CN114033901A

CN114033901A - Novel low-noise large-displacement PVC drain pipe and preparation method thereof

Info

Publication number: CN114033901A
Application number: CN202111182815.2A
Authority: CN
Inventors: 陈厚忠
Original assignee: Hubei Kingbull Pipe Industry Co ltd
Current assignee: Hubei Kingbull Pipe Industry Co ltd
Priority date: 2021-10-11
Filing date: 2021-10-11
Publication date: 2022-02-11

Abstract

The invention discloses a novel low-noise large-displacement PVC drain pipe and a preparation method thereof, belonging to the technical field of PVC drain pipes. According to the invention, a pipe product is reformed, the spiral ribs are additionally arranged on the inner wall to play a role in diversion, water is discharged along the pipe wall through the spiral ribs during drainage, a cavity is formed in the middle, gas is discharged along the middle cavity, and the generation of 'water hammer' is reduced, so that the drainage efficiency is improved, the noise during drainage is reduced, meanwhile, production equipment is adjusted, the middle core layer is filled with barium sulfate, the density of the middle core layer is increased, the density of an inner skin layer and the density of an outer skin layer are reduced, and therefore, when sound is transmitted through the pipe, the densities of the inner wall, the outer wall and the middle core layer are inconsistent, the sound is attenuated, the drainage noise is further reduced, and the water hammer is prevented from damaging the pipe.

Description

Novel low-noise large-displacement PVC drain pipe and preparation method thereof

Technical Field

The invention belongs to the technical field of PVC drain pipes, and particularly relates to a novel low-noise large-displacement PVC drain pipe and a preparation method thereof.

Background

PVC is a material for short, the main component is polyvinyl chloride, other components are added to enhance the heat resistance, toughness and ductility of the PVC, the uppermost layer of the surface film is paint, the middle main component is polyvinyl chloride, the lowermost layer is a back coating adhesive, PVC pipes (comprising PVC-U pipes, PVC-M pipes and PVC-O pipes) and rigid PVC pipes are made of polyvinyl chloride resin, stabilizers, lubricants and the like which are matched and then extruded by a hot pressing method, the PVC pipes are plastic pipes which are developed and applied at the earliest time, the PVC can be divided into soft PVC and hard PVC, wherein the hard PVC approximately accounts for 2/3 in the market, the soft PVC accounts for 1/3, the soft PVC is generally used for floors, ceilings and the surface layer of leather, but the soft PVC contains plasticizers (which are also different from the soft PVC), the physical properties are poor (if a water feeding pipe needs to bear certain water pressure, the soft PVC is not suitable for use), the range of use thereof is limited. The hard PVC does not contain a plasticizer, so the hard PVC is easy to form and has good physical properties, thereby having great development and application values. In the production process of the polyvinyl chloride material, several auxiliary agents such as a stabilizer, a plasticizer and the like must be added, and if all the environmental-friendly auxiliary agents are adopted, the PVC pipe is also a nontoxic, tasteless and environment-friendly product.

PVC drain pipe is applied in a large number in the building trade, and in the use, the single tube in the air water not separate, lead to rivers unstability to produce "water hammer", lead to the drainage noise great, the little drainage ability of flow reduces, can break the PVC drain pipe even for a long time "water hammer" simultaneously, and drain pipe connection return bend department, when receiving the impact, the department of buckling is worn and torn seriously after long-time the impact, influences holistic life.

Disclosure of Invention

Technical problem to be solved

In order to overcome the defects in the prior art, the invention provides a novel low-noise large-displacement PVC drain pipe and a preparation method thereof, and solves the problems that the PVC drain pipe is not broken due to the fact that gas and water in a single pipe are not separated, water flow is unstable, water hammer is generated, drainage noise is large, the flow rate is small, the drainage capacity is reduced, the PVC drain pipe can be broken even by the water hammer for a long time, and the whole service life is influenced due to the fact that when the PVC drain pipe is connected with a bent pipe and is impacted, the bent part is seriously abraded after the water hammer is impacted for a long time.

