Cast film production equipment and production method
By setting multiple independent chambers and water storage pipes on the cooling roller, combined with a vacuum structure, the problem of uneven cooling was solved, achieving uniform cooling of the film and high-quality production.
Patent Information
- Application Number
- CN202511474540.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-15
- Publication Date
- 2025-12-05
AI Technical Summary
Existing cooling roller designs cannot meet the needs of precise, regional cooling, resulting in inconsistent local cooling of the film, generating internal stress, and affecting the film's flatness and mechanical properties.
The cooling roller is divided into multiple independent chambers along the circumference by several first partitions. Combined with independent water storage pipes and nozzle designs, a differentiated cooling strategy is achieved. By precisely controlling the cooling conditions of each area and combining a vacuum structure to remove air and volatiles, uniform cooling is ensured.
It significantly improves the flatness of the film and the quality of the product, and significantly improves the transparency, gloss, flatness, dimensional stability and consistency of mechanical properties of the film.
Smart Images
Figure CN121062099A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of cast film production, and particularly relates to a cast film production device and a production method. BACKGROUND
[0002] The cast film is a high-performance plastic film prepared by extruding molten plastic into a curtain through an extruder die, and then rapidly cooling and setting on a cooling roller. Due to its high production rate, uniform thickness, excellent optical performance, and good dimensional stability, the cast film is widely used in food packaging, pharmaceutical packaging, electronic product protection, agricultural mulching, and many other fields. In the production process, the heat exchange efficiency and uniformity between the high-temperature melt curtain and the cooling roller are the core links that determine the quality of the final film product. The existing cooling roller adopts a whole cooling cavity design, and the roller surface temperature is controlled by adjusting the overall water inlet temperature and flow. In actual production, the global uniform cooling method cannot meet the fine and regional cooling requirements, resulting in inconsistent local cooling shrinkage of the film, generating internal stress, and finally leading to film warping, poor flatness, mechanical property anisotropy, and other problems, which seriously affect the product quality in high-end application fields. SUMMARY
[0003] To solve the above technical problems, the application provides a cast film production device and a production method. A plurality of first partitions divide the interior of the cooling roller into a plurality of independent first chambers in the circumferential direction. The operator can implement differentiated cooling strategies for each region on the cooling roller according to the different cooling requirements that may exist at different circumferential positions of the cast film. Independent water storage pipes and spray heads are designed, so that different first chambers can be sprayed with cooling water of different temperatures or flow rates. By accurately regulating the spraying conditions of each region, the temperature distribution of the entire cooling roller surface can be uniformly adjusted, thereby effectively avoiding inconsistent cooling rates of the film caused by temperature differences on the cooling roller surface and controlling the cooling temperature of different regions. The flatness and product quality of the film are significantly improved.
[0004] The technical solutions adopted by the application are as follows: The lower end of the extruder is provided with an extrusion lip, a cooling roller is matched below the extrusion lip, a sealing assembly is further provided at the lower part of the extruder, the width of the sealing assembly is matched with the width of the cooling roller, the sealing assembly can form a closed space with the cooling roller and the melt curtain extruded by the extrusion lip, and the internal pipeline of the sealing assembly is communicated with a vacuum pump; a plurality of first partitions are circumferentially arranged in the internal part of the cooling roller, the length of the first partitions is consistent with the length of the cooling roller, and the first partitions divide the cooling roller into a plurality of first chambers; a water storage pipe is arranged in the internal part of the cooling roller, the cooling roller and the water storage pipe are arranged in opposite rotation, the end of the water storage pipe is communicated with an external water source through a pipeline and a first water pump in sequence, the water storage pipe is arranged along the length direction of the cooling roller, a plurality of nozzles are arranged at intervals on the water storage pipe, and the plurality of nozzles are arranged in a plurality of rows, and the plurality of nozzles in each row are arranged corresponding to the spacing of the plurality of first chambers divided by the first partitions; and the first chambers are further communicated with a second water pump through a pipeline.
[0005] According to the technical scheme, the plurality of first partitions divide the internal part of the cooling roller into a plurality of independent first chambers in the circumferential direction, the operator can implement differentiated cooling strategies for different regions of the cooling roller according to different cooling requirements of the cast film at different circumferential positions, and the independent water storage pipe and nozzles are designed, so that different first chambers can be sprayed with cooling water of different temperatures or flow rates, the temperature distribution of the surface of the entire cooling roller can be uniformly adjusted by accurately regulating the spraying conditions of each region, the cooling rate of the film caused by the temperature difference of the surface of the cooling roller can be effectively avoided, the cooling temperature of different regions can be controlled in a targeted manner, and the flatness and product quality of the film are significantly improved. The vacuum extraction structure and the partitioned cooling roller assembly are integrated, the vacuum extraction system can effectively remove air and volatile matters between the melt and the cooling roller, and provide an absolutely close cooling environment for the melt, the partitioned cooling roller can implement differentiated cooling for different circumferential regions of the surface, the vacuum extraction avoids the air heat insulation layer and the condensation of volatile matters on the surface of the cast film, so that the temperature of the partitioned cooling can not be affected by condensation caused by being below the dew point, and the cooling process can be further finely regulated and controlled on this basis, the partitioned cooling can compensate the cooling temperature and rate requirements of the cast film in different regions in a targeted manner, and the transparency, gloss, flatness, dimensional stability and consistency of mechanical properties of the film are significantly improved.
