Hard polyvinyl chloride sheet extrusion equipment for packaging

Abstract

The invention relates to the technical field of plastic sheet extrusion, in particular to packaging rigid polyvinyl chloride sheet extrusion equipment which comprises a support and further comprises two sets of forming rollers which are symmetrically distributed on the support and used for extrusion forming, and each forming roller comprises a roller and an inner cylinder assembly which is arranged on the support in a sliding mode and located in the roller. The roller is rotationally connected with the inner cylinder assembly, and guide columns are arranged at the two ends of the roller. The inner cylinder assembly comprises an inflator pump and an air storage cylinder which are communicated with each other, the air storage cylinder is provided with an air blowing piece for guiding air to flow to the inner wall of the roller, a piston assembly slidably connected with the roller is arranged in the inflator pump, and the piston assembly is connected with the guide column in a matched mode; the guide column is used for driving the piston assembly to move in a reciprocating mode to supplement air into the air storage cylinder when rotating along with the roller, and an exhaust groove for guiding out air in the roller is formed in the inflator pump. According to the cooling device, extruded sheets can be cooled during shaping, the sheets can be cooled more uniformly and stably, and the complexity and the technical difficulty of production operation are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of plastic sheet extrusion, and particularly to an extrusion device for rigid polyvinyl chloride sheets for packaging. Background Art

[0002] Polyvinyl chloride (PVC) sheets are plastic sheets made of polyvinyl chloride, which have a variety of excellent properties and are widely used in industries such as architectural decoration, advertising signs, packaging materials, industrial manufacturing, and automobiles. Polyvinyl chloride (PVC) is the abbreviation of polyvinyl chloride material. PVC sheets have characteristics such as flame retardancy, abrasion resistance, chemical corrosion resistance, comprehensive mechanical properties, product transparency, electrical insulation, and relatively easy processing.

[0003] The production of PVC sheets is mainly completed through an extrusion molding process. During extrusion, after PVC resin is mixed with various additives, the material is melted and extruded into sheets through the rotation and heating of the screw of the extruder. The extruded PVC sheets go through subsequent processes such as cooling, cutting, and trimming, and finally become finished products that meet the requirements.

[0004] In the cooling process of PVC sheets, the cooling water bath method and the air cooling method are two widely used technical means. For the cooling water bath method, the core lies in maintaining high-standard cleanliness of the cooling water and precise temperature control. Because any impurities or inappropriate water temperature may have an adverse impact on the surface quality, physical properties, and even long-term stability of PVC sheets. The water bath method not only requires an efficient water treatment system to ensure pure water quality, but also needs to be equipped with a precise temperature control device to achieve precise management of the water temperature. This high-standard water quality management increases the monitoring cost and equipment investment in the production process, thereby increasing the production cost. On the other hand, the air cooling method focuses on achieving uniform and gentle cooling of PVC sheets by precisely regulating the air volume and wind speed. The amount of air volume and the speed of the wind directly affect the uniformity of the cooling effect and whether excessive mechanical stress will be applied to the sheets. In order to ensure the best cooling effect and not damage the sheets, it is necessary to extremely finely regulate the air volume and wind speed during the production process, require high-precision control of the air volume and wind speed, and be equipped with professional technicians for real-time monitoring and adjustment to ensure the stability and reliability of the cooling process, increasing the complexity and technical difficulty of production operations. Summary of the Invention

[0005] Aiming at the above-mentioned shortcomings of the prior art, the present invention provides an extrusion device for rigid polyvinyl chloride sheets for packaging, which can effectively solve the problems of high cost, complex production operation, and great technical difficulty during the extrusion cooling of PVC sheets in the prior art.