(II) technical scheme

In order to achieve the purpose, the invention provides the following technical scheme: the utility model provides a novel big discharge capacity PVC drain pipe of low noise, includes two bodys, and the one end that two bodys are close to each other all is provided with seal assembly, and the one side that two seal assembly are close to each other is fixed connection at the both ends of connecting the elbow respectively, the equal threaded connection in both ends of connecting the elbow has adjusting part, adjusting part's one end is located the body inner wall, the body includes middle sandwich layer, the surface of middle sandwich layer is provided with the cortex, be provided with the cortex in the middle sandwich layer, the surface equidistance of cortex is provided with the solid fixed ring of a plurality of, and the surface of the solid fixed ring of a plurality of all is connected with the internal surface fixed of middle sandwich layer, all is provided with the anchor ring between two adjacent solid fixed rings, the lateral wall of anchor ring sets up respectively between middle sandwich layer and cortex.

As a further scheme of the invention: the reinforcing ring is designed in a spiral mode, and a vacuum cavity is formed among the reinforcing ring, the middle core layer and the inner skin layer.

As a further scheme of the invention: the outer surface of the outer skin layer is provided with a protective layer, and the protective layer is a wear-resistant surface layer made of butadiene rubber, styrene butadiene rubber, chloroprene rubber and polyurethane rubber.

As a further scheme of the invention: the inner wall of cortex is provided with the spiral muscle, the quantity of spiral muscle is 12, the helical direction of spiral muscle is anticlockwise rotation, the spiral arris distance of spiral muscle is < 2.5 m.

As a further scheme of the invention: the sealing assembly comprises a first flange and a second flange, one side of the first flange is fixedly connected with the right end of the pipe body, the right side face of the second flange is fixedly connected with one end of the connecting elbow, a sealing ring is arranged between the first flange and the second flange, and the first flange and the second flange are fixed through a plurality of bolts.

As a further scheme of the invention: the adjusting assembly comprises an inner pipe, the inner pipe is connected in the connecting elbow in a threaded mode, and a thread groove is formed in the outer surface of the inner pipe.

A preparation method of a novel low-noise large-displacement PVC drain pipe comprises the following raw materials:

inner and outer skin layers: 100 parts of polyvinyl chloride resin, 3.2-3.5 parts of calcium zinc stabilizer, 5 parts of calcium carbonate, 0.3-0.5 part of PE wax, 0.2-0.3 part of stearic acid, 0.4-0.8 part of ACR and 1.3-1.5 parts of titanium dioxide;

a middle core layer: 100 parts of polyvinyl chloride resin, 3.6-4.0 parts of calcium zinc stabilizer, 60 parts of barium sulfate, 6 parts of CPE, 0.6-1.0 part of PE wax, 0.3-0.6 part of stearic acid, 0.8-1.2 parts of ACR and 1.3-1.5 parts of titanium dioxide.

The preparation method comprises the following steps:

s1, mixing the raw materials of the inner skin layer and the outer skin layer: weighing the raw materials of polyvinyl chloride resin, a calcium-zinc stabilizer, calcium carbonate, PE wax, stearic acid, ACR and titanium dioxide according to the proportion, putting the raw materials into a bin of a high-temperature and low-temperature mixer, firstly mixing at high temperature, taking out the high-temperature mixture into a cold bin when the temperature of the mixture in the bin reaches 100-125 ℃, and discharging the mixed material when the temperature of the mixture in the cold bin is reduced to 38-48 ℃ to prepare a mixture for later use;

a middle core layer: and weighing the polyvinyl chloride resin, the calcium-zinc stabilizer, the barium sulfate, the CPE, the PE wax, the stearic acid, the ACR and the titanium dioxide according to the proportion, mixing, processing and mixing the raw materials in the same way and under the same conditions as the raw materials of the inner skin layer and the outer skin layer, and finally supporting the mixture.

