A PVC film calendering process

Abstract

The present application discloses a PVC film calendering process, which relates to the field of film production technology, and includes the following steps: S1: a mixer mixes raw materials; S2: an extruder extrude materials; S3: a six-roll calender calenders to form a PVC film; S4: film trimming and winding; the six-roll calender includes a frame and six rollers, the rollers include an axis, an inner cylinder, an outer cylinder and two end plates, the inner cylinder is slidably arranged on the axis, the end plates are arranged on the axis, the outer cylinder is fixedly arranged on the two end plates, the inner cylinder is provided with a first flow channel and a second flow channel, and the rollers are provided with a driving mechanism for driving the inner cylinder to slide back and forth. The present application utilizes a sliding inner cylinder, and the driving mechanism drives the inner cylinder to slide back and forth on the axis, so that the heat transfer oil in the first flow channel and the second flow channel can heat the same position of the outer cylinder back and forth, thereby reducing the temperature difference on the surface of the outer cylinder.

Description

Technical Field

[0001] The present application relates to the technical field of film production, and in particular to a PVC film calendering process. Background Art

[0002] The PVC film calendering process includes the steps of batching, mixing, extrusion plasticization, calendering, cooling and winding. First, the PVC raw material is mixed with plasticizers, stabilizers and other additives in proportion; then, it is plasticized by the extruder and sent to the calender; in the calender, the material is squeezed and stretched by the roller to form a film of the required thickness; then, the edge of the film is cut; finally, the cut film is rolled up. In the whole process, the temperature, speed and pressure must be strictly controlled to ensure the quality and performance of the film.

[0003] The roller in the calender is a heating roller, and a spiral flow channel is formed inside the roller. The heat transfer oil enters the flow channel from one end of the roller and flows out from the other end of the roller, thereby heating the surface of the heating roller. However, as the heat transfer oil flows from one end of the roller to the other end, the heat in the heat transfer oil will gradually dissipate, resulting in a temperature difference at both ends of the roller, which will affect the quality and performance of the film. Summary of the invention

[0004] In order to reduce the temperature difference on the pressing roller, the present application provides a PVC film calendering process.

[0005] A PVC film calendering process provided in this application adopts the following technical solution:

[0006] A PVC film calendering process comprises the following steps: S1: adding PVC raw materials and additives into a mixer in proportion and mixing; S2: feeding the mixed materials into an extruder, where the materials are heated to a molten state and extruded; S3: the extruded materials are calendered multiple times by a six-roll calender to form a PVC film of a desired thickness; S4: trimming and rolling the PVC film; in step S3, the six-roll calender comprises a frame and six pressing rollers, the six pressing rollers are rotatably arranged in the frame, the pressing rollers comprise a shaft body, an inner cylinder, an outer cylinder and two end plates, the inner cylinder is slidably arranged on the shaft body along the axial direction of the shaft body, and the two end plates are The end plates are fixedly arranged on the shaft body and located on both sides of the inner cylinder, and the two ends of the outer cylinder are fixedly sleeved on the two end plates, the inner wall of the outer cylinder fits the outer wall of the inner cylinder, and the outer wall of the inner cylinder is provided with a spiral first flow channel and a second flow channel, and the first and second flow channels have their head and tail ends both located on both sides of the axis direction of the inner cylinder, and the oil supply mechanism supplies heat transfer oil into the first flow channel and the second flow channel, and the heat transfer oil flows in opposite directions in the first flow channel and the second flow channel, and the heat transfer oil flows back to the oil supply mechanism after passing through the first flow channel and the second flow channel, and a driving mechanism is arranged on the pressure roller, and the driving mechanism drives the inner cylinder to slide back and forth on the shaft body.

[0007] By adopting the above technical scheme, the oil supply mechanism supplies the heat transfer oil from the two ends of the inner cylinder into the first flow channel and the second flow channel respectively. The heat transfer oil flows in the first flow channel and the second flow channel and heats the outer cylinder, so that the temperature difference at the two ends of the outer cylinder is smaller. At the same time, the driving mechanism drives the inner cylinder to slide back and forth on the shaft, so that the heat transfer oil in the first flow channel and the second flow channel can reciprocate to heat the same position of the outer cylinder, so that the temperature difference at the local position of the outer cylinder is smaller, thereby further reducing the temperature difference on the surface of the outer cylinder.

[0008] Preferably, the driving mechanism includes a driving member, a driving ring gear, a plurality of driving gears and a screw rod, the plurality of screw rods are threaded through the inner cylinder, one end of the plurality of screw rods is rotatably set in the inner wall of an end plate, and the other end passes through another end plate, the plurality of driving gears are fixedly set on one end of the plurality of screw rods passing through the end plate, the driving ring gear is rotatably set on the outer side wall of the end plate and meshes with the plurality of driving gears, the driving member is set on the outer side wall of the end plate, and the driving end of the driving member is fixedly connected to a driving gear.

