A low-noise drain pipe and a method for manufacturing the same

Abstract

The application discloses a low-noise drainage pipe and a preparation method thereof, and belongs to the technical field of plastic pipes. The low-noise drainage pipe comprises, from inside to outside, a sound insulation layer, a noise reduction layer and a protective layer. The raw materials of the sound insulation layer comprise, in terms of mass fractions, 100 parts of polyvinyl chloride resin, 30-50 parts of a plasticizer, 3-5 parts of a first stabilizer, 4-7 parts of a softening agent, 3-5 parts of a main foaming agent, 0-1 parts of an auxiliary foaming agent and the like. The application further provides a preparation method of the low-noise drainage pipe, which comprises the following steps: mixing and preparing a modified polyvinyl chloride sound insulation layer, mixing and preparing an acrylic copolymer polyvinyl chloride noise reduction layer and mixing and preparing an acrylic copolymer polyvinyl chloride outer protective layer, and then co-extruding the mixed materials through a conical twin-screw extruder to obtain a pipe blank; and the pipe blank is cooled and formed into the low-noise drainage pipe in a vacuum setting and cooling box by adopting an internal pressure and external sizing mode. The low-noise drainage pipe has the advantages of long-term low noise and small linear expansion coefficient.

Description

Technical Field

[0001] This invention relates to the field of plastic pipe technology, specifically to a low-noise drainage pipe and its preparation method. Background Technology

[0002] The noise generated by plastic drainage pipes is caused by several factors. First, the high-speed flow of sewage within the pipe creates shear friction against the pipe wall, resulting in turbulent and eddy currents that collide with each other, converting energy into sound waves. Second, during drainage from high-rise buildings, water falls freely and impacts the pipe wall, striking elbows, tees, inspection ports, and large bends at the bottom, creating instantaneous impact force. Third, during drainage, the downward flow of water compresses and drags air, creating negative pressure within the pipe. The sudden compression and bursting of air produces a bursting sound. Fourth, the impact of water flow and bursting air provide periodic excitation forces to the pipe material. When this periodic excitation force is approximately equal to the pipe's natural frequency, resonance amplification occurs, causing the pipe wall to vibrate like a drum.

[0003] Regarding noise reduction, the domestic high-end market currently mainly uses polypropylene and polyethylene silent drainage pipes. Patent CN201711480385.6 discloses a flame-retardant, high-temperature resistant reinforced polypropylene silent drainage pipe and its application. This patent increases the areal density of the polypropylene silent drainage pipe by adding barium sulfate and glass fiber to the middle layer to achieve noise reduction. However, its long-term noise reduction effect is poor, and its low-temperature impact resistance is also poor. Patent CN223609547 U discloses a silent composite pipe and conveying system. This patent uses high-density polyethylene material, forming a microporous foam middle layer and corona-filled sound insulation layer to create a resonant microporous structure for noise reduction. However, it can only absorb low-frequency noise, and its noise reduction effect is limited.

[0004] Existing technologies primarily use polypropylene or polyethylene silent drainage pipes. Both materials increase their surface density by adding barium sulfate, glass fiber, calcium carbonate, etc., to the intermediate layer or by increasing the overall pipe wall thickness. However, these pipes have a high coefficient of linear expansion and poor ring stiffness, leading to easy deformation and bending of the pipeline after long-term operation following the installation of pipe clamps and supports, significantly impacting noise reduction effectiveness. Therefore, providing a pipe material with long-lasting low noise, a low coefficient of linear expansion, good low-temperature toughness, and high ring stiffness is a technical problem that existing technologies need to solve. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned technical deficiencies and provide a low-noise drainage pipe and its preparation method, solving the technical problem of how to achieve long-term low noise and small coefficient of linear expansion of pipes in the prior art.

[0006] To achieve the above-mentioned technical objectives, the present invention provides a low-noise drainage pipe, comprising a sound insulation layer, a noise reduction layer, and a protective layer arranged sequentially from the inside out; the raw materials of the sound insulation layer, calculated by mass parts, include: 100 parts of polyvinyl chloride resin, 30-50 parts of plasticizer, 3-5 parts of first stabilizer, 4-7 parts of softener, 3-5 parts of main foaming agent, 0-1 parts of auxiliary foaming agent, 0.2-0.5 parts of first internal lubricant, 0.1-0.5 parts of first external lubricant, and 5-10 parts of filler.

[0007] In any embodiment, the plasticizer is one or more of dioctyl terephthalate, dioctyl phthalate, trioctyl phosphate, and tributyl acetylacetonate; and / or, the first stabilizer is one or two of calcium-zinc stabilizers, organotin stabilizers, and lead salt stabilizers; and / or, the softener is one or two of C5-based petroleum resins, C9-based petroleum resins, and ESO epoxidized soybean oil; and / or, the main foaming agent is one or two of azodicarbonamide and sulfonyl hydrazide; and / or, the auxiliary... The foaming agent is one or more of nano zinc oxide, calcium oxide, and sodium bicarbonate; and / or, the first internal lubricant is one or more of zinc stearate, calcium stearate, stearic acid, fatty amide, and monoglyceride; and / or, the first external lubricant is one or more of polyethylene wax, liquid paraffin, and microcrystalline wax; and / or, the filler is one or more of light calcium carbonate, heavy calcium carbonate, calcium sulfate, and nano calcium carbonate; and / or, it further includes 1-3 parts of a first pigment, wherein the first pigment is titanium dioxide.

