Rare earth high weather resistant PPR pipe and production method thereof

Abstract

The application discloses a rare earth high-weatherability PPR pipe and a production method thereof, and comprises the following steps: raw material pretreatment, premix preparation, extrusion molding, inner and outer spray cooling and shaping, cutting and spraying. The rare earth high-weatherability PPR pipe improves performance through the synergistic effect of a rare earth composite stabilizer, titanium white and carbon black. The rare earth composite stabilizer captures free radicals, and forms a triple protection system with the titanium white and the carbon black, thereby significantly enhancing weatherability. The titanium white reduces interface defects through coating and forms complementation with the carbon black. The rare earth cooperates with the titanium white to prolong oxidation induction time and thermal aging life. The carbon black also improves antistatic property. The cooperation of the additives optimizes dispersion, ensures that the pipe tensile strength and elongation at break reach standards, and takes into account weatherability and mechanical property.

Description

Technical Field

[0001] This invention relates to the field of polymer materials, specifically to a rare earth high weather-resistant PPR pipe and its production method. Background Technology

[0002] PPR pipes are a new generation of energy-saving and environmentally friendly building plastic pipes developed in the early 1990s. With their increasingly prominent competitive advantages, they have gained widespread market acceptance and extensive use. However, due to the large number of unstable tertiary carbon atoms in the PPR molecular chain, in the presence of oxygen, only a small amount of energy is needed to remove hydrogen from these tertiary carbon atoms, forming tertiary carbon free radicals. These free radicals are highly reactive and can cause various reactions in the molecular chain, including chain growth and degradation, leading to the loss of the original properties of PP, resulting in pipe discoloration, powdering, cracking, and mechanical damage, severely affecting the pipe's service life. Furthermore, color masterbatches or color powders are commonly used in the pipe manufacturing process to color transparent materials; the quality of these masterbatches and color powders is also a major factor affecting the pipe's weather resistance.

[0003] To address these issues, traditional methods involve adding antioxidants, light stabilizers, and UV absorbers, but the effects are limited, and some of these additives suffer from poor stability and easy migration. Summary of the Invention

[0004] The purpose of this invention is to solve the problems in the background art and provide a rare earth high weather-resistant PPR pipe and its production method.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0006] A method for preparing rare-earth high-weather-resistant PPR pipe includes the following steps:

[0007] S1. Raw material pretreatment: PPR resin is dried, rare earth composite stabilizer is coated and surface activated with silane coupling agent, titanium dioxide is coated with aluminum zirconium composite, carbon black is oxidized with nitric acid, and after filtration and drying, it is dispersed in liquid paraffin to form mother liquor.

[0008] S2. Preparation of premix: The dried PPR resin, surface-activated rare earth composite stabilizer, titanium dioxide, and carbon black mother liquor are put into a high-speed mixer and mixed. Then, color masterbatch, antioxidant, and lubricant are added to form a uniform premix.

[0009] S3. Extrusion molding: The premixed material is fed to a twin-screw extruder through a loss-in-weight feeding system and extruded to form a pipe preform;

[0010] S4. Internal and external spray cooling and shaping: The pipe blank is vacuum sizing, and then the inner and outer walls are simultaneously sprayed and cooled and shaped by the internal and external spray devices (13) of the pipe manufacturing equipment (1).

[0011] S5. Cutting: The cooled and shaped pipe blank is cut using the cutting device of the pipe manufacturing equipment;

[0012] S6. Spraying: The cut pipes are sprayed with a silane coupling agent solution (concentration 1-2%) through the spraying device of the pipe manufacturing equipment, and then dried with hot air at 80-100℃ to form a protective film.

[0013] This invention encapsulates a rare earth composite stabilizer with a silane coupling agent. The siloxane group at one end of the molecule can undergo a condensation reaction with the hydroxyl groups on the rare earth surface, while the organic groups at the other end physically entangle or chemically bond with the PPR resin, reducing surface energy and enhancing compatibility and dispersibility. This allows the rare earth elements to be evenly distributed in the pipe, leveraging their electronic layer structure advantages to capture free radicals, inhibit oxidation reactions, and improve thermal stability. A titanium dioxide-aluminum-zirconium composite coating treatment forms a dense protective film on the particle surface, reducing photocatalytic activity and enhancing UV reflectivity. Carbon black nitric acid oxidation treatment introduces polar groups such as carboxyl and hydroxyl groups, improving affinity with liquid paraffin and resin, and enhancing UV absorption. Internal and external spray cooling and shaping avoid internal stress caused by uneven cooling, ensuring the pipe's mechanical properties. After cutting, a silane coupling agent solution is sprayed on, and the protective film formed after drying has silicon-oxygen bonds that react with the hydroxyl groups on the pipe surface to form chemical bonds. The organic groups face outwards to form a hydrophobic layer, isolating moisture, oxygen, and UV rays, further improving surface hardness and wear resistance, ultimately significantly improving the pipe's weather resistance and service life.

