High-speed extrusion production process and equipment for high-filling PVC (polyvinyl chloride) pipe

Abstract

The invention discloses a high-speed extrusion production process and equipment for a highly-filled PVC (polyvinyl chloride) pipe, which comprises the following steps: firstly, proportioning according to a specified highly-filled PVC formula to prepare highly-filled PVC clinker dry powder for later use, preparing granules of which the model is consistent with that of the highly-filled PVC clinker dry powder, preheating an extruder, and carrying out extrusion molding to obtain the highly-filled PVC pipe. The method comprises the following steps: setting parameters such as temperature and rotating speed of an extruder according to specifications and requirements, mounting at least one side feeding machine at a blanking barrel of the PVC pipe extruder, debugging the side feeding machine, setting the feeding speed of the side feeding machine, putting clinker dry powder into a first feeding device, putting granules into the side feeding machine at the same time, and feeding the granules into a second feeding device; the clinker dry powder and the granules are mixed and enter the extrusion channel, the mixed raw materials are conveyed to the mold through the extrusion channel, and the high-filling PVC pipe is formed through the mold, the granules consistent with PVC resin in model are added through the side feeding device, the internal friction force between the materials is remarkably reduced, and the problems that in the traditional technology, a screw does not feed materials, and the materials emerge from a discharging opening are thoroughly solved.

Description

Technical Field

[0001] This invention relates to the field of PVC pipe manufacturing technology, and more specifically, to a high-speed extrusion production process and equipment for high-filled PVC pipes. Background Technology

[0002] Currently, high-filler PVC formulations are widely used in pipe production. Their core advantage lies in effectively reducing raw material costs by increasing the content of inorganic fillers such as calcium carbonate powder, while improving the physical properties of pipes such as rigidity and wear resistance. They have important application value in building water supply and drainage, municipal pipe networks and other fields.

[0003] In the existing production process, the high calcium carbonate content in the formula results in very loose high-filled PVC clinker with poor dry powder flowability. In actual extrusion production, this poor flowability of clinker causes many problems, such as screw failure to feed, material overflow, and large current fluctuations. These problems not only greatly limit the extrusion speed of high-filled PVC pipes, resulting in low production efficiency, but also seriously affect product quality, leading to various quality defects in the pipes and making it difficult to meet the high-quality demands of the market. Therefore, a technical solution is needed to solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and solve the problem of poor flowability of high-filled PVC clinker dry powder and poor screw feeding, so as to provide a high-speed extrusion production process and equipment for high-filled PVC pipes.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention discloses a high-speed extrusion production process for high-filler PVC pipes, comprising the following steps:

[0007] S1. Raw material preparation: First, prepare the high-filled PVC formula according to the specified formula to obtain high-filled PVC clinker dry powder for later use. Prepare granules with the same PVC resin type as the high-filled PVC clinker dry powder. Select granules with a particle size range of 0.5mm to 10mm after screening for later use.

[0008] S2. Equipment debugging: Turn on the PVC pipe extruder and preheat it. Set the temperature, speed and other parameters of the extruder according to the specifications and requirements of the pipe to be produced. Install at least one side feeder at the discharge barrel of the PVC pipe extruder and debug the side feeder. Set the feeding speed of the side feeder so that PVC granules are added to the discharge port at a ratio of 2% to 20%.

[0009] S3. Raw material addition and extrusion: High-filled PVC clinker dry powder is added to the first feeding device of the extruder, and PVC granules are added to the side feeder at the same time. The high-filled PVC clinker dry powder and PVC granules are mixed and enter the extrusion channel.

[0010] S4. Pipe forming: The mixed PVC raw materials are fed to the extrusion die through the extrusion channel and formed into high-filled PVC pipes through the die.

[0011] Furthermore, in step S1, it is necessary to calculate the proportion of PVC granules to the total PVC material mass. The calculation formula is as follows:

[0012]

[0013] in, The addition ratio for granulated PVC granules. For the quality of PVC granules, The total mass of PVC resin. To ensure the quality of PVC resin in high-filled PVC clinker dry powder;

[0014] The formula for calculating the mass of PVC resin in high-filled PVC clinker powder is as follows:

[0015]

[0016] in, To ensure the quality of high-filled PVC clinker dry powder, The mass fraction of PVC resin in high-filled PVC clinker dry powder.