[0008] In any embodiment, the raw materials of the noise reduction layer include, by weight parts: 100 parts of acrylic copolymer polyvinyl chloride resin, 50-120 parts of reinforcing agent, 0.5-1.0 parts of coupling agent, 2.5-3 parts of second stabilizer, 0.2-0.5 parts of second internal lubricant, 0.2-0.5 parts of second external lubricant, 0.5-2 parts of first processing modifier, and 5-8 parts of first impact modifier.

[0009] In any embodiment, the reinforcing agent is one or more of barium sulfate, ferric oxide, and ferric oxide; and / or, the coupling agent is one or more of titanate TTOP-12, silane coupling agent KH550, silane coupling agent KH570, and silane coupling agent A174; and / or, the second stabilizer is one or more of calcium-zinc stabilizer, organotin stabilizer, and lead salt stabilizer; and / or, the second internal lubricant is one or more of zinc stearate, calcium stearate, stearic acid, fatty amide, and monoglyceride. Multiple; and / or, the second external lubricant is one or more of polyethylene wax, liquid paraffin, and microcrystalline wax; and / or, the first processing modifier is one or two of methyl methacrylate-acrylate copolymer and acrylate-styrene copolymer; and / or, the first impact modifier is one or more of methyl methacrylate-butadiene-styrene terpolymer, chlorinated polyvinyl chloride, and ethylene-vinyl acetate copolymer; and / or, it further includes 1-3 parts of a second pigment, wherein the second pigment is titanium dioxide.

[0010] In any embodiment, the raw materials of the protective layer, calculated by mass parts, include: 100 parts of acrylic copolymer polyvinyl chloride resin, 3 to 10 parts of second filler, 2.8 to 5 parts of third stabilizer, 0.2 to 0.5 parts of third internal lubricant, 0.2 to 0.5 parts of third external lubricant, 0.5 to 3 parts of second processing modifier, and 5 to 10 parts of second impact modifier.

[0011] In any embodiment, the second filler is one or more of heavy calcium carbonate, barium sulfate, light calcium carbonate, talc, calcium sulfate, and nano-calcium carbonate; and / or, the third stabilizer is one or more of calcium-zinc stabilizer, organotin stabilizer, and lead salt stabilizer; and / or, the third internal lubricant is one or more of zinc stearate, calcium stearate, stearic acid, and fatty amide; and / or, the third external lubricant is one or more of polyethylene wax, solid paraffin wax, and microcrystalline wax; and / or, the second processing modifier is one or more of methyl methacrylate-acrylate copolymer and acrylate-styrene copolymer; and / or, the impact modifier is one or more of methyl methacrylate-butadiene-styrene terpolymer, chlorinated polyethylene, and ethylene-vinyl acetate copolymer; and / or, it further includes 1-3 parts of a third pigment, wherein the third pigment is titanium dioxide.

[0012] In any embodiment, the wall thickness ratio of the sound insulation layer, the noise reduction layer, and the protective layer is (1-2):(15-20):1.

[0013] Furthermore, the present invention also proposes a method for preparing the above-mentioned low-noise drainage pipe, comprising the following steps: S1. The raw materials for the sound insulation layer, noise reduction layer, and protective layer are respectively put into a high-speed mixing unit and mixed. First, hot mixing is carried out at 100-125℃ and kept at the temperature for 3-5 minutes. Then, cold mixing is carried out at 30-50℃. Finally, after screening and maturation, the corresponding modified polyvinyl chloride sound insulation layer mixture, acrylic copolymer polyvinyl chloride noise reduction layer mixture, and acrylic copolymer polyvinyl chloride outer protective layer mixture are obtained respectively. S2. The prepared modified polyvinyl chloride sound insulation layer compound, acrylic copolymer polyvinyl chloride noise reduction layer compound, and acrylic copolymer polyvinyl chloride outer protective layer compound are co-extruded through a conical twin-screw extruder to obtain a tube blank; wherein, the barrel temperature of the sound insulation layer is 150-165℃ and the die exit temperature is 165-170℃; the barrel temperature of the noise reduction layer and the protective layer is 170-190℃ and the die exit temperature is 180-200℃; S3. The tube blank enters the vacuum shaping and cooling box and is cooled and formed by internal pressure and external sizing to obtain the low-noise drainage pipe.

[0014] In any embodiment, in step S2, the head compression ratio of the sound insulation layer of the co-extrusion die of the conical twin-screw extruder is 0 to 1, and the head compression ratio of the noise reduction layer and the protective layer of the co-extrusion die is 4 to 6.

[0015] In any embodiment, before step S1, the reinforcing agent of the noise reduction layer is dried at 70°C to 90°C and kept at that temperature for 3 to 5 minutes, and the coupling agent and reinforcing agent of the noise reduction layer are mixed and stirred at 85°C to 93°C for 5 to 15 minutes.

[0016] Compared with the prior art, the beneficial effects of the present invention include: the low-noise drainage pipe proposed in the present invention includes a sound insulation layer, a noise reduction layer and a protective layer arranged sequentially from the inside to the outside; the raw materials of the sound insulation layer, calculated by mass parts, include: 100 parts of polyvinyl chloride resin, 30-50 parts of plasticizer, 3-5 parts of first stabilizer, 4-7 parts of softener, 3-5 parts of main foaming agent, 0-1 parts of auxiliary foaming agent, 0.2-0.5 parts of first internal lubricant, 0.1-0.5 parts of first external lubricant, 5-10 parts of filler and 1-3 parts of first pigment. With the cooperation of each component and structural layer, the low-noise drainage pipe has long-lasting low noise and a small coefficient of linear expansion. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the low-noise drainage pipe of Embodiment 1 of the present invention.

