para-tert-butylphenol, isooctylphenol, cumylphenol, their ethers harpalinae acids or acid chlorides of monocarboxylic acids or mixtures of these circuit breakers, add in the reaction mixture or bisphenolate or bisphenolate, or at any stage while in the reaction mixture still contains phosgene or end groups harpalinae acid, or when used as aprivately chain acid chlorides and esters harpalinae acid until there is enough of phenolic groups forming polymer. Preferably, however, to add a circuit breaker or circuit breakers after vosganian in such place or in such a moment, when phosgene is no longer available, but the catalyst has not yet been added. Alternatively, it is also possible their introduction to the catalyst, together with the catalyst or parallel to it.

In the same way if necessary in synthetic mixture splitters or a mixture of splitters. Usually, however, splitters add to the circuit breakers. As a rule, use trisphenol, quaterphenyl [?] or tricarboxylic anhydrides and tetracosanoic acids or mixtures of polyphenols or acid chlorides. Some of the PR is usable as splitters compounds with three or more than three phenolic hydroxyl groups this is, for example, phloroglucin, 4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-hepten-2, 4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-heptane, 1,3,5-tri-(4-hydroxyphenyl)-benzene, 1,1,1-tri-(4-hydroxyphenyl)-ethane, tri-(4-hydroxyphenyl)-phenylmethane, 2,2-bis-(4,4-(4-hydroxyphenyl)-cyclohexyl]-propane, 2,4-bis-(4-hydroxyphenyl-isopropyl)-phenol, Tetra-(4-hydroxyphenyl)-methane.

Some of the other trifunctional compounds is 2,4-dihydroxybenzoic acid, tremezzina acid, cyanuric chloride and 3,3-bis-(3-methyl-4-hydroxyphenyl)-2-oxo-2,3-dihydroindol.

As splitters preferred 3,3-bis-(3-methyl-4-hydroxyphenyl)-2-oxo-2,3-dihydroindol and 1,1,1-tri-(4-hydroxyphenyl)-ethane.

In the synthesis of polycarbonate with surface phases preferably use such catalysts as tertiary amines, in particular triethylamine, tributylamine, trioctylamine, N-ethylpiperidine, N-methylpiperidine, N-i/n-propylpiperidine; Quaternary ammonium salts such as hydroxide, chloride, hydrosulfate, tetrafluoroborate tetrabutylammonium, tributylamine or tetraethylammonium; and phosphonium compounds of the corresponding ammonium compounds. These compounds are described in the literature as typical catalysts for the process with the surface of separation of the phases available in the market and well-known specialist. The catalysts can be added during synthesis individually, in a mixture or illegal the performance of each other simultaneously or sequentially, if necessary, also to vosganian; preferably, however, to introduce them after the introduction of phosgene, if only as a catalyst is not used onieva combination or mixture niewyk compounds. In this case, preferably the addition of the catalyst to vosganian. The addition of a catalyst or catalysts can be in pure form, in a neutral solvent, preferably in the same solvent used in the synthesis of polycarbonate or in aqueous solution; in the case of tertiary amines in the form of ammonium salts with acids, preferably mineral, especially hydrochloric acid. When using multiple catalysts or the introduction of catalyst parts can, of course, in different places or at different stages to make adding different way. The total amount used of the catalyst is from 0.001 to 10 mol.% the number of used bisphenols, preferably from 0.01 to 8 mol.%, particularly preferably from 0.05 to 5 mol.%.

Synthesis of polycarbonates can be continuous or intermittent manner. Therefore, the reaction can occur in boilers with a stirrer, a reactor in the form of pipes, reactors, pumping or cascades boilers with mixers, or combinations of these tanks. It should use the already mentioned bodies mixing to ensure that the button separation of aqueous and organic phases was possible only when the reaction in the synthesis mixture has ended, i.e. when the mixture is no longer capable of saponification of chlorine, phosgene, or esters harpalinae acid.

After the introduction of phosgene may be appropriate for some time to mix the organic and aqueous phase before adding the splitter (if it has not added together with bisphenolate), the circuit breaker and the catalyst. Best may be a pause after adding any component. The duration of such additional mixing is from 10 seconds to 60 minutes, preferably from 30 seconds to 40 minutes, particularly preferably 1-15 minutes.