S2, preparing the pipeline in a three-layer co-extrusion mode, attaching a reinforcing ring, a fixing ring and a spiral rib in front of the extruder when the extruder is to be driven by the inner skin layer and the middle core layer, and then respectively conveying the mixture of the inner skin layer, the outer skin layer and the middle core layer to a skin layer machine table and a core layer machine table for forming.

S3, sending out the mixture of the formed inner skin layer, outer skin layer and middle core layer from S2, extruding the mixture by a double-screw extruder, setting the barrel temperature of a core layer machine table to be 160-190 ℃, the barrel temperature of a skin layer machine table to be 155-185 ℃, the temperatures of a confluence core and a neck mold to be 150-190 ℃, enabling the screw edge of the inner wall to reach an expected rotation angle through sizing sleeve sizing, water tank cooling and tractor rotation, and then carrying out code spraying, film winding, cutting and detection to finally obtain the finished product of the PVC drain pipe.

As a further scheme of the invention: the thickness of the pipe body is 3.2-3.8 mm, the wall thickness of the pipe is controlled to be 3.2-3.5 mm, the thickness of the middle core layer is controlled to be 2.0-2.6 mm, the water tank cooling adopts an internal pressure external sizing method, compressed air is introduced into the pipe blank, the pipe blank is sized by a vacuum method, the vacuum degree is 0.055-0.070 MPa, and the sizing pressure of the compressed air is 0.02-0.05 MPa, so that the blank is sized.

(III) advantageous effects

Compared with the prior art, the invention has the beneficial effects that:

1. according to the invention, a pipe product is reformed, the spiral ribs are additionally arranged on the inner wall to play a role in diversion, water is discharged along the pipe wall through the spiral ribs during drainage, a cavity is formed in the middle, gas is discharged along the cavity in the middle, and the generation of 'water hammer' is reduced, so that the drainage efficiency is improved, the noise during drainage is reduced, meanwhile, production equipment is adjusted, the single extrusion is three-layer co-extrusion, the filling of the filler is reduced for the inner skin layer and the outer skin layer of the product, the filler of the middle core layer is barium sulfate, the density of the middle core layer is increased, the density of the inner skin layer and the density of the outer skin layer are reduced, and when sound is transmitted through the pipe, the densities of the inner wall, the outer wall and the middle core layer are inconsistent, so that the sound is attenuated, the drainage noise is further reduced, and the generated 'water hammer' is prevented from damaging the pipe body.

2. According to the invention, through the arrangement of the fixing ring, the reinforcing ring and the middle core layer, the annular fixing ring and the spirally designed reinforcing ring can support the inner wall of the pipe body, the circumferential/circumferential strength and the shearing resistance of the pipe wall of the pipe body are enhanced, the strength of the pipe body is improved while the thickness of the pipe body is reduced, and meanwhile, a vacuum cavity is formed among the reinforcing ring, the middle core layer and the inner skin layer, so that the aim of vacuum noise reduction is effectively achieved and the shock resistance of the pipe body is improved.

3. According to the invention, through the arrangement of the connecting elbow, the sealing ring and the inner pipe, the connecting elbow can be detached for replacement by detaching a plurality of bolts, the damage to the whole drain pipe which needs to be replaced after the connecting elbow is impacted for a long time is avoided, the maintenance cost is reduced, meanwhile, the connecting elbow is installed by adjusting the extending length of the inner pipe when the connecting elbow is installed, the application range is wide, and the purpose of limiting the connecting elbow is effectively realized after the inner pipe is inserted into the pipe body, so that the stability of integral connection is improved.

Drawings

FIG. 1 is a schematic perspective view of the present invention;

FIG. 2 is a perspective view of the connecting elbow of the present invention;

FIG. 3 is a schematic perspective view of a cross-section of a tube according to the present invention;

FIG. 4 is a schematic perspective view of an inner skin layer according to the present invention;

FIG. 5 is a schematic three-dimensional structure of the spiral rib of the present invention;

in the figure: 1. a pipe body; 101. an intermediate core layer; 102. an outer skin layer; 103. an inner skin layer; 104. a fixing ring; 105. reinforcing rings; 2. connecting the elbow; 3. a seal assembly; 301. a first flange; 302. a second flange; 303. a seal ring; 304. a bolt; 4. an adjustment assembly; 41. an inner tube; 42. a thread groove; 5. a spiral rib; 6. and (4) a protective layer.