[0006] To achieve the above objectives, the present invention is realized through the following technical solutions: The present invention provides an extrusion device for rigid polyvinyl chloride sheets for packaging, including a bracket, and further including: Two groups of forming rollers symmetrically distributed on the bracket for extrusion molding. The forming roller includes a roller barrel and an inner barrel assembly slidably disposed on the bracket and located inside the roller barrel. The roller barrel is rotatably connected to the inner barrel assembly, and guide columns are provided at both ends of the roller barrel; The inner barrel assembly includes an air inflation cylinder and a gas storage cylinder that communicate with each other. A blowing member for guiding the gas flow to the inner wall of the roller barrel is provided on the gas storage cylinder. A piston assembly slidably connected to the roller barrel is provided in the air inflation cylinder, and the piston assembly is cooperatively connected with the guide column. The guide column is used to drive the piston assembly to reciprocate when following the rotation of the roller barrel to supplement gas into the gas storage cylinder. An exhaust groove for discharging the gas inside the roller barrel is provided on the air inflation cylinder.

[0007] Further, mounting covers are provided at both ends of the roller barrel. The mounting covers are connected to the roller barrel by bolts, and a sealing gasket is provided between the mounting covers and the roller barrel. A belt pulley is coaxially installed between the mounting cover and the guide column. The belt pulley is used to drive the rotation of the roller barrel and the guide column. A guide groove is provided inside the guide column, and the guide groove is annular and inclined and provided on the inner wall of the guide column.

[0008] Further, the piston assembly includes a hollow piston rod slidably disposed on the air inflation cylinder and a first piston disc provided on the hollow piston rod. A partition plate for dividing the inside of the hollow piston rod into an exhaust chamber and an intake chamber is provided inside the hollow piston rod. An exhaust hole communicating with the exhaust chamber is provided on the hollow piston rod. A one-way valve one communicating with the intake chamber is provided at one end of the hollow piston rod close to the first piston disc. A guide post is provided on one side of the hollow piston rod close to the guide column, and the guide post extends into the guide groove.

[0009] Further, a limiting strip is provided on the hollow piston rod, and the limiting strip is slidably connected to the air inflation cylinder. The limiting strip is used to prevent the relative rotation between the hollow piston rod and the air inflation cylinder. The cross section of the end of the hollow piston rod far from the first piston disc is rectangular.

[0010] Further, an intake pipe is provided inside the gas storage cylinder. The two ends of the intake pipe are respectively communicated with the air inflation cylinder, and one-way valves two are provided at both ends of the intake pipe. The one-way valves two are used to open when the first piston disc approaches the gas storage cylinder and close when the first piston disc moves away from the gas storage cylinder to prevent the gas in the gas storage cylinder from flowing back. An intake hole is provided in the middle of the intake pipe. The intake hole is used to introduce gas into the gas storage cylinder and into the blowing member.

[0011] Further, it further includes a second piston disc and a spring. Two groups of second piston discs are provided and slidably disposed on the intake pipe. The two groups of second piston discs are respectively located on both sides of the intake hole. The spring is sleeved on the intake pipe and respectively abuts against the second piston disc and the air inflation cylinder. The spring is used to always push the two groups of second piston discs to approach each other, and the limit distance when the two groups of second piston discs approach is greater than the size of the intake hole.

[0012] Further, the width of the air inlet end of the air blowing member is H, the width of the air exhaust end of the air blowing member is L, and H > L.

[0013] Further, an arc-shaped air guide plate is provided on the air blowing member, and the distance between the end of the arc-shaped air guide plate connected to the air blowing member and the inner wall of the roller is greater than the distance between the end of the arc-shaped air guide plate away from the air blowing member and the inner wall of the roller. Beneficial effects

