CN110014589B

CN110014589B - Production process of plastic pipe

Info

Publication number: CN110014589B
Application number: CN201810211758.8A
Authority: CN
Inventors: 殷军林
Original assignee: Zhejiang Shenfeng Pipe Co ltd
Current assignee: Zhejiang Shenfeng Pipe Co ltd
Priority date: 2018-03-15
Filing date: 2018-03-15
Publication date: 2021-04-30
Anticipated expiration: 2038-03-15
Also published as: CN110014589A

Abstract

The invention relates to the technical field of plastic pipe production, and discloses a production process of a plastic pipe, which comprises the following steps: (1) material preparation and feeding: mixing a plurality of proportioned raw materials and conveying the mixed raw materials into a mixing box of an extruder; (3) electrostatic dust removal: performing electrostatic adsorption on impurities in various raw materials in a mixing box through an electrostatic adsorption device; (4) and (3) extrusion molding: extruding and molding by an extruder to obtain a plastic pipe; (5) and (3) forming and drawing: drawing the formed plastic pipe by a drawing machine; (6) cutting: cutting the plastic pipe; (7) and (3) cooling: the plastic tube was cooled. The invention has the following advantages and effects: various raw materials in the mixing box are subjected to electrostatic adsorption through the electrostatic adsorption device, so that impurities are adsorbed on the metal coil, and the effect of improving the forming and processing quality of the plastic pipe is achieved; and the impurities adsorbed on the metal coil are collected in the dust removal cloth bag through the exhaust fan; has the effect of environmental protection.

Description

Production process of plastic pipe

Technical Field

The invention relates to the technical field of plastic pipe production, in particular to a production process of a plastic pipe.

Background

The plastic pipe includes PPR pipe, PE pipe, PVC pipe, etc. and is produced with plastic grains of synthetic resin as material, stabilizer, lubricant, plasticizer, etc. and through extrusion in an extruder.

At present, Chinese patent with application publication number CN106738747A and application publication date of 2017, 5 and 31 discloses a plastic pipe production process. The ingredients of the dosing pool are PE materials, and are dehumidified at the temperature of 80-90 ℃, dried by a hot air dryer and then enter an extruder for extrusion processing.

But at the in-process of batching storage in batching pond, because of batching pond is generally naked in this field for batching in batching pond long-time storage back, impurity such as dust in the air can fall in batching pond, thereby causes impurity such as the dust of mixing in the plastic tubing after the processing, influences the quality of plastic tubing.

Disclosure of Invention

The invention aims to provide a production process of a plastic pipe, which adsorbs dust in ingredients in an electrostatic adsorption mode in the feeding process so as to improve the processing quality of the plastic pipe.

The technical purpose of the invention is realized by the following technical scheme: a production process of a plastic pipe comprises the following steps:

(1) material preparation and feeding: mixing a plurality of proportioned raw materials and conveying the mixed raw materials into a mixing box of an extruder;

(2) electrostatic dust removal: performing electrostatic adsorption on impurities in various raw materials in a mixing box through an electrostatic adsorption device;

(3) and (3) extrusion molding: extruding and molding by an extruder to obtain a plastic pipe;

(4) and (3) forming and drawing: drawing the formed plastic pipe by a drawing machine;

(5) cutting: cutting the plastic pipe;

(6) and (3) cooling: the plastic tube was cooled.

The invention is further provided with: in the step (2), the electrostatic adsorption device comprises a metal coil spirally arranged on the inner wall of the mixing box body of the mixing box, a cathode wire vertically suspended in the middle of the mixing box body, and a power supply with an anode connected with the metal coil and a cathode connected with the cathode wire.

The invention is further provided with: the top of the mixing box body is provided with an air inlet; the electrostatic adsorption device further comprises an exhaust fan, a dust collection pipe arranged between the air inlet of the exhaust fan and the mixing box body, an air outlet pipe arranged at the air outlet of the mixing box body, a dust removal cloth bag arranged on the air outlet pipe, and a first filter screen arranged at the top of the mixing box body and provided with a covering air inlet.

The invention is further provided with: the electrostatic adsorption device also comprises a vibrator arranged on the outer wall of the mixing box body.

The invention is further provided with: the inner wall of the top of the mixing box body is provided with a plurality of air inlet branch pipes distributed in a circumferential array manner, and the peripheral outer wall of the top of the mixing box body is provided with an air inlet main pipe communicated with the air inlet branch pipes; a first reversing three-way valve is arranged between the air outlet pipe and the air outlet of the exhaust fan, and the air inlet main pipe is communicated with a valve port of the first reversing three-way valve; a second reversing three-way valve is arranged between the dust collection pipe and the air inlet of the exhaust fan, an air inlet pipe is further connected to a valve port of the second reversing three-way valve, and a second filter screen is arranged at the pipe orifice of the air inlet pipe.

