CN114872225A - Preparation equipment and process of PVC flame-retardant plastic particles for wires and cables - Google Patents
Preparation equipment and process of PVC flame-retardant plastic particles for wires and cables Download PDFInfo
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- CN114872225A CN114872225A CN202210808095.4A CN202210808095A CN114872225A CN 114872225 A CN114872225 A CN 114872225A CN 202210808095 A CN202210808095 A CN 202210808095A CN 114872225 A CN114872225 A CN 114872225A
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
- B29B9/00—Making granules
- B29B9/02—Making granules by dividing preformed material
- B29B9/06—Making granules by dividing preformed material in the form of filamentary material, e.g. combined with extrusion
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
- B29B9/00—Making granules
- B29B9/12—Making granules characterised by structure or composition
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2027/00—Use of polyvinylhalogenides or derivatives thereof as moulding material
- B29K2027/06—PVC, i.e. polyvinylchloride
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Abstract
The invention belongs to the technical field of plastic particles, and particularly relates to a preparation device and a preparation process of PVC flame-retardant plastic particles for wires and cables, wherein the preparation device comprises an extruder, a temperature measurement module and a controller; when the extruder is used for processing and producing plastic particles, the heating coil of the screw extruder has larger hysteresis so as to cause irregular change of parameters of a controlled heating object, and the temperature state of a melt in the screw extruder has the characteristics of nonlinearity, large time hysteresis and the like compared with the water temperature in the charging barrel, so that the temperature control effect on the screw extruder is not ideal enough.
Description
Technical Field
The invention belongs to the technical field of plastic particles, and particularly relates to equipment and a process for preparing PVC flame-retardant plastic particles for wires and cables.
Background
Polyvinyl chloride (PVC) is a general-purpose plastic with wide application, the flexibility of the PVC can be adjusted by adding different amounts of plasticizers, and the PVC is widely applied to wire and cable materials; PVC is an amorphous homopolymer formed by polymerizing polyethylene monomers, has an oxygen index of over 45, and has good weather resistance, electrical insulation and self-extinguishing property; PVC has poor thermal stability, slight decomposition starts when the PVC is heated to about 100 ℃, and the processing temperature of the PVC is usually over 160 ℃, so that various additives are required to be added during PVC processing, the PVC has certain plasticity, toughness and softness, but the oxygen index is reduced, and a flame retardant is required to be added for a cable material with high flame retardant requirement.
The industrial production of PVC cable materials has various modes due to different equipment: comprises double-roller open milling and grain cutting, single screw extruder granulation, double screw extruder granulation, buchner granulation and double-stage extruder granulation; the double-stage extruder set with the double screws and the single screw in the same direction has the advantages that the double-screw extruder set can realize high rotating speed and high yield due to the backpressure of the double-screw inorganic head, the discharging temperature is easy to control, the rotating speed of the single screw is low, the internal heating is low, water cooling is introduced into the screw, the cooling extrusion and air cooling and hot granulation are facilitated, and the production capacity is greatly improved.
In the operation process of the screw extruder, in order to ensure the product quality, the temperature of the screw extruder needs to be accurately controlled, and the heating coil of the screw extruder has larger hysteresis, so that the parameter of a controlled heating object is irregularly changed; the multi-section temperature in the double-screw extruder is usually controlled by adopting the traditional PID, the temperature control system of the extruder is easily interfered by external factors, the temperature of water in a material cylinder of the screw extruder is usually measured to reflect the temperature state of melt in the screw extruder, and the temperature state of the melt in the screw extruder is compared with the temperature of water in the material cylinder, so that the temperature control effect on the screw extruder is not ideal, and meanwhile, the parameters of the traditional PID control method are fixed, so that the effectiveness of the temperature control method can be ensured on the basis of strictly controlling the heating process of each section of the screw extruder, and the material is in the temperature range of the technological requirement in the process of extruding.
In view of the above, the invention provides equipment and a process for preparing PVC flame-retardant plastic particles for wires and cables, which solve the technical problems.
Disclosure of Invention
In order to solve the defects of the prior art, the invention provides equipment and a process for preparing PVC flame-retardant plastic particles for wires and cables; the wire with the exposed section is embedded in the wire groove formed in the surface of the screw rod of the extruder, the melt is acted by the screw rod of the extruder and is in contact with the exposed section of the wire arranged in the wire groove in the surface of the screw rod, and then the heat of the melt is directly conducted to the wire, so that the detection of the temperature parameter of the melt in the screw rod area of the extruder is increased, and the detection precision of the actual temperature of the screw rod extruder is improved.