The organic phase may consist of one solvent or mixtures of several solvents. A suitable solvent is a chlorinated hydrocarbon (aliphatic and/or aromatic), preferably dichloromethane, trichloroethylene, 1,1,1-trichloroethane, 1,1,2-trichloroethane and chlorobenzene, and mixtures thereof. It is also possible, however, to use aromatic hydrocarbons such as benzene, toluene, meta-, para - or ortho-xylene or aromatic ethers such as anisole, alone, in a mixture of chlorinated hydrocarbons, or in addition to them. In another form of execution of the synthesis used solvents that do not dissolve the polycarbonate, but only cause it to swell. Therefore, in combination with Rast is Oriflame you can also use substances, non-solvents polycarbonate. The solvents can be used, and solvents, which are dissolved in the aqueous phase, as, for example, tetrahydrofuran, 1,3/1,4-dioxane or 1,3-dioxolane, if the partner-solvent forms the second organic phase.

The reaction mixture consisting of at least two phases, the last reaction and containing at most trace amounts (<2 ppm) esters harpalinae acid, left to stand for phase separation. The alkaline aqueous phase is completely or partially return in the synthesis of polycarbonate as the aqueous phase or served on wastewater treatment, where the separated solvent and catalyst and return them. In another embodiment, the processing after separation of the organic impurities, in particular solvents and residues of polymers, and optionally after adjusting the pH to a certain value, for example by adding sodium hydroxide, separating the salt, which, for example, can be used for the electrolysis of alkali metal chlorides, and the aqueous phase again when necessary direct the synthesis.

The organic phase containing the polycarbonate, it is possible at this stage to clear away all dirt - alkali ions or catalyst. Even after one or more processes of the separation of the organic phase contains certain quantities of alkaline water is phase into small droplets, and a catalyst, usually a tertiary amine. Procedure division (deposition) can also support passing the organic phase through tanks deposition, boilers with stirring, precipitating tanks or separators or combinations of these devices, and on all or some stages of separation, if necessary, using active or passive mixing water can be added.

After this rough separation of the alkaline aqueous phase organic phase one or more times washed with dilute acids: mineral, carbon, hydroxycarbonyl and/or sulfonic acids. Preferred aqueous solutions of mineral acids, particularly hydrochloric acid, phosphorous acid and phosphoric acid, and mixtures of these acids. The concentration of these acids must be in the range of from 0.001 to 50 wt.%, preferably from 0.01 to 5 wt.%.

In addition, the organic phase is repeatedly washed demineralized or distilled water. Separation of the organic phase, possibly dispersed with parts of the organic phase, after the individual steps of washing is carried out using tanks deposition, boilers with stirring, precipitating tanks or separators or combinations thereof, and between stages of washing, if necessary, using active or passive mixing, the can is add water.

Between the individual steps of the washing or after washing, you can optionally add acid, preferably dissolved in the solvent, which is the basis of the polymer solution. At this stage, it is preferable to use gaseous hydrogen chloride and phosphoric or phosphorous acid, which optionally can also be used in mixtures.

In the next step, this purified solution served in the evaporation extruder according to the invention with a special geometrical parameters of the augers.

The polycarbonates obtained by the method according to the invention, to modify their properties can be added conventional additives and additives (for example, supporting and reinforcing substances). Adding additives and additives help extend the service life (for example, stabilizers, hydrolysis or decomposition), to improve the color stability (for example, heat stabilizers and UV stabilizers), to simplify processing (for example, tools that facilitate the retrieval of forms, and tools that contribute to the yield strength), improve consumer qualities (e.g. antistatics), improved fire protection, affect the appearance (for example, organic dyes, pigments) or changes the properties of the polymer in accordance with certain loads (modifiers toughness, fine minerals, fiber, quartz is flour, fiberglass and carbon fiber).

The following is the explanation of the invention on the basis of figure 1, illustrating the example execution.

The polymer solution is directed to the feed line 1 into the open down the heat exchanger in the form of a tube bundle 2. The heat exchanger in the form of a tube bundle heat the coolant, which serves at the point 3, and taken off to the point 4. At the end of the pipe, a polymer solution with a pressure drop goes into the tank of the separator 5, located directly above the extruder. The released gas divert the pipeline for vapor 6. The product falls directly in the input area 7 of the extruder and through the seal 8 is fed into the first degassing zone 9, with the degassing dome 10. After that you will find other areas of congestion (seal) 8 and the degassing zone 9. Before the last degassing dome in the kneading zone 11 through the feed point 12 is injected nitrogen. The feed point 13 also add additives and, if necessary, the molten polymer, which is mixed with a stream of the polymer in the zone of increasing pressure and mixing 14.