[0009] By adopting the above technical solution, the driving member drives a driving gear to rotate, and the driving gear drives multiple driving gears to rotate synchronously through the driving ring gear, and the multiple driving gears drive multiple screws to rotate, so that the inner cylinder can slide on the shaft, and the driving member can drive the inner cylinder to slide back and forth on the shaft by continuously rotating forward and reverse at intervals.

[0010] Preferably, the length of the outer cylinder is greater than that of the inner cylinder, and a first liquid storage cavity and a second liquid storage cavity are formed at both ends of the inner cylinder in the axial direction. A flow hole is opened on the inner cylinder along its own axial direction, and the flow hole connects the first flow channel and the second flow channel, and the two ends of the flow hole are respectively connected to the first liquid storage cavity and the second liquid storage cavity.

[0011] By adopting the above technical solution, when the inner cylinder moves toward the direction close to the first liquid storage chamber, the heat transfer oil in the first liquid storage chamber flows into the first flow channel and the second flow channel through the circulation hole, and part of the heat transfer oil in the first flow channel and the second flow channel will move toward the direction close to the second liquid storage chamber, so that the heat transfer oil in the first flow channel and the second flow channel can communicate with each other, and part of the heat transfer oil in the first flow channel and the second flow channel will flow into the second liquid storage chamber. Similarly, when the inner cylinder moves toward the direction close to the second liquid storage chamber, the heat transfer oil will flow into the first liquid storage chamber. With such a configuration, during the reciprocating movement of the inner cylinder, the heat transfer oil in the first flow channel and the second flow channel can communicate with each other, thereby further reducing the temperature difference between the first flow channel and the second flow channel.

[0012] Preferably, a plurality of the flow holes are provided at equal intervals along the circumference of the inner cylinder.

[0013] By adopting the above technical solution, during the movement of the inner cylinder, the multiple flow holes enable the heat transfer oil in the first flow channel and the second flow channel to communicate better.

[0014] Preferably, a driving cylinder is fixedly provided on the inner side walls of the two end plates close to each other, a sliding hole is opened in the driving cylinder, a spiral guide groove is opened on the side wall of the driving cylinder located in the sliding hole, the inner cylinder is located in the flow hole and a screw is rotatably provided, the screw passes through the first flow channel and the second flow channel, both ends of the screw are slidably provided in the two sliding holes, both ends of the screw are fixedly provided with guide blocks, and the two guide blocks are respectively slidably provided in the two spiral guide grooves.

[0015] By adopting the above technical solution, the inner cylinder will drive the screw to move during its movement, and the two ends of the screw will move in the sliding holes of the two driving cylinders. The screw drives the two guide blocks to slide in the spiral guide grooves of the two driving cylinders, thereby driving the screw to rotate. During the reciprocating movement of the inner cylinder, the screw can rotate reciprocatingly, thereby facilitating the communication of the heat transfer oil in the first flow channel and the second flow channel.

[0016] Preferably, a plurality of guide plates are arranged on the inner cylinder in the first flow channel and the second flow channel, the guide plates are located on one side of the screw, and the guide plates are used to prevent the heat transfer oil from impacting the screw.

[0017] By adopting the above technical solution, when the screw rotates to transport the heat transfer oil to communicate with each other in the first flow channel and the second flow channel, the guide plate blocks the screw, so that the heat transfer oil flowing in the first flow channel and the second flow channel will not impact on the screw, thereby achieving a better effect of the screw communicating the heat transfer oil.

[0018] Preferably, an inner cavity is opened in the shaft body, an oil supply pipe connected with the oil supply mechanism is arranged in the inner cavity of the shaft body, a first sealing ring and a second sealing ring are arranged at intervals on the oil supply pipe, a first oil supply cavity is formed between the first sealing ring, the second sealing ring, the outer wall of the oil supply pipe and the inner wall of the shaft body, a fifth oil supply hole connected with the first oil supply cavity is opened on the oil supply pipe, a first oil supply ring groove is opened on the inner side wall of the inner cylinder, a first oil supply hole connected with the first oil supply cavity and the first oil supply ring groove is opened in the shaft body, a second oil supply hole connected with the first oil supply ring groove and the first flow channel is opened in the inner cylinder; a third sealing ring is arranged at the end of the oil supply pipe, a second oil supply cavity is formed between the third sealing ring and the inner wall of the shaft body located at the end of the inner cavity, a second oil supply ring groove is opened on the inner side wall of the inner cylinder, a third oil supply hole connected with the second oil supply cavity and the second oil supply ring groove is opened in the shaft body, and a fourth oil supply hole connected with the second oil supply ring groove and the second flow channel is opened in the inner cylinder.