[0006] Further, a filter is arranged between the pipeline communicated with the vacuum pump and the sealing assembly, so that the volatile matters in the gas extracted by the vacuum pump can be filtered, and the filter can avoid the condensation of the volatile matters in the pipeline or the vacuum pump, and avoid blockage or damage.
[0007] Preferably, the sealing assembly comprises a first sealing plate, a second sealing plate and two third sealing plates, the upper ends of the first sealing plate and the second sealing plate are connected with the lower part of the extruder respectively, the two third sealing plates are arranged on the two sides of the first sealing plate and the second sealing plate respectively to form a box body, and an interface is arranged on the third sealing plate on one side and communicates with the vacuum pump through a pipeline.
[0008] By adopting the technical scheme, the first sealing plate and the second sealing plate form sealing in the width direction of the cooling roller, and the two third sealing plates form sealing in the vertical direction of the first sealing plate, thereby forming a box body structure and the surface of the cooling roller to jointly form a complete closed chamber surrounding the sticking point, the interface is arranged on the third sealing plate to provide a reasonable and convenient position for the connection of the vacuum pipeline, and interference of the pipeline with the melt curtain or other components is avoided.
[0009] Preferably, the first sealing plate is located in the flowing direction of the melt curtain, the distance between the lower end of the first sealing plate and the cast film formed by the melt curtain on the cooling roller is between 0 and 50 microns, that is, the distance between the lower end of the first sealing plate and the cooling roller is equal to the thickness of the cast film, the second sealing plate is located on the side of the melt curtain away from the first sealing plate, the lower end of the second sealing plate is in close contact with the cooling roller, and the two third sealing plates are in sealing contact with the side edges of the corresponding sides of the cooling roller.
[0010] By adopting the technical scheme, the distance between the lower end of the first sealing plate and the cast film is between 0 and 50 microns, the small gap ensures that the formed film can continuously and stably separate from the vacuum chamber without being scratched or blocked, the small gap greatly limits the flow of external air flowing into the vacuum chamber from the first sealing plate position, and in cooperation with the air exhaust rate of the vacuum pump, the negative pressure in the chamber can be easily maintained, effective sealing under dynamic conditions is realized, and at the same time, direct friction and wear of the first sealing plate on the surface of the high-precision cooling roller are avoided; the second sealing plate is in close contact with the cooling roller, external air is maximally prevented from being brought into the vacuum chamber from the second sealing plate; the sealing of the two side edges of the vacuum chamber is realized, air is prevented from being sucked from the two sides of the cooling roller, and the uniformity of the negative pressure environment on the width of the entire cooling roller surface is ensured.
[0011] Preferably, the lower end of each third sealing plate is provided with a T-shaped sliding block close to one end of the cooling roller, T-shaped sliding grooves are arranged at the two side edges of the cooling roller respectively, the T-shaped sliding grooves are annular, and the T-shaped sliding grooves are coaxially arranged with the cooling roller.
[0012] The slider and the sliding groove cooperate to form a labyrinth seal, effectively blocking the airflow, and the T-shaped sliding groove allows the third sealing plate to have a small amount of floating space in the radial direction, avoiding being stuck or worn out, and facilitating the installation and positioning of the first sealing plate and the second sealing plate.
[0013] Further, the lower part of the first sealing plate and the second sealing plate is provided as a curved surface cooperating with the cooling roller. Further, the lower part of the first sealing plate and the second sealing plate is provided with a contact part, and the material of the contact part is high-performance engineering plastic.
[0014] The lower part of the sealing plate is provided as a curved surface cooperating with the cooling roller, which can increase the fit between the sealing plate and the roller surface of the cooling roller, facilitate the smooth flow of the melt curtain from the box body of the sealing assembly, and the high-performance engineering plastic has low friction coefficient, high wear resistance and self-lubricating properties, which can minimize the wear and scratch on the high-finish cooling roller surface, resist chemical corrosion of plastic volatile substances, and avoid sealing failure caused by material deterioration.
[0015] Preferably, one end of the cooling roller is provided with a water storage cavity, one side of the cooling roller is provided with a plurality of openings, the water storage cavity is communicated with the first chamber through the plurality of openings, the water storage cavity is communicated with a second water pump through a pipeline, one side of each first chamber is provided with a plurality of openings, and the openings of each first chamber are arranged at the edge of the end part of the first chamber.
[0016] The above technical scheme drives the cooling water to be discharged from the first chamber, enters the water storage cavity through the openings, and forms a complete cooling water circulation loop under the driving of the second water pump, the first water pump inputs the external water source into the water storage pipe, the water storage pipe pumps the cooling water into the first chamber through the spray head, and the second water pump continuously pumps the water contacting the roller surface of the cooling roller into the water storage cavity through the openings of the first chamber, so that the cooling medium can continuously exchange heat and maintain stable cooling efficiency, the water of each first chamber is collected in the water storage cavity at one end of the cooling roller through the plurality of openings, and the pipeline connection is facilitated; the openings are arranged at the edge of the end part of each first chamber, so that the gravity can be fully utilized, which makes the cooling water in the chamber flow naturally and be discharged through the openings as much as possible without residue, avoids the water accumulation phenomenon, completely drains the water, ensures that the fresh cooling water is not mixed with the residual warm water each time, guarantees the highest efficiency of each cooling, and the water temperature in the chamber can quickly respond to the change of the sprayed water temperature, thereby enhancing the response speed and precision of the partition temperature control, solving the potential problem of incomplete drainage, and making the circulation system more reliable.