[0017] Furthermore, in step S1, the formula for calculating the mass of the PVC granules used is derived as follows:

[0018]

[0019] Substituting this further into the formula for calculating the mass of PVC resin in highly filled PVC clinker powder, we get:

[0020] .

[0021] Furthermore, in step S1, the formula for calculating the total mass of PVC resin is derived as follows:

[0022] .

[0023] Furthermore, in step S1, PVC granules with particle sizes of 1 mm and 4 mm are screened out respectively.

[0024] Furthermore, in step S2, there are two side feeders, and the two feeders simultaneously feed PVC granules with particle sizes of 1mm and 4mm respectively.

[0025] Furthermore, a high-speed extrusion equipment for high-filled PVC pipes is provided to realize the above-mentioned high-speed extrusion production process of high-filled PVC pipes. It includes an extrusion channel, a feeding assembly, a first feeding device, a second feeding device, and a third feeding device. The feeding assembly includes a feeding cylinder, the lower end of which is connected to the extrusion channel. The first feeding device is connected to the feeding cylinder. The first feeding device feeds high-filled PVC clinker dry powder to the feeding cylinder through a screw. The second feeding device and the third feeding device can both feed the PVC granules to the feeding cylinder through a screw.

[0026] Furthermore, the second feeding device includes a first feeding body and a first connecting cylinder, and the third feeding device includes a second feeding body and a second connecting cylinder. The first feeding body feeds material to the first connecting cylinder via a screw, and the first connecting cylinder is installed at the upper end of the discharge cylinder. The second feeding body feeds material to the second connecting cylinder via a screw, and the second connecting cylinder is installed at the upper end of the first connecting cylinder. The discharge cylinder, the first connecting cylinder, and the second connecting cylinder are detachably connected.

[0027] Furthermore, the feeding assembly includes a dispersing device, which includes a stirrer that is rotatable and located inside the feeding cylinder, below all the feed inlets of the feeding cylinder.

[0028] Furthermore, the stirrer includes two stirring half-rings and a central rod. The two stirring half-rings are vertically mounted on the central rod, and the stirring half-rings are equipped with a plurality of dispersing plates, which are inclined.

[0029] The beneficial effects of this invention are:

[0030] 1. This invention adds granular material of the same type as PVC resin through a side feeding device, combined with a dispersing device in the feeding cylinder, breaking the agglomeration structure of high-filled PVC clinker dry powder from both process and structural aspects, significantly reducing the internal friction between materials, and completely solving the problems of screw not feeding and material overflowing from the feeding port in traditional processes. The stable feeding and extrusion process provides a guarantee for high-speed extrusion. Compared with traditional processes, the extrusion speed of this invention is improved.

[0031] 2. This invention uses two side feeders to feed two different particle sizes of granules. The different particle sizes of the granules can further optimize the agglomeration of high-filled PVC clinker dry powder, and solve the problems of screw not feeding and material overflowing from the discharge port. At the same time, the equipment adopts a detachable design, and the number of side feeders can be flexibly adjusted according to production needs. There is no need to carry out large-scale modification of the existing PVC pipe extruder, and the equipment modification cost is low. The PVC granule addition ratio and particle size in the process can be flexibly adjusted according to different specifications of pipes and different calcium carbonate filling amounts, which can adapt to the production needs of various high-filled PVC pipes. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of an extrusion device in this embodiment.

[0033] Figure 2 This is a partial schematic diagram of this embodiment.

[0034] Figure 3 This is a schematic diagram of a stirrer in this embodiment.

[0035] Reference numerals: 1. Extrusion channel; 2. Feeding assembly; 21. Feeding cylinder; 22. Dispersing device; 221. Agitator; 222. Agitating half-ring; 2221. Outer frame; 2222. Dispersing plate; 2223. First region; 2224. Second region; 223. Central rod; 3. First feeding device; 4. Second feeding device; 41. First feeding body; 42. First connecting cylinder; 5. Third feeding device; 51. Second feeding body; 52. Second connecting cylinder. Detailed Implementation

[0036] The technical solutions in this embodiment will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] This embodiment discloses a high-speed extrusion production process for high-filler PVC pipes, including the following steps:

[0038] S1. Raw material preparation: First, the ingredients are prepared according to the specified high-filled PVC formula to obtain high-filled PVC clinker dry powder for later use. Particles with the same PVC resin type as the high-filled PVC clinker dry powder are prepared. Particles with a particle size range of 0.5mm to 10mm are selected for later use. Preferably, PVC particles with two particle sizes of 1mm and 4mm are selected to further improve the mixing uniformity and flowability.