The invention relates to a preparation device of PVC flame-retardant plastic particles for wires and cables, which comprises an extruder, a temperature measurement module and a controller, wherein the temperature measurement module is used for detecting the temperature state of a melt in the extruder; the extruder further comprises.
The wire casing, the wire casing has been seted up on the screw rod surface of extruder, the wire casing extends to on the outside screw rod section of extruder along the inside screw rod section of extruder.
The temperature measurement module, the temperature measurement module still includes wire, electrode holder and power, at least one the wire is fixed to be laid in the wire casing, install the brush piece that has the annular distribution on the electrode holder, one side of brush piece and the wire sliding contact of wire casing tip, the opposite side and the controller electric connection of brush piece, be in the electric connection state when brush piece and wire contact, closed return circuit is constituteed to brush piece, wire, power and controller.
Exposed sections are arranged on the wires, and the exposed sections of the wires are located at different positions of the wire grooves.
The controller is used for controlling the operation of the plastic particle preparation equipment.
Preferably, an aerogel layer is arranged in the wire slot, and the wire slot wraps the non-exposed section of the wire through the aerogel layer.
Preferably, the surface of the aerogel layer is provided with raised stripes perpendicular/parallel to the screw axis of the extruder.
Preferably, the exposed section surface of the lead is higher than the non-exposed section surface of the lead, and the exposed section edge of the lead is flush with the screw surface of the extruder.
Preferably, the exposed section of the lead is made of a nickel-chromium alloy material.
Preferably, the surface of the exposed section of the lead is embossed.
Preferably, the plurality of lead wires on the side of the brush piece are intermittently covered in pairs on the circumferential surface of the extruder screw.
Preferably, the controller controls the power supply to vary its electrical power parameter when the brush blade is intermittently in contact with the conductor.
Preferably, the plurality of wires on the side of the brush sheet are respectively wrapped around the circumferential surface of the extruder screw.
The preparation process of the PVC flame-retardant plastic particles for the wires and the cables is suitable for the PVC plastic particle preparation equipment and comprises the following steps.
S1, material pretreatment: sieving PVC resin with 60 mesh sieve, sieving plasticizer with 80 mesh sieve, adding filler, color paste, stabilizer and antioxidant into plasticizer, stirring to obtain paste slurry, grinding repeatedly for 2-4 times while controlling the fineness of slurry below 45 μm, and keeping the ratio of solid to liquid phases in the slurry at 1:3 by using plasticizer as solvent phase.
S2, kneading: introducing a 0.17-0.22MPa steam engine into the mixer for heating, putting PVC resin and a stabilizer after the mixer operates in no-load mode for 3min, stirring at a low speed of 200-350r/min for 2-5min, simultaneously adding color paste and a plasticizer during the low-speed stirring process, completely adding the slurry in S1 after the temperature of the materials in the mixer rises to 86 ℃, controlling the mixer to stir at a high speed of more than 1000r/min until the temperature rises to 102 ℃, discharging the materials into a cooling mixer for cold mixing to 25-35 ℃, and discharging to finish kneading.
S3, plasticizing and forming: and (3) adding the kneaded material in the S2 into a double-stage screw extruder for extrusion granulation, wherein the first stage is a homodromous meshed type double-screw extruder, the second stage is a single-screw extruder, and the processing temperature of the first-stage screw is controlled to be 145-165 ℃ and the processing temperature of the second-stage screw is controlled to be 170 ℃.
S4, temperature regulation: in the granulating process of the double-stage screw extruder in S3, conducting the temperature parameters of the melt in the extruder through the wires arranged in the screw wire grooves of the extruder, carrying out feedback regulation on the heating parameters of the extruder through the recognition of the electrical parameters in the wires by the controller, and controlling the temperature regulation process by adopting a PID method.
S5, cutting into granules and warehousing: and finally, in S3, an air-cooled grinding surface hot granulating mode is adopted, and granules enter a storage bin through a cyclone separator and a vibrating screen, are metered, packaged and stored.
The beneficial effects of the invention are as follows.
1. According to the preparation equipment and the preparation process of the PVC flame-retardant plastic particles for the wires and the cables, the wire with the exposed section is embedded in the wire groove arranged on the surface of the screw rod of the extruder, so that the melt is in contact with the exposed section of the wire arranged in the wire groove on the surface of the screw rod under the action of the screw rod of the extruder, the heat of the melt is directly conducted to the wire, the temperature parameter of the melt is reflected by measuring the change of the electrical parameter of the wire, the detection on the temperature parameter of the melt in the screw rod area of the extruder is increased, and the detection precision of the actual temperature of the screw rod extruder is improved.