[0017] Preferably, the interior of the water storage pipe is provided with a plurality of second partitions in the circumferential direction, the second partitions divide the water storage pipe in the radial direction into a plurality of water storage cavities, the included angle between each water storage cavity corresponds to each first chamber, and each water storage cavity corresponds to a column of the spray heads.
[0018] By adopting the technical scheme, a plurality of independent water storage cavities are formed by arranging the second partitions in the water storage pipe, each water storage cavity is connected to a cooling water source of different temperature through an independent water supply pipeline and a valve, different circumferential regions of the cooling roller can be supplied with cooling water of completely different temperatures, the partitioned water storage cavities have corresponding included angles with the first chambers, and each column of the spray heads belongs to one water storage cavity, so that the spatial synchronization of the water supply partition and the heated partition of the cooling roller is ensured, when the cooling roller rotates, the fixed water storage pipe can continuously spray cooling water of a preset temperature to the surface area of the cooling roller in the corresponding region, so as to accurately control the temperature of different angular partitions of the roller surface, thereby realizing directional and accurate cooling of the film.
[0019] Preferably, one side of the cooling roller is provided with a rotating driving assembly, the water storage pipe is provided with a first bearing at a position in contact with both ends of the cooling roller, the cooling roller is rotationally connected to the water storage pipe through the first bearing, the distance between the first partition and the side of the water storage pipe is greater than the height of the spray head protruding from the water storage pipe, the driving assembly comprises a support assembly, a driving bracket and a rotating motor, the rotating motor is installed on the support assembly, the output end of the rotating motor is fixed to the driving bracket, the driving bracket is fixed to the end of the water storage cavity, the support assembly comprises a first support rod and a second support rod, the driving bracket comprises a first mounting ring, the rotating motor is fixed to the first support rod, the first mounting ring is fixed to the second support rod, a plurality of first connecting rods are arranged at the center of the first mounting ring to form a connecting block, the output end of the rotating motor is fixed to the center of the connecting block, the rotating motor and the connecting block are coaxially arranged with the cooling roller, and the first mounting ring is fixed to the end of the water storage cavity through a plurality of second connecting rods.
[0020] The cooling roller and the water storage pipe can be arranged in relative rotation, and the first bearing is used for rotation connection, so that the relative movement of the cooling roller and the water storage pipe does not interfere with each other, the distance of the first partition plate close to the water storage pipe is greater than the height of the nozzle protruding from the water storage pipe, so that the bottom of the first partition plate does not collide with the fixed nozzle when the cooling roller rotates; the driving assembly is composed of a supporting assembly, a driving bracket and a rotating motor, which provides a reliable power source for the rotation of the cooling roller, one end of the water storage cavity away from the driving bracket is fixed with the end of the cooling roller, and the power is transmitted in sequence through the rotating motor, the driving bracket, the end of the water storage cavity and the cooling roller; through the first mounting ring, the connecting rod, the connecting block and the like, the coaxiality of the output shaft of the rotating motor and the axis of the cooling roller is ensured, stable operation is ensured, the first supporting rod fixes the motor, the second supporting rod fixes the first mounting ring, and a stable supporting frame is formed.
[0021] Preferably, the cooling roller is provided with a third supporting rod on the side away from the rotating motor, the third supporting rod is provided with a second mounting ring, the second mounting ring is coaxially arranged with the cooling roller, the outer edge of the end of the cooling roller is rotationally connected with the second mounting ring through a second bearing, and the water storage pipe is provided with a fourth supporting rod at one end close to the second mounting ring.
[0022] The third supporting rod and the second mounting ring are arranged at one end of the cooling roller away from the driving motor, which provides necessary support for the roller body of the cooling roller, prevents the connection of the second supporting rod from supporting the roller body of the cooling roller, and ensures the rotation accuracy of the whole. The end of the cooling roller is supported by the second bearing connected to the second mounting ring, which realizes reliable rotation support of the cooling roller and cooperates with the bearing at one end of the driving motor to rotate; the fourth supporting rod can support and fix the non-rotating water storage pipe, ensuring the accuracy of the position of the nozzle, and together with the supporting rods at the driving end and the other end, forming a complete equipment rack.
[0023] A cast film production method using the above-mentioned cast film production equipment, comprising the following steps: Step 1: Start the extruder and the feeding system, and start the rotation of the cooling roller, adjust the rotation speed to match the preset production line speed, start the first water pump to pump the external cooling water into the water storage pipe, start the second water pump to start pumping water from the water storage cavity, and establish a cooling water circulation; Step 2: The cooling water temperature is initially set to the range required by the process; Step 3: After the melt curtain is stably running, start the vacuum pump, and adjust the vacuum degree in the sealing assembly to the best value required by the process; Step 4: The air and the heat-decomposed volatile substances between the melt curtain and the cooling roller are rapidly extracted by the vacuum pump, filtered by the filter, and discharged. The cooling water in the water storage pipe is sprayed into the corresponding first chamber of the cooling roller through the spray head, and the roller surface is cooled. The cooled water flows to the opening at the edge of each first chamber under the action of gravity, is collected in the water storage cavity, and is extracted by the second water pump to complete the circulation.
