Novel heat-preservation polypropylene random copolymer glass fiber reinforced pipe and preparation method thereof

Abstract

The invention discloses a novel thermal insulation polypropylene random copolymer glass fiber reinforced pipe and a preparation method thereof, and belongs to the technical field of PPR pipes. The polypropylene random copolymer glass fiber reinforced pipe sequentially comprises a PP-R antibacterial layer, a PP-R glass fiber reinforced layer, a PP-R hot melting layer, a closed-cell foaming layer and a protective layer from the center to the periphery. The protective layer is made of a high-density polyethylene material, is wear-resistant and scratch-resistant, and effectively protects the closed-cell foaming layer; the closed-cell foaming layer is made of a low-density polyethylene material, and is healthy, environment-friendly, free of peculiar smell and long in service life. The PP-R hot melting layer is made of polypropylene random copolymer and is made of the same material as the PP-R pipe fitting, welding is convenient, connector connection is reliable, the PP-R glass fiber reinforced layer is made of glass fiber modified polypropylene, the impact resistance, the pressure resistance and the heat temperature resistance of the pipe are improved, the linear expansion coefficient of the pipe is reduced, installation is more attractive, the inner layer is the polypropylene random copolymer modified silver ion antibacterial layer, and the service life of the PP-R pipe fitting is prolonged. The antibacterial effect reaches the I-grade standard.

Description

Technical Field

[0001] This application relates to a novel thermal insulation random copolymer polypropylene glass fiber reinforced pipe and its preparation method, belonging to the field of PP-R pipe technology. Background Technology

[0002] PP-R pipes (random copolymer polypropylene pipes) are a type of plastic pipe material used in building water supply and drainage systems. They have excellent heat and pressure resistance, hygiene and environmental protection, energy saving and heat insulation properties, and can be used in building hot and cold water supply systems, direct drinking water systems, underfloor heating circulation pipes, food / beverage conveying pipelines, chemical fluid conveying, solar heating systems, hospital and school drinking water networks, agricultural irrigation systems, etc.

[0003] Chinese Patent 202011105644.9 discloses an antibacterial and anti-scaling PPR composite pipe structure, comprising an inner antibacterial and anti-scaling structural layer, a middle first heat- and oxygen-resistant PP-R structural layer, and an outer second heat- and oxygen-resistant PP-R structural layer. Antibacterial masterbatch is introduced into the inner layer to inhibit bacterial growth, achieving the antibacterial purpose. Chinese Patent 201711277151.1 discloses a composite PE-PPR toughened pipe, in which antibacterial masterbatch is added to the inner layer for effective antibacterial action, and various composite toughening agents are added to the outer layer to improve the pipe's cold brittleness. Summary of the Invention

[0004] According to one aspect of this application, a novel thermally insulated random copolymer polypropylene glass fiber reinforced pipe is provided, wherein the random copolymer polypropylene glass fiber reinforced pipe comprises, from the center to the periphery, a PP-R antibacterial layer, a PP-R glass fiber reinforcing layer, a PP-R hot-melt layer, a closed-cell foam layer, and a protective layer; wherein the PP-R antibacterial layer, the PP-R glass fiber reinforcing layer, the PP-R hot-melt layer, the closed-cell foam layer, and the protective layer are sequentially adhered together.

[0005] Specifically, the inner wall of the protective layer adheres to the outer wall of the closed-cell foam layer, the inner wall of the closed-cell foam layer adheres to the outer wall of the PP-R hot-melt layer, the inner wall of the PP-R hot-melt layer adheres to the outer wall of the PP-R fiberglass reinforced layer, and the inner wall of the PP-R fiberglass reinforced layer adheres to the outer wall of the PP-R antibacterial layer.

[0006] Optionally, the protective layer may be composed of 99-99.9% polyethylene particles and 1-0.1% color masterbatch by weight percentage.

[0007] Optionally, the polyethylene particles in the protective layer are high-density polyethylene particles.

[0008] Optionally, in the protective layer, the melt mass flow rate of high-density polyethylene particles at 190°C and 5 kg is 0.2-0.3 g / 10 min.

[0009] Specifically, in the protective layer, the melt flow rate of high-density polyethylene particles at 190°C and 5 kg is 0.26 g / 10 min.