2. According to the equipment and the process for preparing the PVC flame-retardant plastic particles for the wires and the cables, the temperature parameters of a melt in an extruder are conducted through a wire arranged in a screw wire slot of the extruder, the proportional gain P, the integral time constant Ti and the differential time constant Td are respectively determined according to the output value of a temperature detection signal, the detected temperature deviation change and the corresponding temperature regulation feedback quantity of a controller, and the no-load of the screw extruder and the introduction of aqueous solutions with different temperatures are subjected to fine adjustment to ensure the precision of temperature measurement.
Drawings
The invention will be further explained with reference to the drawings.
FIG. 1 is a perspective view of an apparatus for producing plastic particles in the present invention.
FIG. 2 is a view showing a state where the brush piece is in contact with the surrounding distribution leads in the present invention.
Fig. 3 is a partially enlarged view of a portion a in fig. 1.
FIG. 4 is a flow chart of the process for preparing plastic particles in the present invention.
FIG. 5 is a graph showing experimental data of the apparatus for manufacturing plastic particles in the present invention.
In the figure: 1. an extruder; 2. a wire slot; 21. an aerogel layer; 22. stripes; 3. a wire; 4. an electrode holder; 41. an electric brush sheet.
Detailed Description
In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further described with the specific embodiments.
As shown in fig. 1 to 5, the PVC flame retardant plastic particle preparation apparatus for electric wires and cables according to the present invention comprises an extruder 1, a temperature measurement module and a controller, wherein the temperature measurement module is used for detecting a temperature state of a melt in the extruder 1; the extruder 1 further comprises.
Temperature measurement module, temperature measurement module still includes wire 3, electrode holder 4 and power, at least one 3 fixed the laying of wire are in the wire casing 2, install the brush piece 41 of annular distribution on the electrode holder 4, 3 tip sliding contact of wire in one side of brush piece 41 and the wire casing 2, the opposite side and the controller electric connection of brush piece 41, be in the electric connection state when brush piece 41 contacts with wire 3, closed return circuit is constituteed to brush piece 41, wire 3, power and controller.
Exposed sections are arranged on the wires 3, and the exposed sections of the wires 3 are located at different positions of the wire casing 2.
The controller is used for controlling the operation of the plastic particle preparation equipment.
In the prior art, when the extruder 1 is used for processing and producing plastic particles, the heating coil of the screw extruder 1 has large hysteresis, which causes irregular change of parameters of a heating object, the multi-section temperature in the screw extruder 1 is usually controlled by adopting the traditional PID, and the temperature control system of the extruder 1 is easily interfered by external factors, and the temperature of water in the material cylinder of the screw extruder 1 is usually measured to reflect the temperature state of melt in the screw extruder 1, and the temperature state of melt in the screw extruder 1 is compared with the temperature of water in the material cylinder, so that the temperature control effect of the screw extruder 1 is not ideal.
Therefore, the invention arranges the wires 3 with exposed sections in the wire casing 2 arranged on the surface of the screw rod of the extruder 1, extends the wire casing 2 to the screw rod section outside the extruder 1 along the screw rod section inside the extruder 1, leads the wires 3 arranged in the wire casing to be in electrical contact with the electric brush sheet 41 on the electrode frame 4 outside the extruder 1, when the screw extruder 1 runs, the melt is acted by the screw rod of the extruder 1 and is in contact with the exposed sections of the wires 3 arranged in the wire casing 2 on the surface of the screw rod, then directly conducts the heat of the melt to the wires 3, a plurality of wires 3 arranged on the surface of the screw rod of the extruder 1 are arranged at different positions of the screw rod of the extruder 1, changes the resistivity of the wires 3 by conducting the heat temperature of the melt through the contact of the exposed sections of the wires 3, and leads the ends of the wires 3 on the screw rod outside the extruder 1 are in the rotating process, the temperature sensor is in sliding contact with an elastic electric brush piece 41 on an electrode frame 4 and is transmitted to a controller through the electric brush piece 41 on the electrode frame 4, then the change of the electric parameter in the lead 3 is identified through the controller, and the temperature parameter of the melt in the contact area of the screw rod of the extruder 1 is further reflected.
