Investigation of the contact interaction of the working bodies of machines with raw cotton

. Based on the technological process of processing raw cotton, the friction conditions of various units of friction pairs interacting with raw cotton and cotton fiber are analyzed with the elucidation of the influencing factors on the friction force in the contact zone. When rubbing composite polymer materials with raw cotton, depending on the contact conditions of rubbing pairs in various friction units with repeated contact formation and destruction of bonds in the contact zone, electric charges arise and accumulate, which increases the tension in the double electric layer in the contact zone. Forming electric charges in the contact zone, together with other components of the friction force, significantly affect the change in the antifriction properties of the materials used. Based on the analysis of a friction pair in contact with raw cotton and cotton fiber, the main shortcomings of the existing methods for assessing the antifriction properties of the studied polymeric materials and coatings based on them were established, as a result of which specific requirements were developed for the development of methods and installations for determining the complex antifriction properties of the material of rubbing parts, pairs of working bodies of cotton machines and mechanisms. General requirements have been established for materials for working in a friction pair in contact interaction with raw cotton and cotton fiber under various conditions of humidity and exposure to any climatic factors, as well as varying degrees of contamination of the mass of raw cotton. Considering certain requirements for assessing the antifriction properties of the developed compositions of polymeric materials, a modular installation was created for a one-time assessment of temperature, friction force, and static electric charge using modern information technologies.


Introduction
The technological process of primary processing of raw cotton includes the following main technological operations: acceptance from cotton-growing farms and storage of raw cotton; giving raw cotton from storage places (riots, warehouses) to drying-cleaning and cleaning shops, where it is dried and cleaned from large and small litter; supply of raw cotton for ginning; fiber cleaning; seed linting; fiber and lint pressing; selection and shipment of seeds [1].*Corresponding author: polegon11@mail.ruE3S Web of Conferences 365, 04001 (2023) https://doi.org/10.1051/e3sconf/202336504001CONMECHYDRO -2022 The supply of raw cotton from one technological operation to another, for example, from cleaning to ginning, is carried out through a transport and distribution system, which includes pneumatic transport, screw and belt conveyors, and elevators.
Throughout the entire technological process of primary processing, raw cotton interacts with various surfaces of the working bodies of mechanization, pneumatic transport systems, and technological equipment.It should be noted here that the total area of surfaces in contact with raw cotton and fiber significantly exceeds that in all subsequent textile production -spinning and weaving [2].
To improve the reliability and durability of technological equipment of the cottoncleaning industry in friction units interacting with raw cotton, taking into account the increasing complicating operating conditions, polymeric materials and compositions based on them are most widely used.
The state of the friction surfaces of the working bodies of machines and mechanisms of cotton ginning plants has a significant impact on the quality indicators of product processing (fiber, lint, seeds) and, at the same time, on the productivity of the technological process [3].
The above indicators depend on the nature of the contact of the working surfaces, the direction and magnitude of the speed of movement of the raw cotton, as well as on the state of the surface of the counterbody with which the cotton fiber interacts.Although the use of polymeric materials and coatings based on them gives positive results in their application, however, to ensure the necessary properties in the contact zone and, in general, in friction units, it is necessary to establish a predetermined set of antifriction properties with their evaluation under simulated conditions.

Methods
In the course of the research, a system-structural method was used to study the indicators of antifriction of friction units with the participation of raw cotton and cotton fiber; analytical evaluation of the process of contact interaction of polymeric materials and coatings based on them with raw cotton and cotton fiber; methods of system analysis aimed at choosing different options for solving the problem and choosing a unified method for determining the antifriction properties of polymeric materials and their compositions during friction with raw cotton under various conditions of contact interaction; methods of mathematical modeling of the process of contact interaction of rubbing surfaces using real operating conditions of a pair of friction units of machines and mechanisms of the technological process of harvesting, storing and processing raw cotton; extrapolation method with an analysis of the operating conditions of friction units with the transition to simulation on an improved device being created to determine the antifriction properties during friction of polymeric materials with raw cotton and cotton fiber; a combination-synthesizing method for creating new compositions of polymeric materials based on the combination of measuring the friction force, temperature and the magnitude of the static electric charge in the contact zone during the interaction of polymeric materials and coatings based on them with raw cotton, as well as the creation of improved devices for determining antifriction and wear-resistant indicators in the contact zone during their friction [4].
And also, when determining the friction force, a circuit for switching on a strain and compression sensor according to a bridge circuit with a record on a computer was used; a method of converting temperature into an electrical signal, using the phenomenon of thermoEMF and changes in conductivity; to determine the magnitude of the electrostatic charge in the contact zone, a method was used to determine the excess charge of an electrified material by measuring the voltage on a known capacitance.