[0010] Optionally, the closed-cell foam layer may be composed of 99-99.9% low-density polyethylene particles and 1-0.1% color masterbatch by weight percentage.

[0011] Optionally, in the closed-cell foam layer, the melt mass flow rate of low-density polyethylene particles is 0.5-2 g / 10 min.

[0012] Specifically, in the closed-cell foam layer, the melt mass flow rate of low-density polyethylene particles is 1.9 g / 10 min.

[0013] In this application, the test standard for the melt flow rate of low-density polyethylene particles in the closed-cell foam layer is ISO 1133.

[0014] Optionally, the PP-R hot melt layer material comprises 97-99% random copolymer polypropylene particles and 3-1% color masterbatch by weight percentage.

[0015] Optionally, in the PP-R hot melt layer, the melt mass flow rate of random copolymer polypropylene particles at 230°C and 2.16 kg is 0.1-0.5 g / 10 min.

[0016] Specifically, in the PP-R hot melt layer, the melt mass flow rate of random copolymer polypropylene particles at 230℃ and 2.16Kg is 0.28g / 10min.

[0017] Optionally, in the PP-R hot melt layer, the random copolymer polypropylene particles are Nordic Chemicals RA150E grade random copolymer polypropylene particles.

[0018] Optionally, the PP-R glass fiber reinforcement layer is made of glass fiber modified random copolymer polypropylene particles.

[0019] Optionally, the glass fiber modified random copolymer polypropylene particles comprise 8-10% glass fiber and 90-92% random copolymer polypropylene particles by weight percentage.

[0020] Optionally, the glass fiber is a silicate fiber and / or a silica fiber.

[0021] Optionally, the fiberglass retention length is ≤0.4mm.

[0022] Alternatively, the fiberglass grade is Jushi Group 508A.

[0023] Optionally, in the PP-R glass fiber reinforced layer, the melt mass flow rate of random copolymer polypropylene particles at 230℃ and 2.16Kg is 0.1-0.5g / 10min.

[0024] Specifically, in the PP-R glass fiber reinforced layer, the melt mass flow rate of random copolymer polypropylene particles at 230℃ and 2.16Kg is 0.28g / 10min.

[0025] Optionally, the PP-R antibacterial layer material comprises 96-98% random copolymer polypropylene particles, 1-3% color masterbatch, and 1-4% PP antibacterial masterbatch by weight percentage.

[0026] Optionally, in the PP-R antibacterial layer, the melt mass flow rate of random copolymer polypropylene particles at 230°C and 2.16 kg is 0.1-0.5 g / 10 min.

[0027] Specifically, in the PP-R antibacterial layer, the melt mass flow rate of random copolymer polypropylene particles at 230℃ and 2.16Kg is 0.28g / 10min.

[0028] Optionally, in the PP-R antibacterial layer, the random copolymer polypropylene particles are Nordic Chemicals RA150E grade random copolymer polypropylene particles.

[0029] Optionally, in the PP-R antibacterial layer, the PP antibacterial masterbatch is an inorganic silver-based antibacterial agent.

[0030] Optionally, in the PP-R antibacterial layer, the PP antibacterial masterbatch is RHM-PPR540 grade PP antibacterial masterbatch.

[0031] Optionally, by weight percentage, the masterbatch comprises 20-60% fully degradable material, 20-55% pigment, 0.05-0.5% surface treatment agent, 5-25% lubricating dispersant, 0-30% filler, 0.2-2% thermo-oxidative stabilizer, and 0-2% other additives.

[0032] Alternatively, the fully degradable material is P34HB.

[0033] Optionally, the pigment is titanium dioxide.

[0034] Optionally, the thermo-oxidative stabilizer is calcium / zinc.

[0035] Optionally, the surface treatment agent is a phthalate ester.

[0036] Optionally, the lubricating dispersant is polyethylene wax.

[0037] Alternatively, the filler may be calcium carbonate and barium sulfate.

[0038] Optionally, the weight ratio of calcium carbonate to barium sulfate is (1-3):1; preferably 2:1.