[0014] The technical solution provided by the present invention has the following beneficial effects compared with the known prior art: First, the pulley provided on the mounting cover is used to drive the mounting cover and the roller to rotate to shape the extruded PVC. At the same time, by cooperating with the guide groove inside the guide post on the mounting cover and the guide post, the hollow piston rod and the piston disk 1 are reciprocally pushed and pulled, and the cold air provided by the external device is input into the air storage cylinder and blown towards the inner wall of the roller to cool the roller. The gas inside the roller is then discharged through the exhaust holes on the hollow piston rod and cooled again and recycled, so that the roller is cooled while shaping the extruded PVC material. During the production process, it is not necessary to extremely finely regulate the air volume and air speed, and at the same time, it does not require technicians to monitor and adjust in real time, which is more uniform and stable, reducing the complexity and technical difficulty of production operations; Second, through the air inlet pipe and the check valve 2 located on both sides of the air inlet pipe, the gas entering the air storage cylinder is prevented from flowing back into the inflator. At the same time, in cooperation with the piston disk 2 and the spring on the air inlet pipe, the gas in the air storage cylinder can be continuously blown towards the inner wall of the roller to maintain the stability of the roller cooling. Finally, through the special setting of the air blowing member, the flow rate of the cold air blown out is increased, and in cooperation with the arc-shaped air guide plate, the cold air is guided to other positions of the inner wall of the roller to pre-cool the roller and maintain the high-efficiency cooling effect of the roller. Description of the drawings

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0016] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a partial cross-sectional view of the forming roller of the present invention; Figure 3 It is a connection diagram of the inflator and the roller of the present invention; Figure 4 It is a connection diagram of the piston disk 1 and the hollow piston rod of the present invention; Figure 5 It is a cross-sectional view of the roller of the present invention; Figure 6 It is a diagram showing the change of the internal gas flow state of the forming roller of the present invention; Figure 7 It is a structural diagram of the piston disk II and the intake pipe after continuous inflation in the air storage cylinder of the present invention.

[0017] Reference numerals: 1, bracket; 2, forming roller; 21, roller; 22, mounting cover; 221, guide post; 2211, guide groove; 23, inflating cylinder; 231, piston disk I; 2301, exhaust groove; 232, hollow piston rod; 2321, exhaust hole; 2322, guide post; 2323, check valve I; 2324, limit strip; 233, partition plate; 24, air storage cylinder; 241, intake pipe; 2411, check valve II; 2412, intake hole; 242, piston disk II; 243, spring; 25, blowing member; 251, arc-shaped air guide plate. Detailed implementation manners

[0018] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0019] The present invention will be further described below with reference to the embodiments. Embodiment

[0020] An extrusion device for rigid polyvinyl chloride sheets for packaging, referring to the attached Figure 1-7 , includes a bracket 1, and further includes: Two sets of forming rollers 2 for extrusion molding are symmetrically distributed on the bracket 1. After passing through the extruder, the PVC sheet is shaped by the two sets of forming rollers 2. The forming roller 2 includes a roller barrel 21 and mounting covers 22 located at both ends of the roller barrel 21. The roller barrel 21 is a hollow cylindrical shape, and the mounting cover 22 is connected to the roller barrel 21 by bolts. A gasket is provided between the mounting cover 22 and the roller barrel 21. A pulley is coaxially installed between the mounting cover 22 and the guide post 221, and the pulley is used to drive the roller barrel 21 and the guide post 221 to rotate. A guide groove 2211 is provided in the guide post 221, and the guide groove 2211 is annular and obliquely arranged on the inner wall of the guide post 221. The forming roller 2 further includes an inner cylinder assembly slidably arranged on the bracket 1 and located inside the roller barrel 21. Through the cooperation of the inner cylinder assembly and the guide post 221, the inner cylinder assembly is guided to reciprocate to supplement cold air into the roller barrel 21, thereby cooling the roller barrel 21, and then cooling the extruded sheet. The roller barrel 21 is rotationally connected to the inner cylinder assembly. Through the relative rotation of the roller barrel 21 and the inner cylinder assembly, the roller barrel 21 can continuously cool the extruded PVC sheet, and at the same time ensure that the supplemented cold air can always blow towards the side where the PVC sheet is extruded; The inner cylinder assembly includes an air inflation cylinder 23 and a gas storage cylinder 24 that are interconnected. A blowing member 25 for guiding the gas flow to the inner wall of the roller barrel 21 is provided on the gas storage cylinder 24. A piston assembly slidably connected to the roller barrel 21 is provided in the air inflation cylinder 23, and the piston assembly is cooperatively connected to the guide post 221. The guide post 221 is used to drive the piston assembly to reciprocate to supplement gas into the gas storage cylinder 24 when following the rotation of the roller barrel 21. An exhaust groove 2301 for discharging the gas inside the roller barrel 21 is provided on the air inflation cylinder 23.