Detailed Description

The technical solution of the present patent will be described in further detail with reference to the following embodiments.

As shown in fig. 1 to 5, the present invention provides a technical solution: the utility model provides a novel big discharge capacity PVC drain pipe of low noise, including two bodys 1, the one end that two bodys 1 are close to each other all is provided with seal assembly 3, the one side that two seal assembly 3 are close to each other is fixed connection respectively at the both ends of connecting elbow 2, the equal threaded connection in both ends of connecting elbow 2 has adjusting part 4, adjusting part 4's one end is located 1 inner wall of body, body 1 includes middle sandwich layer 101, the surface of middle sandwich layer 101 is provided with exocarp 102, be provided with endotheca layer 103 in middle sandwich layer 101, the surface equidistance of endotheca layer 103 is provided with the solid fixed ring 104 of a plurality of, the surface of the solid fixed ring 104 of a plurality of all is connected with the internal surface fixed of middle sandwich layer 101, all be provided with reinforcing ring 105 between two adjacent solid fixed ring 104, reinforcing ring 105's lateral wall sets up respectively between middle sandwich layer 101 and endotheca layer 103.

Specifically, as shown in fig. 1, 3 and 5, the reinforcing ring 105 is designed in a spiral manner, the annular fixing ring 104 and the reinforcing ring 105 designed in a spiral manner can support the inner wall of the pipe body 1, so as to enhance the circumferential/circumferential strength and the shearing resistance of the pipe wall of the pipe body 1, improve the strength of the pipe body 1 while reducing the thickness of the pipe body 1, form a vacuum cavity between the reinforcing ring 105 and the intermediate core layer 101 and the inner skin layer 103, effectively achieve the purpose of vacuum noise reduction and improve the shock resistance of the pipe body 1, the intermediate core layer 101 is filled with barium sulfate, so as to increase the density of the intermediate core layer 101 and reduce the densities of the inner skin layer 103 and the outer skin layer 102, so that when sound is transmitted through the pipe, the densities of the inner wall, the outer wall and the intermediate core layer 101 are inconsistent, so as to cause sound attenuation, further reduce the drainage noise, the protective layer 6 is arranged on the outer surface of the outer skin layer 102, the wear-resisting top layer that inoxidizing coating 6 was made by butadiene rubber, butadiene styrene rubber, chloroprene rubber and polyurethane rubber, through the setting of inoxidizing coating 6, improves the wear-resisting effect on 1 surperficial of body, effectively protects body 1, and the inner wall of cortex 103 is provided with spiral muscle 5, and the quantity of spiral muscle 5 is 12, and the helical direction of spiral muscle 5 is anticlockwise rotation, and the spiral ridge distance of spiral muscle 5 < 2.5 m.

Specifically, as shown in fig. 1 and 2, the sealing assembly 3 includes a first flange 301 and a second flange 302, one side of the first flange 301 is fixedly connected with the right end of the pipe body 1, the connecting elbow 2 can be detached for replacement by disposing the first flange 301 and the second flange 302, the connecting elbow 2 can be detached for replacement by detaching a plurality of bolts 304, the connecting elbow 2 is prevented from being damaged after being impacted for a long time, the maintenance cost is reduced, the right side surface of the second flange 302 is fixedly connected with one end of the connecting elbow 2, a sealing ring 303 is disposed between the first flange 301 and the second flange 302, the first flange 301 and the second flange 302 are fixed by a plurality of bolts 304, the adjusting assembly 4 includes an inner pipe 41, the inner pipe 41 is inserted into the pipe body 1 to effectively limit the connecting elbow 2 by disposing the inner pipe 41, so as to improve the stability of the overall connection, the inner pipe 41 is screwed into the connecting elbow 2, the outer surface of the inner tube 41 is provided with a threaded groove 42.