The invention is further provided with: in step (1), multiple raw materials are placed in advance in the raw materials bucket and are realized carrying in the blending box in proportion in step (a) through the vacuum material loading machine, the vacuum material loading machine includes:

the vacuum hopper is arranged on a mixing box body of the mixing box, and a separation assembly for separating the vacuum hopper into a plurality of material suction cavities is arranged in the vacuum hopper;

the blanking assembly is arranged at the bottom of the vacuum hopper and is used for simultaneously opening and closing the plurality of material suction cavities;

the material suction assembly comprises a plurality of material suction pipelines respectively communicated with the side wall of the material suction cavity and material suction nozzles which are arranged on the material suction pipelines and are used for respectively sucking the raw materials in the raw material barrels;

the vacuum assembly comprises a plurality of vacuum branch pipes respectively communicated with the top of the material suction cavity, an electric regulating valve arranged in the middle of each vacuum branch pipe, a vacuum main pipe simultaneously communicated with the plurality of vacuum branch pipes and an air compressor communicated with the vacuum main pipe, wherein the electric regulating valve is electrically connected with a controller of the air compressor;

and the filter assembly comprises a plurality of film-coated filter cylinders which are respectively arranged at the tops of the material suction cavities and cover the vacuum branch pipes.

The invention is further provided with: a feeding hole is formed at the bottom of the vacuum hopper, and a feeding pipe which covers the feeding hole and is connected with the top of the mixing box body is arranged on the outer wall of the bottom of the vacuum hopper; the blanking assembly comprises a turning plate which is hinged to the bottom of the vacuum hopper and used for abutting against the lower surface of the blanking port to realize sealing, a balancing weight which is arranged on one side of the turning plate and enables the turning plate to abut against the blanking port through gravity, and a blanking valve which is arranged in the middle of the blanking pipe; when the turning plate is in a state of closing the feed opening, the lower surface of the separation component is abutted against the upper surface of the turning plate.

The invention is further provided with: the inner wall of the blanking pipe is provided with a spiral sheet, and the spiral sheet is positioned between the turning plate and the blanking valve.

In conclusion, the invention has the following beneficial effects:

1. by arranging the electrostatic dust collection device in the mixing box body, after the power supply is switched on, an electric field is formed between the metal coil and the cathode wire, when the actual electric field strength is close to the breakdown electric field of air, air is ionized to form a large number of positive ions and free electrons, the free electrons drift to the positive pole along with the electric field and collide with neutral molecules or particles in impurities in the deviation process, charged particles are formed after the impurities adsorb the electrons and continuously move towards the positive pole where the metal coil is located, and finally the impurities are adsorbed on the metal coil, so that the impurities in the raw materials are subjected to electrostatic adsorption, and the finished product quality of the plastic pipe is improved; meanwhile, impurities adsorbed on the metal coil can be sucked by an air extractor and then collected in a dust removal cloth bag;

2. when raw materials are proportioned, the flow of different electric regulating valves is firstly regulated, so that the air extraction efficiency of the air compressor to different material suction cavities is different, the suction force of a plurality of material suction nozzles to the raw materials in a plurality of raw material barrels is different, a plurality of raw materials can be sucked into a vacuum hopper according to the proportion in unit time, finally, when the air compressor stops working and opens a blanking assembly, the mixing of the plurality of raw materials is realized in the process of entering a mixing box body, the operations are repeated for a plurality of times, and a large amount of mixed raw materials can be stored in the mixing box body, so that the production efficiency can be improved;

3. open the unloading subassembly and make the raw materials fall into the in-process of compounding box, the raw materials falls into the flight of unloading pipe earlier, and multiple raw materials can improve the mixture degree of consistency after the flight department bumps.

Drawings

FIG. 1 is a schematic view of the present invention at the vacuum feeder and mixing box;

FIG. 2 is a schematic view of a partial structure of the present invention at a vacuum feeder;

FIG. 3 is a schematic diagram of the present invention at the mixing box and electrostatic adsorption apparatus.