Results and Discussion
For the first time, studies of the process of contact interaction of fibrous materials with various structural materials were carried out by A.Yu. Later this statement was proved in the work of R.G.Makhkamov in the study of the interaction of raw cotton with the surfaces of structural materials, particularly metals, from the point of view of optimizing the surface roughness of the counterbody, aimed at reducing the mechanical damage to the fibers.He showed that the force of interaction of raw cotton with metal surfaces increases either due to the micro-cutting of cotton fibers on microprotrusions of surfaces or due to an increase in adhesive interactions associated with an increase in the moisture content of raw cotton [5].
Based on the research conducted by S.S.Negmatov during the contact interaction of polymeric and composite materials with raw cotton, it was shown that for most of the studied materials, with an increase in the sliding speed, the friction coefficient first increases and reaches an extremum, and then decreases with a further increase.At the same time, it was revealed that the dependence of the coefficient of friction of polymeric materials with raw cotton on the sliding speed at low and medium pressures has an extreme character.In this case, the appearance and accumulation of electric charges lead to an increase in the tension in the double electric layer in the contact zone, which, in turn, leads to an increase in the electrical component of the friction force due to the orientation of the dipoles at the phase boundary and the structure, inhomogeneity of the contacting bodies.
Depending on the conditions of the interaction of raw cotton with the working surfaces of machines and mechanisms, in the course of the technological process of its processing in friction units, the types of contact of cotton fiber with the surface change [6].
In the friction units of machines and mechanisms associated with the formation of riots of raw cotton, the storage of cotton in riots, its disassembly, and supply to production (belt conveyors, mobile receiving devices, riot breakers, a tunnel machine, and a yard pneumatic transport system), friction surfaces are in direct contact with cotton-raw (Fig. 1).The friction force acting on the mass of raw cotton (Ftr) includes the force of separation of the raw cotton from the mass, depending on the adhesion of the cotton lobules in the riot, which is determined by the variety, grade, humidity, contamination and bulk density of the raw cotton; as well as the force of lateral resistance acting on the cutter when moving the rebel boom in the horizontal plane.
F tr is the friction force of the splitter with raw cotton; ω is the number of revolutions of the peg working body of the RP; 1 is raw cotton; 2 is working body of milling type; 3 is pegs.When accepting raw cotton from motor transport bodies by mobile receiving-feeding devices (PL, PLA, KhPP brands), the raw cotton poured into the hopper of the receiving device is transported to an inclined elevator, the belt of which is equipped with strips with pegs [7].
The mass of raw cotton entering the elevator is captured by the pegs of the elevator, part of it is torn off from the total cotton mass and then transported upwards to the discharge opening (Fig. 2).The main parameters characterizing the operation of the elevator of the receiving device are the force of friction of raw cotton on the surfaces of wedge-shaped pegs, the adhesion force of cotton fibers to each other, the speed of the tape and the size of the working surfaces of the pegs and the elevator bar.The adhesion force of cotton fibers depends on the height and width of the pegs, as well as the force of separation of the pegs from the tape, depending on the size of the pegs, the speed of the elevator belt, and the parameters of the raw cotton itself (grade, humidity, and contamination).
F tr is the friction force of the splitter with raw cotton; V is speed of movement of the working body KhPP. 1 is raw cotton; 2 is rubberized tape; 3 is pegs.Fig. 2. Scheme of interaction of the peg working body of a mobile reloader of cotton grade KhPP Raw cotton, selected from the thickness of the riot by pegs, is transported to an inclined conveyor, with the help of which it is loaded into the body of a transport trailer.During the tunneling machine, the same forces act as during the operation of the riot breaker, as well as during the transportation of the mass of raw cotton by the pegs of the belt elevator of mobile receiving devices.Dismantled by the riot breaker RB, RP raw cotton is fed into the pipeline (circular section) of the pneumatic transport system of the cotton plant, by which it is transported from the storage area to the production workshops.On straight sections of pipes, raw cotton's relative speed of movement reaches values of 20÷25 m/s.Raw cotton is transported mainly in the lower part of the pipeline (Fig. 3).
F tr is the friction force of the splitter with raw cotton; V 0 is sliding speed; V 1 is airflow speed.