[0039] In this step, it is necessary to accurately calculate the proportion of PVC granules to the total PVC material to ensure that the amount added is reasonable. The relevant calculation formula is as follows:

[0040] The proportion of PVC granules to the total PVC material needs to be calculated using the following formula:

[0041] (Formula 1)

[0042] in, The addition ratio for granulated PVC granules is 2% to 20% depending on the flowability of the formulation. For the quality of PVC granules, The total mass of PVC resin. To ensure the quality of PVC resin in high-filled PVC clinker dry powder;

[0043] The formula for calculating the mass of PVC resin in high-filled PVC clinker powder is as follows:

[0044] (Formula 2)

[0045] in, To ensure the quality of high-filled PVC clinker dry powder, The mass fraction of PVC resin in high-filled PVC clinker dry powder is determined by the formulation and is usually 30%-50%.

[0046] The derived formula for calculating the mass of the PVC granules used is as follows:

[0047] (Formula 3)

[0048] Substituting equation two into equation three, we get:

[0049] (Formula 4)

[0050] Meanwhile, the formula for calculating the total mass of PVC resin is derived as follows:

[0051] (Formula 5)

[0052] Calculation example: Given the conditions that production is required... (Weight of high-filled PVC clinker dry powder) = 50kg (Mass fraction of PVC resin in high-filled PVC clinker powder) = 40%, (PVC granule addition ratio) = 5%, calculate. (Quality of PVC granules) and (Total PVC resin mass):

[0053] First calculate (Quality of PVC resin in high-filled PVC clinker powder):

[0054]

[0055] calculate (Quantity of PVC granules):

[0056]

[0057] calculate (Total PVC resin mass):

[0058]

[0059] Or through the formula:

[0060]

[0061] The results of the two formulas above are consistent. When 50kg of high-filled PVC clinker dry powder (containing 20kg of PVC) is added, and a small particle addition ratio of 5% is adopted, about 1.05kg of granulated PVC small particles need to be added, and the total PVC material mass is about 21.05kg.

[0062] In actual production, the required mass of small particles per hour can be calculated according to the extruder feed rate (e.g., 50 kg / h dry powder) using the formula above. This allows for setting the side feeder speed to ensure accurate proportioning. When the calcium carbonate filling amount increases, the feed rate can be appropriately increased. (The addition ratio of PVC granules), at this point, the corresponding ratio can be quickly calculated using Equation 4. No need to readjust the overall formula.

[0063] This embodiment uses two different particle sizes of granules; simply add... Split into (Mass of pellets from the first side feeder) and (The mass of pellets from the second side feeder), and Simply set the feeding speed of the two side feeders. For example, set the PVC mass ratio in the dry powder formula to 35%, the total addition ratio of small particles to 15%, and the extruder feed rate to 60 kg / h, and calculate:

[0064]

[0065] On average, each of the two side feeders delivers 1.855 kg / h of material.

[0066] S2. Equipment Debugging: Turn on the PVC pipe extruder and preheat it. Set the temperature, speed and other parameters of the extruder according to the specifications and requirements of the pipe to be produced. Install at least one side feeder at the discharge barrel of the PVC pipe extruder. In this embodiment, PVC granules with two particle sizes of 1mm and 4mm are selected, so two side feeders are set to feed the two particle sizes of granules respectively. Debug the side feeders. Based on the PVC granule mass obtained by the above calculation formula and the extruder feed rate, set the feeding speed of the side feeders so that the PVC granules are accurately added to the discharge port at a ratio of 2% to 20%.