[0014] Preferably, the pipe manufacturing equipment includes a frame and a screw extrusion device, a vacuum sizing box, an internal and external spraying device, a traction machine, a cutting device, and a spraying device arranged sequentially on the frame. The traction machine, the vacuum sizing box, and the cutting device are all mature technologies in the existing manufacturing of PPR pipes, so they will not be described in detail in this case.

[0015] This invention uses a screw extruder to extrude the material, followed by vacuum sizing in a vacuum sizing box. Then, it employs internal and external spraying devices for cooling and shaping to prevent internal stress caused by uneven cooling, thus ensuring the pipe's mechanical properties. Afterward, the material is cut off by a cutting device, and finally, a silane coupling agent solution is sprayed onto it using a spraying device. The resulting protective film after drying further enhances surface hardness and wear resistance. Through the close cooperation of these devices, the invention fully leverages the role of each stage of the production process in improving pipe performance, thereby producing rare earth high-weather-resistant PPR pipes with strong weather resistance and stable quality.

[0016] Preferably, the internal and external spraying device includes a cooling tank, an outer wall annular spraying mechanism, an inner wall annular spraying mechanism, an internally hollow water inlet shaft, and a heat-insulating water inlet pipe. Three or more of the outer wall annular spraying mechanisms are fixed on the cooling tank. The internally hollow water inlet shaft passes through the outer wall annular spraying mechanisms. One end of the internally hollow water inlet shaft is fixedly connected to the middle of the extrusion die of the screw extrusion device, and the other end is located at the outlet of the cooling tank. The inner wall annular spraying mechanism is sleeved and fixed on the internally hollow water inlet shaft and corresponds to the outer wall annular spraying mechanism. A pipe through channel is formed between the outer wall annular spraying mechanism and the inner wall annular spraying mechanism. The heat-insulating water inlet pipe is fixedly connected to the starting end of the internally hollow water inlet shaft and communicates with it. In order to prevent the cooling water from being affected by high temperature in the extrusion die, the heat-insulating water inlet pipe is wrapped with a high-temperature resistant material, and the flow rate is relatively fast.

[0017] In this invention, cooling water is introduced into an insulated inlet pipe, then passes through an inlet shaft, and is sprayed out from an inner wall annular spray mechanism to cool the inner wall of the pipe after vacuum sizing. Simultaneously, an outer wall annular spray mechanism also operates, resulting in uniform cooling of both the inner and outer walls of the pipe and creating intense convective heat transfer. Compared to the static or slow-flowing state of the coolant in immersion cooling, spraying can more quickly remove heat from the pipe surface, significantly shortening cooling time, improving production efficiency, reducing material performance degradation at high temperatures, maintaining the stabilizing effect of rare earth elements and other additives, and ensuring uniform coverage of the inner and outer walls with coolant. This prevents internal stress caused by uneven cooling, ensures the dimensional accuracy and mechanical stability of the pipe, and reduces the risk of cracking during use.

[0018] The further spray cooling circulation filtration system ensures the cleanliness of the coolant, prevents impurities from contaminating the pipe surface, lays the foundation for the formation of a high-quality protective film for the subsequent spraying of silane coupling agent solution, enhances the pipe's ability to isolate external erosion, improves surface hardness and wear resistance, and comprehensively enhances the weather resistance of rare earth high weather-resistant PPR pipes.

[0019] Preferably, both the outer wall annular spray mechanism and the inner wall annular spray mechanism include an annular main pipe and spray heads. A plurality of spray heads are disposed on the side wall of the annular main pipe and are interconnected with the annular main pipe. The spray heads of the outer wall annular spray mechanism are disposed on the inner wall of the annular main pipe, and the spray heads of the inner wall annular spray mechanism are disposed on the outer wall of the annular main pipe. Water enters through the annular main pipe and is sprayed out through the spray heads.

[0020] Preferably, the hollow water inlet shaft has a balance ring at its end. The balance ring includes a ring body with rollers along the circumferential direction. The rollers roll in the same direction as the pipe. The inner wall of the ring body is fixedly connected to the water inlet shaft.

[0021] The present invention uses a balance ring to be placed on the outlet of the cooling tank, so that the water inlet shaft can always be kept horizontal. By reducing the friction with the inner wall of the pipe blank through the roller, the pipe blank can be evenly sprayed at every position of the inner wall during continuous production, thus enhancing the cooling effect.