[0019] By adopting the above technical scheme, the oil supply mechanism supplies heat transfer oil into the oil supply pipe, a part of the heat transfer oil in the oil supply pipe flows into the first oil supply cavity through the fifth oil supply hole, the heat transfer oil in the first oil supply cavity passes through the first oil supply hole, the first oil supply ring groove and the second oil supply hole in sequence to enter the first flow channel, another part of the heat transfer oil in the oil supply pipe flows into the second oil supply cavity from the opening at its end, the heat transfer oil in the second oil supply cavity passes through the third oil supply hole, the second oil supply ring groove and the fourth oil supply hole in sequence to enter the second flow channel, thereby being able to supply the heat transfer oil into the first flow channel and the second flow channel at the same time.

[0020] Preferably, the second sealing ring is located on the side of the first sealing ring close to the third sealing ring, a first oil outlet cavity is formed between the second sealing ring, the third sealing ring, the outer wall of the oil supply pipe and the inner wall of the shaft body, a second oil outlet cavity is formed between the first sealing ring, the outer wall of the oil supply pipe and the inner wall of the shaft body and located on the side away from the first oil supply cavity, the second oil outlet cavity is communicated with the oil supply mechanism, an oil outlet pipe connecting the first oil outlet cavity and the second oil outlet cavity is passed through the first sealing ring and the second sealing ring; a first oil outlet ring groove is provided on the inner side wall of the inner cylinder, a first oil outlet hole connecting the first flow channel and the first oil outlet ring groove is provided in the inner cylinder, a second oil outlet hole connecting the first oil outlet ring groove and the first oil outlet cavity is provided in the shaft body, a second oil outlet ring groove is provided on the inner side wall of the inner cylinder, a third oil outlet hole connecting the second flow channel and the second oil outlet ring groove is provided in the inner cylinder, and a fourth oil outlet hole connecting the second oil outlet ring groove and the second oil outlet cavity is provided in the shaft body.

[0021] By adopting the above technical solution, the heat transfer oil in the first flow channel flows from the first oil outlet hole into the first oil outlet ring groove, and then flows back to the oil supply mechanism through the second oil outlet hole, the first oil outlet cavity, the oil outlet pipe and the second oil outlet cavity in sequence; the heat transfer oil in the second flow channel flows from the third oil outlet hole into the second oil outlet ring groove, and then flows back to the oil supply mechanism through the fourth oil outlet hole and the second oil outlet cavity in sequence, thereby being able to simultaneously supply the heat transfer oil in the first flow channel and the second flow channel back to the oil supply mechanism.

[0022] In summary, the present application includes at least one of the following beneficial technical effects:

[0023] 1. Using the slidable inner cylinder, the oil supply mechanism supplies the heat transfer oil into the first flow channel and the second flow channel from both ends of the inner cylinder respectively. The heat transfer oil flows in the first flow channel and the second flow channel and heats the outer cylinder, so that the temperature difference between the two ends of the outer cylinder is smaller. At the same time, the driving mechanism drives the inner cylinder to slide back and forth on the shaft, so that the heat transfer oil in the first flow channel and the second flow channel can reciprocate and heat the same position of the outer cylinder, so that the temperature difference at a local position of the outer cylinder is smaller, thereby further reducing the temperature difference on the surface of the outer cylinder;

[0024] 2. With the help of the circulation hole, when the inner cylinder moves toward the first liquid storage chamber, the heat transfer oil in the first liquid storage chamber flows into the first flow channel and the second flow channel through the circulation hole, and part of the heat transfer oil in the first flow channel and the second flow channel moves toward the second liquid storage chamber, so that the heat transfer oil in the first flow channel and the second flow channel can communicate with each other, and part of the heat transfer oil in the first flow channel and the second flow channel can flow into the second liquid storage chamber. Similarly, when the inner cylinder moves toward the second liquid storage chamber, the heat transfer oil will flow into the first liquid storage chamber. During the reciprocating movement of the inner cylinder, the heat transfer oil in the first flow channel and the second flow channel can communicate with each other, thereby further reducing the temperature difference between the first flow channel and the second flow channel;

[0025] 3. Through the screw, the inner cylinder will drive the screw to move during its movement, and the two ends of the screw will move in the sliding holes of the two driving cylinders. The screw drives the two guide blocks to slide in the spiral guide grooves of the two driving cylinders, thereby driving the screw to rotate. During the reciprocating movement of the inner cylinder, the screw can rotate reciprocatingly, thereby facilitating the communication of the heat transfer oil in the first flow channel and the second flow channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Flow chart of the PVC film calendering process for this application;

[0027] Figure 2 The PVC film calendering process for this application is a schematic diagram highlighting a six-roll calender;

[0028] Figure 3 The schematic diagram of the PVC film calendering process for this application is to highlight the pressing rollers;

[0029] Figure 4 For this application, the PVC film calendering process is an exploded view highlighting the rollers;

[0030] Figure 5 The PVC film calendering process for this application is a cross-sectional view highlighting the rollers;

[0031] Figure 6 For this application Figure 5 The enlarged schematic diagram at A in the middle;

[0032] Figure 7 For this application Figure 5 The enlarged schematic diagram of point B in the middle;

[0033] Figure 8 For this application Figure 5 The enlarged schematic diagram at C in the middle;

[0034] Fig. 9 For the PVC film calendering process of this application, an exploded cross-sectional view is provided to highlight the guide block;

[0035] Fig.10 A cross-sectional view of the guide plate is shown highlighting the PVC film calendering process for this application.