[0067] like Figures 1-3 As shown, to achieve PVC granule feeding via two side feeders, this embodiment discloses a high-speed extrusion device for high-filler PVC pipes, including an extrusion channel 1, a feeding assembly 2, a first feeding device 3, a second feeding device 4, and a third feeding device 5. The feeding assembly 2 includes a feeding cylinder 21, the lower end of which is connected to the extrusion channel 1. The first feeding device 3 is connected to the feeding cylinder 21. The first feeding device 3 feeds high-filler PVC clinker powder to the feeding cylinder 21 via a screw. The second feeding device 4 and the third feeding device 5 can both feed PVC granules to the feeding cylinder 21 via screws. Each feeding device discharges material via a separate screw, corresponding to the conveying of different granules. The feeding device 4 includes a first feeding body 41 and a first connecting cylinder 42, and the third feeding device 5 includes a second feeding body 51 and a second connecting cylinder 52. The first feeding body 41 feeds material to the first connecting cylinder 42 through a screw. The first connecting cylinder 42 is installed at the upper end of the discharge cylinder 21. The second feeding body 51 feeds material to the second connecting cylinder 52 through a screw. The second connecting cylinder 52 is installed at the upper end of the first connecting cylinder 42. The discharge cylinder 21, the first connecting cylinder 42, and the second connecting cylinder 52 are detachably connected, which facilitates the installation, disassembly, and maintenance of the equipment. The number of side feeders can be flexibly adjusted according to production needs.

[0068] The feeding assembly 2 includes a dispersing device 22, which includes a stirrer 221. The stirrer 221 is rotatable and located inside the feeding cylinder 21. The stirrer 221 is located below all the feed inlets of the feeding cylinder 21 and can forcibly stir and mix the materials fed by the first feeding device 3, the second feeding device 4, and the third feeding device 5. This further breaks down the agglomerated structure of the high-filled PVC clinker dry powder, allowing PVC particles to penetrate the high-filled PVC clinker dry powder, avoiding agglomeration in the extrusion channel, and improving the uniformity and flowability of the material mixture.

[0069] The agitator 221 in this embodiment includes two stirring half-rings 222 and a central rod 223. The central rod 223 is connected to an external motor and reducer, and is locked to an external rotating shaft pin. The two stirring half-rings 222 are vertically mounted on the central rod 223. The two vertically staggered stirring half-rings 222 can alternately stir and disperse the material when the agitator 221 rotates, resulting in better material dispersion and mixing. It can continuously turn the material in the feeding cylinder 21 and facilitate the accumulation of material in the feeding cylinder 21. The stirring half-rings 222 include a semi-circular outer frame 2221 and multiple dispersing plates 2222. The semi-circular outer frame 2221 corresponds to the cylindrical internal shape of the feeding cylinder 21. Each outer frame 2221 is divided by the central rod 223. The system is divided into a first region 2223 and a second region 2224. The dispersing plate 2222 is inclined, with its length direction parallel to the axis of the central rod 223. The preferred inclination angle is 30° to 60°. This not only enhances the mixing and dispersing effect of the agitator 221 but also guides the material to flow towards the extrusion channel 1. The dispersing plates 2222 in the first region 2223 and the dispersing plates 2222 in the second region 2224 have opposite inclination directions. The dispersing plates 2222 with different inclination directions can flip the material twice, once in the forward direction and once in the reverse direction, when the mixing half-ring 222 rotates. This makes the material turning effect of the agitator 221 better, allowing the granular material to be fully mixed with the powder during the feeding process, and ensuring that the material has better flowability in the extrusion channel 1.

[0070] S3. Raw material addition and extrusion: High-filled PVC clinker dry powder is fed into the first feeding device of the extruder, and PVC granules are fed into the side feeder at the same time. The high-filled PVC clinker dry powder and PVC granules are mixed and enter the extrusion channel. In this embodiment, two side feeders are used to feed PVC granules with particle sizes of 1mm and 4mm at the same time. After the high-filled PVC clinker dry powder and PVC granules are initially mixed in the feed cylinder 21, they enter the extrusion channel 1 and are further mixed evenly during the screw rotation and pushing process. The PVC granules are interspersed between the dry powder particles, breaking the dry powder agglomeration structure, reducing the friction between materials, and making the materials conveyed forward evenly and smoothly.

[0071] S4. Pipe forming: The mixed PVC raw materials are fed to the extrusion die through the extrusion channel and formed into high-fill PVC pipe blanks through the die; the pipe blanks are cooled and shaped in a vacuum cooling and shaping box, pulled at a constant speed by a traction machine, and then cut to the set length by a cutting machine. Finally, after inspection and packaging, the finished high-fill PVC pipes are obtained.