[0022] Preferably, the cutting device has a V-shaped receiving plate at its end, and a transfer plate at its rear end. The transfer plate includes a first horizontal plate, a second horizontal plate, a rotating shaft, and a drive motor. The first horizontal plate is fixedly connected to the V-shaped receiving plate, the rotating shaft is fixedly connected to the second horizontal plate, the drive motor is fixed on the V-shaped receiving plate, and the rotating shaft is fixedly connected to the drive motor. The cutting device can use a circular saw blade for cutting.

[0023] This invention uses a V-shaped receiving plate to allow the cut pipe to enter the V-shaped receiving plate, and then move to a transfer plate. The second horizontal plate of the transfer plate is rotated and flipped by a drive motor, causing the cut pipe to fall onto the unloading bin of the spraying device, thereby completing the continuous operation of the pipe from the cutting device to the spraying device.

[0024] Preferably, the spraying device includes a feeding hopper, a clamping and rotating mechanism, a first slide rail, a conveyor belt, a second slide rail, a spray gun, and a drying chamber. The feeding hopper is located in front of and below the second horizontal plate. The conveyor belt is located below the feeding hopper. The drying chamber is located at the end of the conveyor belt. Two clamping and rotating mechanisms are located on both sides of the conveyor belt. The clamping and rotating mechanisms are slidably mounted on the second slide rail. The second slide rail is slidably mounted on the first slide rail. The spray gun is slidably mounted on the frame via the slide rail. The spray gun is located above the clamping and rotating mechanism.

[0025] This invention uses a feeding hopper to allow pipes flipped by a transfer plate to fall into the hopper for storage. The bottom of the feeding hopper then opens, allowing the bottommost pipe to fall onto a conveyor belt. The conveyor belt transports the pipe to a clamping and rotating mechanism, which reciprocates via a first slide rail and moves up and down via a second slide rail, thus clamping and rotating the inner wall of the pipe. A spray gun then sprays a silane coupling agent solution onto the outer wall of the pipe. The pipe is then released and transported to a drying oven for hot air drying to form a protective film, completing the coating process and ensuring continuous production.

[0026] The bottom of the feeding hopper is equipped with a push plate, which is controlled by an electric push rod fixed to the frame to achieve the function of feeding one pipe at a time.

[0027] The up-and-down movement of the second slide rail can clamp pipes of different diameters.

[0028] Preferably, the clamping and rotating mechanism includes an inner support plate, a radial telescopic mechanism, a fixed cylinder, a clamping electric push rod, and a rotary motor. The rotary motor is fixed on the frame, the fixed cylinder is fixed on the output end of the rotary motor, and the clamping electric push rod is fixed on the fixed cylinder. Several radial telescopic mechanisms are circumferentially distributed on the side wall of the clamping electric push rod. The inner support plate is disposed on the radial telescopic mechanism. The radial telescopic mechanism includes a first rod and a second rod arranged in a cross pattern, a fixed block, and a movable shaft. The middle of the first rod and the second rod are movably connected. Both ends of the first rod and the second rod are movably connected to the fixed block through the movable shaft. The fixed block at one end of the second rod is fixed on the inner support plate, and the fixed block at the other end is fixed on the push rod end of the clamping electric push rod. The fixed block at one end of the first rod is fixed on the fixed cylinder, and the other end is fixed on the inner support plate. A sliding groove is provided on the fixed block on which the first rod is fixed to the inner support plate, and the movable shaft on the fixed block on which the first rod is fixed to the inner support plate slides on the sliding groove.

[0029] This invention achieves scissor-like extension and retraction by extending and retracting the clamping electric push rod, thereby driving the movement of the first and second rods. This allows the inner support plate to expand outward or extend and retract inward, thus clamping and releasing the inner wall of the pipe. During clamping, the pipe can be rotated by a rotary motor to achieve uniform spraying. During release, the inner support plate retracts inward and no longer contacts the inner wall of the pipe, making it easy to remove the pipe from the clamping and rotating mechanism.

[0030] A rare earth high weather-resistant PPR pipe, comprising the following components by weight: 80-90 parts PPR resin, 3-5 parts rare earth composite stabilizer, 2-4 parts titanium dioxide, 0.5-1 parts carbon black, 1-2 parts color masterbatch, and 1-3 parts auxiliary additives.

[0031] Rare earth composite stabilizers are complexes of rare earth oxides (such as cerium oxide and lanthanum oxide) and organic ligands (such as stearic acid and salicylic acid), or commercially available rare earth stabilizers (such as rare earth organotin composite stabilizers).