Reference numerals: 1. a raw material barrel; 21. a vacuum hopper; 211. a partition assembly; 2111. a partition plate; 212. a feeding port; 213. a discharging pipe; 2131. a spiral sheet; 22. a blanking assembly; 221. turning over a plate; 222. a balancing weight; 223. a blanking valve; 23. a material suction assembly; 231. a suction pipeline; 232. a material suction nozzle; 24. a vacuum assembly; 241. vacuum tube separation; 242. an electric control valve; 243. a vacuum manifold; 244. an air compressor; 2441. a controller; 25. a filter assembly; 251. a membrane-covered filter cartridge; 3. a material suction cavity; 41. a metal coil; 42. a cathode line; 43. a power source; 44. an exhaust fan; 45. a dust collection pipe; 46. an air outlet pipe; 47. a dust removal cloth bag; 48. a first filter screen; 49. a vibrator; 51. air inlet branch pipes; 52. an air inlet main pipe; 53. a first direction-changing three-way valve; 54. a second direction-changing three-way valve; 55. an air inlet pipe; 56. a second filter screen; 6. a mixing box body; 61. and an air inlet.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Example 1: a production process of a plastic pipe comprises the following steps:

(5) cutting: cutting the plastic pipe;

(6) and (3) cooling: the plastic tube was cooled.

As shown in fig. 1 and 2, in step (1), the raw materials have four types, namely plastic particles, stabilizers, lubricants and plasticizers, and the four types of raw materials are stored in four raw material barrels 1 in advance and are synchronously conveyed into a mixing box in proportion through a vacuum feeding machine, wherein the vacuum feeding machine comprises a vacuum hopper 21, a blanking assembly 22, a suction assembly 23, a vacuum assembly 24 and a filtering assembly 25.

As shown in fig. 2, the cross section of the vacuum hopper 21 is circular, a feed opening 212 is formed at the bottom of the vacuum hopper 21, a feed pipe 213 covering the feed opening 212 is integrally provided on the outer wall of the bottom of the vacuum hopper 21, and the bottom of the feed pipe 213 is connected to the mixing box body 6 (see fig. 1) of the mixing box. Meanwhile, a partition assembly 211 for partitioning the vacuum hopper 21 into four material suction chambers 3 is arranged in the vacuum hopper 21; partition assembly 211 includes four partition plates 2111 arranged in a circumferential array along the centerline of vacuum hopper 21.

As shown in fig. 2, the discharging assembly 22 includes a turning plate 221 hinged to the bottom of the vacuum hopper 21 through a pin (not labeled) and configured to abut against the lower surface of the discharging opening 212 to achieve sealing, a weight 222 integrally disposed on one side of the turning plate 221 and configured to cause the turning plate 221 to abut against the discharging opening 212 through gravity, and a discharging valve 223 installed in the middle of the discharging pipe 213. When the turning plate 221 is in a natural state due to the action of the weight block 222, the upper surface of the turning plate 221 abuts against the lower surface of the feed opening 212 and the lower surfaces of the plurality of partition plates 2111, and the weight block 222 is located inside the feed pipe 213. Meanwhile, the spiral piece 2131 is welded on the inner wall of the discharging pipe 213, and the spiral piece 2131 is positioned between the turning plate 221 and the discharging valve 223.

As shown in fig. 1, the material suction assembly 23 includes four material suction pipes 231 respectively communicated with the side walls of the four material suction chambers 3, and material suction nozzles 232 installed on the four material suction pipes 231 and respectively used for sucking the raw materials in the four raw material buckets 1.

As shown in fig. 1 and 2, the vacuum assembly 24 includes four vacuum branch pipes 241, four electrically-controlled regulating valves 242, a vacuum manifold 243, and an air compressor 244. The four vacuum branch pipes 241 are communicated with the tops of the four material suction cavities 3; an electric control valve 242 is installed at the middle part of the vacuum branch pipe 241, and the electric control valve 242 is electrically connected with a controller 2441 of the air compressor 244; the vacuum manifold 243 is connected to the four vacuum branch pipes 241, and one end of the vacuum manifold 243 is connected to the air compressor 244.

As shown in fig. 2, the filter assembly 25 includes four membrane-coated filter cartridges 251 fixedly connected to the tops of the four suction chambers 3, respectively, and covering the vacuum branch pipes 241.

The operation implementation process of the step (1): the flow rates of the electric control valves 242 of the four vacuum branch pipes 241 are adjusted by a controller 2441 of the air compressor 244, so that the air extraction efficiency of the air compressor 244 to different material suction chambers 3 is different, the suction force of the four material suction nozzles 232 to the raw materials in the raw material barrels 1 is different, and the four raw materials can be sucked into the vacuum hopper 21 according to the ratio in unit time; then, when the raw materials in the vacuum hopper 21 reach a predetermined amount, the air compressor 244 is turned off, the turning plate 221 is turned downwards by overcoming the gravity of the balancing weight 222 after receiving the gravity of the four raw materials, so that the multiple raw materials fall into the spiral piece 2131 of the blanking pipe 213, a mixing route is added to the four raw materials in the flowing process of the spiral piece 2131, the mixing degree of the four raw materials is increased, and the blanking valve 223 is opened, so that the multiple raw materials fall into the mixing box body 6 of the mixing box of the extruder; the last operation that repeats for a large amount of raw materials through mixing can be stored to the compounding box 6 of compounding case in a large number of times for needn't stir the processing to multiple raw materials in advance, improved the efficiency of batching.