Fig. 3. The scheme of interaction of the working bodies of the pneumatic pipeline
The raw cotton is in intensive contact with the pipeline walls at lower speeds or higher weight concentrations of the mixture (i.e., at high productivity).In this case, the friction force of cotton with the pipeline's inner surface, the surface's state, and its roughness play an important role.The presence of large friction forces or roughness leads to the fact that the transported raw cotton begins to twist into clods, forming flagella in the fiber.This is especially evident when changing the direction of movement of cotton flow with air in the elbows of the pipeline [8].
In the transport and distribution network of cotton ginning plants, screw conveyors are used for internal and intershop transportation of raw cotton from one technological process to the next, as well as for the redistribution of cotton between gin batteries and purifiers.Conveyors of this type are also used in cotton cleaners from small litter.In all these cases, there are specific features of the interaction of raw cotton with the elements of the screw feather and the casing of the screw conveyor (Fig. 4).
F tr is friction force of the splitter with raw cotton; V is the sliding speed; ω is the number of revolutions of the screw conveyor.

Fig. 4. Scheme of interaction of the working bodies of the screw conveyor
When raw cotton moves through pneumatic pipes, the raw cotton rubs against the inner surface of the screw conveyor trough or against the grate surface (for screw cleaners) with the interaction of cotton with the transition surfaces formed during the production of holes.In screw conveyors (conveyors), raw cotton moves relative to the helical surface of the screw feather, the transition surface of the screw itself to its periphery, absorbing the action of the friction forces of cotton on the surface of the feather of the screw, the forces of relative displacement, as well as centrifugal forces when the filling factor of the screw exceeds unit [9].
In the interaction of raw cotton with the main and transitional surfaces, screw conveyors can become clogged with cotton, which causes sudden failures and reduces the reliability of their operation.They are associated mainly with changes in the friction conditions of cotton.When cotton interacts with the transitional surfaces of the screws and the mesh surfaces of the grate, microdamage to the fibers can occur, especially during slaughtering.
Pneumatic transport installations incorporate separators that serve to separate air from raw cotton and clean the latter from fine litter.Air separation takes place on a mesh surface made of perforated sheet steel.Cotton particles under the action of the airflow are pressed against the separator mesh's surface, and the scraper drum's blades remove the cotton and send it to the vacuum valve.Here the main role is played by the force of friction on the inner surface of the mesh and on the surfaces of the holes in the mesh [10].
One of the responsible friction units in cleaning raw cotton from fine and coarse litter is cleaner.Raw cotton supplied for processing usually contains large (more than 8 mm) and small organic impurities in the form of parts of leaves, stems, flaps of cotton bolls, etc., as well as mineral impurities -sand, dust, and clods of earth.These impurities must be removed during the technological process.
Following the qualitative composition of weeds, two types of cleaners are used: to remove small weeds, combined with the joint operation of loosening drums and mesh surfaces, and to remove large weeds that have saw and saw drums, a brush for stringing raw cotton particles on saw teeth and breaker bars [11].
In coarse litter cleaners, the main active surfaces interacting with raw cotton are the surfaces of the teeth of nail files, saws, and the surfaces of grates (Fig. 5 and 6).Here, more severe conditions are observed for the fibers since the process of interaction with the transitional surfaces of the nail files, the surface of saws and grates, i.e., the friction of the cotton saw surface sector -on the rounded or flat surface of the grate, the adhesion of cotton volatiles that prevents the release of weed impurities.
F tr is the friction force of the splitter with raw cotton; V is sliding speed; ω is number of revolutions of the working body of the fine litter cleaner with raw cotton; 1 is raw cotton; 2 is pins; 3 is chute; 4 is screw Fig. 5. Scheme of interaction of the working bodies of the fine litter cleaner with raw cotton F tr is the friction force of the splitter with raw cotton; V is sliding speed; ω is the number of revolutions of the working body of the coarse litter cleaner; 1 is raw cotton; 2 is chute; 3 is regeneration drum.