[0032] The rare earth high weather-resistant PPR pipe of the present invention improves performance through the synergistic effect of rare earth composite stabilizer, titanium dioxide and carbon black. The rare earth composite stabilizer captures free radicals and forms a triple protection system with titanium dioxide (high reflectivity) and carbon black (high absorption rate), which significantly enhances weather resistance.

[0033] Furthermore, the coating of titanium dioxide reduces interface defects and complements carbon black. Rare earth elements work synergistically to extend oxidation induction time and thermal aging life. Carbon black also improves antistatic properties. Combined with additives to optimize dispersion, it ensures that the tensile strength and elongation at break of the pipe meet the standards, taking into account both weather resistance and mechanical properties.

[0034] In summary, the beneficial effects of this invention are as follows:

[0035] 1. This invention coats a rare earth composite stabilizer with a silane coupling agent. The siloxane group at one end of the molecule can undergo a condensation reaction with the hydroxyl groups on the surface of the rare earth element, while the organic group at the other end reacts with the PPR. The resin undergoes physical entanglement or chemical bonding, reducing surface energy and enhancing compatibility and dispersibility. This allows rare earth elements to be evenly distributed within the pipe, leveraging their electronic layer structure advantages to capture free radicals, inhibit oxidation reactions, and improve thermal stability. Titanium dioxide-aluminum-zirconium composite coating treatment forms a dense protective film on the particle surface, reducing photocatalytic activity and enhancing UV reflectivity. Carbon black nitric acid oxidation treatment introduces polar groups such as carboxyl and hydroxyl groups, increasing affinity with liquid paraffin and resin, and enhancing UV absorption. Internal and external spray cooling and shaping avoid internal stress caused by uneven cooling, ensuring the pipe's mechanical properties. After cutting, a silane coupling agent solution is sprayed on, and the resulting protective film, after drying, forms a chemical bond between its silicon-oxygen bonds and the hydroxyl groups on the pipe surface. The organic groups face outwards, forming a hydrophobic layer that isolates moisture, oxygen, and UV rays, further improving surface hardness and wear resistance, ultimately significantly enhancing the pipe's weather resistance and service life.

[0036] 2. This invention uses a screw extruder to extrude the material, followed by vacuum sizing in a vacuum sizing box. Then, it employs internal and external spraying devices for cooling and shaping to prevent internal stress caused by uneven cooling, thus ensuring the mechanical properties of the pipe. Afterward, the material is cut off by a cutting device, and then a silane coupling agent solution is sprayed onto it using a spraying device. The resulting protective film after drying further enhances surface hardness and wear resistance. Through the close cooperation of these devices, the production process fully leverages the performance-enhancing effects of each step, producing rare-earth high-weather-resistant PPR pipes with strong weather resistance and stable quality. The circulating filtration system for further spraying and cooling ensures the cleanliness of the coolant, preventing impurities from contaminating the pipe surface. This lays the foundation for the subsequent application of the silane coupling agent solution to form a high-quality protective film, enhancing the pipe's ability to isolate it from external erosion, improving surface hardness and wear resistance, and comprehensively improving the weather resistance of the rare-earth high-weather-resistant PPR pipes.

[0037] 3. This invention achieves scissor-like extension and retraction by extending and retracting the clamping electric push rod, thereby driving the movement of the first and second rods. This allows the inner support plate to expand outward or extend and retract inward, thus clamping and releasing the inner wall of the pipe. During clamping, the pipe can be rotated by a rotary motor to achieve uniform spraying. During release, the inner support plate retracts inward and no longer contacts the inner wall of the pipe, making it easy to remove the pipe from the clamping and rotating mechanism.

[0038] 4. The rare earth high weather-resistant PPR pipe of the present invention improves performance through the synergistic effect of rare earth composite stabilizer, titanium dioxide and carbon black. The rare earth composite stabilizer captures free radicals and forms a triple protection system with titanium dioxide (high reflectivity) and carbon black (high absorption rate), which significantly enhances weather resistance. Attached Figure Description

[0039] Figure 1 This is an overall schematic diagram of the pipe manufacturing equipment of the present invention;

[0040] Figure 2 This is a side view of the pipe manufacturing equipment of the present invention;

[0041] Figure 3 This is a schematic diagram of the internal and external spraying device of the present invention;

[0042] Figure 4 This is a schematic diagram of the balancing ring of the present invention;

[0043] Figure 5 This is a schematic diagram of the V-shaped receiving plate and the transfer plate of the present invention;

[0044] Figure 6 This is a schematic diagram of the clamping and rotating mechanism of the present invention;

[0045] Figure 7 This is a schematic diagram of the assembled inner support plate, clamping electric push rod, and radial telescopic mechanism of the present invention;