[0018] Figure 2 This is a schematic diagram of the co-extrusion mold of Embodiment 1 of the present invention.

[0019] Explanation of reference numerals in the attached diagram: 1. Sound insulation layer; 2. Noise reduction layer; 3. Protective layer. Detailed Implementation

[0020] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60~120 and 80~110 are listed for a specific parameter, it is also expected that ranges of 60~110 and 80~120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1~3, 1~4, 1~5, 2~3, 2~4, and 2~5. In this application, unless otherwise stated, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0~5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0021] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0022] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0023] This specific embodiment provides a low-noise drainage pipe, comprising a sound insulation layer, a noise reduction layer, and a protective layer arranged sequentially from the inside out. The raw materials of the sound insulation layer, calculated by weight, include: 100 parts polyvinyl chloride resin, 30-50 parts plasticizer, 3-5 parts first stabilizer, 4-7 parts softener, 3-5 parts main foaming agent, 0-1 part auxiliary foaming agent, 0.2-0.5 parts first internal lubricant, 0.1-0.5 parts first external lubricant, 5-10 parts filler, and 1-3 parts first pigment. The raw materials of the noise reduction layer, calculated by weight, include: 100 parts acrylic copolymer polyvinyl chloride resin, 50-120 parts reinforcing agent, 0.5-1.0 parts coupling agent, and 2.5 parts second stabilizer. The protective layer comprises, by mass percentage, 100 parts of acrylic copolymer polyvinyl chloride resin, 3-10 parts of second filler, 2.8-5 parts of third stabilizer, 0.2-0.5 parts of third internal lubricant, 0.2-0.5 parts of third external lubricant, 5-10 parts of second impact modifier, and 1-3 parts of third pigment; the sound insulation layer, the noise reduction layer, and the protective layer have a wall thickness ratio of (1-2):(15-20):1.

[0024] In some embodiments, in the sound insulation layer, the plasticizer is one or more of dioctyl terephthalate, dioctyl phthalate, trioctyl phosphate, and tributyl acetylacetonate; the first stabilizer is one or two of calcium-zinc stabilizers, organotin stabilizers, and lead salt stabilizers; the softener is one or two of C5-based petroleum resins, C9-based petroleum resins, and ESO epoxidized soybean oil; the main foaming agent is one or two of azodicarbonamide and sulfonyl hydrazide; the auxiliary foaming agent is one or more of nano-zinc oxide, calcium oxide, and sodium bicarbonate; the first internal lubricant is one or more of zinc stearate, calcium stearate, stearic acid, fatty amide, and monoglyceride; the first external lubricant is one or more of polyethylene wax, liquid paraffin, and microcrystalline wax; the filler is one or more of light calcium carbonate, heavy calcium carbonate, calcium sulfate, and nano-calcium carbonate; and the first pigment is titanium dioxide.

[0025] In some embodiments, in the noise reduction layer, the reinforcing agent is one or more of barium sulfate, iron(III) oxide, and ferric oxide; the coupling agent is one or more of titanate TTOP-12, silane coupling agent KH550, silane coupling agent KH570, and silane coupling agent A174; the second stabilizer is one or more of calcium-zinc stabilizer, organotin stabilizer, and lead salt stabilizer; the second internal lubricant is one or more of zinc stearate, calcium stearate, stearic acid, fatty amide, and monoglyceride; the second external lubricant is one or more of polyethylene wax, liquid paraffin, and microcrystalline wax; the first processing modifier is one or two of methyl methacrylate-acrylate copolymer and acrylate-styrene copolymer; the first impact modifier is one of methyl methacrylate-butadiene-styrene terpolymer, chlorinated polyvinyl chloride, and ethylene-vinyl acetate copolymer; and the second pigment is titanium dioxide.

[0026] In some embodiments, the second filler is one or more of heavy calcium carbonate, barium sulfate, light calcium carbonate, talc, calcium sulfate, and nano-calcium carbonate; the third stabilizer is one or more of calcium-zinc stabilizer, organotin stabilizer, and lead salt stabilizer; the third internal lubricant is one or more of zinc stearate, calcium stearate, stearic acid, and fatty amide; the third external lubricant is one or more of polyethylene wax, solid paraffin wax, and microcrystalline wax; the second processing modifier is one or more of methyl methacrylate-acrylate copolymer and acrylate-styrene copolymer; the impact modifier is one or more of methyl methacrylate-butadiene-styrene terpolymer, chlorinated polyethylene, and ethylene-vinyl acetate copolymer; and the third pigment is titanium dioxide.