The following examples are intended for illustrative explanation of the invention and do not impose restrictions on him.

The relative viscosity of the polycarbonate by definition is the ratio of the viscosity of the polymer solution to the viscosity of the pure solvent. It is usually measured in dichloromethane at a concentration which tion in 5 g of polymer per one liter of the solvent at 25°C.

Control example 1

6750 kg/h of a solution containing 65% polycarbonate, served in a degassing extruder corresponding to Fig.6. The instantaneous evaporation of the solution temperature is 230°C. All sections are equipped with screw elements corresponding to the current technical level. Zone a-L, equipped with two-way elements, and area M - way. The relative viscosity of a solution of the polycarbonate is 1,295. The rotation speed of the extruder is equal to 350 rpm Absolute inlet pressure (zone a) is 1.4 bar, and the pressure in the zones C, E, G, J and L gradually reduce to 1 bar (abs.) up to 5 mbar (abs). In the area To as selective displacer served and dispersed nitrogen in the amount of 15 kg/h

Temperature after viparyayah extruder is 398,4°C, the residual content of chlorobenzene below 400 ppm. The yellowness index is 1.9.

Example 2

6750 kg/h of a solution containing 65% polycarbonate, served in a degassing extruder corresponding to Fig.6. The instantaneous evaporation of the solution temperature is 230°C. Zone a, b, C, D, E, F, G, and M is equipped with the screw elements corresponding to the current technical level. Zone J, K and L is equipped with the screw elements according to the invention. The relative viscosity of a solution of the polycarbonate is 1,295. The rotation speed of the extruder is equal to 350/min Absolute pressure in I the de (zone a) is 1.4 bar, as the pressure in the zones C, E, G, J and L gradually reduce to 1 bar (abs.) up to 5 mbar (abs). In the area To as selective displacer served and dispersed nitrogen in the amount of 15 kg/h

Temperature after viparyayah extruder is 386,7°C, the residual content of chlorobenzene below 400 ppm. The yellowness index is 1.5.

Reference example 3

7500 kg/h of a solution containing 65% polycarbonate, served in a degassing extruder corresponding to Fig.7. Before entering the extruder solution pre-heated using a heat exchanger in the form of a tube bundle 1. All sections are equipped with screw elements corresponding to the current technical level. Zone a-L, equipped with two-way elements, and area M - way. The relative viscosity of a solution of the polycarbonate is 1,295. The rotation speed of the extruder is equal to 350 rpm Absolute inlet pressure (zone a) is 1.4 bar, and the pressure in the zones C, E, G, J and L gradually reduce to 1 bar (abs.) up to 5 mbar (abs). In the area To as selective displacer served and dispersed nitrogen in the amount of 15 kg/h

Temperature after viparyayah extruder is RUB 399.4°C, the residual content of chlorobenzene below 400 ppm, and the yellowness index is 2.2.

Example 4

7500 kg/h of a solution containing 65% polycarbonate, served in a degassing extruder corresponding to Fig.6. Up to the instant in which pariwana the solution temperature is 230°C. Zones a, b, C, D, E, F, G, and M is equipped with the screw elements corresponding to the current technical level. Zone J, K and L is equipped with the screw elements according to the invention. The relative viscosity of a solution of the polycarbonate is 1,295. The rotation speed of the extruder is equal to 350 rpm Absolute inlet pressure (zone a) is 1.4 bar, and the pressure in the zones C, E, G, J and L gradually reduce to 1 bar (abs.) up to 5 mbar (abs). In the area To as selective displacer served and dispersed nitrogen in the amount of 15 kg/h

Temperature after viparyayah extruder 388°C, the residual content of chlorobenzene below 400 ppm, and the yellowness index is 1.7.

1. The method of extrusion of plastics with the use of screw elements for multi-shaft auger machines in pairs rotating in one direction and pairs just cleaning each other by scraping auger shaft with two or more turn of the screw Z, the center distance a and an outer diameter DE, characterized in that the sum of the angles of comb pairs of elements greater than 0 and less than

2. The method according to claim 1, characterized in that the profiles are creating and the created profile screw elements in each case composed of 6*Z or more arcs of a circle with a radius greater than zero or equal to zero and less than or equal to A, and the circular arc end point is x pass each other tangentially.