Fig. 6. Scheme of interaction between the working bodies of the coarse litter cleaner
The most difficult conditions for the interaction of raw cotton (fiber, lint) with the working surface are observed in saw and feller gins and fiber cleaners and linters.In gins, the separation of fibers from seeds is carried out.The raw roller formed in the working chamber of the gin must have a certain density so that under the action of the saw teeth, it can rotate to continuously supply cotton to the teeth of the saw blades at the arc of their entry into the working chamber.Here, the action of friction forces on the sector of the surface of the saw, grate, and seed combs of the forces of the capture of the fibers by the teeth of the saws, impact forces, etc., is observed.(Fig. 7 and 8).
The mechanical process of separating fibers from seeds in the working chamber occurs due to the interaction of raw cotton with the saw cylinder, grate, and seed comb.One of the main requirements for the surfaces of the working chamber is the minimum resistance to the movement of the raw roller.In the case of an increase in friction forces with a change in the characteristics of the incoming raw cotton, the power consumption increases and even the termination of the ginning process.Therefore, the correct selection of the microgeometry of the surfaces and materials of the working chamber is essential for increasing the efficiency of the genie [12].
The interaction of raw cotton with the transitional surfaces of the teeth of saws and grates in the working area leads to damage to the fibers.At the same time, these surfaces are subjected to intense wear, resulting in the saws losing their performance.
F tr is the friction force of the splitter with raw cotton; V is sliding speed; ω is the number of revolutions of the working body of the saw gin with raw cotton.After the ginning of raw cotton, the cotton fiber enters the fiber cleaners to clean it from litter, and other impurities and defects.The main working bodies in the fiber cleaner are the saw drum and the grate.The main requirement for fiber cleaners is the preservation of the fiber's natural physical and mechanical properties when interacting with the specified working bodies, where, in addition to friction forces, impact forces from the grate act on the fiber.
The fiber in the fiber cleaner with an airflow enters the receiving mouth, is captured by the teeth of the rotating saws of the saw cylinder, and is frayed along the grate.As a result of interaction with the transitional surfaces of the teeth of saws and grates, the fibers can be damaged.In addition, during impact interaction on the edge of the grate (as discussed above), fibers that have received serious mechanical damage during previous transitions can break, increasing the fluff content [13].
The study and comprehensive analysis of the operating conditions of the main working bodies of cotton-cleaning and cotton-processing machines and mechanisms designed for the complex mechanization of the processes of harvesting, transporting, and processing raw cotton shows that they have general and specific shortcomings.
Their general disadvantages include relatively low productivity and high power consumption, which are inherent in their design, and specific disadvantages include damage to the fiber and cotton seeds, the formation of free fiber as a result of impact during the interaction of the surface of metal working bodies with raw cotton, the possible ignition of raw cotton upon collision with impurities present in cotton, as well as due to the occurrence of static electricity in the friction zone of the cotton-metal pair and a high coefficient of friction when interacting with raw cotton [14].
Based on this, it is necessary to solve the problem of developing new polymer composites to manufacture parts for rubbing pairs of working bodies of cotton processing machines.And this, in turn, requires having methods and installations for studying highquality and high-precision determination of the complex antifriction properties of composite polymer materials.As noted, the existing methods and installations have certain disadvantages; they do not allow determining the density of static electricity and temperature arising in the friction zone of the polymer-cotton pair, taking into account the operating modes and operating conditions of the working bodies of cotton processing machines and mechanisms.
During the interaction of polymeric materials with raw cotton, due to repeated contact formation and destruction of bonds in the contact zone, electric charges accumulate from time to time.Under the considered conditions of contact interaction of raw cotton and cotton fiber, depending on the contact conditions, the magnitude and direction of the friction force of raw cotton and cotton fiber, the indicators of raw cotton and the contacting solid material, in some cases, the magnitude of electric charges reaches 26 10-7 Cl and become factors for increasing the tension and electric force in the double electric layer on the friction surface, leading to an increase in the friction force in the contact zone, in special cases leading to sparking in the contact zone [15].
The high electrization of polymeric materials enhances the electrophysical, physical and mechanical processes in the friction zone and worsens their antifriction properties, as a result of which the efficiency of the friction pair decreases, which limits the efficiency of the material used and composite polymer coatings in the working bodies of machines.
One of the external operational factors affecting the properties of the polymer and its durability is the temperature in the friction zone.With an increase in temperature, relaxation processes are activated, leading to the destruction of the residual polarization and facilitating the neutralization of bound charges, and the electrical conductivity sharply increases, which plays a decisive role in the relaxation of the homocharge [16].
The relaxation of a heterocharge usually occurs at a lower temperature than the relaxation of a homocharge, then with an increase in the friction temperature, the charge of polar polymers generally first increases and then decreases, which requires the need to control triboelectric phenomena depending on the temperature field at the friction contact during the interaction of polymeric materials with raw cotton.
The analysis of the operating conditions of the working bodies of machines and mechanisms operating in contact interaction with raw cotton are carried out, which states that to further expand the scope of polymeric materials and coatings based on them for parts of friction units, unified methods for assessing the tribotechnical characteristics of a friction pair "polymer -cotton" and improvement of existing installations [17].This achieves the development of technology that allows the creation of new types of PM and effective compositions of polymer coatings based on them for friction units operating in contact interaction with raw cotton, providing the necessary reliability and durability of machines and mechanisms, taking into account their specific operating conditions.