[0024] Preferably, in step 2, the temperature of the cooling water is initially set to a range required by the process, that is, the temperature of the roller surface of the cooling roller in the middle and rear sections of the cooling roller is higher than the temperature of the roller surface when the film contacts the cooling roller.
[0025] By adopting the above technical solution, the film is instantaneously rapidly cooled at the inlet, that is, a quenching effect is generated, and the surface is solidified first. When the film runs to the middle and rear sections of the cooling roller, the temperature of the roller surface of the cooling roller is slightly increased, and a slight tempering effect can be generated on the inside of the film.
[0026] In summary, due to the adoption of the above technical solution, the beneficial effects of the present application are: The first partition plates divide the inside of the cooling roller into a plurality of independent first chambers in the circumferential direction. The operator can implement different cooling strategies for different regions on the cooling roller according to the different cooling requirements of the cast film at different circumferential positions. The independent water storage pipes and spray heads are designed, so that cooling water with different temperatures or flow rates can be sprayed into different first chambers. By accurately controlling the spraying conditions of each region, the temperature distribution of the entire surface of the cooling roller can be uniformly adjusted, so that the cooling rate of the film caused by the temperature difference of the roller surface of the cooling roller is effectively avoided, and the cooling temperature of different regions is controlled in a targeted manner. The flatness and product quality of the film are significantly improved. BRIEF DESCRIPTION OF DRAWINGS
[0027] The present application will be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a structural schematic view of a cast film production equipment in the present application; Figure 2 is an enlarged structural schematic view of the A part in the present application Figure 1 Figure 3 is a first sealing plate structure schematic view in the present application Figure 1 Figure 4 is a structural schematic view of a cast film cooling roller assembly in the present application Figure 5 is a cross-sectional structural schematic view of a cooling roller in the present application Figure 6 is an internal structural schematic view of a water storage pipe in the present application. REFERENCE NUMERALS
[0028] 1-extruder, 2-cooling roller, 3-cast film, 4-first sealing plate, 5-second sealing plate, 6-third sealing plate, 7-extrusion lip, 8-contact part, 9-first partition plate, 10-opening, 11-water storage pipe, 1101-first water storage cavity, 1102-second water storage cavity, 1103-nozzle, 12-first bearing, 13-water storage cavity, 14-first mounting ring, 15-connecting block, 16-first connecting rod, 17-rotary motor, 18-first supporting rod, 19-second supporting rod, 20-third supporting rod, 21-fourth supporting rod, 22-second mounting ring. DETAILED DESCRIPTION
[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.
[0030] The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings. Figures 1-6 The present application will be described in detail. Embodiment 1
[0031] A cast film production device, with reference to the accompanying drawings Figure 1 The lower end of the extruder 1 is provided with an extrusion lip 7, and a cooling roller 2 is arranged below the extrusion lip 7. The lower part of the extruder 1 is further provided with a sealing assembly. The width of the sealing assembly is matched with the width of the cooling roller 2. The sealing assembly can form a closed space with the melt curtain extruded by the cooling roller 2 and the extrusion lip 7. The internal pipeline of the sealing assembly is communicated with a vacuum pump. The inside of the cooling roller 2 is provided with a plurality of first partition plates 9 along the circumference. The length of the first partition plates 9 is consistent with the length of the cooling roller 2. With reference to the accompanying drawings Figure 5The first partition plate 9 divides the cooling roller 2 into a plurality of first chambers; the inside of the cooling roller 2 is provided with a water storage pipe 11, the cooling roller 2 is provided opposite to the water storage pipe 11, the end of the water storage pipe 11 is communicated with an external water source through a pipeline and a first water pump in sequence, the water storage pipe 11 is arranged along the length direction of the cooling roller 2, a plurality of spray heads 1103 are arranged on the water storage pipe 11 at intervals, the plurality of spray heads 1103 are arranged in a plurality of rows, and the plurality of rows of spray heads 1103 are arranged corresponding to the spacing of the plurality of first chambers divided by the first partition plate 9; the first chamber is also communicated with a second water pump through a pipeline; the plurality of first partition plates 9 divide the inside of the cooling roller 2 into a plurality of independent first chambers in the circumferential direction, and the cooling roller 2 can implement differentiated cooling strategies for different regions according to the different cooling needs of the cast film 3 at different circumferential positions; the independent water storage pipe 11 and the spray head 1103 are designed, so that different first chambers can be sprayed with cooling water of different temperatures or flow rates, so that the temperature distribution of the entire surface of the cooling roller 2 can be uniformly adjusted by accurately adjusting the corresponding spraying conditions of each region, thereby effectively avoiding the inconsistent cooling rate of the film caused by the temperature difference of the roller surface of the cooling roller 2, and the cooling temperature of different regions is controlled, and the flatness and product quality of the film are significantly improved; the vacuum pumping structure and the partition cooling cooling roller 2 assembly are integrated, the vacuum pumping system can effectively remove the air and volatile substances between the melt and the cooling roller 2, and provide an absolutely attached cooling environment for the melt, the partition cooling roller 2 can implement differentiated cooling for different circumferential regions of the surface, and the vacuum pumping avoids the air heat insulation layer and the volatile substances to condense on the surface of the cast film 3, so that the partition cooling temperature can not consider condensation caused by being below the dew point, and further fine adjustment of the cooling process can be carried out on this basis, the partition cooling can be carried out, the cooling temperature requirement and the rate requirement of the cast film 3 in different regions can be compensated, and the transparency, gloss, flatness, dimensional stability and consistency of mechanical properties of the film are significantly improved.