As an embodiment of the present invention, an aerogel layer 21 is disposed in the wire slot 2, and the wire slot 2 wraps the non-exposed section of the wire 3 through the aerogel layer 21; the screw rod of extruder 1 is at the operation in-process, the fixed non-exposed section of laying wire 3 in wire casing 2, receive the temperature influence of fuse-element in the extruder 1 equally, through setting up aerogel layer 21 in wire casing 2, can provide sufficient heat-proof quality in the narrow and small space in wire casing 2, aerogel material possesses the high strength characteristic in the environment of extruder 1 simultaneously, be convenient for install in wire casing 2, and maintain the temperature precision of the exposed section conduction feedback of wire 3, thereby the operational effect of plastic pellet preparation equipment has been promoted.
As an embodiment of the present invention, the surface of the aerogel layer 21 is provided with raised stripes 22, and the stripes 22 are perpendicular/parallel to the screw axis direction of the extruder 1; through setting up at the perpendicular stripe 22 arch of 1 screw shaft of the aerogel layer 21 surface/parallel to extruder, in twin-screw extruder 1, it is protruding to mesh on the screw surface perpendicular to screw shaft axial stripe 22, be convenient for drive the fuse-element of contact along with the pivoted screw together and move in extruder 1, maintain twin-screw extruder 1's high yield, in single-screw extruder 1, it is protruding to be parallel to 1 axial stripe 22 of screw shaft of extruder, be convenient for leave out the whole area of the fuse-element that 1 internal contact of extruder arrived, reduce the fuse-element of remaining in extruder 1 inside, maintain the operational effect of single-screw extruder 1 cooling working condition.
As an embodiment of the present invention, the exposed section surface of the wire is higher than the non-exposed section surface of the wire, and the exposed section edge of the wire 3 is flush with the screw surface of the extruder 1; the exposed section of the lead 3 is arranged to be protruded from the non-exposed section and used for filling the fall of the exposed section of the lead 3 and the aerogel layer 21, so that a concave angle is prevented from being formed at the end part of the exposed section of the lead 3, the melt in the extruder 1 is prevented from being adhered in the exposed section, the edge of the guided exposed section is flush with the surface of the screw of the extruder 1, the balanced acting force on the melt in the operation process of the screw of the extruder 1 is kept, and the operation effect of the plastic particle preparation equipment is maintained.
As an embodiment of the present invention, the exposed section of the lead 3 is made of nichrome material; the nickel-chromium alloy is selected as the exposed section material of the lead 3, the interference amount of temperature change to the resistance value of the lead 3 is conveniently reflected by utilizing the higher resistance temperature coefficient of the nickel-chromium alloy, the change of the electrical parameter of the lead 3 is obviously reflected in the controller, the red copper material is selected for the non-exposed section of the lead 3, the influence of external screw temperature conduction is reduced, and the operation effect of the plastic particle preparation equipment is maintained.
As an embodiment of the present invention, the exposed surface of the lead 3 is embossed; embossing is carried out in the exposed section of the lead 3, so that the surface area of the exposed section of the lead 3 is increased, the contact area between the exposed section of the lead 3 and the melt is increased, the exposed section of the lead 3 can reflect the temperature change of the moving melt in the extruder 1 in time, the surface subjected to embossing treatment increases the wear resistance of the exposed section of the lead 3, prolongs the service life of the temperature detection performance of the exposed section of the lead 3, and improves the operation effect of the plastic particle preparation equipment.
As an embodiment of the present invention, a plurality of the lead wires 3 on the brush piece 41 side are intermittently covered in pairs on the circumferential surface of the screw of the extruder 1; when laying many wires 3 in the wire casing 2 on the extruder 1 screw rod, through extending the peripheral surface that covers extruder 1 screw rod respectively with the wire 3 of brush piece 41 side, make many wires 3 contact with brush piece 41 respectively along with the rotatory in-process of screw rod, be applicable to the high rotational speed's of twin-screw extruder 1 operating mode, reduce the consumptive material quantity of brush piece 41, in time feed back the temperature parameter that each wire 3 corresponds extruder 1 screw rod position to the controller in, keep the detection precision to the inside fuse-element temperature parameter of extruder 1, thereby maintain the operational effect of plastic pellet preparation equipment.