[0072] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A high-speed extrusion production process for high-filler PVC pipes, characterized in that, Includes the following steps: S1. Raw material preparation: First, prepare the high-filled PVC formula according to the specified formula to obtain high-filled PVC clinker dry powder for later use. Prepare granules with the same PVC resin type as the high-filled PVC clinker dry powder. Select granules with a particle size range of 0.5mm to 10mm after screening for later use. S2. Equipment debugging: Turn on the PVC pipe extruder and preheat it. Set the temperature, speed and other parameters of the extruder according to the specifications and requirements of the pipe to be produced. Install at least one side feeder at the discharge barrel of the PVC pipe extruder and debug the side feeder. Set the feeding speed of the side feeder so that PVC granules are added to the discharge port at a ratio of 2% to 20%. S3. Raw material addition and extrusion: High-filled PVC clinker dry powder is added to the first feeding device of the extruder, and PVC granules are added to the side feeder at the same time. The high-filled PVC clinker dry powder and PVC granules are mixed and enter the extrusion channel. S4. Pipe forming: The mixed PVC raw materials are fed to the extrusion die through the extrusion channel and formed into high-filled PVC pipes through the die.

2. The high-speed extrusion production process for high-filler PVC pipes according to claim 1, characterized in that, In step S1, it is necessary to calculate the proportion of PVC granules to the total PVC material mass. The calculation formula is as follows: in, The addition ratio for granulated PVC granules. For the quality of PVC granules, The total mass of PVC resin. To ensure the quality of PVC resin in high-filled PVC clinker dry powder; The formula for calculating the mass of PVC resin in high-filled PVC clinker powder is as follows: in, To ensure the quality of high-filled PVC clinker dry powder, The mass fraction of PVC resin in high-filled PVC clinker dry powder.

3. The high-speed extrusion production process for high-filler PVC pipes according to claim 2, characterized in that, In step S1, the formula for calculating the mass of the PVC granules used is derived as follows: Substituting this into the formula for calculating the mass of PVC resin in highly filled PVC clinker powder, we get: 。 4. The high-speed extrusion production process for high-filler PVC pipes according to claim 2, characterized in that, In step S1, the formula for calculating the total mass of PVC resin is derived as follows: 。 5. The high-speed extrusion production process for high-filler PVC pipes according to claim 1, characterized in that, In step S1, PVC granules with particle sizes of 1 mm and 4 mm are screened out respectively.

6. The high-speed extrusion production process for high-filler PVC pipes according to claim 5, characterized in that, In step S2, there are two side feeders, and the two feeders simultaneously feed PVC granules with particle sizes of 1mm and 4mm respectively.

7. A high-speed extrusion equipment for high-filled PVC pipes, used to implement the high-speed extrusion production process of high-filled PVC pipes as described in any one of claims 1 to 6, characterized in that, The device includes an extrusion channel (1), a feeding assembly (2), a first feeding device (3), a second feeding device (4), and a third feeding device (5). The feeding assembly (2) includes a feeding cylinder (21), the lower end of which is connected to the extrusion channel (1). The first feeding device (3) is connected to the feeding cylinder (21). The first feeding device (3) feeds high-filled PVC clinker dry powder to the feeding cylinder (21) through a screw. The second feeding device (4) and the third feeding device (5) can both feed the PVC granules to the feeding cylinder (21) through a screw.

8. The high-speed extrusion equipment for high-filling PVC pipes according to claim 7, characterized in that, The second feeding device (4) includes a first feeding body (41) and a first connecting cylinder (42). The third feeding device (5) includes a second feeding body (51) and a second connecting cylinder (52). The first feeding body (41) feeds material to the first connecting cylinder (42) through a screw. The first connecting cylinder (42) is installed at the upper end of the discharge cylinder (21). The second feeding body (51) feeds material to the second connecting cylinder (52) through a screw. The second connecting cylinder (52) is installed at the upper end of the first connecting cylinder (42). The discharge cylinder (21), the first connecting cylinder (42), and the second connecting cylinder (52) are detachably connected.

9. The high-speed extrusion equipment for high-filling PVC pipes according to claim 7, characterized in that, The feeding assembly (2) includes a dispersing device (22), which includes a stirrer (221). The stirrer (221) is rotatable and is located inside the feeding cylinder (21). The stirrer (221) is located below all the feed inlets of the feeding cylinder (21).

10. The high-speed extrusion equipment for high-filling PVC pipes according to claim 9, characterized in that, The stirrer (221) includes two stirring half-rings (222) and a central rod (223). The two stirring half-rings (222) are vertically mounted on the central rod (223). The stirring half-rings (222) are equipped with a plurality of dispersing plates (2222), which are inclined.

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