[0039] Optionally, other additives include pentaerythritol dioctadecyl alcohol, pentaerythritol β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and octyltin maleate in a weight ratio of 1:1:2.5.

[0040] The preparation method of the masterbatch in this application can be conventionally selected by those skilled in the art.

[0041] Optionally, the thickness ratio of the PP-R antibacterial layer, the PP-R fiberglass reinforcement layer, and the PP-R hot melt layer is (0.6-0.9):(0.8-1.2):(0.8-1.2).

[0042] Specifically, the thickness ratio of the PP-R antibacterial layer, the PP-R fiberglass reinforcement layer, and the PP-R hot melt layer is 0.8:1:1.

[0043] For example, in PP-R dn20×2.8 specification, the thickness of the PP-R antibacterial layer is (0.8-0.9) mm, the thickness of the PP-R hot melt layer is (1.0-1.2) mm, and the thickness of the PP-R fiberglass reinforcement layer is (1.0-1.2) mm.

[0044] Optionally, the thickness of the closed-cell foam layer is (4.5-5.5) mm.

[0045] Optionally, the thickness of the protective layer is (0.3-0.5) mm.

[0046] Another aspect of this invention provides a method for preparing a novel thermally insulating random copolymer polypropylene glass fiber reinforced pipe, comprising the following steps: (1) The raw materials for the PP-R hot melt layer, the PP-R glass fiber reinforced layer, the PP-R antibacterial layer, the closed-cell foam layer and the protective layer are respectively fed into the main extruder hopper, the first auxiliary extruder hopper, the second auxiliary extruder hopper, the third auxiliary extruder hopper and the fourth auxiliary extruder hopper; (2) Heating each hopper of the extruder; (3) The main extruder, the first auxiliary machine and the second auxiliary machine are co-extruded in three layers, cooled and shaped, and the product is printed with ink to obtain PP-R inner tube; (4) The PP-R inner tube enters the high-temperature chamber, and the raw material of the closed-cell foam layer begins to be sprayed to obtain glass fiber reinforced PP-R insulation pipe; (5) When the glass fiber reinforced PP-R insulation pipe passes through the fourth auxiliary machine, the raw material of the protective layer begins to be extruded and coated, marked and printed, pulled straight, cut, and flipped to obtain a new type of heat-insulating random copolymer polypropylene glass fiber reinforced pipe.

[0047] Optionally, in step (3), the cooling and shaping temperature is (30-40)℃.

[0048] The beneficial effects that this application can produce include: The protective layer of this application uses high-density polyethylene, which is wear-resistant and scratch-resistant, effectively protecting the closed-cell foam layer. The closed-cell foam layer is made of low-density polyethylene, which is healthy, environmentally friendly, odorless, and has a long service life. The PP-R hot-melt layer is random copolymer polypropylene, the same material as the PP-R pipe fittings, which facilitates welding and ensures reliable joint connections. The PP-R fiberglass reinforcement layer is made of fiberglass-modified random copolymer polypropylene particles, which improves the impact resistance and pressure resistance of the pipe and makes installation more aesthetically pleasing. The inner layer is a random copolymer polypropylene modified silver ion antibacterial layer, with an antibacterial effect reaching Class I standard. Attached Figure Description

[0049] Figure 1 This is a structural schematic diagram of the novel thermal insulation random copolymer polypropylene glass fiber reinforced pipe of this application.

[0050] Figure 2 This is a test report on the antibacterial properties of the novel thermal insulation random copolymer polypropylene glass fiber reinforced pipe prepared in Example 1. Detailed Implementation

[0051] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0052] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels. Example

[0053] A novel type of thermally insulated random copolymer polypropylene glass fiber reinforced pipe is available for use in low-temperature environments. For example... Figure 1 As shown, with a DN20×2.8 specification, the random copolymer polypropylene glass fiber reinforced pipe consists of a (0.8-0.9) mm PP-R antibacterial layer, a (1.0-1.2) mm PP-R glass fiber reinforcement layer, a (1.0-1.2) mm PP-R hot melt layer, a 4.5 mm closed-cell foam layer, and a 0.4 mm protective layer, from the center outwards. The PP-R antibacterial layer, PP-R glass fiber reinforcement layer, PP-R hot melt layer, closed-cell foam layer, and protective layer are sequentially adhered together.