[0036] Figure numerals: 1, frame; 2, pressure roller; 201, shaft; 202, inner cylinder; 203, outer cylinder; 204, end plate; 3, first flow channel; 4, second flow channel; 5, driving mechanism; 51, driving member; 52, driving gear ring; 53, driving gear; 54, screw; 6, first liquid storage chamber; 7, second liquid storage chamber; 8, flow hole; 9, driving cylinder; 10, sliding hole; 11, spiral guide groove; 12, screw; 13, guide block; 14, guide plate; 15, oil supply pipe; 16, first sealing ring; 17, second sealing Ring; 18, first oil supply chamber; 19, fifth oil supply hole; 20, first oil supply ring groove; 21, first oil supply hole; 22, second oil supply hole; 23, third sealing ring; 24, second oil supply chamber; 25, second oil supply ring groove; 26, third oil supply hole; 27, fourth oil supply hole; 28, first oil outlet chamber; 29, second oil outlet chamber; 30, oil outlet pipe; 31, first oil outlet ring groove; 32, first oil outlet hole; 33, second oil outlet hole; 34, second oil outlet ring groove; 35, third oil outlet hole; 36, fourth oil outlet hole; 37, receiving hole. DETAILED DESCRIPTION

[0037] The following is combined with Figure 1-Figure 10 This application is described in further detail.

[0038] The embodiment of the present application discloses a PVC film calendering process.

[0039] Reference Figure 1 , a PVC film calendering process comprises the following steps:

[0040] S1: Weigh the formula according to the technical requirements, put the PVC raw materials and additives into the mixer in proportion, stir the materials at high speed, and cool the materials after stirring;

[0041] S2: The mixed and cooled materials are fed into an extruder, where they are melted and plasticized by high temperature and shearing action, and the melted and plasticized materials are extruded;

[0042] S3: The extruded material enters a six-roll calender, and the roller 2 of the six-roll calender forms a PVC film of a desired thickness after multiple calendering. The calendered PVC film is cooled by a cooling roller to reduce the film temperature, so that it has a certain strength and toughness;

[0043] S4: trimming and rolling the PVC film, and then cutting the rolled semi-finished product into finished products of specified width.

[0044] Reference Figure 2 The six-roll calender includes a frame 1 and six pressing rollers 2. The six pressing rollers 2 are rotatably arranged in the frame 1, and the PVC film passes between the six pressing rollers 2 in sequence.

[0045] Reference Figure 3 and Figure 4 The pressure roller 2 includes a shaft body 201, an inner cylinder 202, an outer cylinder 203 and two end plates 204. The two ends of the shaft body 201 rotate in the frame 1. The inner cylinder 202 is slidably mounted on the shaft body 201 along the axis direction of the shaft body 201. The outer cylinder 203 is sleeved on the outer side of the inner cylinder 202. The length of the outer cylinder 203 is greater than the length of the inner cylinder 202, and the inner side wall of the outer cylinder 203 fits the outer side wall of the inner cylinder 202. The two end plates 204 are fixedly mounted on the shaft body 201 and are located on both sides of the axis direction of the inner cylinder 202. The two ends of the inner side wall of the outer cylinder 203 in the axis direction are fixedly connected to the outer side walls of the two end plates 204.

[0046] The outer wall of the inner cylinder 202 is provided with a first flow channel 3 and a second flow channel 4 , both of which are spiral-shaped. Both ends of the first flow channel 3 and the second flow channel 4 are closed and located on both sides of the axis direction of the inner cylinder 202 .

[0047] Reference Figure 5 and Figure 6A hollow inner cavity is formed in the shaft body 201, and an oil supply pipe 15 is installed in the inner cavity of the shaft body 201. One end of the oil supply pipe 15 is connected to the oil supply mechanism, and the other end is open and extends to the end of the inner cavity of the shaft body 201. The first sealing ring 16, the second sealing ring 17 and the third sealing ring 23 are installed on the oil supply pipe 15 in sequence. The first sealing ring 16, the second sealing ring 17, the outer wall of the oil supply pipe 15 and the inner wall of the shaft body 201 form a first oil supply cavity 18. A plurality of fifth oil supply holes 19 are opened on the oil supply pipe 15, and the fifth oil supply holes 19 connect the oil supply pipe 15 and the first oil supply cavity 18.