[0021] Among them, the piston assembly includes a hollow piston rod 232 slidably arranged on the air inflation cylinder 23 and a first piston disc 231 arranged on the hollow piston rod 232. A partition plate 233 for dividing the inside of the hollow piston rod 232 into an exhaust chamber and an intake chamber is provided in the hollow piston rod 232. An exhaust hole 2321 communicated with the exhaust chamber is provided on the hollow piston rod 232. A one-way valve 2323 communicated with the intake chamber is provided at one end of the hollow piston rod 232 close to the first piston disc 231. A guide post 2322 is provided on one side of the hollow piston rod 232 close to the guide post 221, and the guide post 2322 extends into the guide groove 2211. Through the setting of the one-way valve 2323, when the first piston disc 231 moves towards the gas storage cylinder 24 following the hollow piston rod 232, the gas is squeezed into the intake pipe 241. When the first piston disc 231 moves away from the gas storage cylinder 24 following the hollow piston rod 232, the external gas is drawn into the air inflation cylinder 23 and then squeezed into the intake pipe 241 again. A limiting strip 2324 is provided on the hollow piston rod 232, and the limiting strip 2324 is slidably connected to the air inflation cylinder 23. The limiting strip 2324 is used to prevent the relative rotation of the hollow piston rod 232 and the air inflation cylinder 23. The cross-section of the end of the hollow piston rod 232 away from the first piston disc 231 is rectangular.

[0022] In the above technical solution, the pulley provided on the mounting cover 22 is used to drive the mounting cover 22 and the roller 21 to rotate to shape the extruded PVC. While shaping, by cooperating the guide groove 2211 inside the guide post 221 on the mounting cover 22 with the guide post 2322, the hollow piston rod 232 and the first piston disc 231 are reciprocally pushed and pulled, and the cold air provided by an external device is input into the air storage cylinder 24 and blown towards the inner wall of the roller 21 on the side close to the extruded PVC sheet, so as to continuously and stably cool the roller 21. The cooling of the roller 21 is more uniform, thereby improving the cooling effect on the extruded PVC sheet. The gas inside the roller 21 is then discharged through the exhaust hole 2321 on the hollow piston rod 232, cooled again and recycled, so that the roller 21 is cooled while shaping the extruded PVC material. During the production process, it is not necessary to extremely finely regulate the air volume and air speed, and at the same time, it is not necessary for technicians to monitor and adjust in real time, which is more stable and reliable, reducing the complexity and technical difficulty of production operations.

[0023] In addition, an air inlet pipe 241 is provided in the air storage cylinder 24, and both ends of the air inlet pipe 241 are respectively communicated with the inflating cylinder 23. One-way valves II 2411 are provided at both ends of the air inlet pipe 241. The one-way valves II 2411 are used to open when the first piston disc 231 approaches the air storage cylinder 24 and close when the first piston disc 231 moves away from the air storage cylinder 24, preventing the gas in the air storage cylinder 24 from flowing back. An air inlet hole 2412 is provided in the middle of the air inlet pipe 241, and the air inlet hole 2412 is used to introduce the gas into the air storage cylinder 24 and into the blowing member 25.

[0024] In addition to this, it also includes a second piston disc 242 and a spring 243. Two groups of the second piston discs 242 are provided and slidably arranged on the air inlet pipe 241. The two groups of the second piston discs 242 are respectively located on both sides of the air inlet hole 2412. The spring 243 is sleeved on the air inlet pipe 241 and respectively abuts against the second piston disc 242 and the inflating cylinder 23. The spring 243 is used to always push the two groups of the second piston discs 242 to approach each other, and the limit distance when the two groups of the second piston discs 242 approach is greater than the size of the air inlet hole 2412.