[0054] By weight percentage, the protective layer consists of 99% high-density polyethylene particles (Shanghai Petrochemical YGH041, purchased from Shanghai Petrochemical) and 1% color masterbatch; the closed-cell foam layer consists of 99.4% low-density polyethylene particles (Iran Petrochemical 2420H) and 0.6% color masterbatch; the PP-R hot-melt layer consists of 98% random copolymer polypropylene particles (Borealis RA150E) and 2% color masterbatch; the PP-R glass fiber reinforced layer consists of glass fiber modified random copolymer polypropylene particles (Borealis RA150E), of which glass fiber (grade: Jushi Group 508A) is 9wt%, glass fiber retention length ≤0.4mm, and random copolymer polypropylene particles are 91wt%; the PP-R antibacterial layer consists of 97% random copolymer polypropylene particles (Borealis RA150E), 1% color masterbatch, and 2% PP antibacterial masterbatch (RHM-PPR540).

[0055] The masterbatch formula is as follows: P34HB (4HB content 15%): 30kg; titanium dioxide: 42kg; calcium / zinc: 2kg; calcium carbonate (1250 mesh): 10kg; barium sulfate: 5kg; phthalate: 0.1kg; polyethylene wax (average molecular weight 3000): 10kg; octyltin maleate: 0.5kg; pentaerythritol diphosphite: 0.2kg; pentaerythritol β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate: 0.2kg.

[0056] The preparation method of the masterbatch is as follows: the temperature of the high-speed mixer is raised to 110°C, and then the weighed calcium carbonate and barium sulfate are put into the high-speed mixer and mixed at high speed. With the help of the friction between the calcium carbonate and the inner wall of the high-speed mixer, the temperature of the calcium carbonate and barium sulfate reaches above 100°C. After 2.5 minutes, the metered phthalate coupling agent is added and the mixture is stirred at high speed at a mixing temperature of 110°C for 5 minutes. Then, the mixture is cooled and mixed at low speed. The processed material is then released for use. Titanium dioxide, sieved through a 200-mesh sieve, is added to a high-speed mixer along with polyethylene wax for high-speed mixing at approximately 70°C for 8 minutes. Then, pre-treated calcium carbonate and barium sulfate are added and mixed for another 2 minutes. Next, P34HB, calcium / zinc stabilizer, octyltin maleate, pentaerythritol β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and pentaerythritol diphosphite are added sequentially and mixed at high speed for 2 minutes. The mixture is then switched to low-speed cooling and stirring until the temperature drops below 60°C, at which point the blend is discharged. The blended material is then fed into a twin-screw extruder for compounding and plasticizing, followed by extrusion granulation. The selected twin-screw extruder has a screw length-to-diameter ratio of 36:1 and a screw diameter of φ75. The twin-screw processing temperature is set sequentially from the feeding section to the die head: 80℃—100℃—110℃—120℃—125℃—130℃—130℃—125℃, where the last two zones are the die head temperature and the first six zones are the die body temperature. The screw speed is 120 rpm. Granulation is performed underwater, followed by drying and cooling.