As shown in fig. 1 and 3, in step (2), the electrostatic precipitator includes a metal coil 41, a cathode line 42, and a power supply 43. The metal coil 41 is fixedly connected to the inner wall of the mixing box body 6 of the mixing box of the extruder in a spiral shape; cathode ray 42 is along vertical direction fixed connection in compounding box 6 and be located the middle part of compounding box 6, and power 43 fixed connection is on the outer wall of compounding box 6, and the positive pole of power 43 links to each other and the negative pole is connected with cathode ray 42 upper end with metal coil 41's upper end.

As shown in fig. 2, the electrostatic dust collector further comprises an exhaust fan 44, a dust suction pipe 45, an air outlet pipe 46, a dust collection cloth bag 47, a first filter screen 48 and a vibrator 49. An air inlet 61 is formed in the top of the mixing box body 6, and the first filter screen 48 is installed on the top of the mixing box body 6 and covers the air inlet 61; the suction fan 44 is located on the ground; the dust suction pipe 45 is connected to the side wall of the bottom of the mixing box body 6, a second reversing three-way valve 54 is arranged between the dust suction pipe 45 and the exhaust fan 44, the rest valve ports of the second reversing three-way valve 54 are also connected with an air inlet pipe 55, and a second filter screen 56 is fixedly connected to the pipe orifice of the air inlet pipe 55; the air outlet pipe 46 is connected with the air outlet of the exhaust fan 44 through a first reversing three-way valve 53, the rest valve ports of the first reversing three-way valve 53 are connected with an air inlet main pipe 52, the air inlet main pipe 52 is connected with a plurality of air inlet branch pipes 51, one ends of the air inlet branch pipes 51 far away from the air inlet main pipe 52 are connected to the top of the mixing box body 6, and the air inlet branch pipes 51 are distributed in a circumferential array; the dust removal cloth bag 47 is arranged at one end of the air outlet pipe 46 far away from the first reversing three-way valve 53; the vibrator 49 is installed on the outer wall of the mixing box body 6.

The operation implementation process of the step (2): in four kinds of raw materialss process unloading valve 223 and enter into the compounding box 6 of compounding box, switch on 43 earlier, make and form the electric field between metal coil 41 and cathode ray 42, the air ionization takes place when the breakdown electric field of actual electric field intensity and air is close, form a large amount of positive ions and free electron, free electron drifts to the positive pole along with the electric field, collide with neutral molecule or granule in the impurity at the skew in-process, these impurity have formed the charged particle behind the absorption electron, continue to move towards the positive pole at metal coil 41 place, finally make impurity absorption on metal coil 41, thereby make the impurity in the plastic granules carry out electrostatic absorption.

Meanwhile, the air inlet pipe 55 is communicated with the air inlet 61 of the exhaust fan 44 and the air inlet main pipe 52 is communicated with the air outlet of the exhaust fan 44 by changing the flow direction of the first reversing three-way valve 53 and the second reversing three-way valve 54, the exhaust fan 44 is opened at the moment, the exhaust fan 44 pumps air into the mixing box body 6 through the air inlet main pipe 52 and the air inlet branch pipe 51, and the falling raw materials are blown away, so that impurities in the raw materials are not easy to fall quickly after the raw materials are blown away and discharged, and the adsorption effect of the impurities on the metal coil 41 is improved; meanwhile, the mixing uniformity of the raw materials can be improved in the blowing process.

After the dust collection bag is used for a period of time, more impurities are adsorbed on the metal coil 41, when the impurities on the metal coil 41 are treated, the flow directions of the first reversing three-way valve 53 and the second reversing three-way valve 54 are changed, so that the dust collection pipe 45 is communicated with the air inlet 61 of the exhaust fan 44, the air outlet pipe 46 is communicated with the air outlet of the exhaust fan 44, and at the moment, the exhaust fan 44 is opened, so that the impurities enter the dust collection bag 47 along with the air circulation to be collected; at the same time, the vibrator 49 is turned on in the process, so that the foreign substances adsorbed on the metal coil 41 are easily detached, thereby facilitating the collection by the exhaust fan 44.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present invention.