[0032] In the embodiment, the number of the first partition plates 9 is 8, and the number of the first chambers is 8, and the number of the first chambers near the end of the water storage cavity 13 is 9. Embodiment 2
[0033] In the embodiment, a filter is arranged between the pipeline communicated with the vacuum pump and the sealing assembly, so that the volatile substances in the gas pumped away by the vacuum pump are filtered, and the condensation of the volatile substances in the pipeline or the vacuum pump is avoided to cause blockage or damage. Embodiment 3
[0034] In the embodiment, the sealing assembly is arranged on the water storage pipe 11, and the sealing assembly is arranged on the water storage pipe 11. Figure 2The sealing assembly comprises a first sealing plate 4, a second sealing plate 5 and two third sealing plates 6, the upper ends of the first sealing plate 4 and the second sealing plate 5 are connected with the lower part of the extruder 1 respectively, and the two third sealing plates 6 are arranged on the two sides of the first sealing plate 4 and the second sealing plate 5 respectively to form a box body, one of the third sealing plates 6 is provided with an interface, and the interface is communicated with the vacuum pump through a pipeline; the first sealing plate 4 and the second sealing plate 5 form sealing in the width direction of the cooling roller 2, and the two third sealing plates 6 form sealing in the vertical direction of the first sealing plate 4, thereby forming a box body structure and a complete closed cavity surrounding the sticking point together with the surface of the cooling roller 2, the interface arranged on the third sealing plate 6 provides a reasonable and convenient position for the connection of the vacuum pipeline, and interference of the pipeline with the melt curtain or other components is avoided. Embodiment 4
[0035] In the embodiment, the first sealing plate 4 is located in the flowing direction of the melt curtain, the distance between the lower end of the first sealing plate 4 and the cast film 3 formed by the melt curtain on the cooling roller 2 is between 0 and 50 μm, that is, the distance between the lower end of the first sealing plate 4 and the cooling roller 2 is equal to the thickness of the cast film 3; the second sealing plate 5 is located on the side of the melt curtain away from the first sealing plate 4, the lower end of the second sealing plate 5 is closely attached to the cooling roller 2, and the two third sealing plates 6 are respectively in sealing contact with the side edges of the corresponding side of the cooling roller 2; the distance between the lower end of the first sealing plate 4 and the cast film 3 is between 0 and 50 μm, and the small gap ensures that the formed film can continuously and stably leave the vacuum cavity without being scratched or blocked, the small gap greatly limits the flow of external air from the first sealing plate 4 into the vacuum cavity, and in cooperation with the air exhaust rate of the vacuum pump, the negative pressure in the cavity can be easily maintained, thereby realizing effective sealing under dynamic conditions, and at the same time, direct friction and wear of the first sealing plate 4 on the surface of the high-precision cooling roller 2 are avoided; the second sealing plate 5 is closely attached to the cooling roller 2, thereby maximizing the isolation of external air from being brought into the vacuum cavity from the second sealing plate 5; the sealing of the two side edges of the vacuum cavity is realized, air is prevented from being sucked from the two sides of the cooling roller 2, and the uniformity of the negative pressure environment on the entire width of the surface of the cooling roller 2 is ensured. Embodiment 5
[0036] In the embodiment, the lower end of each third sealing plate 6 is provided with a T-shaped sliding block, and the two side edges of the cooling roller 2 are respectively provided with T-shaped sliding grooves, the T-shaped sliding grooves are annular, and the T-shaped sliding grooves are coaxially arranged with the cooling roller 2; the sliding block and the sliding groove cooperate to form a labyrinth sealing, effectively block the airflow, the T-shaped sliding groove design allows the third sealing plate 6 to have a small amount of floating space in the radial direction, avoids being stuck or worn, and facilitates the installation and positioning of the first sealing plate 4 and the second sealing plate 5. Embodiment 6
[0037] In this embodiment, refer to the attached drawings Figure 3 The lower part of the first sealing plate 4 and the second sealing plate 5 is provided as a curved surface matched with the cooling roller 2. In this embodiment, the lower part of the first sealing plate 4 and the second sealing plate 5 is provided with a contact part 8, the material of the contact part 8 is high-performance engineering plastic material; the lower part of the sealing plate is provided as a curved surface matched with the cooling roller 2, which can increase the adhesion between the sealing plate and the roller surface of the cooling roller 2, facilitate the melt curtain to flow out of the box body of the sealing assembly stably, high-performance engineering plastic has low friction coefficient, high wear resistance and self-lubricating characteristics, which can minimize the wear and scratch on the high-finish cooling roller 2 surface, resist chemical corrosion of plastic volatile matter, and avoid sealing failure caused by material deterioration.