As an embodiment of the present invention, the controller controls the power supply to change its electric power parameter while the brush piece 41 is intermittently in contact with the lead wire 3; the electric power parameter of the power supply is changed through the controller, different wires 3 electrically connected with the electric brush pieces 41 are matched, on the basis that the exposed sections of the wires 3 sense different temperatures, the electric parameter of the power supply input wire 3 is changed, the electric parameter difference fed back by the detection temperature of the exposed sections of the wires 3 at different positions of the screw rod of the extruder 1 is increased, the controller can conveniently measure the temperature parameter, the detection precision of the controller on the temperature parameter is enhanced, and therefore the operation effect of the plastic particle preparation equipment is improved.
As an embodiment of the present invention, a plurality of the wires 3 on the brush piece 41 side are respectively wrapped around the circumferential surface of the screw of the extruder 1; when a plurality of wires 3 are distributed in the wire grooves 2 on the screw rod of the extruder 1, the wires 3 on the side of the electric brush piece 41 are respectively covered on the circumferential surface of the screw rod of the extruder 1 in a surrounding manner, so that the plurality of wires 3 are kept in a contact state with the electric brush piece 41 along with the rotation process of the screw rod, the device is suitable for the working condition of the single-screw extruder 1 with low rotating speed, the temperature parameters of the wires 3 corresponding to the screw rod position of the extruder 1 are continuously fed back to the controller, the detection precision of the temperature parameters of the melt inside the extruder 1 is kept, and the operation effect of the plastic particle preparation equipment is maintained.
The preparation process of the PVC flame-retardant plastic particles for the wires and the cables is suitable for the PVC plastic particle preparation equipment and comprises the following steps.
S1, material pretreatment: sieving PVC resin with 60 mesh sieve, sieving plasticizer with 80 mesh sieve, adding filler, color paste, stabilizer and antioxidant into plasticizer, stirring to obtain paste slurry, grinding repeatedly for 2-4 times while controlling the fineness of slurry below 45 μm, and keeping the ratio of solid to liquid phases in the slurry at 1:3 by using plasticizer as solvent phase.
S2, kneading: introducing a 0.17-0.22MPa steam engine into the mixer for heating, putting PVC resin and a stabilizer after the mixer operates in no-load mode for 3min, stirring at a low speed of 200-350r/min for 2-5min, simultaneously adding color paste and a plasticizer during the low-speed stirring process, completely adding the slurry in S1 after the temperature of the materials in the mixer rises to 86 ℃, controlling the mixer to stir at a high speed of more than 1000r/min until the temperature rises to 102 ℃, discharging the materials into a cooling mixer for cold mixing to 25-35 ℃, and discharging to finish kneading.
S3, plasticizing and forming: and (3) adding the kneaded material in the S2 into a double-stage screw extruder 1 for extrusion granulation, wherein the first stage is a homodromous meshed type double-screw extruder 1, the second stage is a single-screw extruder 1, and the processing temperature of the first-stage screw is controlled to be 145-170 ℃ and the processing temperature of the second-stage screw is controlled to be 120-165 ℃.
S4, temperature regulation: in the granulating process of the double-stage screw extruder 1 in S3, conducting the temperature parameters of the melt in the extruder 1 through the wires 3 arranged in the screw wire grooves 2 of the extruder 1, carrying out feedback regulation on the heating parameters of the extruder 1 through the recognition of the electrical parameters in the wires 3 by the controller, and controlling the temperature regulation process by adopting a PID method; and respectively determining a proportional gain P, an integral time constant Ti and a differential time constant Td according to the output value of the temperature detection signal, the detected temperature deviation amount change and the corresponding temperature regulation feedback amount of the controller, and carrying out fine adjustment on the no-load of the screw extruder 1 and the introduction of aqueous solutions with different temperatures to ensure the accuracy of temperature measurement.
S5, cutting into granules and warehousing: and finally, in S3, an air-cooled grinding surface hot granulating mode is adopted, and granules enter a storage bin through a cyclone separator and a vibrating screen, are metered, packaged and stored.
The specific workflow is as follows.