[0057] The preparation process of the novel thermal insulation random copolymer polypropylene glass fiber reinforced pipe includes the following steps: S1. Raw material preparation: Put the PP-R hot melt layer raw material into the main extruder hopper, the PP-R glass fiber reinforced layer raw material into the first auxiliary extruder hopper, the PP-R antibacterial layer mixed material into the second auxiliary extruder hopper, the closed-cell foam layer raw material into the third auxiliary extruder hopper, and the protective layer raw material into the fourth auxiliary extruder hopper. S2. Equipment heating: Heating the main extruder, the first auxiliary machine, the second auxiliary machine, the third auxiliary machine, and the fourth auxiliary machine; S3, the main extruder, the first auxiliary machine and the second auxiliary machine produce glass fiber reinforced PP-R pipes through three-layer co-extrusion; S4. Fiberglass reinforced PP-R pipes undergo shaping in a vacuum cooling chamber; then, using a traction machine, the pipes are pulled into the cooling chamber for further cooling and shaping; the cooling and shaping temperature is 35℃. S5. After product inkjet printing, a PP-R inner tube is obtained; S6. The PP-R inner tube enters the high-temperature chamber, and the raw material of the closed-cell foam layer begins to be sprayed to obtain the glass fiber reinforced PP-R insulation pipe. The specific operation method is as follows: two compressed gases, nitrogen and coal gas, are used, with the weight ratio of nitrogen and coal gas controlled at 2:1. At the same time, the foaming process is carried out under a pressure of 2.5Mpa, combined with the rotation of the screw (the screw speed is 55rpm for the main machine and 20rpm for the auxiliary machine). S7. When the glass fiber reinforced PP-R insulation pipe passes through the fourth auxiliary machine, the raw material for the protective layer begins to be extruded and coated. S8. Marking and printing on the glass fiber reinforced PP-R insulation pipe; S9. Straightening by Traction: The printed pipes are straightened by a tracked traction machine. S10. The material is cut into sections of the specified length by a cutting machine under the action of a tracked traction machine. S11. Finished products are flipped and removed from the shelf by a flipping rack; S11. Packaging and warehousing.

[0058] A novel thermal insulation random copolymer polypropylene fiberglass reinforced pipe differs from Example 1 in that, by weight percentage, the closed-cell foam layer is composed of 99% low-density polyethylene particles (Iran Petrochemical 2420H) and 1% color masterbatch. The material of the PP-R glass fiber reinforced layer, wherein the glass fiber content in the glass fiber modified random copolymer polypropylene particles is 3wt%.

[0059] The specific implementation method of a novel thermal insulation random copolymer polypropylene glass fiber reinforced pipe is the same as in Example 1.

[0060] A novel thermal insulation random copolymer polypropylene glass fiber reinforced pipe differs from Example 1 in that: by weight percentage, the closed-cell foam layer is composed of 99.9% low-density polyethylene particles (Iran Petrochemical 2420H) and 0.1% color masterbatch; the PP-R glass fiber reinforced layer is composed of glass fiber modified random copolymer polypropylene particles containing 15wt% glass fiber.

[0061] The specific implementation method of a novel thermal insulation random copolymer polypropylene glass fiber reinforced pipe is the same as in Example 1.

[0062] A novel thermal insulation random copolymer polypropylene fiberglass reinforced pipe differs from Example 1 in that: by weight percentage, the closed-cell foam layer is composed of 99.6% low-density polyethylene particles (Iran Petrochemical 2420H) and 0.4% color masterbatch; the thickness ratio of PP-R hot-melt layer: PP-R fiberglass reinforced layer: PP-R antibacterial layer is 2.5:5:2.5, the PP-R dn20×2.8 specification has a PP-R antibacterial layer thickness of 0.7mm, a PP-R hot-melt layer thickness of 0.7mm, and a PP-R fiberglass reinforced layer thickness of 1.4mm.

[0063] The specific implementation method of a novel thermal insulation random copolymer polypropylene glass fiber reinforced pipe is the same as in Example 1.

[0064] A novel thermal insulation random copolymer polypropylene fiberglass reinforced pipe differs from Example 1 in that: by weight percentage, the closed-cell foam layer is made of 99.6% low-density polyethylene particles (Iran Petrochemical 2420H) and 0.4% color masterbatch; the PP-R antibacterial layer is made of 98wt% random copolymer polypropylene (grade: Borealis RA150E) and 2wt% color masterbatch; the PP-R hot-melt layer:PP-R fiberglass reinforced layer:PP-R inner layer thickness ratio is 3:3:4; the PP-R specification is dn20×2.8; the PP-R hot-melt layer thickness is 0.84mm; the PP-R fiberglass reinforced layer thickness is 0.84mm; and the PP-R inner layer thickness is 1.12mm.