[0046] Figure 8 This is a schematic diagram showing the connection between the inner support plate, the clamping electric push rod, and the radial telescopic mechanism of the present invention;

[0047] Figure 9 This is a schematic diagram of the present invention for clamping the electric push rod and the fixed cylinder;

[0048] Figure 10 This is a schematic diagram of the inner support plate and fixing block of the present invention;

[0049] Figure 11 This is a side sectional view of the material feeding hopper of the present invention;

[0050] 1. Pipe manufacturing equipment; 10. Frame; 11. Screw extrusion device; 12. Vacuum sizing box; 13. Internal and external spraying device; 14. Traction machine; 15. Cutting device; 16. Spraying device; 13. Internal and external spraying device; 131. Cooling tank; 132. Outer wall annular spraying mechanism; 133. Inner wall annular spraying mechanism; 134. Hollow water inlet shaft; 135. Insulated water inlet pipe; 136. Pipe through channel; 137. Annular main pipe; 138. Spray head; 17. Balance ring; 171. Ring body; 172. Roller; 151. v 152. Receiving plate; 153. Transfer plate; 154. First horizontal plate; 155. Second horizontal plate; 156. Rotating shaft; Drive motor; 167. Feeding bin; 18. Clamping and rotating mechanism; 168. First slide rail; 169. Conveyor belt; 160. Second slide rail; 161. Spray gun; 162. Drying oven; 183. Inner support plate; 194. Radial telescopic mechanism; 185. Fixed cylinder; 186. Clamping electric push rod; 197. Rotating motor; 198. First rod; 199. Second rod; 190. Fixed block; 191. Movable shaft; 192. Slide groove. Detailed Implementation

[0051] The following specific embodiments are merely illustrative of the present invention and are not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to these embodiments without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of the present invention.

[0052] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0053] Example 1

[0054] A method for preparing rare-earth high-weather-resistant PPR pipe includes the following steps:

[0055] S1. Raw material pretreatment: PPR resin is dried, rare earth composite stabilizer is coated and surface activated with silane coupling agent, titanium dioxide is coated with aluminum zirconium composite, carbon black is oxidized with nitric acid, and after filtration and drying, it is dispersed in liquid paraffin to form mother liquor.

[0056] S2. Preparation of premix: The dried PPR resin, surface-activated rare earth composite stabilizer, titanium dioxide, and carbon black mother liquor are put into a high-speed mixer and mixed. Then, color masterbatch, antioxidant, and lubricant are added to form a uniform premix.

[0057] S3. Extrusion molding: The premixed material is fed to a twin-screw extruder through a loss-in-weight feeding system and extruded to form a pipe preform;

[0058] S4. Internal and external spray cooling and shaping: The pipe blank is vacuum sizing, and then the inner and outer walls are simultaneously sprayed and cooled and shaped by the internal and external spray devices 13 of the pipe manufacturing equipment 1.

[0059] S5. Cutting: The cooled and shaped pipe blank is cut by the cutting device 15 of the pipe manufacturing equipment 1;

[0060] S6. Spraying: The cut pipe is sprayed with silane coupling agent solution through the spraying device 16 of the pipe making equipment 1, and then dried with hot air to form a protective film.

[0061] like Figures 1-2 As shown, the pipe manufacturing equipment 1 includes a frame 10 and a screw extrusion device 11, a vacuum sizing box 12, an internal and external spraying device 13, a traction machine 14, a cutting device 15, and a spraying device 16 arranged sequentially on the frame 10.

[0062] like Figures 3-4 As shown, the internal and external spraying device 13 includes a cooling tank 131, an outer wall annular spraying mechanism 132, an inner wall annular spraying mechanism 133, an internally hollow water inlet shaft 134, and a heat-insulating water inlet pipe 135. Three or more of the outer wall annular spraying mechanisms 132 are fixed to the cooling tank 131. The internally hollow water inlet shaft 134 passes through the outer wall annular spraying mechanism 132. One end of the internally hollow water inlet shaft 134 is fixedly connected to the middle of the extrusion die of the screw extrusion device 11, and the other end is located at the outlet of the cooling tank 131. The inner wall annular spraying mechanism 133 is sleeved and fixed on the internally hollow water inlet shaft 134 and corresponds to the outer wall annular spraying mechanism 132. A pipe through-channel 136 is formed between the outer wall annular spraying mechanism 132 and the inner wall annular spraying mechanism 133. The heat-insulating water inlet pipe 135... 5. The inner wall annular spray mechanism 133 is fixedly connected to and communicates with the starting end of the hollow water inlet shaft 134. Both the outer wall annular spray mechanism 132 and the inner wall annular spray mechanism 133 include an annular main pipe 137 and spray heads 138. Several spray heads 138 are provided on the side wall of the annular main pipe 137 and communicate with it. The spray heads 138 of the outer wall annular spray mechanism 132 are provided on the inner wall of the annular main pipe 137, and the spray heads 138 of the inner wall annular spray mechanism 133 are provided on the outer wall of the annular main pipe 137. The end of the hollow water inlet shaft 134 is provided with a balance ring 17. The balance ring 17 includes a ring body 171. The ring body 171 is provided with rollers 172 along the circumferential direction. The rolling direction of the rollers 172 is the same as the direction of the pipe. The inner wall of the ring body 171 is fixedly connected to the water inlet shaft 134.