inner skin layer 103 and outer skin layer 102: 100 parts of polyvinyl chloride resin, 3.2-3.5 parts of calcium zinc stabilizer, 5 parts of calcium carbonate, 0.3-0.5 part of PE wax, 0.2-0.3 part of stearic acid, 0.4-0.8 part of ACR and 1.3-1.5 parts of titanium dioxide;

the intermediate core layer 101: 100 parts of polyvinyl chloride resin, 3.6-4.0 parts of calcium zinc stabilizer, 60 parts of barium sulfate, 6 parts of CPE, 0.6-1.0 part of PE wax, 0.3-0.6 part of stearic acid, 0.8-1.2 parts of ACR and 1.3-1.5 parts of titanium dioxide.

The preparation method comprises the following steps:

s1, mixing the raw materials of the inner skin layer 103 and the outer skin layer 102: weighing the raw materials of polyvinyl chloride resin, a calcium-zinc stabilizer, calcium carbonate, PE wax, stearic acid, ACR and titanium dioxide according to the proportion, putting the raw materials into a bin of a high-temperature and low-temperature mixer, firstly mixing at high temperature, taking out the high-temperature mixture into a cold bin when the temperature of the mixture in the bin reaches 100-125 ℃, and discharging the mixed material when the temperature of the mixture in the cold bin is reduced to 38-48 ℃ to prepare the mixture for later use;

the intermediate core layer 101: the polyvinyl chloride resin, the calcium-zinc stabilizer, the barium sulfate, the CPE, the PE wax, the stearic acid, the ACR and the titanium dioxide are weighed according to the proportion and mixed, the mixing processing mode and conditions are the same as those of the raw materials of the inner skin layer 103 and the outer skin layer 102, and finally the mixture is supported.

S2, preparing the pipeline in a three-layer co-extrusion mode, attaching a reinforcing ring 105, a fixing ring 104 and a spiral rib 5 in front of the extruder when the extruder is to be driven by the inner skin layer 103 and the middle core layer 101, and then respectively conveying the mixture of the inner skin layer 103, the outer skin layer 102 and the middle core layer 101 to a skin layer machine table and a core layer machine table for forming.

S3, sending out the mixture of the formed inner skin layer 103, the outer skin layer 102 and the middle core layer 101 from the S2, extruding the mixture through a double-screw extruder, setting the machine barrel temperature of a core layer machine table to be 160-190 ℃, setting the machine barrel temperature of a skin layer machine table to be 155-185 ℃, setting the temperature of a confluence core and a neck mold to be 150-190 ℃, setting through a sizing sleeve, cooling through a water tank and rotating through a tractor to enable the screw edge of the inner wall to reach an expected rotation angle, and then carrying out code spraying, film winding, cutting and detection to finally obtain the finished product of the PVC drain pipe.

The thickness of the pipe body 1 is 3.2-3.8 mm, the wall thickness of the pipe is controlled to be 3.2-3.5 mm, the thickness of the middle core layer 101 is controlled to be 2.0-2.6 mm, internal pressure external sizing is adopted for cooling the water tank, compressed air is introduced into the pipe blank, the pipe blank is sized by a vacuum method, the vacuum degree is 0.055-0.070 MPa, and the sizing pressure of the compressed air is 0.02-0.05 MPa, so that the blank is sized.

In conclusion, the following results are obtained:

through reforming transform the 1 product of body, the inner wall increases spiral muscle 5, play the water conservancy diversion effect, let water pass through spiral muscle 5 during the drainage and get rid of along the pipe wall, middle formation cavity, gas gets rid of along middle cavity, reduce the production of "water hammer", the noise when having improved drainage efficiency simultaneously also reduced the drainage has been improved like this, adjust production facility simultaneously, this single extrusion is the three-layer crowded altogether, product endotheca 103 and exocutic layer 102 reduce the packing of filler, middle sandwich layer 101 filler is barium sulfate, thereby increase the density of middle sandwich layer 101, reduce the density of endotheca 103 and exocutic layer 102, when sound propagates through tubular product like this, the density of ectotheca and middle sandwich layer 101 is inconsistent, lead to sound to produce the decay, thereby further reduce the drainage noise, avoid the "water hammer" that produces to cause the damage to body 1.