[0048] A first oil supply annular groove 20 is provided on the inner wall of the inner cylinder 202 and outside the first oil supply cavity 18. Two first oil supply holes 21 are provided on the shaft 201. The two first oil supply holes 21 communicate with the first oil supply cavity 18 and the first oil supply annular groove 20. A second oil supply hole 22 is provided in the inner cylinder 202 along its radial direction. The second oil supply hole 22 communicates with the first oil supply annular groove 20 and the inlet end of the first flow channel 3.

[0049] The oil supply mechanism supplies heat transfer oil into the oil supply pipe 15, a part of the heat transfer oil in the oil supply pipe 15 flows into the first oil supply chamber 18 through the fifth oil supply hole 19, and the heat transfer oil in the first oil supply chamber 18 enters the first flow channel 3 through the first oil supply hole 21, the first oil supply ring groove 20 and the second oil supply hole 22 in sequence, so that the heat transfer oil circulates in the first flow channel 3.

[0050] Reference Figure 5 and Figure 7 The third sealing ring 23 is located at the open end of the oil supply pipe 15. The third sealing ring 23 and the inner wall of the shaft body 201 at the inner cavity end form a second oil supply cavity 24. The open end of the oil supply pipe 15 is located in the second oil supply cavity 24. A second oil supply annular groove 25 is provided on the inner side wall of the inner cylinder 202 and located outside the second oil supply cavity 24. Two third oil supply holes 26 are provided on the shaft body 201. The two third oil supply holes 26 are connected to the second oil supply cavity 24 and the second oil supply annular groove 25. A fourth oil supply hole 27 is provided in the inner cylinder 202 along its own radial direction. The fourth oil supply hole 27 is connected to the second oil supply annular groove 25 and the inlet end of the second flow channel 4.

[0051] Reference Figure 5 , Figure 6 and Figure 7, another part of the heat transfer oil in the oil supply pipe 15 flows into the second oil supply chamber 24 through the opening at the end of the oil supply pipe 15, and the heat transfer oil in the second oil supply chamber 24 enters the second flow channel 4 through the third oil supply hole 26, the second oil supply ring groove 25 and the fourth oil supply hole 27 in sequence, so that the heat transfer oil flows in the second flow channel 4. Thus, the heat transfer oil can be supplied to the first flow channel 3 and the second flow channel 4 at the same time, and the flow directions of the heat transfer oil in the first flow channel 3 and the second flow channel 4 are opposite. The oil supply mechanism supplies the heat transfer oil from both ends of the inner cylinder 202 into the first flow channel 3 and the second flow channel 4 respectively, and the heat transfer oil flows in the first flow channel 3 and the second flow channel 4 and heats the outer cylinder 203, so that the temperature difference between the two ends of the outer cylinder 203 is smaller.

[0052] A first oil outlet chamber 28 is formed between the second sealing ring 17, the third sealing ring 23, the outer wall of the oil supply pipe 15 and the inner wall of the shaft body 201. A rotary joint is installed on the end of the shaft body 201 away from the second oil supply chamber 24. A second oil outlet chamber 29 is formed between the first sealing ring 16, the outer wall of the oil supply pipe 15, the inner wall of the shaft body 201 and the rotary joint. Eight oil outlet pipes 30 are passed through the first sealing ring 16 and the second sealing ring 17. Both ends of the oil outlet pipes 30 are connected to the first oil outlet chamber 28 and the second oil outlet chamber 29, and the rotary joint is connected to the oil return end of the oil supply mechanism.

[0053] A first oil outlet groove 31 is provided on the inner side wall of the inner cylinder 202, and a first oil outlet hole 32 is provided in the inner cylinder 202 along its radial direction, the first oil outlet hole 32 connects the first oil outlet groove 31 and the outlet end of the first flow channel 3, and two second oil outlet holes 33 are provided on the shaft 201, the second oil outlet holes 33 connect the first oil outlet groove 31 and the first oil outlet cavity 28. The heat transfer oil in the first flow channel 3 flows from the first oil outlet hole 32 into the first oil outlet groove 31, and then flows back to the oil supply mechanism through the second oil outlet hole 33, the first oil outlet cavity 28, the oil outlet pipe 30, the second oil outlet cavity 29 and the rotary joint in sequence.

[0054] A second oil outlet ring groove 34 is provided on the inner side wall of the inner cylinder 202, and a third oil outlet hole 35 is provided in the inner cylinder 202 along its radial direction, the third oil outlet hole 35 is connected to the second oil outlet ring groove 34 and the outlet end of the second flow channel 4, and two fourth oil outlet holes 36 are provided on the shaft 201, the fourth oil outlet holes 36 are connected to the second oil outlet ring groove 34 and the second oil outlet cavity 29. The heat transfer oil in the second flow channel 4 flows from the third oil outlet hole 35 into the second oil outlet ring groove 34, and then flows back to the oil supply mechanism through the fourth oil outlet hole 36, the second oil outlet cavity 29 and the rotary joint in sequence, so that the heat transfer oil in the first flow channel 3 and the second flow channel 4 can be simultaneously supplied back to the oil supply mechanism.