When the device works, a lead 3 provided with an exposed section is embedded in a slot 2 arranged on the surface of a screw rod of an extruder 1, when the screw extruder 1 runs, a melt is acted by the screw rod of the extruder 1 and is contacted with the exposed section of the lead 3 arranged in the slot 2 on the surface of the screw rod, then the heat of the melt is directly conducted to the lead 3, a plurality of leads 3 arranged on the surface of the screw rod of the extruder 1 are positioned at different positions of the screw rod of the extruder 1, the resistivity of the lead 3 is changed by the contact of the exposed sections of the leads 3 and the heat temperature of the conductive melt, the end part of the lead 3 positioned on the screw rod outside the extruder 1 is in sliding contact with an elastic electric brush sheet 41 on an electrode frame 4 in the rotating process and is transmitted to a controller through the electric brush sheet 41 on the electrode frame 4, and then the change of the electric parameters in the lead 3 is identified through the controller, compared with the existing feedback control of a temperature adjusting device in a material cylinder of the extruder 1, the temperature parameter of the melt in the contact area of the screw rod of the extruder 1 is reflected, the heat of the melt is required to be transmitted to a heat-conducting medium in the material cylinder of the extruder 1 and then detected by a temperature sensor, the exposed section of the melt contacting with the lead 3 is directly shortened by the heat-conducting medium, the detection of the temperature parameter of the melt in the screw rod area of the extruder 1 is increased, and the detection precision of the actual temperature of the screw rod extruder 1 is improved; the non-exposed section of the lead 3 fixedly arranged in the wire groove 2 is also influenced by the temperature of a melt in the extruder 1 during the operation process of a screw of the extruder 1, the aerogel layer 21 arranged in the wire groove 2 can provide enough heat insulation performance in a narrow space in the wire groove 2, and meanwhile, the aerogel material has the characteristic of high strength in the environment of the extruder 1, is convenient to install in the wire groove 2 and maintains the temperature precision of conduction feedback of the exposed section of the lead 3; the nickel-chromium alloy is selected as the exposed section material of the lead 3, the interference amount of temperature change to the resistance value of the lead 3 is conveniently reflected by utilizing the higher resistance temperature coefficient of the nickel-chromium alloy, the change of the electrical parameter of the lead 3 is obviously reflected in the controller, and the red copper material is selected as the non-exposed section of the lead 3, so that the influence of the temperature conduction of the external screw is reduced; embossing is carried out in the exposed section of the lead 3, so as to increase the surface area of the exposed section of the lead 3, and the embossed surface reduces the adhesiveness of a melt material, so that the exposed section of the lead 3 can reflect the temperature change of the moving melt in the extruder 1 in time; the electric power parameter of the power supply is changed through the controller, the electric power parameter of the power supply is changed by matching with different wires 3 electrically connected with the electric brush pieces 41, on the basis that the exposed sections of the wires 3 sense different temperatures, the electric parameter of the power supply input wires 3 is changed, the electric parameter difference fed back by the detection temperature of the exposed sections of the wires 3 at different positions of the screw rod of the extruder 1 is increased, the controller can conveniently measure the temperature parameter, and the detection precision of the controller on the temperature parameter is enhanced.
To verify the practical application effect of the present invention, the following experiment was performed.
1. And (4) preparing a test.
The temperature of the material barrel of each section of the screw extruder is controlled, and the temperature gradient of corresponding numerical values among the sections is ensured, so that the mixing and the plasticization of the melt are facilitated; the temperature measurement is carried out by sequentially introducing water solutions with different temperatures into the screw extruder, the temperature detection value of the surface of the screw in the screw extruder is taken as a 1# measurement point, the temperature measurement value in the charging barrel in the screw extruder is taken as a 2# measurement point, the temperature measurement precision is compared during the comparison, and the comparison is taken as comparison group data.
2. And (4) testing.
2.1 control experiment.
The temperature of the screw extruder can gradually rise after the heating device is opened, the temperature of the screw extruder can gradually decrease after the cooling water valve is opened, and the temperature control transfer function of the screw extruder can be approximately expressed by an order delay function.
In the formula: k denotes the static gain, T is the inertia constant, γ is the lag time, and S is the laplace transform factor.
According to the data of the comparison test, in the process of introducing liquid into the screw extruder to carry out comparison group test, the detection error of the 1# measuring point on the temperature parameter change in the screw extruder is lower, namely the temperature parameter with higher precision is detected in time.
2.2 example analysis.
Carrying out example analysis on temperature control of the screw extruder, dividing the screw into four sections according to the operating condition requirement of the screw extruder, and respectively setting the heating temperatures to be T1=135 ℃, T =150 ℃, T3=160 ℃, and T4=155 ℃; the kneading material of PVC resin is added into the screw extruder for processing, the temperature detection mode of the scheme is adopted to carry out temperature detection on the screw extruder charging barrel, and the PVC plastic particles produced are processed into the PVC sheath for the electric wire and cable, and the combustion test is carried out.
The test device comprises: the device comprises a combustion test box, a smoke measuring device, a cable bracket, a temperature measuring instrument and data acquisition equipment.