Through the setting of solid fixed ring 104, reinforcing ring 105 and middle sandwich layer 101, the annular solid fixed ring 104 and the reinforcing ring 105 of spiral design can support body 1 inner wall, strengthen the shear resistance of 1 circumference of body/hoop intensity and pipe wall, improve its intensity when attenuate 1 thickness of body, form the vacuum cavity between reinforcing ring 105 and middle sandwich layer 101 and the cortex 103 simultaneously, improve the shock resistance of body 1 when effectively realizing the purpose of making an uproar falls in the vacuum.

Through connecting elbow 2, the setting of sealing washer 303 and inner tube 41, pull down a plurality of bolts 304 and can pull down connecting elbow 2 and change, avoid connecting elbow 2 to receive to damage after the impact for a long time and need to change whole drain pipe, reduce cost of maintenance, the length that stretches out through adjusting inner tube 41 when installing connecting elbow 2 is installed to it simultaneously, application scope light, and inner tube 41 still effectively realize connecting the spacing purpose of elbow 2 after inserting body 1, thereby improve the stability of monolithic phase.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

Although the preferred embodiments of the present patent have been described in detail, the present patent is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present patent within the knowledge of those skilled in the art.

Claims

1. The utility model provides a novel big discharge capacity PVC drain pipe of low noise, includes two bodys (1), its characterized in that: one end of each of the two pipe bodies (1) close to each other is provided with a sealing component (3), one surface of each of the two sealing components (3) close to each other is fixedly connected with the two ends of the connecting elbow (2) respectively, both ends of the connecting elbow (2) are in threaded connection with adjusting components (4), one end of each adjusting component (4) is positioned on the inner wall of the pipe body (1), the pipe body (1) comprises a middle core layer (101), an outer skin layer (102) is arranged on the outer surface of the middle core layer (101), an inner skin layer (103) is arranged in the middle core layer (101), a plurality of fixing rings (104) are arranged on the outer surface of the inner skin layer (103) at equal intervals, the outer surfaces of the fixing rings (104) are fixedly connected with the inner surface of the middle core layer (101), a reinforcing ring (105) is arranged between every two adjacent fixing rings (104), the side walls of the reinforcing ring (105) are respectively arranged between the middle core layer (101) and the inner skin layer (103).

2. The novel low-noise large-displacement PVC drain pipe according to claim 1, characterized in that: the reinforcing ring (105) is designed in a spiral mode, and a vacuum cavity is formed among the reinforcing ring (105), the middle core layer (101) and the inner skin layer (103).

3. The novel low-noise large-displacement PVC drain pipe according to claim 1, characterized in that: the outer surface of the outer skin layer (102) is provided with a protective layer (6), and the protective layer (6) is a wear-resistant surface layer made of butadiene rubber, styrene butadiene rubber, chloroprene rubber and polyurethane rubber.

4. The novel low-noise large-displacement PVC drain pipe according to claim 3, characterized in that: the inner wall of cortex (103) is provided with spiral muscle (5), the quantity of spiral muscle (5) is 12, the helical direction of spiral muscle (5) is anticlockwise rotation, the spiral edge distance of spiral muscle (5) is < 2.5 m.

5. The novel low-noise large-displacement PVC drain pipe according to claim 1, characterized in that: seal assembly (3) include first flange (301) and second flange (302), the right-hand member fixed connection of one side and body (1) of first flange (301), the right flank of second flange (302) and the one end fixed connection of connecting elbow (2), be provided with between first flange (301) and second flange (302) sealing washer (303), it is fixed through a plurality of bolt (304) between first flange (301) and second flange (302).