[0027] This specific embodiment also proposes a method for preparing the above-mentioned low-noise drainage pipe, including the following steps: S1. Weigh the raw materials for the sound insulation layer, noise reduction layer, and protective layer respectively, and put the weighed raw materials into a high-speed mixing unit for mixing. First, perform hot mixing at 100-125℃ and keep warm for 3-5 minutes, then perform cold mixing at 30-50℃. Finally, after sieving and curing, obtain the modified polyvinyl chloride sound insulation layer mixture, the acrylic copolymer polyvinyl chloride noise reduction layer mixture, and the acrylic copolymer polyvinyl chloride outer protective layer mixture. Before step S1, the reinforcing agent of the noise reduction layer is dried at 70℃-90℃ and kept warm for 3-5 minutes. The coupling agent and reinforcing agent of the noise reduction layer are mixed and stirred at 85℃-93℃ for 5-15 minutes. S2. The prepared modified polyvinyl chloride sound insulation layer compound, acrylic copolymer polyvinyl chloride noise reduction layer compound, and acrylic copolymer polyvinyl chloride outer protective layer compound are co-extruded through a conical twin-screw extruder to obtain a tube blank; wherein, the barrel temperature of the sound insulation layer is 150-165℃, and the die exit temperature is 165-170℃; the barrel temperature of the noise reduction layer and the protective layer is 170-190℃, and the die exit temperature is 180-200℃; the die head compression ratio of the sound insulation layer in the co-extrusion die of the conical twin-screw extruder is 0-1, and the die head compression ratio of the noise reduction layer and the protective layer in the co-extrusion die is 4-6; S3. The tube blank enters the vacuum shaping and cooling box and is cooled and formed by internal pressure and external sizing to obtain the low-noise drainage pipe.

[0028] The low-noise drainage pipe proposed in this invention has the following advantages: 1. Low air noise.

[0029] ① The middle noise-reducing layer is filled with high-density inorganic filler, which increases the areal density of the pipe: a. The water flow impacts the heavy material of the inner wall with great inertia. When sound waves are incident on the middle high-density layer, they are not easily moved by the vibration of the sound waves, the sound wave energy is blocked, and the transmitted noise is greatly reduced; b. With more fillers, the movement of molecular chains is restricted. When the pipe wall is excited to vibrate, the internal friction of the polymer converts the mechanical energy of the vibration into heat energy and dissipates it, thus suppressing the sound transmission of the solid structure. ② Sound insulation layer: Soft foam sound insulation layer a. When water flow and air bubbles impact the inner wall, the elastic deformation of the soft layer buffers the impact force, significantly reducing the initial vibration amplitude of the pipe wall; b. The soft layer is an elastic vibration damping pad: the water impact vibration is first dissipated by the soft foam layer and is difficult to transmit to the outer dense pipe wall, thus cutting off the solid sound transmission chain; c. Eliminate the abnormal noise of water hitting a hard wall and solve the harsh noise of water falling into the wall; d. Foaming forms closed / open micropores: Turbulent water flow generates air noise that enters the bubble pores. The air inside the pores rubs against each other, and the bubble walls deform. The sound energy is converted into heat and absorbed, reducing the reflection and outward transmission of sound waves. Open-pore bubbles absorb the mid-to-high frequency water flow noise, while closed-pore bubbles buffer the impact.

[0030] ③ Outer protective layer with hardened pipe wall: structural support to prevent deformation of the intermediate noise reduction layer and noise generation with the fixed pipe clamps.

[0031] 2. Low coefficient of linear expansion, below 4 x 10⁻⁶. -5mm / mm℃, horizontal and vertical pipes do not deform under thermal expansion and contraction. Because polyvinyl chloride (PVC) is a non-polar molecule with high electronegativity, large chlorine atoms and acrylate groups, significant steric hindrance, and rigid chain segments, it does not easily expand when heated. In contrast, polypropylene (PP) and polyethylene (PE) are polar molecules with low electronegativity, small methyl and hydrogen atoms, low steric hindrance, and flexible chain segments, making them easy to expand when heated.

[0032] 3. Good low-temperature impact resistance. The noise reduction layer and protective layer are made of acrylic copolymer polyvinyl chloride raw materials. This resin is made by graft copolymerization of non-toxic PVC material and ultra-fine particle acrylic (i.e., acrylic resin) elastomer. While maintaining the excellent performance of polyvinyl chloride resin, it has good low-temperature impact resistance. At the same time, the appropriate amount of filling in the middle layer can convert the impact kinetic energy into heat energy dissipation, which significantly improves the impact resistance. However, if the filling ratio is too large, the filler dispersion will be poor, which will affect the impact effect.

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0034] In this invention, the terms "some embodiments," "this embodiment," and examples are used to describe a subset of all possible embodiments. However, it is understood that "some embodiments" can be the same subset or different subsets of all possible embodiments and can be combined with each other without conflict.

[0035] If the application documents contain similar descriptions such as "first / second", the following explanation shall be added: In the following description, the terms "first / second / third" are used only to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first / second / third" may be interchanged in a specific order or sequence where permitted, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein.

[0036] In this embodiment, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, object A and / or object B can represent three situations: object A exists alone, object A and object B exist simultaneously, and object B exists alone.

[0037] The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0038] Example 1

[0039] This embodiment proposes a low-noise drainage pipe, combined with... Figure 1 It includes a sound insulation layer 1, a noise reduction layer 2, and a protective layer 3 arranged sequentially from the inside out; the raw materials of the sound insulation layer 1, calculated by weight, include: 100 parts of polyvinyl chloride resin, 50 parts of plasticizer, 3.5 parts of stabilizer, 5 parts of softener, 3.8 parts of main foaming agent, 0.4 parts of auxiliary foaming agent, 0.3 parts of internal lubricant, 0.2 parts of external lubricant, 6 parts of filler, and 2 parts of pigment; The raw materials of the noise reduction layer 2, calculated by mass parts, include: 100 parts of acrylic copolymer polyvinyl chloride resin, 120 parts of reinforcing agent, 0.8 parts of coupling agent, 2.5 parts of stabilizer, 0.4 parts of internal lubricant, 0.2 parts of external lubricant, 1 part of processing modifier, 7 parts of impact modifier, and 2 parts of pigment.