[0065] A novel thermal insulation random copolymer polypropylene pipe differs from Example 1 in that: by weight percentage, the closed-cell foam layer is composed of 99.6% low-density polyethylene particles (Iran Petrochemical 2420H) and 0.4% color masterbatch; the PP-R inner pipe is a PP-R three-layer composite pipe, with the middle and outer layers being random copolymer polypropylene material (brand name Borealis RA150E), and the inner layer consisting of 97% random copolymer polypropylene particles (Borealis RA150E), 1% color masterbatch, and 2% PP antibacterial masterbatch (RHM-PPR540). The pipe adopts a three-layer composite structure with a three-layer ratio of outer layer: middle layer: inner layer of 3:5:2. The PP-R dn20×2.8 specification has an inner antibacterial layer thickness of 0.56mm, an outer layer thickness of 0.84mm, and a middle layer thickness of 1.4mm.

[0066] Experiment 1: Impact resistance: Drop hammer impact test, conducted in accordance with GB / T14152.

[0067] Test subjects: The polypropylene pipes prepared in Example 1 were used as sample 1, with 25 pipes of 20cm length in each group. The polypropylene pipes prepared in Comparative Examples 1-5 were used as control samples 1-5, with 25 pipe samples of 20cm length in each group.

[0068] Test method: 1. Place the sample in a low-temperature test chamber, and control the temperature of the low-temperature test chamber at 0±1℃; Sample conditioning, placement time is 60 min; The drop hammer impact test used a DN25 hammer head with an impact height of 1m and a hammer head weight of 1.5kg. 4. Start the drop hammer tester to conduct a drop hammer impact test on the sample.

[0069] 5. Remove the samples from the low-temperature bath and record the number of damaged samples.

[0070]

[0071] Experiment 2: Antibacterial Performance Test The polypropylene pipe prepared in Example 1 was used as sample 1, and the polypropylene pipes prepared in Comparative Examples 1-5 were used as control samples 1-5.

[0072] The testing standards and methods are as follows: 1. T / CIAA 002-2019 Antibacterial Random Copolymer Polypropylene (PP-R) Pipe*; 2. JC / T939-2004 Antibacterial Performance of Antibacterial Plastic Pipes for Building. Antibacterial durability test: Samples were immersed in a distilled water bath at 50±2℃ for 16 hours before testing. The test results are shown in Table 2.

[0073] Experiment 3: Linear expansion coefficient test: The test shall be conducted in accordance with Appendix A of CJ / T258-2014, and the test conditions shall be (20-95)℃.

[0074] The polypropylene pipe prepared in Example 1 was used as sample 1, and the polypropylene pipes prepared in Comparative Examples 1-5 were used as control samples 1-5. The test results are shown in Table 3.

[0075]

[0076] Test 4: Pressure Resistance Test A hydrostatic strength test was conducted at 95℃ according to GB / T6111-2018 standard. The hydrostatic ring stress was 4.5MPa, and no cracking or leakage was observed after 22 hours according to the standard. Three samples were tested for each instance, each 300mm in length. One end of the pipe was sealed, and the other end was connected to a pressure burst testing machine. The hydrostatic strength of the samples was tested, and the results are shown in Table 4 below.

[0077] The test results above show that the composite materials in the examples produce pipes with excellent performance across all parameters. However, adjusting the composition or proportion of raw materials in each layer affects the pipe's performance. Specifically, in Comparative Example 1, reducing the fiberglass content of the middle fiberglass reinforcement layer increases the pipe's linear expansion coefficient, reducing its drop hammer impact resistance and pressure resistance. In Comparative Example 2, increasing the fiberglass content of the middle layer decreases the linear expansion coefficient, but reduces the pipe's 95°C pressure resistance. In Comparative Example 3, adjusting the three-layer structure ratio, with the middle PP-R fiberglass reinforcement layer accounting for half the total thickness of the inner layers, reduces the linear expansion coefficient, but also lowers the pipe's pressure resistance. In Comparative Example 4, adjusting the innermost layer's raw material formula, omitting nano-silver antibacterial masterbatch, results in a pipe lacking antibacterial properties. In Comparative Example 5, changing the middle layer material to random copolymer polypropylene for all three layers, and adjusting the three-layer structure ratio, increases the pipe's linear expansion coefficient, while reducing both drop hammer impact resistance and pressure resistance.