For this purpose, the main requirements for the development of installation methods for determining the complex antifriction properties of the material are formulated, which allow for developing recommendations for the selection of composite polymer materials used for parts of rubbing pairs of working bodies of cotton machines and mechanisms operating in conditions of frictional interaction with raw cotton [18 -19].
Specific requirements include the following: when working in contact with raw cotton, polymeric and composite polymeric materials should not contaminate or color cotton, increase mechanical damage to cotton fiber and seeds; the developed method and installation when working on friction and wear should make it possible to determine the coefficient of friction with raw cotton, as well as the possibility of determining wear resistance under conditions that meet the requirements of cotton processing machines and mechanisms, but taking into account the moisture content of raw cotton and its contamination; in connection with the specific properties of raw cotton (deformability, compressibility under load, tenacity of raw cotton), the dependence of characteristics on humidity, electrification during friction with a polymer material, scoring properties (properties of raw cotton to scratch the surface of the material due to the presence of weed impurities in it, parts of the leaf, stem, flaps, sand, dust and small stones that are deeply embedded in the fiber, significant shock-shaking effects are required to remove them) and its relatively easy flammability should not accumulate static electricity charges in the polymer-cotton contact zone, especially in the used composite polymeric materials under the conditions of studying their antifriction properties and to form a spark when colliding with solids present in raw cotton under the operating conditions of the working bodies of machines and mechanisms [20][21].
General requirements for materials include: -the selected polymeric materials or their compositions should provide good manufacturability and economy; -methods and equipment for producing products from polymers or composite polymer coatings on their surface in various geometric dimensions in simple or complex configurations; -composite polymeric materials must have a set of required performance properties while maintaining resistance at temperatures from -20 °C to +80 °C at ambient humidity up to 75% and the influence of any climatic factors; -when working on friction and wear, composite polymer materials must have sufficiently good antifriction properties and wear resistance and operate in the speed range of 0-8.0 m/s and loads of 0.001-0.05MPa.Based on the established specific requirements and general requirements for materials, it becomes necessary to solve the problem of developing new polymer composites to manufacture parts for friction units operating in contact interaction with raw cotton and cotton fiber, depending on their operating conditions.And this circumstance, in turn, requires having methods and installations for studying high-quality and highly accurate determination of the complex antifriction properties of composite polymer materials with predetermined properties for specific friction units [22][23].
Based on the established requirements, a modular installation was created to determine the antifriction properties of antistatic heat-conducting antifriction and antifriction-wearresistant composite polymer materials and coatings based on them (Fig. 9). 1 is arrow; 2 is axis; 3 is cylindrical box; 4 is copper electrodes; 5 is piston; 6 is raw cotton; 7 is sample with composite polymer coatings; 8 is disk; 9 is load system; 10 is cable sensor DS18B20 for temperature measurement; 11 is sensor cable 2N3819 for measuring electrostatic charge.In the first variant, charges are removed using copper electrodes, at the ends of which pistons are fixed.With such a measurement of charges, an additional error appears due to the electrification of the electrodes [24][25].
On the machine, a 2N3819 sensor is installed at a certain distance from the charged surface of the polymer coating, which makes it easier to obtain reliable data.The sensor is a metal plate with needle electrodes immersed in cotton.The amount of charge is measured by a static voltmeter, which is transferred from the charged surface to the sensor by electrostatic induction.At the same time, experiments have shown that the accuracy of measuring the values of charges during contact and non-contact removal of charges is almost the same.The sensor is isolated from the unit body with PTFE gaskets.Isolation of the friction zone using the high dielectric properties of PTFE improves the accuracy of measuring electrostatic charges.This is also facilitated by the additional capacitance in the measuring circuit [26][27].
According to the known capacity of the system and the potential measured by a static voltmeter, the charge value is determined by the formula: where U is the voltage measured with a static voltmeter; C csv is the capacitance of a static voltmeter; С сrp is the capacity of the rubbing pair; С cac is the capacity of the additional capacitor.
The maximum charge of static electricity is achieved at different times of friction with raw cotton.The time for forming the maximum charge during the formation of static electricity charges for all polymeric materials ranges from 20 to 145 s.Therefore, in all experiments, the magnitude of static electricity charges is measured after 180 s.
Determining the magnitude of the charge of static electricity in the friction zone is removed using electrodes.The magnitude of the charges of static electricity is determined by measuring the magnitude of the potential using the sensor 2N3819, described in [28][29].
To prevent the leakage of charges formed as a result of friction, individual parts, and assemblies of the tribometer are insulated with fluoroplastic gaskets.The magnitude of the charges of static electricity and their density is determined by measuring the magnitude of the potential using the sensor 2N3819.
The charges are removed using a metal brush, at the ends of which flexible wires are attached.With such a measurement of charges, an additional error appears due to the electrization of the brush itself [30][31].
The application of the sensor, which is a metal plate with needle electrodes immersed in cotton, is set at a certain distance from the charged surface of the polymer coating, which allows more reliable data to be obtained.The amount of charge transferred from the charged surface to the sensor by electrostatic induction is measured with a static voltmeter.In this case, the accuracy of measurements of the values of charges during contact and noncontact removal of charges will be almost the same.Isolation of the friction zone using the high dielectric properties of PTFE improves the accuracy of measuring electrostatic charges.This is also facilitated by the additional capacitance in the measuring circuit [32][33].
The temperature in the friction zone is measured using a DS18B20 sensor, the principle of operation of which is based on the change in EMF depending on temperature.The DS18B20H sensor is located on the bottom of the cylindrical box, on which copper electrodes are installed.