The test conditions are as follows: the air inlet pressure is 12-16Pa, the temperature is maintained at 20-26 ℃, and the relative humidity is maintained at 40-65%.
Air speed in the combustor: 1.20-1.30 m/s.
The methane gas for combustion is in homogeneous bottle package, and the heat value is 37 +/-1 MJ/m 3 。
Test time: and 20 min.
Sample treatment: the cable pattern should be pretreated for at least 24 hours under test conditions, with the binder removed prior to pretreatment.
And (3) test results: the post combustion data are shown in the following table.
According to the test result of the combustion test, the maximum burning and carbonizing length of the PVC cable is found to be 2.08m, which is less than the requirement that the burning and carbonizing length of the burning and carbonizing part in GB12666.1-7-1990 is not more than 2.5m, and the test result is judged to be qualified, so that the electric wire and cable prepared from the PVC flame-retardant plastic particles in the scheme meet the use standard.
In summary, according to the plastic particle preparation equipment disclosed by the invention, compared with the measurement of the screw extruder barrel region, the temperature detection of the screw region is improved, the temperature detection precision in an instant state is improved, and the use effect of the plastic particle preparation equipment disclosed by the invention can be verified to have corresponding beneficial effects.
The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (10)
1. The equipment for preparing the PVC flame-retardant plastic particles for the wires and the cables comprises an extruder (1), a temperature measurement module and a controller, wherein the temperature measurement module is used for detecting the temperature state of a melt in the extruder (1); characterized in that the extruder (1) further comprises:
the screw extruder comprises a wire groove (2), wherein the wire groove (2) is formed in the surface of a screw of the extruder (1), and the wire groove (2) extends to a screw section outside the extruder (1) along the screw section inside the extruder (1);
the temperature measurement module further comprises a lead (3), an electrode frame (4) and a power supply, the lead (3) is fixedly arranged in the wire slot (2), the electrode frame (4) is provided with brush pieces (41) which are distributed annularly, one side of each brush piece (41) is in sliding contact with the lead (3) at the end part of the wire slot (2), the other side of each brush piece (41) is electrically connected with the controller, the brush pieces (41) are in an electrically connected state when being in contact with the lead (3), and the brush pieces (41), the lead (3), the power supply and the controller form a closed loop;
exposed sections are arranged on the wires (3), and the exposed sections of the wires (3) are positioned at different positions of the wire slot (2);
the controller is used for controlling the operation of the plastic particle preparation equipment.
2. The PVC flame-retardant plastic particle preparation equipment for wires and cables according to claim 1, characterized in that: be equipped with aerogel layer (21) in wire casing (2), wire casing (2) wrap up the non-naked section of wire (3) through aerogel layer (21).
3. The PVC flame-retardant plastic particle preparation equipment for wires and cables according to claim 2, characterized in that: the surface of the aerogel layer (21) is provided with raised stripes (22), and the stripes (22) are vertical/parallel to the axial direction of a screw of the extruder (1).
4. The PVC flame-retardant plastic particle preparation equipment for wires and cables according to claim 2, characterized in that: the exposed section surface of the lead (3) is higher than the non-exposed section surface of the lead (3), and the exposed section edge of the lead (3) is flush with the screw surface of the extruder (1).
5. The PVC flame-retardant plastic particle preparation equipment for wires and cables according to claim 4, characterized in that: the exposed section of the lead (3) is made of a nickel-chromium alloy material.
6. The PVC flame-retardant plastic particle preparation equipment for wires and cables according to claim 5, characterized in that: the surface of the exposed section of the lead (3) is subjected to embossing treatment.
7. The PVC flame-retardant plastic particle preparation equipment for wires and cables according to claim 1, characterized in that: the plurality of conducting wires (3) on the side of the electric brush piece (41) are in pairs and discontinuously covered on the circumferential surface of the screw of the extruder (1).
8. The apparatus for preparing PVC flame-retardant plastic particles for electric wires and cables according to claim 7, wherein: the controller controls the power supply to change its electrical power parameters when the brush blade (41) is intermittently in contact with the conductor (3).
9. The PVC flame-retardant plastic particle preparation equipment for wires and cables according to claim 1, characterized in that: the conducting wires (3) on the side of the electric brush piece (41) are respectively covered on the circumferential surface of the screw of the extruder (1) in a surrounding way.