[0038] The high-performance engineering plastic is polytetrafluoroethylene. Embodiment 7
[0039] In this embodiment, refer to the attached drawings Figure 4 One end of the cooling roller 2 is provided with a water storage cavity 13, one side of the cooling roller 2 is provided with a plurality of openings 10, the water storage cavity 13 is communicated with the first chamber through a plurality of openings 10, the water storage cavity 13 is communicated with a second water pump through a pipeline, one side of each first chamber is provided with a plurality of openings 10, and the openings 10 of each first chamber are arranged at the edge of the end part of the first chamber; under the driving of the second water pump, the cooling water is discharged from the first chamber, enters the water storage cavity 13 through the openings 10, and forms a complete cooling water circulation loop, the first water pump inputs the external water source into the water storage pipe 11, the water storage pipe 11 pumps the cooling water into the first chamber through the spray head 1103, the second water pump continuously pumps the water contacting the roller surface of the cooling roller 2 into the water storage cavity 13 through the openings 10 of the first chamber, which ensures that the cooling medium can continuously exchange heat and maintain stable cooling efficiency; the water collected from the first chambers through the plurality of openings 10 is integrated in the water storage cavity 13 at one end of the cooling roller 2, which is convenient for the connection of the pipeline; the openings 10 are arranged at the edge of the end part of each first chamber, so that the gravity can be fully utilized, which makes the cooling water in the chamber flow naturally and as much as possible without residue through the openings 10, avoids the water accumulation phenomenon, and completely drains the water, which means that the fresh cooling water sprayed each time will not be mixed with the residual warm water, ensures that each cooling is the most efficient, and the water temperature in the chamber can quickly respond to the change of the sprayed water temperature, thereby enhancing the response speed and precision of the partition temperature control, solving the potential problem of incomplete drainage, and making the circulation system more reliable. Embodiment 8
[0040] In this embodiment, refer to the attached drawings Figure 6The interior of the water storage pipe 11 is provided with a plurality of second partitions in the circumferential direction, which divide the water storage pipe 11 radially into a plurality of water storage cavities, the included angle between each water storage cavity corresponds to each first chamber, and each water storage cavity corresponds to a column of the spray heads 1103; by arranging the second partitions in the water storage pipe 11, a plurality of independent water storage cavities are formed, each water storage cavity is connected to a cooling water source of different temperature through an independent water supply pipeline and a valve, which can supply cooling water of completely different temperatures to different circumferential regions of the cooling roller 2, realize the ability of partition temperature control, the partition included angle of the water storage cavity corresponds to the first chamber, and each column of spray heads 1103 is exclusively assigned to a water storage cavity, which ensures the spatial synchronization of the water supply partition and the heated partition of the cooling roller 2; when the cooling roller 2 rotates, the fixed water storage pipe 11 can continuously spray cooling water of a preset temperature to the roller surface region of the cooling roller 2 rotating to the corresponding region, thereby realizing precise regulation and control of the temperature of different angular partitions of the roller surface, and realizing directional and precise cooling of the film.
[0041] The water storage cavities include a first water storage cavity 1101, a second water storage cavity 1102, and an eighth water storage cavity. Example 9
[0042] The cooling roller 2 is provided with a rotating driving assembly on one side, the water storage pipe 11 is provided with a first bearing 12 at the position where it contacts the two ends of the cooling roller 2, the cooling roller 2 is rotatably connected with the water storage pipe 11 through the first bearing 12, the distance from the first partition plate 9 to the side close to the water storage pipe 11 is greater than the height of the nozzle 1103 protruding from the water storage pipe 11, the driving assembly comprises a supporting assembly, a driving bracket and a rotating motor 17, the rotating motor 17 is installed on the supporting assembly, the output end of the rotating motor 17 is fixed with the driving bracket, the driving bracket is fixed with the end of the water storage cavity 13, the supporting assembly comprises a first supporting rod 18 and a second supporting rod 19, the driving bracket comprises a first mounting ring 14, the rotating motor 17 is fixed with the first supporting rod 18, the first mounting ring 14 is fixed with the second supporting rod 19, a plurality of first connecting rods 16 are arranged at the center of the first mounting ring 14 to form a connecting block 15, the output end of the rotating motor 17 is fixed with the center of the connecting block 15, the rotating motor 17 and the connecting block 15 are coaxially arranged with the cooling roller 2; the first mounting ring 14 is fixed with the end of the water storage cavity 13 through a plurality of second connecting rods; the cooling roller 2 and the water storage pipe 11 can be relatively rotatably arranged, the first bearing 12 realizes the rotating connection, so that the relative movement of the cooling roller 2 and the water storage pipe 11 does not interfere with each other, the distance from the first partition plate 9 to the side close to the water storage pipe 11 is greater than the height of the nozzle 1103 protruding from the water storage pipe 11, so that the bottom of the first partition plate 9 does not collide with the fixed nozzle 1103 when the cooling roller 2 rotates; the driving assembly is composed of the supporting assembly, the driving bracket and the rotating motor 17, which provides a reliable power source for the rotation of the cooling roller 2, the end of the water storage cavity 13 away from the driving bracket is fixed with the end of the cooling roller 2, and the power is transmitted in sequence through the rotating motor 17, the driving bracket, the end of the water storage cavity 13 and the cooling roller 2; through the first mounting ring 14, the connecting rod and the connecting block 15 and other structures, the coaxiality of the output shaft of the rotating motor 17 and the axis of the cooling roller 2 is ensured, stable operation is ensured, the first supporting rod 18 fixes the motor, the second supporting rod 19 fixes the first mounting ring 14, and a stable supporting frame is formed. Embodiment 10
[0043] In the embodiment, the third support rod 20 is arranged on the side of the cooling roller 2 away from the rotating motor 17, the second mounting ring 22 is arranged on the third support rod 20, the second mounting ring 22 is coaxially arranged with the cooling roller 2, the outer edge of the end of the cooling roller 2 is rotationally connected with the second mounting ring 22 through the second bearing, and the water storage pipe 11 is provided with the fourth support rod 21 at one end close to the second mounting ring 22; the third support rod 20 and the second mounting ring 22 are arranged at the end of the cooling roller 2 away from the driving motor, thereby providing necessary support for the roller body of the cooling roller 2, preventing the connection of the second support rod 19 from being unable to support the roller body of the cooling roller 2, and ensuring the overall rotation accuracy; the end support of the cooling roller 2 is connected on the second mounting ring 22 through the second bearing, thereby realizing reliable rotation support of the cooling roller 2 and cooperating with the bearing at the end of the driving motor to rotate; the fourth support rod 21 is arranged to support and fix the non-rotating water storage pipe 11, thereby ensuring the accuracy of the position of the nozzle 1103, and together with the support rods at the driving end and the other end, the fourth support rod 21 constitutes a complete equipment rack.