[0063] like Figure 5As shown, the cutting device 15 has a V-shaped receiving plate 151 at its end, and a transfer plate 152 at its rear end. The transfer plate 152 includes a first horizontal plate 153, a second horizontal plate 154, a rotating shaft 155, and a drive motor. The first horizontal plate 153 is fixedly connected to the V-shaped receiving plate 151, the rotating shaft 155 is fixedly connected to the second horizontal plate 154, the drive motor is fixed on the V-shaped receiving plate 151, and the rotating shaft 155 is fixedly connected to the drive motor.

[0064] like Figures 6-11 As shown, the spraying device 16 includes a feeding bin 161, a clamping and rotating mechanism 18, a first slide rail 162, a conveyor belt 163, a second slide rail 164, a spray gun 165, and a drying chamber 166. The feeding bin 161 is located in front of and below the second horizontal plate 154. The conveyor belt 163 is located below the feeding bin 161. The drying chamber 166 is located at the end of the conveyor belt 163. Two clamping and rotating mechanisms 18 are located on both sides of the conveyor belt 163. The clamping and rotating mechanisms 18 slide vertically on the second slide rail 164. The second slide rail 164 slides back and forth on the first slide rail 162. The spray gun 165 slides back and forth on the frame 10. The spray gun 165 is located above the clamping and rotating mechanism 18. The clamping and rotating mechanism 18 includes an inner support plate 181, a radial telescopic mechanism 19, and a fixed... The system comprises a fixed cylinder 183, a clamping electric push rod 184, and a rotary motor 186. The rotary motor 186 is fixed to the frame 10. The fixed cylinder 183 is fixed to the output end of the rotary motor 186. The clamping electric push rod 184 is fixed to the fixed cylinder 183. Several radial telescopic mechanisms 19 are circumferentially distributed on the side wall of the clamping electric push rod 184. An inner support plate 181 is provided on the radial telescopic mechanism 19. The radial telescopic mechanism 19 includes first rods 191 arranged in a cross pattern. The first rod 191 is movably connected to the middle of the second rod 192 via the second rod 192, the fixed block 193, and the movable shaft 194. Both ends of the first rod 191 and the second rod 192 are movably connected to the fixed block 193 via the movable shaft 194. The fixed block 193 at one end of the second rod 192 is fixed to the inner support plate 181, and the fixed block 193 at the other end is fixed to the push rod end of the clamping electric push rod 184. The fixed block 193 at one end of the first rod 191 is fixed... One end of the fixed cylinder 183 is fixed to the inner support plate 181. The first rod 191 is fixed to the fixed block 193 on the inner support plate 181, and a sliding groove 195 is provided on the fixed block 193. The movable shaft 194 on the fixed block 193 on the inner support plate 181 slides on the sliding groove 195. The bottom of the feeding hopper is provided with a push plate 160. The push plate 160 is controlled by a push plate electric push rod 167, which is fixed on the frame to realize the function of feeding one pipe at a time.

[0065] A rare earth high weather-resistant PPR pipe, by weight, comprises the following components: 80 parts PPR resin, 3 parts rare earth composite stabilizer, 2 parts titanium dioxide, 0.5 parts carbon black, 1 part color masterbatch, and 1 part auxiliary additives.