6. The novel low-noise large-displacement PVC drain pipe according to claim 1, characterized in that: the adjusting assembly (4) comprises an inner pipe (41), the inner pipe (41) is connected in the connecting elbow (2) in a threaded mode, and a thread groove (42) is formed in the outer surface of the inner pipe (41).

7. The preparation method of the novel low-noise large-displacement PVC drain pipe is characterized by comprising the following raw materials:

inner skin layer (103) and outer skin layer (102): 100 parts of polyvinyl chloride resin, 3.2-3.5 parts of calcium zinc stabilizer, 5 parts of calcium carbonate, 0.3-0.5 part of PE wax, 0.2-0.3 part of stearic acid, 0.4-0.8 part of ACR and 1.3-1.5 parts of titanium dioxide;

intermediate core layer (101): 100 parts of polyvinyl chloride resin, 3.6-4.0 parts of calcium zinc stabilizer, 60 parts of barium sulfate, 6 parts of CPE, 0.6-1.0 part of PE wax, 0.3-0.6 part of stearic acid, 0.8-1.2 parts of ACR and 1.3-1.5 parts of titanium dioxide.

The preparation method comprises the following steps:

s1, mixing the raw materials of the inner skin layer (103) and the outer skin layer (102): weighing the raw materials of polyvinyl chloride resin, a calcium-zinc stabilizer, calcium carbonate, PE wax, stearic acid, ACR and titanium dioxide according to the proportion, putting the raw materials into a bin of a high-temperature and low-temperature mixer, firstly mixing at high temperature, taking out the high-temperature mixture into a cold bin when the temperature of the mixture in the bin reaches 100-125 ℃, and discharging the mixed material when the temperature of the mixture in the cold bin is reduced to 38-48 ℃ to prepare a mixture for later use;

intermediate core layer (101): and weighing the polyvinyl chloride resin, the calcium-zinc stabilizer, the barium sulfate, the CPE, the PE wax, the stearic acid, the ACR and the titanium dioxide according to the proportion, mixing, processing modes and conditions are the same as those of the raw materials of the inner skin layer (103) and the raw materials of the outer skin layer (102), and finally supporting the mixture.

S2, preparing a pipeline in a three-layer co-extrusion mode, when an inner skin layer (103) and a middle core layer (101) wait to move an extruder, attaching a reinforcing ring (105), a fixing ring (104) and a spiral rib (5) in front of the extruder, and then respectively conveying the mixture of the inner skin layer (103), an outer skin layer (102) and the middle core layer (101) to a skin layer machine table and a core layer machine table for carrying out extrusion molding;

s3, sending out the mixture of the formed inner skin layer (103), the outer skin layer (102) and the middle core layer (101) in the step S2, extruding the mixture through a double-screw extruder, setting the barrel temperature of a core layer machine table to be 160-190 ℃, setting the barrel temperature of a skin layer machine table to be 155-185 ℃, setting the barrel temperature of a confluence core and a neck mold to be 150-190 ℃, setting through a sizing sleeve, cooling through a water tank and rotating through a tractor to enable the screw edge of the inner wall to reach an expected rotation angle, and then carrying out code spraying, film winding, cutting and detection to finally obtain the finished product of the PVC drain pipe.

8. The novel low-noise large-displacement PVC drain pipe and the preparation method thereof according to claim 7, wherein the method comprises the following steps: the thickness of the pipe body (1) is controlled to be 3.2-3.8 mm, the wall thickness of the pipe is controlled to be 3.2-3.5 mm, the thickness of the middle core layer (101) is controlled to be 2.0-2.6 mm, the water tank cooling adopts an internal pressure external sizing method, compressed air is introduced into the pipe blank, the pipe blank is sized by a vacuum method, the vacuum degree is 0.055-0.070 MPa, and the sizing pressure of the compressed air is 0.02-0.05 MPa, so that the blank is sized.