[0044] Embodiments 11-13 A cast film production method using the cast film production equipment described above, comprising the following steps: Step 1: start the extruder 1 and the feeding system to start plasticizing the material, start the driving motor of the cooling roller 2 to start the rotation of the cooling roller 2, adjust the rotation speed to match the preset production line speed, start the first water pump to pump external cooling water into the water storage pipe 11, start the second water pump to start pumping water from the water storage cavity 13, and establish a cooling water circulation; Step 2: preliminarily set the cooling water temperature to the range required by the process; The preliminarily set cooling water temperature to the range required by the process is that the cooling roller 2 roll surface temperature at the middle and later stages of the cooling roller 2 is higher than the cooling roller 2 roll surface temperature when the film contacts the cooling roller 2; Step 3: draw the extruded melt curtain from the extrusion lip 7, make it smoothly adhere to the surface of the rotating cooling roller 2, pass under the first sealing plate 4, and finally enter the subsequent traction and winding device; after the melt curtain runs stably, start the vacuum pump, observe the vacuum gauge on the vacuum pump, and gradually adjust the vacuum degree in the sealing assembly to the best value required by the process through the adjustment of the vacuum pipeline valve; Step 4: The air and the heat-decomposed volatile substances between the melt curtain and the cooling roller 2 are rapidly extracted by the vacuum pump, filtered by the filter, and then discharged. The cooling water in the water storage pipe 11 is sprayed into the first chamber of the corresponding cooling roller 2 through the water spray head 1103, so as to cool the roller surface. The cooled water flows to the opening 10 at the edge of the first chamber under the action of gravity, is collected in the water storage cavity 13, and is extracted by the second water pump to complete the circulation. According to the real-time cooling effect of the cast film 3 at different widths and circumferential positions, the valve and the temperature adjusting device on the independent water supply pipeline of each water storage cavity are adjusted to accurately control the temperature or flow of the cooling water to different areas, so as to realize directional and accurate cooling of the film.
[0045] The optical performance and other indicators of the film were detected after the temperature of Examples 12-13 was set according to Table 1; wherein the regions 1-8 are the cycle from the vacuum-extracted region to the gradually returned vacuum-extracted region.
[0046] Comparative Examples 1-2 do not set the vacuum extraction structure, and the optical performance and other indicators of the film are detected after the temperature is set according to Table 1.
[0047] The obtained detection data is shown in Table 1: Table 1: Temperature setting, optical performance and observation characterization detection table of Examples 11-13 and Comparative Examples 1-2
[0048] As can be seen from Table 1, since the air and water vapor between the melt and the roller surface are removed by vacuum extraction, they can safely set the cooling roller inlet temperature to be much lower than the ambient dew point without condensation, thereby preparing a high-quality film. The inlet temperature of Example 2 is 10°C, the cooling intensity is the largest, the quenching effect is the best, and the crystal growth is inhibited to the maximum extent, so the lowest haze and the highest transparency and gloss are obtained. In order to avoid condensation, the cooling roller of Comparative Example 1 is constantly kept at 17°C and cannot be lowered any further, which leads to insufficient cooling intensity. Due to uneven cooling and insufficient efficiency, the film has a high degree of crystallinity, the scattering of light by the spherulites causes the haze to increase significantly, the transparency and gloss also decrease accordingly, and a slight cloudy white spot appears on the surface, so the optical performance is not as good as that of Examples 1-3. Comparative Example 3 simulates the inlet temperature of Example 1, but lacks the vacuum extraction structure and cannot remove the water vapor formed at the dew point. The water vapor condenses instantly to form countless tiny water droplets, which form water stains and pits on the film, seriously affecting the quality of the film.