[0025] It should be noted that the width of the air inlet end of the blowing member 25 is H, and the width of the air exhaust end of the blowing member 25 is L, and H > L. Through the special structure of the blowing member 25, when guiding the cold air to blow towards the inner wall of the roller 21, the flow rate of the cold air is accelerated, and the cooling effect is improved. An arc-shaped air guide plate 251 is provided on the blowing member 25, and the distance between the end of the arc-shaped air guide plate 251 connected to the blowing member 25 and the inner wall of the roller 21 is greater than the distance between the end of the arc-shaped air guide plate 251 far from the blowing member 25 and the inner wall of the roller 21. The arc-shaped air guide plate 251 is used to guide the blown cold air to pre-cool the inner wall of the roller 21 far from the PVC sheet.

[0026] In the above technical solution, through the air inlet pipe 241 and the check valves II 2411 located on both sides of the air inlet pipe 241, the gas entering the air storage cylinder 24 is prevented from flowing back into the air inflation cylinder 23. At the same time, in cooperation with the piston disk II 242 and the spring 243 on the air inlet pipe 241, the gas in the air storage cylinder 24 can be continuously blown towards the inner wall of the roller 21, maintaining the stability of the cooling of the roller 21. Finally, through the special setting of the air blowing member 25, the flow rate of the cold air blown out is increased, and in cooperation with the arc-shaped air guide plate 251, the cold air is guided to other positions on the inner wall of the roller 21 to pre-cool the roller 21, further improving the efficient cooling effect of the roller 21.

[0027] Working principle: The pulley provided on the mounting cover 22 is used to drive the mounting cover 22 and the roller 21 to rotate to shape the extruded PVC. While the roller 21 is rotating and shaping the extruded PVC material, by cooperating with the guide groove 2211 inside the guide post 221 on the mounting cover 22 and the guide post 2322, the hollow piston rod 232 and the piston disk I 231 are reciprocally pushed and pulled, and the cold air provided by the external device is input into the air storage cylinder 24 and blown towards the inner wall of the roller 21 to cool the roller 21. Thus, cooling is carried out while shaping the PVC sheet. When the gas in the air storage cylinder 24 continuously increases, the exhaust hole 2321 provided on the hollow piston rod 232 discharges the gas, and after re-cooling, it is cyclically introduced for use. In order to better cool the roller 21 to cool the extruded PVC sheet, by setting the check valves II 2411 on both sides of the air inlet pipe 241, the gas entering the air storage cylinder 24 is prevented from flowing back into the air inflation cylinder 23. At the same time, in cooperation with the piston disk II 242 and the spring 243 on the air inlet pipe 241, the gas in the air storage cylinder 24 can be continuously blown towards the inner wall of the roller 21, making the cooling of the extruded PVC sheet more uniform, and at the same time maintaining the stability of the cooling of the roller 21. Finally, by making the width of the air inlet end of the air blowing member 25 greater than the width of the air exhaust end of the air blowing member 25, the flow rate of the cold air blown out is increased, and in cooperation with the arc-shaped air guide plate 251, the cold air is guided to other positions on the inner wall of the roller 21 to pre-cool the roller 21, improving the efficient cooling effect of the roller 21.

[0028] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A rigid polyvinyl chloride sheet extrusion device for packaging, comprising a bracket (1), characterized in that: Also includes: Two groups of forming rollers (2) for extrusion forming are symmetrically distributed on the support (1), the forming rollers (2) comprising rollers (21) and an inner cylinder assembly slidably arranged on the support (1) and located inside the rollers (21), the rollers (21) being rotatably connected to the inner cylinder assembly, and guide posts (221) are provided at both ends of the rollers (21); The inner cylinder assembly comprises an inflating cylinder (23) and an air storage cylinder (24) which are interconnected, and the air storage cylinder (24) is provided with a blowing member (25) for guiding gas to flow toward the inner wall of the roller (21). The inflating cylinder (23) is provided with a piston assembly which is slidably connected to the roller (21), and the piston assembly is cooperatively connected to a guide column (221). The guide column (221) is used to drive the piston assembly to reciprocate when following the rotation of the roller (21) to replenish gas in the air storage cylinder (24). The inflating cylinder (23) is provided with an exhaust groove (2301) for guiding the gas inside the roller (21).