[0066] Working principle: such as Figures 1-11 As shown, the premixed material is fed to a twin-screw extruder via a loss-in-weight feeding system to form a pipe preform. The preform is then pulled by a traction machine 14 and enters a vacuum sizing box 12 for vacuum sizing. Afterward, the pipe passes through the cooling tank 131 of the inner and outer spraying device 13, through the pipe penetration channel 136, and cooling water enters the insulated water inlet pipe 135. The cooling water then passes through the inlet shaft 134 and is sprayed from the spray heads 138 of the inner wall annular spraying mechanism 133 to spray the vacuum-sizing pipe. The inner wall is cooled, and the outer wall annular spray mechanism also starts working, thus uniformly cooling the inner and outer walls of the pipe and forming strong convective heat transfer. While cooling, continuous production of the pipe is ensured. After that, the pipe is cut and falls onto the V-shaped receiving plate 151, and then moves to the transfer plate 152. The second horizontal plate 154 of the transfer plate 152 is rotated and flipped by the drive motor, so that the cut pipe falls onto the unloading bin 161 of the spraying device. The push plate electric push rod 167 drives the push plate 161. The movement of 60 causes the bottom of the feeding hopper 161 to open, discharging one pipe at a time. The pipe at the bottom falls onto the conveyor belt 163, which transports it to the clamping and rotating mechanism 18. The clamping and rotating mechanism 18 moves towards the center via the first slide rail, and the clamping electric push rod 184 retracts, causing the inner support plate 181 to expand outward, clamping the inner wall of the pipe. Then, it is rotated by the rotary motor 186, and the spray gun moves back and forth via the slide rail to spray the silane coupling agent solution onto the pipe. On the outer wall of the material, the clamping electric push rod 184 extends, causing the inner support plate 181 to extend and retract inward, releasing the pipe. The clamping rotation mechanism returns to its position via the first slide rail, and the pipe is transported to the drying oven for hot air drying to form a protective film, completing the spraying work. The finished pipe has its performance improved by the synergistic effect of rare earth composite stabilizer, titanium dioxide, and carbon black. The rare earth composite stabilizer captures free radicals and forms a triple protection system with titanium dioxide (high reflectivity) and carbon black (high absorption rate), significantly enhancing weather resistance.

[0067] Example 2

[0068] Unlike Example 1,

[0069] A rare earth high weather-resistant PPR pipe, by weight, has the following components: 85 parts PPR resin, 4 parts rare earth composite stabilizer, 3 parts titanium dioxide, 0.8 parts carbon black, 1.5 parts color masterbatch, and 2 parts auxiliary additives.

[0070] Example 3

[0071] Unlike Example 1,

[0072] A rare earth high weather-resistant PPR pipe, by weight, has the following components: 90 parts PPR resin, 5 parts rare earth composite stabilizer, 4 parts titanium dioxide, 1 part carbon black, 2 parts color masterbatch, and 3 parts auxiliary additives.

[0073] The tubes prepared in Examples 1, 2, and 3 were subjected to the following tests, and the data are as follows:

[0074]

[0075] The above experimental data referenced the performance differences between ordinary PPR pipes and high weather-resistant PPR pipes in the document. Combined with the different contents of rare earth composite stabilizers, titanium dioxide, carbon black and other components in the three examples, the rare earth high weather-resistant PPR pipes are superior to ordinary PPR pipes in terms of oxidation induction time, impact strength, low-temperature drop hammer impact performance, hydraulic strength and aging resistance. Moreover, with the reasonable increase of the content of relevant weather-resistant components, the performance shows a trend of gradual optimization.