[0040] The raw materials of the protective layer 3, calculated by mass parts, include: 100 parts of acrylic copolymer polyvinyl chloride resin, 5 parts of filler, 3.2 parts of stabilizer, 0.3 parts of internal lubricant, 0.2 parts of external lubricant, 1 part of processing modifier, 7 parts of impact modifier, and 2 parts of pigment.

[0041] The wall thickness ratio of the sound insulation layer 1, the noise reduction layer 2, and the protective layer 3 is 1.5:20:1.

[0042] The polyvinyl chloride resin of the sound insulation layer is SG-3 type resin; the plasticizer of the sound insulation layer is dioctyl terephthalate; the stabilizer of the sound insulation layer is organotin stabilizer; the softener of the sound insulation layer is ESO epoxidized soybean oil; the main foaming agent of the sound insulation layer is azodicarbonamide; the auxiliary foaming agent of the sound insulation layer is nano zinc oxide; the internal lubricant of the sound insulation layer is monoglyceride; the external lubricant of the sound insulation layer is polyethylene wax; the filler of the sound insulation layer is nano calcium carbonate; and the pigment of the sound insulation layer is titanium dioxide.

[0043] The reinforcing agent of the noise reduction layer is barium sulfate; the coupling agent of the noise reduction layer is titanate TTOP-12; the stabilizer of the noise reduction layer is calcium zinc stabilizer; the internal lubricant of the noise reduction layer is zinc stearate; the external lubricant of the noise reduction layer is polyethylene wax; the processing modifier of the noise reduction layer is methyl methacrylate-acrylate copolymer; the impact modifier of the noise reduction layer is methyl methacrylate-butadiene-styrene terpolymer; and the pigment of the noise reduction layer is titanium dioxide.

[0044] The filler of the protective layer is light calcium carbonate; the stabilizer of the protective layer is calcium zinc stabilizer; the internal lubricant of the protective layer is calcium stearate; the external lubricant of the protective layer is polyethylene wax; the processing modifier of the protective layer is methyl methacrylate-acrylate copolymer; the impact modifier of the protective layer is methyl methacrylate-butadiene-styrene terpolymer; and the pigment of the protective layer is titanium dioxide.

[0045] This embodiment also proposes a method for preparing the above-mentioned low-noise drainage pipe, including the following steps: S1. Dry the noise reduction layer filler at 78℃ and keep it warm for 5 minutes. Add the coupling agent to the filler and stir at 90℃ for 10 minutes to allow the coupling agent to be fully absorbed. S2. Weigh the raw materials for the sound insulation layer, noise reduction layer, and protective layer respectively, and put the weighed raw materials into the high-speed mixing unit for mixing. First, perform hot mixing at 115℃, then cold mixing at 46℃, and finally, after screening and maturation, obtain the modified polyvinyl chloride sound insulation layer mixture, the acrylic copolymer polyvinyl chloride noise reduction layer mixture, and the acrylic copolymer polyvinyl chloride outer protective layer mixture. S3. The prepared modified polyvinyl chloride sound insulation layer mixture, acrylic copolymer polyvinyl chloride noise reduction layer mixture, and acrylic copolymer polyvinyl chloride outer protective layer mixture are co-extruded through a conical twin-screw extruder to obtain a tube blank. The temperature of the sound insulation layer barrel is 160℃, and the temperature at the mold exit is 170℃. The temperature of the barrel for the noise reduction layer and protective layer is 185℃, and the temperature at the mold exit is 195℃. The die head compression ratio of the sound insulation layer of the co-extrusion die of the conical twin-screw extruder is 0, while the die head compression ratio of the noise reduction layer and the protective layer of the co-extrusion die is 5; combined with Figure 2 The structure of the co-extrusion die is derived from existing technology.

[0046] S4. The tube blank enters the vacuum shaping and cooling box and is cooled and formed by internal pressure and external sizing to obtain the low-noise drainage pipe.

[0047] Example 2

[0048] This embodiment proposes a low-noise drainage pipe and its preparation method, comprising a sound insulation layer, a noise reduction layer, and a protective layer arranged sequentially from the inside out. The sound insulation layer comprises, by weight, 100 parts polyvinyl chloride resin, 50 parts plasticizer, 3.5 parts stabilizer, 5 parts softener, 3.9 parts main foaming agent, 0.5 parts auxiliary foaming agent, 0.3 parts internal lubricant, 0.2 parts external lubricant, 6 parts filler, and 2 parts pigment. The noise reduction layer comprises, by weight, 100 parts acrylic copolymer polyvinyl chloride resin, 3.9 parts main foaming agent, 0.5 parts auxiliary foaming agent, 0.3 parts internal lubricant, 0.2 parts external lubricant, 6 parts filler, and 2 parts pigment. The raw materials of the protective layer, calculated by mass, include: 100 parts of strengthening agent, 0.8 parts of coupling agent, 2.8 parts of stabilizer, 0.4 parts of internal lubricant, 0.2 parts of external lubricant, 1 part of processing modifier, 6 parts of impact modifier, and 2 parts of pigment; the raw materials of the protective layer include: 100 parts of acrylic copolymer polyvinyl chloride resin, 6 parts of filler, 3.0 parts of stabilizer, 0.3 parts of internal lubricant, 0.2 parts of external lubricant, 1 part of processing modifier, 6 parts of impact modifier, and 2 parts of pigment; the wall thickness ratio of the sound insulation layer, noise reduction layer, and protective layer is 1.5:20:1.