2. The rigid polyvinyl chloride sheet extrusion equipment for packaging according to claim 1, characterized in that: Mounting covers (22) are provided at both ends of the roller (21), and the mounting covers (22) are connected to the roller (21) via bolts, and a sealing gasket is provided between the mounting cover (22) and the roller (21), and a pulley is coaxially installed between the mounting cover (22) and the guide column (221), and the pulley is used to drive the roller (21) and the guide column (221) to rotate, and a guide groove (2211) is provided in the guide column (221), and the guide groove (2211) is annular and obliquely arranged on the inner wall of the guide column (221).

3. The rigid polyvinyl chloride sheet extrusion equipment for packaging according to claim 2, characterized in that: The piston assembly comprises a hollow piston rod (232) slidably arranged on the inflation cylinder (23) and a piston disk (231) arranged on the hollow piston rod (232); a partition plate (233) for dividing the hollow piston rod (232) into an exhaust chamber and an intake chamber is arranged in the hollow piston rod (232); an exhaust hole (2321) communicating with the exhaust chamber is arranged on the hollow piston rod (232); a one-way valve (2323) communicating with the intake chamber is arranged at one end of the hollow piston rod (232) close to the piston disk (231); a guide column (2322) is arranged on one side of the hollow piston rod (232) close to the guide column (221), and the guide column (2322) extends into the guide groove (2211).

4. The rigid polyvinyl chloride sheet extrusion equipment for packaging according to claim 3, characterized in that: A limit strip (2324) is provided on the hollow piston rod (232), and the limit strip (2324) is slidably connected to the inflation cylinder (23), the limit strip (2324) is used to prevent the hollow piston rod (232) and the inflation cylinder (23) from rotating relative to each other, and the cross-section of one end of the hollow piston rod (232) away from the piston disc (231) is rectangular.

5. The rigid polyvinyl chloride sheet extrusion equipment for packaging according to claim 1, characterized in that: An air intake pipe (241) is provided in the air storage cylinder (24), and both ends of the air intake pipe (241) are respectively connected to the inflation cylinder (23), and both ends of the air intake pipe (241) are provided with a second check valve (2411). The second check valve (2411) is used to open when the piston disc (231) approaches the air storage cylinder (24), and to close when the piston disc (231) moves away from the air storage cylinder (24), so as to prevent the gas in the air storage cylinder (24) from flowing back. An air intake hole (2412) is provided in the middle of the air intake pipe (241), and the air intake hole (2412) is used to introduce gas into the air storage cylinder (24) and into the blowing member (25).

6. The rigid polyvinyl chloride sheet extrusion equipment for packaging according to claim 1, characterized in that: It also includes a second piston disc (242) and a spring (243). The second piston disc (242) is provided with two groups and is slidably arranged on the air intake pipe (241), and the two groups of second piston discs (242) are respectively located on both sides of the air intake hole (2412). The spring (243) is sleeved on the air intake pipe (241) and respectively presses against the second piston disc (242) and the inflation cylinder (23). The spring (243) is used to always push the two groups of second piston discs (242) closer to each other, and the maximum distance when the two groups of second piston discs (242) are close to each other is greater than the size of the air intake hole (2412).

7. The rigid polyvinyl chloride sheet extrusion equipment for packaging according to claim 1, characterized in that: The width of the air inlet end of the air blowing member (25) is H, the width of the air outlet end of the air blowing member (25) is L, and H>L.

8. The rigid polyvinyl chloride sheet extrusion equipment for packaging according to claim 1, characterized in that: The blowing member (25) is provided with an arc-shaped air guide plate (251), and the distance between one end of the arc-shaped air guide plate (251) connected to the blowing member (25) and the inner wall of the roller (21) is greater than the distance between one end of the arc-shaped air guide plate (251) away from the blowing member (25) and the inner wall of the roller (21).

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