[0078] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A novel thermally insulated random copolymer polypropylene glass fiber reinforced pipe, characterized in that, The random copolymer polypropylene glass fiber reinforced pipe consists of a PP-R antibacterial layer, a PP-R glass fiber reinforcement layer, a PP-R hot melt layer, a closed-cell foam layer, and a protective layer, arranged sequentially from the center to the periphery. The PP-R antibacterial layer, PP-R glass fiber reinforcement layer, PP-R hot melt layer, closed-cell foam layer, and protective layer are adhered together in sequence. The protective layer comprises, by weight percentage, 99-99.9% polyethylene particles and 1-0.1% color masterbatch; The closed-cell foam layer comprises 99-99.9% low-density polyethylene particles and 1-0.1% color masterbatch by weight percentage. The PP-R hot melt layer comprises 97-99% random copolymer polypropylene particles and 3-1% color masterbatch by weight percentage. The material of the PP-R glass fiber reinforced layer is glass fiber modified random copolymer polypropylene particles; The PP-R antibacterial layer comprises, by weight percentage, 96-98% random copolymer polypropylene particles, 1-3% color masterbatch, and 1-4% PP antibacterial masterbatch.

2. The novel thermal insulation random copolymer polypropylene glass fiber reinforced pipe according to claim 1, characterized in that, By weight percentage, glass fiber modified random copolymer polypropylene particles contain 8-10% glass fiber and 90-92% random copolymer polypropylene particles.

3. The novel thermal insulation random copolymer polypropylene glass fiber reinforced pipe according to claim 2, characterized in that, The fiberglass retention length is ≤0.4mm.

4. The novel thermal insulation random copolymer polypropylene glass fiber reinforced pipe according to claim 2, characterized in that, Fiberglass is a silicate fiber and / or a silica fiber.

5. The novel thermal insulation random copolymer polypropylene glass fiber reinforced pipe according to claim 1, characterized in that, The thickness ratio of the PP-R antibacterial layer, the PP-R fiberglass reinforcement layer, and the PP-R hot melt layer is (0.6-0.9):(0.8-1.2):(0.8-1.2).

6. The novel thermal insulation random copolymer polypropylene glass fiber reinforced pipe according to claim 1, characterized in that, In the PP-R antibacterial layer, the PP antibacterial masterbatch is an inorganic silver-based antibacterial agent.

7. The novel thermal insulation random copolymer polypropylene glass fiber reinforced pipe according to any one of claims 1-6, characterized in that, In the PP-R hot melt layer, the melt mass flow rate of random copolymer polypropylene particles at 230℃ and 2.16Kg is 0.1-0.5g / 10min.

8. The novel thermal insulation random copolymer polypropylene glass fiber reinforced pipe according to any one of claims 1-6, characterized in that, In the PP-R glass fiber reinforced layer, the melt mass flow rate of random copolymer polypropylene particles at 230℃ and 2.16Kg is 0.1-0.5g / 10min.

9. The novel thermal insulation random copolymer polypropylene glass fiber reinforced pipe according to any one of claims 1-6, characterized in that, In the PP-R antibacterial layer, the melt flow rate of random copolymer polypropylene particles at 230℃ and 2.16Kg is 0.1-0.5g / 10min.

10. A method for preparing a novel thermally insulating random copolymer polypropylene glass fiber reinforced pipe according to any one of claims 1-9, characterized in that, Includes the following steps: (1) The raw materials for the PP-R hot melt layer, the PP-R glass fiber reinforced layer, the PP-R antibacterial layer, the closed-cell foam layer and the protective layer are respectively fed into the main extruder hopper, the first auxiliary extruder hopper, the second auxiliary extruder hopper, the third auxiliary extruder hopper and the fourth auxiliary extruder hopper; (2) Heating each hopper of the extruder; (3) The main extruder, the first auxiliary machine and the second auxiliary machine are co-extruded in three layers, cooled and shaped, and the product is printed with ink to obtain PP-R inner tube; (4) The PP-R inner tube enters the high-temperature chamber, and the raw material of the closed-cell foam layer begins to be sprayed to obtain glass fiber reinforced PP-R insulation pipe; (5) When the glass fiber reinforced PP-R insulation pipe passes through the fourth auxiliary machine, the raw material of the protective layer begins to be extruded and coated, marked and printed, pulled straight, cut, and flipped to obtain a new type of heat-insulating random copolymer polypropylene glass fiber reinforced pipe.

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