[0049] In this embodiment, the polyvinyl chloride resin of the sound insulation layer is SG-3 type resin, the plasticizer of the sound insulation layer is dioctyl phthalate, the stabilizer of the sound insulation layer is calcium-zinc stabilizer, the softener of the sound insulation layer is C5 series petroleum resin, the main foaming agent of the sound insulation layer is azodicarbonamide, the auxiliary foaming agent of the sound insulation layer is nano zinc oxide, the internal lubricant of the sound insulation layer is monoglyceride, the external lubricant of the sound insulation layer is polyethylene wax, the filler of the sound insulation layer is nano calcium carbonate, and the pigment of the sound insulation layer is titanium dioxide.

[0050] The reinforcing agent of the noise reduction layer is iron(III) oxide, the coupling agent of the noise reduction layer is silane coupling agent KH550, the stabilizer of the noise reduction layer is organotin stabilizer, the internal lubricant of the noise reduction layer is zinc stearate, the external lubricant of the noise reduction layer is polyethylene wax, the processing modifier of the noise reduction layer is methyl methacrylate-acrylate copolymer, the impact modifier of the noise reduction layer is chlorinated polyethylene, and the pigment of the noise reduction layer is titanium dioxide.

[0051] The filler of the protective layer is light calcium carbonate, the stabilizer of the protective layer is calcium zinc stabilizer, the internal lubricant of the protective layer is stearic acid, the external lubricant of the protective layer is solid paraffin, the processing modifier of the protective layer is methyl methacrylate-acrylate copolymer, the impact modifier of the protective layer is methyl methacrylate-butadiene-styrene terpolymer, and the pigment of the protective layer is titanium dioxide.

[0052] This embodiment also proposes a method for preparing the above-mentioned low-noise drainage pipe, including the following steps: S1. Dry the noise reduction layer filler at 90℃ and keep it warm for 5 minutes. Add the coupling agent to the filler and stir at 93℃ for 15 minutes to allow the coupling agent to be fully absorbed.

[0053] S2. Weigh the raw materials for the sound insulation layer, noise reduction layer, and protective layer respectively, and put the weighed raw materials into the high-speed mixing unit for mixing. First, perform hot mixing at 110℃ and keep warm for 5 minutes, then perform cold mixing at 40℃. Finally, after screening and maturation, the modified polyvinyl chloride sound insulation layer mixture, acrylic copolymer polyvinyl chloride noise reduction layer mixture, and acrylic copolymer polyvinyl chloride outer protective layer mixture are obtained. S3. The prepared modified polyvinyl chloride sound insulation layer mixture, acrylic copolymer polyvinyl chloride noise reduction layer mixture, and acrylic copolymer polyvinyl chloride outer protective layer mixture are co-extruded through a conical twin-screw extruder. The barrel temperature of the sound insulation layer is 155℃, and the temperature at the die exit is 168℃; the barrel temperature of the noise reduction layer and the protective layer is 175℃, and the temperature at the die exit is 185℃; the die head compression ratio of the sound insulation layer of the co-extrusion die of the conical twin-screw extruder is 0, and the die head compression ratio of the noise reduction layer and the protective layer of the co-extrusion die is 5.

[0054] S4. The tube blank enters the vacuum shaping and cooling box and is cooled and formed by internal pressure and external sizing to obtain the low-noise drainage pipe.

[0055] Example 3

[0056] This embodiment also proposes a low-noise drainage pipe and its preparation method, including a sound insulation layer, a noise reduction layer and a protective layer arranged sequentially from the inside to the outside.

[0057] The sound insulation layer raw materials, by weight, include: 100 parts polyvinyl chloride resin, 50 parts plasticizer, 3.5 parts stabilizer, 5 parts softener, 3.8 parts main foaming agent, 0.5 parts auxiliary foaming agent, 0.3 parts internal lubricant, 0.2 parts external lubricant, 7 parts filler, and 2 parts pigment; The noise reduction layer raw materials, by weight, include: 100 parts acrylic copolymer polyvinyl chloride resin, 100 parts reinforcing agent, 0.8 parts coupling agent, 2.7 parts stabilizer, 0.4 parts internal lubricant, 0.2 parts external lubricant, 1 part processing modifier, 5 parts impact modifier, and 2 parts pigment.

[0058] The protective layer raw materials, by weight, include: 100 parts acrylic copolymer polyvinyl chloride resin, 5 parts filler, 3 parts stabilizer, 0.3 parts internal lubricant, 0.2 parts external lubricant, 1 part processing modifier, 7 parts impact modifier, and 2 parts pigment.

[0059] The wall thickness ratio of the sound insulation layer, the noise reduction layer, and the protective layer is 1:20:1.

[0060] The polyvinyl chloride resin of the sound insulation layer is SG-3 type resin, the plasticizer of the sound insulation layer is dioctyl terephthalate, the stabilizer of the sound insulation layer is calcium zinc stabilizer, the softener of the sound insulation layer is ESO epoxidized soybean oil, the main foaming agent of the sound insulation layer is azodicarbonamide, the auxiliary foaming agent of the sound insulation layer is nano zinc oxide, the internal lubricant of the sound insulation layer is monoglyceride, the external lubricant of the sound insulation layer is polyethylene wax, the filler of the sound insulation layer is light calcium carbonate, and the pigment of the sound insulation layer is titanium dioxide.