Conclusions
Analyzes of studies devoted to the process of contact interaction of fibrous materials with various materials are carried out, in which, mainly to assess the antifriction properties, they proceed from the point of view of the roughness of the surfaces of the counterbody under study.
The antifriction conditions and the occurrence of the friction force during the contact interaction of raw cotton in the friction units operating under various conditions of contact with the fibrous mass in the working bodies of the cotton processing equipment involved in the technological process, the formation of riots and storage in riots, its disassembly, and supply to production were studied.
The main parameters affecting the friction force, which characterizes the performance of friction units paired with raw cotton and cotton fiber, have been found out.It has been established that in the implementation of the technological process of preparing and processing raw cotton in the nodes of machines and mechanisms, the components of the friction force depend on adhesion, grade, humidity, and contamination of raw cotton, as well as to the geometric shapes and sizes of parts in contact with the fibrous mass.
It has been determined that it is advisable to take the friction force as a criterion for evaluating the work of a particular working surface, which affects the quality characteristics of raw cotton, fiber, and energy parameters of machines and mechanisms.
Based on a comprehensive analysis of the operation of cotton-cleaning and cottonprocessing machines and mechanisms for the applied and proposed polymeric materials and coatings based on them in friction units interacting with raw cotton and cotton fiber, specific requirements were determined for the simultaneous assessment of antifriction properties, taking into account specific operating conditions and general requirements for materials friction pairs.
Based on the established requirements, a unified modular installation was created for determining anti-friction-wear-resistant polymeric materials and coatings based on them, which makes it possible to develop the production of products with predetermined properties for specific friction units operating in interaction with raw cotton or cotton fiber.
It has been established that for the development of antifriction polymeric materials and coatings based on them, working in contact interaction with the fibrous mass, the main indicators to be evaluated are the friction force, the temperature in the friction zone and the magnitude of the static electric charge formed in the contact zone.

Fig. 1 .
Fig. 1.Scheme of interaction of the peg working body of the pneumatic mechanical disassembler of the raw cotton feeder brand RP

Fig. 7 .Fig. 8 .
Fig. 7. Scheme of interaction of the working bodies of the saw gin with raw cotton

Fig. 9 .
Fig. 9. Technological scheme of the installation for determining the friction force, temperature, and electrostatic charge in the friction zone