3. The method according to claim 2, characterized in that in each case one pair of screw elements of the so-called corresponding arcs of the circle created and create a profile of the screw is different in that
the angles corresponding arcs have equal value,
- the sum of the respective radii of the arcs is equal to the distance between the axes,
in each case one of the lines connecting the center of the arc of a circle creating a profile of the screw with its endpoints, runs parallel to one of the lines connecting the center of the circular arc of the generated profile of the screw with its end points,
- direction at the end point of any arc of a circle creating a profile of the screw from the center of the arc of a circle in each case opposite directions at the endpoints of the corresponding circular arc of the generated profile of the screw from the center of the arc of a circle,
- the center of the arc of a circle creating a profile of the screw is from the center of the circular arc of the generated profile of the screw at this distance, which corresponds to the distance between the axes,
the line connecting the center of the arc of a circle creating a profile of the screw with the center of the circular arc of the generated profile of the screw parallel to the line connecting the center of rotation creates a profile of the screw with the center of rotation of the generated profile auger,
- direction of the people, where it is necessary to shift the center of the arc of a circle creating a profile of the screw, to cover the center of the corresponding arc of the generated profile of the screw, is identical to that in which it is necessary to shift the center of rotation creates a profile of the screw, to cover the center of rotation of the generated profile of the screw.

4. The method according to claim 2, characterized in that at least one arc of the ridge profile follows an arc of a circle with a radius of 0.

5. The method according to claim 2, characterized in that at least one arc of the ridge profile follows an arc of a circle of radius greater than 0 and less than 1/10 of the diameter of the screw.

6. The method according to claim 2, characterized in that the arc of the ridge and arc groove while moving around the profile occur alternately.

7. The method according to claim 1, characterized in that the number of the symmetry axis of the screw elements corresponds to the number of moves.

8. The method according to claim 1, characterized in that the screw elements have point symmetry, but not mirror symmetry.

9. The method according to claim 1, wherein the screw elements are designed as conveying elements.

10. The method according to claim 1, characterized in that the screw elements used in the degassing zone or in the area of transportation.

11. The method according to claim 1, characterized in that between the screw elements and the housing and/or between adjacent screw elements having gaps in sizes ranging from 1 to 0.001 of the diameter of the screw profile.

12. The method according to claim 1, characterized in that the plastics are thermoplastics or elastomers.

13. The method according to item 12, characterized in that thermoplastic used polycarbonate, polyamide, complex polyester, in particular polybutylene terephthalate and polyethylene terephthalate, a simple polyester, thermoplastic polyurethane, Polyacetal, photopolymer, in particular polyvinylidene fluoride, polyethersulfone, polyolefin, in particular polyethylene and polypropylene, polyimide, polyacrylate, in particular poly(methyl)methacrylate, Polyphenylene oxyde, polyster, polyetherketone, polyaryletherketones, polymerizati styrene, in particular polystyrene, copolymers of styrene, in particular a copolymer of styrene and Acrylonitrile, copolymers of Acrylonitrile, butadiene and styrene, and polyvinyl chloride or mixture at least two of the foregoing thermoplastics.

14. The method according to item 13, characterized in that thermoplastic used polycarbonate or a mixture of polycarbonate with other polymers.

15. The method according to 14, characterized in that the polycarbonate produced by the method with the phase boundary or means of transesterification in the melt.

16. The method according to item 12, characterized in that the elastomer used is a styrene-butadiene rubber, natural rubber, butadiene rubber, isoprene rubber, ethylene-propylene-dienes is th rubber, ethylene-propylene rubber, butadiene-Acrylonitrile rubber, hydrogenated nitrile rubber, butyl rubber, halobutyl rubber, chloroprene rubber, ethylene-vinyl acetate rubber, polyurethane rubber, thermoplastic polyurethane, gutta-percha, ariety rubber, fluorine rubber, silicone rubber, sulfide rubber, chlorosulfonyl-polyethylene rubber, or a combination of at least two of these elastomers.

17. The method according to any one of claims 1 to 16, characterized in that the polymer add fillers or reinforcing substances or additives to polymers, or organic or inorganic pigments, or mixtures thereof.