10. A preparation process of PVC flame-retardant plastic particles for wires and cables is characterized by comprising the following steps: the preparation process is suitable for the equipment for preparing the PVC plastic particles for the electric wires and the cables, which comprises the following steps:
s1, material pretreatment: sieving PVC resin by a 60-mesh sieve, sieving a plasticizer by a 80-mesh sieve, adding a filler, a color paste, a stabilizer and an antioxidant into the plasticizer, stirring into pasty slurry, carrying out reciprocating grinding for 2-4 times, controlling the fineness of the slurry to be below 45 mu m, and taking the plasticizer as a solvent phase to keep the solid-liquid phase ratio in the slurry at 1: 3;
s2, kneading: introducing a 0.17-0.22MPa steam engine into the mixer for heating, putting PVC resin and a stabilizer after the mixer operates in no-load mode for 3min, stirring at a low speed of 200-350r/min for 2-5min, simultaneously adding color paste and a plasticizer in the low-speed stirring process, completely adding the slurry in S1 after the temperature of the materials in the mixer rises to 86 ℃, controlling the mixer to stir at a high speed of more than 1000r/min until the temperature rises to 102 ℃, discharging the materials into a cooling mixer for cold mixing to 25-35 ℃, and discharging to finish kneading;
s3, plasticizing and forming: adding the kneaded material in the S2 into a double-stage screw extruder (1) for extrusion granulation, wherein the first stage is a homodromous meshed type double-screw extruder (1), the second stage is a single-screw extruder (1), the processing temperature of the first-stage screw is controlled to be 145-170 ℃, and the processing temperature of the second-stage screw is controlled to be 120-165 ℃;
s4, temperature regulation: in the granulating process of the double-stage screw extruder (1) in S3, conducting the temperature parameters of the melt in the extruder (1) through the wires (3) arranged in the screw wire grooves (2) of the extruder (1), carrying out feedback regulation on the heating parameters of the extruder (1) through the recognition of the controller on the electrical parameters in the wires (3), and controlling the temperature regulation process by adopting a PID method;
s5, cutting into granules and warehousing: and finally, in S3, an air-cooled grinding surface hot granulating mode is adopted, and granules enter a storage bin through a cyclone separator and a vibrating screen, are metered, packaged and stored.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202210808095.4A CN114872225A (en) | 2022-07-11 | 2022-07-11 | Preparation equipment and process of PVC flame-retardant plastic particles for wires and cables |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210808095.4A CN114872225A (en) | 2022-07-11 | 2022-07-11 | Preparation equipment and process of PVC flame-retardant plastic particles for wires and cables |
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2489865Y (en) * | 2001-07-20 | 2002-05-08 | 中国石油化工股份有限公司 | Mixing reactor |
| CN104441571A (en) * | 2014-11-04 | 2015-03-25 | 北京石油化工学院 | Method for measuring temperature of polymer melt on screw rod surface |
| CN104817788A (en) * | 2015-05-07 | 2015-08-05 | 邹文君 | High-flame-retarding low-smoke modified polyvinyl ethylene cable material and preparation method thereof |
| CN110871520A (en) * | 2019-12-12 | 2020-03-10 | 成都瑞琦医疗科技有限责任公司 | Granulation system of organic composite material master batch |
| CN213675386U (en) * | 2020-10-30 | 2021-07-13 | 郑州佳诺实业有限公司 | Double-screw extruder with temperature detection function |
| CN216609994U (en) * | 2021-10-27 | 2022-05-27 | 四川洪天新型建材有限公司 | PVC tubular product screw extruder |
-
2022
- 2022-07-11 CN CN202210808095.4A patent/CN114872225A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2489865Y (en) * | 2001-07-20 | 2002-05-08 | 中国石油化工股份有限公司 | Mixing reactor |
| CN104441571A (en) * | 2014-11-04 | 2015-03-25 | 北京石油化工学院 | Method for measuring temperature of polymer melt on screw rod surface |
| CN104817788A (en) * | 2015-05-07 | 2015-08-05 | 邹文君 | High-flame-retarding low-smoke modified polyvinyl ethylene cable material and preparation method thereof |
| CN110871520A (en) * | 2019-12-12 | 2020-03-10 | 成都瑞琦医疗科技有限责任公司 | Granulation system of organic composite material master batch |
| CN213675386U (en) * | 2020-10-30 | 2021-07-13 | 郑州佳诺实业有限公司 | Double-screw extruder with temperature detection function |
| CN216609994U (en) * | 2021-10-27 | 2022-05-27 | 四川洪天新型建材有限公司 | PVC tubular product screw extruder |
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