[0061] The reinforcing agent of the noise reduction layer is barium sulfate, the coupling agent of the noise reduction layer is titanate TTOP-12, the stabilizer of the noise reduction layer is calcium zinc stabilizer, the internal lubricant of the noise reduction layer is monoglyceride, the external lubricant of the noise reduction layer is polyethylene wax, the processing modifier of the noise reduction layer is methyl methacrylate-acrylate copolymer, the impact modifier of the noise reduction layer is methyl methacrylate-butadiene-styrene terpolymer, and the pigment of the noise reduction layer is titanium dioxide.

[0062] The filler of the protective layer is nano-calcium carbonate, the stabilizer of the protective layer is calcium-zinc stabilizer, the internal lubricant of the protective layer is zinc stearate, the external lubricant of the protective layer is polyethylene wax, the processing modifier of the protective layer is methyl methacrylate-acrylate copolymer, the impact modifier of the protective layer is chlorinated polyethylene, and the pigment of the protective layer is titanium dioxide.

[0063] This embodiment also proposes a method for preparing the above-mentioned low-noise drainage pipe, including the following steps: S1. Dry the noise reduction layer filler at 80℃ and keep it warm for 5 minutes. Add the coupling agent to the filler and stir at high speed at 88℃ for 10 minutes to allow the coupling agent to be fully absorbed.

[0064] S2. Weigh the raw materials for the sound insulation layer, noise reduction layer, and protective layer respectively, and put the weighed raw materials into the high-speed mixing unit for mixing. First, perform hot mixing at 115℃ and keep warm for 5 minutes, then perform cold mixing at 40℃. Finally, after screening and maturation, the modified polyvinyl chloride sound insulation layer mixture, acrylic copolymer polyvinyl chloride noise reduction layer mixture, and acrylic copolymer polyvinyl chloride outer protective layer mixture are obtained. S3. The prepared modified polyvinyl chloride sound insulation layer mixture, acrylic copolymer polyvinyl chloride noise reduction layer mixture, and acrylic copolymer polyvinyl chloride outer protective layer mixture are co-extruded through a conical twin-screw extruder. The temperature of the sound insulation layer barrel is 155℃, and the temperature at the mold exit is 165℃. The temperature of the barrel for the noise reduction layer and protective layer is 175℃, and the temperature at the mold exit is 190℃. The die head compression ratio of the sound insulation layer of the co-extrusion die of the conical twin-screw extruder is 0, and the die head compression ratio of the noise reduction layer and the protective layer of the co-extrusion die is 5. S4: The tube blank enters the vacuum shaping and cooling box and is cooled and formed by internal pressure and external sizing to produce a low-noise drainage pipe.

[0065] Examples 1-3 respectively prepared a dn110X4.2mm low-noise drainage pipe, and the test performance is as follows: Test method: Tests were conducted at the Vanke Test Tower according to GB / T312-2009 "Noise Test of Building Drainage Piping System (Structural Sound)"; and according to GB / T 9647-2015 "Determination of Ring Stiffness of Thermoplastic Pipes", GB / T 14152 "Test Method for External Impact Resistance of Thermoplastic Pipes - Clockwise Rotation Method" and GB / T 1036-2008 "Determination of Linear Expansion Coefficient of Plastics at -30℃ -30℃ - Quartz Dilatometer Method". The results are shown in Tables 1 and 2.

[0066] Table 1: Comparison Results of Noise Tests

[0067] Table 2

[0068] As can be seen from Tables 1 and 2, the low-noise drainage pipe proposed in this invention has a significant noise reduction effect. It has a lower sound pressure level than polypropylene silent drainage pipes, polyethylene silent drainage pipes, and cast iron pipes on the market, and also has a lower coefficient of linear expansion, better low-temperature impact resistance, and higher ring stiffness.

[0069] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A low-noise drainage pipe, characterized in that, It includes a sound insulation layer, a noise reduction layer, and a protective layer arranged sequentially from the inside out; the raw materials of the sound insulation layer, calculated by mass parts, include: 100 parts of polyvinyl chloride resin, 30-50 parts of plasticizer, 3-5 parts of first stabilizer, 4-7 parts of softener, 3-5 parts of main foaming agent, 0-1 parts of auxiliary foaming agent, 0.2-0.5 parts of first internal lubricant, 0.1-0.5 parts of first external lubricant, and 5-10 parts of filler.

2. The low-noise drainage pipe according to claim 1, characterized in that, The plasticizer is one or more of dioctyl terephthalate, dioctyl phthalate, trioctyl phosphate, and tributyl acetylacetonate; and / or, the first stabilizer is one or two of calcium-zinc stabilizers, organotin stabilizers, and lead salt stabilizers; and / or, the softener is one or two of C5-based petroleum resins, C9-based petroleum resins, and ESO epoxidized soybean oil; and / or, the main foaming agent is one or two of azodicarbonamide and sulfonyl hydrazide; and / or, the auxiliary foaming agent is... The product comprises one or more of nano zinc oxide, calcium oxide, and sodium bicarbonate; and / or, the first internal lubricant comprises one or more of zinc stearate, calcium stearate, stearic acid, fatty amide, and monoglyceride; and / or, the first external lubricant comprises one or more of polyethylene wax, liquid paraffin, and microcrystalline wax; and / or, the filler comprises one or more of light calcium carbonate, heavy calcium carbonate, calcium sulfate, and nano calcium carbonate; and / or, the product further comprises 1-3 parts of a first pigment, wherein the first pigment is titanium dioxide.