Claims

1. A method for preparing rare-earth high-weather-resistant PPR pipe, characterized in that, Includes the following steps: S1. Raw material pretreatment: PPR resin is dried, rare earth composite stabilizer is coated and surface activated with silane coupling agent, titanium dioxide is coated with aluminum zirconium composite, carbon black is oxidized with nitric acid, and after filtration and drying, it is dispersed in liquid paraffin to form mother liquor. S2. Preparation of premix: The dried PPR resin, surface-activated rare earth composite stabilizer, titanium dioxide, and carbon black mother liquor are put into a high-speed mixer and mixed. Then, color masterbatch, antioxidant, and lubricant are added to form a uniform premix. S3. Extrusion molding: The premixed material is fed to a twin-screw extruder through a loss-in-weight feeding system and extruded to form a pipe preform; S4. Internal and external spray cooling and shaping: The pipe blank is vacuum sizing, and then the inner and outer walls are simultaneously sprayed and cooled and shaped by the internal and external spray devices (13) of the pipe manufacturing equipment (1). S5. Cutting: The cooled and shaped pipe blank is cut by the cutting device (15) of the pipe manufacturing equipment (1); S6. Spraying: The cut pipe is sprayed with silane coupling agent solution through the spraying device (16) of the pipe making equipment (1), and then dried with hot air at 80-100℃ to form a protective film. The pipe manufacturing equipment (1) includes a frame (10) and a screw extrusion device (11), a vacuum sizing box (12), an internal and external spraying device (13), a traction machine (14), a cutting device (15), and a spraying device (16) arranged sequentially on the frame (10). The internal and external spraying device (13) includes a cooling tank (131), an outer wall annular spraying mechanism (132), an inner wall annular spraying mechanism (133), a hollow water inlet shaft (134), and a heat-insulating water inlet pipe (135). Three or more of the outer wall annular spraying mechanisms (132) are fixed on the cooling tank (131). The hollow water inlet shaft (134) passes through the outer wall annular spraying mechanism (132). One end of the hollow water inlet shaft (134) is connected to the screw extrusion device (11). The middle part of the extrusion die head is fixedly connected, and the other end is set on the outlet of the cooling tank (131). The inner wall annular spray mechanism (133) is sleeved and fixed on the hollow water inlet shaft (134) and corresponds to the outer wall annular spray mechanism (132). A pipe through channel (136) is formed between the outer wall annular spray mechanism (132) and the inner wall annular spray mechanism (133). The heat-insulating water inlet pipe (135) is fixedly connected to the starting end of the hollow water inlet shaft (134) and communicates with each other. Both the outer wall annular spray mechanism (132) and the inner wall annular spray mechanism (133) include an annular main pipe (137) and spray heads (138). Several spray heads (138) are provided on the side wall of the annular main pipe (137) and are interconnected with the annular main pipe (137). The spray heads (138) of the outer wall annular spray mechanism (132) are provided on the inner wall of the annular main pipe (137), and the spray heads (138) of the inner wall annular spray mechanism (133) are provided on the outer wall of the annular main pipe (137). The hollow water inlet shaft (134) is provided with a balance ring (17) at its end. The balance ring (17) includes a ring body (171). The ring body (171) is provided with a roller (172) along the circumferential direction. The rolling direction of the roller (172) is the same as that of the pipe. The inner wall of the ring body (171) is fixedly connected to the water inlet shaft (134). The cutting device (15) is provided with a V-shaped receiving plate (151) at its end. The rear end of the V-shaped receiving plate (151) is provided with a transfer plate (152). The transfer plate (152) includes a first horizontal plate (153), a second horizontal plate (154), a rotating shaft (155), and a drive motor. The first horizontal plate (153) is fixedly connected to the V-shaped receiving plate (151). The rotating shaft (155) is fixedly connected to the second horizontal plate (154). The drive motor is fixed on the V-shaped receiving plate (151). The rotating shaft (155) is fixedly connected to the drive motor.

2. The method for preparing a rare-earth high-weather-resistant PPR pipe according to claim 1, characterized in that, The spraying device (16) includes a feeding bin (161), a clamping and rotating mechanism (18), a first slide rail (162), a conveyor belt (163), a second slide rail (164), a spray gun (165), and a drying chamber (166). The feeding bin (161) is located in front of the second horizontal plate (154). The conveyor belt (163) is located below the feeding bin (161). The drying chamber (166) is located at the end of the conveyor belt (163). Two clamping and rotating mechanisms (18) are located on both sides of the conveyor belt (163). The clamping and rotating mechanism (18) slides up and down on the second slide rail (164). The second slide rail (164) slides back and forth on the first slide rail (162). The spray gun (165) slides back and forth on the frame (10). The spray gun (165) is located above the clamping and rotating mechanism (18).

3. The method for preparing a rare-earth high-weather-resistant PPR pipe according to claim 2, characterized in that, The clamping and rotating mechanism (18) includes an inner support plate (181), a radial telescopic mechanism (19), a fixed cylinder (183), a clamping electric push rod (184), and a rotary motor (186). The rotary motor (186) is fixed on the frame (10), the fixed cylinder (183) is fixed on the output end of the rotary motor (186), the clamping electric push rod (184) is fixed on the fixed cylinder (183), and several radial telescopic mechanisms (19) are circumferentially distributed on the side wall of the clamping electric push rod (184). The inner support plate (181) is provided on the radial telescopic mechanism (19).

4. The method for preparing a rare-earth high-weather-resistant PPR pipe according to claim 3, characterized in that, The radial telescopic mechanism (19) includes a first rod (191) and a second rod (192) arranged in a cross configuration, a fixed block (193), and a movable shaft (194). The first rod (191) and the second rod (192) are movably connected at their middle portions. Both ends of the first rod (191) and the second rod (192) are movably connected to the fixed block (193) via the movable shaft (194). The fixed block (193) at one end of the second rod (192) is fixed to the inner support plate (181), and the other end of the fixed block (193) is fixed to the inner support plate (181). The fixed block (193) is fixed on the push rod end of the clamping electric push rod (184). The fixed block (193) at one end of the first rod (191) is fixed on the fixed cylinder (183), and the other end is fixed on the inner support plate (181). The fixed block (193) on the inner support plate (181) of the first rod (191) is provided with a sliding groove (195). The movable shaft (194) on the fixed block (193) on the inner support plate (181) of the first rod (191) slides on the sliding groove (195).

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