Claims

1. A production process of a plastic pipe is characterized by comprising the following steps: the method comprises the following steps:

(5) cutting: cutting the plastic pipe;

(6) and (3) cooling: cooling the plastic pipe;

in the step (2), the electrostatic adsorption device comprises a metal coil (41) spirally arranged on the inner wall of the mixing box body (6) of the mixing box, a cathode wire (42) vertically suspended in the middle of the mixing box body (6), and a power supply (43) with an anode connected with the metal coil (41) and a cathode connected with the cathode wire (42); an air inlet (61) is formed in the top of the mixing box body (6); the electrostatic adsorption device also comprises an exhaust fan (44), a dust collection pipe (45) arranged between an air inlet of the exhaust fan (44) and the mixing box body (6), an air outlet pipe (46) arranged at an air outlet of the mixing box body (6), a dust collection cloth bag (47) arranged on the air outlet pipe (46), and a first filter screen (48) which is arranged at the top of the mixing box body (6) and is provided with a cover air inlet (61); a plurality of air inlet branch pipes (51) distributed in a circumferential array are arranged on the inner wall of the top of the mixing box body (6), and an air inlet main pipe (52) communicated with the air inlet branch pipes (51) is arranged on the outer wall of the periphery of the top of the mixing box body (6); a first reversing three-way valve (53) is arranged between the air outlet pipe (46) and an air outlet of the exhaust fan (44), and the air inlet main pipe (52) is communicated with a valve port of the first reversing three-way valve (53); a second reversing three-way valve (54) is arranged between the dust collection pipe (45) and an air inlet of the exhaust fan (44), an air inlet pipe (55) is further connected to a valve port of the second reversing three-way valve (54), and a second filter screen (56) is arranged at a pipe orifice of the air inlet pipe (55).

2. A process for the production of a plastic tube according to claim 1, wherein: the electrostatic adsorption device also comprises a vibrator (49) arranged on the outer wall of the mixing box body (6).

3. A process for the production of a plastic tube according to claim 1, wherein: in step (1), multiple raw materials are placed in raw materials bucket (1) in advance and realize in proportion synchronous transport to the compounding box through the vacuum material loading machine, the vacuum material loading machine includes:

the vacuum hopper (21) is arranged on a mixing box body (6) of the mixing box, and a separating assembly (211) used for separating the vacuum hopper (21) into a plurality of material suction cavities (3) is arranged in the vacuum hopper (21);

the blanking assembly (22) is arranged at the bottom of the vacuum hopper (21) and is used for opening and closing the plurality of suction cavities (3) simultaneously;

the material suction assembly (23) comprises a plurality of material suction pipelines (231) which are respectively communicated with the side wall of the material suction cavity (3), and material suction nozzles (232) which are arranged on the material suction pipelines (231) and are used for respectively sucking the raw materials in the raw material barrels (1);

the vacuum assembly (24) comprises a plurality of vacuum branch pipes (241) respectively communicated with the top of the material suction cavity (3), an electric regulating valve (242) arranged in the middle of each vacuum branch pipe (241), a vacuum main pipe (243) simultaneously communicated with the plurality of vacuum branch pipes (241), and an air compressor (244) communicated with the vacuum main pipe (243), wherein the electric regulating valve (242) is electrically connected with a controller (2441) of the air compressor (244);

the filter assembly (25) comprises a plurality of membrane-coated filter cartridges (251) which are respectively arranged at the top of the material suction cavity (3) and cover the vacuum branch pipes (241).

4. A process for the production of a plastic tube according to claim 3, wherein: a feed opening (212) is formed at the bottom of the vacuum hopper (21), and a feed pipe (213) which covers the feed opening (212) and is connected with the top of the mixing box body (6) is arranged on the outer wall of the bottom of the vacuum hopper (21); the blanking assembly (22) comprises a turning plate (221) which is hinged to the bottom of the vacuum hopper (21) and used for abutting against the lower surface of the blanking port (212) to realize sealing, a balancing weight (222) which is arranged on one side of the turning plate (221) and enables the turning plate (221) to abut against the blanking port (212) through gravity, and a blanking valve (223) which is arranged in the middle of the blanking pipe (213); when the turning plate (221) is in a state of closing the feed opening (212), the lower surface of the separation component (211) is abutted against the upper surface of the turning plate (221).

5. A process for the production of a plastic tube according to claim 4, wherein: the inner wall of the blanking pipe (213) is provided with a spiral sheet (2131), and the spiral sheet (2131) is positioned between the turning plate (221) and the blanking valve (223).