[0055] Reference Figure 3 and Figure 4, a driving mechanism 5 is installed on the end disk 204, and the driving mechanism 5 can drive the inner cylinder 202 to slide back and forth on the shaft body 201. The driving mechanism 5 includes a driving member 51, a driving gear ring 52, three driving gears 53 and a screw rod 54. The screw rod 54 is rotatably installed on the two end disks 204, and the three screw rods 54 are installed at equal intervals along the circumference of the end disk 204. One end of the screw rod 54 passes through an end disk 204, and the three driving gears 53 are fixedly installed at the end of the screw rod 54 passing through the end disk 204 and are located at the outer side wall of the end disk 204. The driving gear ring 52 is rotatably installed on the outer side wall of the end disk 204, and the three driving gears 53 are located on the outer peripheral side of the driving gear ring 52 and mesh with the driving gear ring 52. The driving member 51 is fixedly installed on the outer side wall of the end disk 204, and the driving end of the driving member 51 is fixedly connected to a driving gear 53. In the present application, the driving member 51 can be selected as a servo motor.

[0056] The driving member 51 drives a driving gear 53 to rotate, and the driving gear 53 drives the other three driving gears 53 to rotate synchronously through the driving ring gear 52. The three driving gears 53 drive the three screw rods 54 to rotate synchronously, thereby driving the inner cylinder 202 to slide back and forth on the shaft 201, so that the heat transfer oil in the first flow channel 3 and the second flow channel 4 can reciprocate to heat the same position of the outer cylinder 203, so that the temperature difference at the local position of the outer cylinder 203 is smaller, further reducing the temperature difference on the surface of the outer cylinder 203.

[0057] Reference Figure 5 and Figure 7 The length of the outer cylinder 203 is greater than that of the inner cylinder 202. The first liquid storage cavity 6 and the second liquid storage cavity 7 are respectively formed between the two end walls of the inner cylinder 202 in the axial direction, the inner wall of the outer cylinder 203, the outer wall of the shaft 201 and the inner walls of the two end plates 204. The inner cylinder 202 is provided with flow holes 8 along its own axial direction. There are eight flow holes 8 at equal intervals along the circumference of the inner cylinder 202. The flow holes 8 are connected to the first flow channel 3 and the second flow channel 4, and the two ends of the flow holes 8 are respectively connected to the first liquid storage cavity 6 and the second liquid storage cavity 7.

[0058] Reference Figure 4 , Figure 8 and Fig. 9 On the inner side wall of each end plate 204 close to the inner cylinder 202, eight driving cylinders 9 are fixedly installed at equal intervals along the circumference of the end plate 204. Eight receiving holes 37 are opened at equal intervals along the circumference of the end walls of the inner cylinder 202. The driving cylinder 9 is slidably installed in the receiving holes 37. The end of the driving cylinder 9 close to the inner cylinder 202 is opened with a sliding hole 10 along the axial direction of the inner cylinder 202. The inner side wall of the driving cylinder 9 located at the sliding hole 10 is symmetrically opened with two spiral guide grooves 11.

[0059] Reference Figure 7 , Figure 8 and Fig. 9 The inner cylinder 202 is located in each flow hole 8 and a screw 12 is rotatably installed. The screw 12 passes through the first flow channel 3 and the second flow channel 4, and the diameter of the screw 12 is smaller than the diameter of the flow hole 8. The two ends of the screw 12 are respectively slidably installed in the sliding holes 10 of the two inner cylinders 202, and two guide blocks 13 are symmetrically fixedly installed at both ends of the screw 12. The guide blocks 13 at the ends of the screw 12 are slidably installed in the spiral guide groove 11 of the driving cylinder 9.

[0060] Heat transfer oil is stored in the first liquid storage chamber 6 and the second liquid storage chamber 7. When the inner cylinder 202 moves toward the first liquid storage chamber 6, the heat transfer oil in the first liquid storage chamber 6 flows into the first flow channel 3 and the second flow channel 4 through the circulation hole 8, and part of the heat transfer oil in the first flow channel 3 and the second flow channel 4 will move toward the second liquid storage chamber 7, so that the heat transfer oil in the first flow channel 3 and the second flow channel 4 can communicate with each other, and part of the heat transfer oil in the first flow channel 3 and the second flow channel 4 will flow into the second liquid storage chamber 7.

[0061] At the same time, the inner cylinder 202 will drive the screw 12 to move during the process, and the two ends of the screw 12 will move in the sliding holes 10 of the two driving cylinders 9. The screw 12 drives the two guide blocks 13 to slide in the spiral guide grooves 11 of the two driving cylinders 9, thereby driving the screw 12 to rotate, thereby improving the efficiency of the heat transfer oil in the first flow channel 3 and the second flow channel 4.