3. The low-noise drainage pipe according to claim 1, characterized in that, The raw materials of the noise reduction layer, by weight, include: 100 parts of acrylic copolymer polyvinyl chloride resin, 50-120 parts of reinforcing agent, 0.5-1.0 parts of coupling agent, 2.5-3 parts of second stabilizer, 0.2-0.5 parts of second internal lubricant, 0.2-0.5 parts of second external lubricant, 0.5-2 parts of first processing modifier, and 5-8 parts of first impact modifier.

4. The low-noise drainage pipe according to claim 3, characterized in that, The reinforcing agent is one or more of barium sulfate, ferric oxide, and ferric oxide; and / or, the coupling agent is one or more of titanate TTOP-12, silane coupling agent KH550, silane coupling agent KH570, and silane coupling agent A174; and / or, the second stabilizer is one or more of calcium-zinc stabilizer, organotin stabilizer, and lead salt stabilizer; and / or, the second internal lubricant is one or more of zinc stearate, calcium stearate, stearic acid, fatty amide, and monoglyceride; and / Or, the second external lubricant is one or more of polyethylene wax, liquid paraffin, and microcrystalline wax; and / or, the first processing modifier is one or two of methyl methacrylate-acrylate copolymer and acrylate-styrene copolymer; and / or, the first impact modifier is one or more of methyl methacrylate-butadiene-styrene terpolymer, chlorinated polyvinyl chloride, and ethylene-vinyl acetate copolymer; and / or, it further includes 1-3 parts of a second pigment, wherein the second pigment is titanium dioxide.

5. The low-noise drainage pipe according to claim 1, characterized in that, The raw materials of the protective layer, calculated by mass parts, include: 100 parts of acrylic copolymer polyvinyl chloride resin, 3-10 parts of the second filler, 2.8-5 parts of the third stabilizer, 0.2-0.5 parts of the third internal lubricant, 0.2-0.5 parts of the third external lubricant, 0.5-3 parts of the second processing modifier, and 5-10 parts of the second impact modifier.

6. The low-noise drainage pipe according to claim 5, characterized in that, The second filler is one or more of heavy calcium carbonate, barium sulfate, light calcium carbonate, talc, calcium sulfate, and nano calcium carbonate; and / or, the third stabilizer is one or more of calcium-zinc stabilizer, organotin stabilizer, and lead salt stabilizer; and / or, the third internal lubricant is one or more of zinc stearate, calcium stearate, stearic acid, and fatty amide; and / or, the third external lubricant is one or more of polyethylene wax, solid paraffin wax, and microcrystalline wax; and / or, the second processing modifier is one or more of methyl methacrylate-acrylate copolymer and acrylate-styrene copolymer; and / or, the impact modifier is one or more of methyl methacrylate-butadiene-styrene terpolymer and chlorinated polyethylene and ethylene-vinyl acetate copolymer; and / or, it further includes 1-3 parts of a third pigment, wherein the third pigment is titanium dioxide.

7. The low-noise drainage pipe according to claim 1, characterized in that, The wall thickness ratio of the sound insulation layer, the noise reduction layer, and the protective layer is (1-2):(15-20):

1.

8. A method for preparing a low-noise drainage pipe according to any one of claims 1-7, characterized in that, Includes the following steps: S1. The raw materials for the sound insulation layer, noise reduction layer, and protective layer are respectively put into a high-speed mixing unit and mixed. First, hot mixing is carried out at 100-125℃ and kept at the temperature for 3-5 minutes. Then, cold mixing is carried out at 30-50℃. Finally, after screening and maturation, the corresponding modified polyvinyl chloride sound insulation layer mixture, acrylic copolymer polyvinyl chloride noise reduction layer mixture, and acrylic copolymer polyvinyl chloride outer protective layer mixture are obtained respectively. S2. The prepared modified polyvinyl chloride sound insulation layer compound, acrylic copolymer polyvinyl chloride noise reduction layer compound, and acrylic copolymer polyvinyl chloride outer protective layer compound are co-extruded through a conical twin-screw extruder to obtain a tube blank; wherein, the barrel temperature of the sound insulation layer is 150-165℃ and the die exit temperature is 165-170℃; the barrel temperature of the noise reduction layer and the protective layer is 170-190℃ and the die exit temperature is 180-200℃; S3. The tube blank enters the vacuum shaping and cooling box and is cooled and formed by internal pressure and external sizing to obtain the low-noise drainage pipe.

9. The method for preparing a low-noise drainage pipe according to claim 8, characterized in that, In step S2, the head compression ratio of the sound insulation layer of the co-extrusion die of the conical twin-screw extruder is 0 to 1, and the head compression ratio of the noise reduction layer and the protective layer of the co-extrusion die is 4 to 6.

10. The method for preparing a low-noise drainage pipe according to claim 8, characterized in that, Before step S1, the process further includes drying the reinforcing agent of the noise reduction layer at 70℃~90℃ and keeping it at that temperature for 3~5 minutes, mixing the coupling agent and reinforcing agent of the noise reduction layer, and stirring at 85℃~93℃ for 5 minutes~15 minutes.

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