[0062] Similarly, when the inner cylinder 202 moves toward the second liquid storage chamber 7, the heat transfer oil in the second liquid storage chamber 7 will flow into the first flow channel 3 and the second flow channel 4, and part of the heat transfer oil in the first flow channel 3 and the second flow channel 4 will flow into the first liquid storage chamber 6.

[0063] Reference Figure 4 and Fig.10 A plurality of guide plates 14 are fixedly installed on the inner cylinder 202 in both the first flow channel 3 and the second flow channel 4. The guide plates 14 are parallel to the screw 12. The guide plates 14 are located on the upstream side of the screw 12 close to the flow direction of the heat transfer oil, and the middle part of the guide plates 14 protrudes outwards away from the screw 12. In the process of the screw 12 rotating to transport the heat transfer oil to communicate with each other in the first flow channel 3 and the second flow channel 4, the guide plates 14 shield the screw 12, so that the heat transfer oil flowing in the first flow channel 3 and the second flow channel 4 will not impact on the screw 12, so that the effect of the screw 12 communicating with the heat transfer oil is better.

[0064] The implementation principle of a PVC film calendering process in the embodiment of the present application is as follows: the oil supply mechanism supplies the heat transfer oil from the two ends of the inner cylinder 202 into the first flow channel 3 and the second flow channel 4 respectively, and the heat transfer oil flows in the first flow channel 3 and the second flow channel 4 and heats the outer cylinder 203, so that the temperature difference at the two ends of the outer cylinder 203 is smaller. The driving member 51 drives a driving gear 53 to rotate, and the driving gear 53 drives the other three driving gears 53 to rotate synchronously through the driving gear ring 52, and the three driving gears 53 drive the three screws 54 to rotate synchronously, thereby driving the inner cylinder 202 to slide back and forth on the shaft 201, so that the heat transfer oil in the first flow channel 3 and the second flow channel 4 can reciprocate and heat the same position of the outer cylinder 203, so that the temperature difference at the local position of the outer cylinder 203 is smaller, and the temperature difference on the surface of the outer cylinder 203 is further reduced.

[0065] The above are only optional embodiments of the present disclosure and are not intended to limit the present disclosure. For those skilled in the art, the present disclosure may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A PVC film calendering process, characterized in that: The following steps are involved: S1: Put PVC raw materials and additives into a mixer according to proportion and mix; S2: The mixed material is fed into an extruder, where the material is heated to a molten state and extruded; S3: The extruded material is calendered multiple times by a six-roll calender to form a PVC film of desired thickness; S4: trimming and rolling the PVC film; In step S3, the six-roll calender comprises a frame (1) and six pressure rollers (2), the six pressure rollers (2) are rotatably arranged in the frame (1), the pressure rollers (2) comprise an axle (201), an inner cylinder (202), an outer cylinder (203) and two end plates (204), the inner cylinder (202) is slidably arranged on the axle (201) along the axial direction of the axle (201), the two end plates (204) are fixedly arranged on the axle (201) and located on both sides of the inner cylinder (202), the two ends of the outer cylinder (203) are fixedly sleeved on the two end plates (204), the inner side wall of the outer cylinder (203) fits the inner cylinder (201) and the inner side wall of the outer cylinder (203) fits the inner cylinder (201). 2), a spiral first flow channel (3) and a second flow channel (4) are provided on the outer wall of the inner cylinder (202), the first and second ends of the first flow channel (3) and the second flow channel (4) are both located on both sides of the axis direction of the inner cylinder (202), the oil supply mechanism supplies heat transfer oil into the first flow channel (3) and the second flow channel (4), the flow directions of the heat transfer oil in the first flow channel (3) and the second flow channel (4) are opposite, and the heat transfer oil flows through the first flow channel (3) and the second flow channel (4) and then flows back to the oil supply mechanism, the pressure roller (2) is provided with a driving mechanism (5), and the driving mechanism (5) drives the inner cylinder (202) to slide back and forth on the shaft (201).

2. A PVC film calendering process according to claim 1, characterized in that: The driving mechanism (5) comprises a driving member (51), a driving gear ring (52), a plurality of driving gears (53) and a screw rod (54); the plurality of screw rods (54) are all threaded through the inner cylinder (202); one end of the plurality of screw rods (54) is rotatably arranged in the inner wall of an end plate (204), and the other end passes through another end plate (204); the plurality of driving gears (53) are fixedly arranged on one end of the plurality of screw rods (54) passing through the end plate (204); the driving gear ring (52) is rotatably arranged on the outer wall of the end plate (204) and meshes with the plurality of driving gears (53); the driving member (51) is arranged on the outer wall of the end plate (204), and the driving end of the driving member (51) is fixedly connected to a driving gear (53).

3. A PVC film calendering process according to claim 1, characterized in that: The length of the outer cylinder (203) is greater than the length of the inner cylinder (202), and a first liquid storage chamber (6) and a second liquid storage chamber (7) are formed at two ends of the inner cylinder (202) in the axial direction. A flow hole (8) is opened on the inner cylinder (202) along its own axial direction, and the flow hole (8) connects the first flow channel (3) and the second flow channel (4), and the two ends of the flow hole (8) are respectively connected to the first liquid storage chamber (6) and the second liquid storage chamber (7).

4. A PVC film calendering process according to claim 3, characterized in that: A plurality of flow holes (8) are provided at equal intervals along the circumference of the inner cylinder (202).

5. A PVC film calendering process according to claim 3, characterized in that: A driving cylinder (9) is fixedly arranged on the inner side walls of the two end plates (204) close to each other, a sliding hole (10) is opened in the driving cylinder (9), and a spiral guide groove (11) is opened on the side wall of the driving cylinder (9) located in the sliding hole (10). The inner cylinder (202) is rotatably arranged with a screw rod (12) in the circulation hole (8), and the screw rod (12) passes through the first flow channel (3) and the second flow channel (4). Both ends of the screw rod (12) are slidably arranged in the two sliding holes (10), and both ends of the screw rod (12) are fixedly arranged with guide blocks (13), and the two guide blocks (13) are respectively slidably arranged in the two spiral guide grooves (11).

6. A PVC film calendering process according to claim 5, characterized in that: A plurality of guide plates (14) are arranged on the inner cylinder (202) in the first flow channel (3) and the second flow channel (4); the guide plates (14) are located on one side of the screw (12); and the guide plates (14) are used to prevent the heat transfer oil from impacting the screw (12).

7. A PVC film calendering process according to claim 1, characterized in that: The shaft body (201) is provided with an inner cavity, an oil supply pipe (15) connected to the oil supply mechanism is arranged in the inner cavity of the shaft body (201), a first sealing ring (16) and a second sealing ring (17) are arranged on the oil supply pipe (15) at intervals, a first oil supply cavity (18) is formed between the first sealing ring (16), the second sealing ring (17), the outer wall of the oil supply pipe (15) and the inner wall of the shaft body (201), a fifth oil supply hole (19) connected to the first oil supply cavity (18) is arranged on the oil supply pipe (15), a first oil supply annular groove (20) is arranged on the inner side wall of the inner cylinder (202), and a first oil supply hole (19) connected to the first oil supply cavity (18) and the first oil supply annular groove (20) is arranged in the shaft body (201). An oil supply hole (21), a second oil supply hole (22) connecting the first oil supply ring groove (20) and the first flow channel (3) is provided in the inner cylinder (202); a third sealing ring (23) is provided at the end of the oil supply pipe (15), and a second oil supply cavity (24) is formed between the third sealing ring (23) and the inner wall of the shaft body (201) at the end of the inner cavity, a second oil supply ring groove (25) is provided on the inner side wall of the inner cylinder (202), a third oil supply hole (26) connecting the second oil supply cavity (24) and the second oil supply ring groove (25) is provided in the shaft body (201), and a fourth oil supply hole (27) connecting the second oil supply ring groove (25) and the second flow channel (4) is provided in the inner cylinder (202).

8. A PVC film calendering process according to claim 7, characterized in that: The second sealing ring (17) is located on the side of the first sealing ring (16) close to the third sealing ring (23); a first oil outlet cavity (28) is formed between the second sealing ring (17), the third sealing ring (23), the outer wall of the oil supply pipe (15) and the inner wall of the shaft body (201); a second oil outlet cavity (29) is formed between the first sealing ring (16), the outer wall of the oil supply pipe (15) and the inner wall of the shaft body (201) and on the side away from the first oil supply cavity (18); the second oil outlet cavity (29) is connected to the oil supply mechanism; an oil outlet pipe (30) connecting the first oil outlet cavity (28) and the second oil outlet cavity (29) is provided inside the first sealing ring (16) and the second sealing ring (17); the inner cylinder A first oil outlet groove (31) is provided on the inner side wall of the inner cylinder (202), a first oil outlet hole (32) connecting the first flow channel (3) and the first oil outlet groove (31) is provided in the inner cylinder (202), a second oil outlet hole (33) connecting the first oil outlet groove (31) and the first oil outlet cavity (28) is provided in the shaft body (201), a second oil outlet groove (34) is provided on the inner side wall of the inner cylinder (202), a third oil outlet hole (35) connecting the second flow channel (4) and the second oil outlet groove (34) is provided in the inner cylinder (202), and a fourth oil outlet hole (36) connecting the second oil outlet groove (34) and the second oil outlet cavity (29) is provided in the shaft body (201).

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