[0049] It should be noted that: The foregoing description of the disclosed embodiments enables a person skilled in the art to make or use the application. Modifications of these embodiments will occur to persons of skill in the art, and, while certain modifications are discussed, it is desired to be protected in accordance with the spirit and scope of the application. Therefore, the application is not limited to the specific embodiments shown and described, but only by the scope of the appended claims, unless otherwise specified.
Claims
1. A cast film production apparatus characterized by, The lower end of the extruder (1) is provided with an extrusion lip (7), and a cooling roller (2) is arranged below the extrusion lip (7). The lower part of the extruder (1) is further provided with a sealing assembly, the width of the sealing assembly matches the width of the cooling roller (2), the sealing assembly can form a closed space with the cooling roller (2) and the melt curtain extruded by the extrusion lip (7), and the internal pipeline of the sealing assembly is communicated with a vacuum pump. A plurality of first partitions (9) are arranged in the cooling roller (2) in the circumferential direction, the length of the first partitions (9) is consistent with the length of the cooling roller (2), and the first partitions (9) divide the cooling roller (2) into a plurality of first chambers. A water storage pipe (11) is arranged in the cooling roller (2), the cooling roller (2) and the water storage pipe (11) are arranged in opposite rotation, the end of the water storage pipe (11) is communicated with an external water source through a pipeline and a first water pump in sequence, the water storage pipe (11) is arranged along the length direction of the cooling roller (2), a plurality of nozzles (1103) are arranged on the water storage pipe (11) at intervals, the plurality of nozzles (1103) are arranged in a plurality of rows, and the plurality of nozzles (1103) arranged in the plurality of rows are arranged at intervals corresponding to the plurality of first chambers divided by the first partitions (9) respectively. The first chambers are further communicated with a second water pump through a pipeline.
2. A cast film production apparatus according to claim 1, characterized in that The sealing assembly comprises a first sealing plate (4), a second sealing plate (5) and two third sealing plates (6), the upper ends of the first sealing plate (4) and the second sealing plate (5) are connected with the lower part of the extruder (1) respectively, and the two third sealing plates (6) are arranged on the two sides of the first sealing plate (4) and the second sealing plate (5) respectively to form a box body, and an interface is arranged on the third sealing plate (6) on one side, and the interface is communicated with the vacuum pump through a pipeline.
3. A cast film production apparatus according to claim 2, characterized in that The first sealing plate (4) is located in the flowing direction of the melt curtain, the distance between the lower end of the first sealing plate (4) and the casting film (3) formed by the melt curtain on the cooling roller (2) is between 0 and 50 microns, that is, the distance between the lower end of the first sealing plate (4) and the cooling roller (2) is equal to the thickness of the casting film (3); the second sealing plate (5) is located on the side of the melt curtain away from the first sealing plate (4), the lower end of the second sealing plate (5) is closely attached to the cooling roller (2), and the two third sealing plates (6) are respectively in sealing contact with the side edges of the cooling roller (2) on the corresponding sides.
4. A cast film production apparatus according to claim 3, characterized in that The lower end of each third sealing plate (6) is provided with a T-shaped sliding block close to one end of the cooling roller (2), and T-shaped sliding grooves are arranged at the two side edges of the cooling roller (2) respectively, the T-shaped sliding grooves are annular, and the T-shaped sliding grooves are coaxially arranged with the cooling roller (2).
5. A cast film production apparatus according to claim 1, wherein, One end of the cooling roller (2) is provided with a water storage cavity (13), one side of the cooling roller (2) is provided with a plurality of openings (10), the water storage cavity (13) is communicated with the first cavity through a plurality of openings (10), the water storage cavity (13) is communicated with the second water pump through the pipeline, one side of each first cavity is provided with a plurality of openings (10), and the opening (10) of each first cavity is arranged at the edge of the end of the first cavity.
6. A cast film production apparatus according to claim 5, characterized in that The inside of the water storage pipe (11) is provided with a plurality of second partitions in the circumferential direction, the second partitions divide the water storage pipe (11) into a plurality of water storage cavities in the radial direction, the included angle between each water storage cavity corresponds to each first cavity, and each water storage cavity corresponds to a column of spray heads (1103).
7. A cast film production apparatus according to claim 6, characterized in that One side of the cooling roller (2) is provided with a rotating driving assembly, the part where the water storage pipe (11) contacts the two ends of the cooling roller (2) is provided with a first bearing (12), the cooling roller (2) is rotatably connected with the water storage pipe (11) through the first bearing (12), the distance between the first partition (9) close to one side of the water storage pipe (11) is greater than the height of the spray head (1103) protruding from the water storage pipe (11), the driving assembly comprises a supporting assembly, a driving support and a rotating motor (17), the rotating motor (17) is installed on the supporting assembly, the output end of the rotating motor (17) is fixed with the driving support, the driving support is fixed with the end of the water storage cavity (13), the supporting assembly comprises a first supporting rod (18) and a second supporting rod (19), the driving support comprises a first mounting ring (14), the rotating motor (17) is fixed with the first supporting rod (18), the first mounting ring (14) is fixed with the second supporting rod (19), a connecting block (15) is arranged at the center of the first mounting ring (14) through a plurality of first connecting rods (16), the output end of the rotating motor (17) is fixed with the center of the connecting block (15), and the rotating motor (17) and the connecting block (15) are coaxially arranged with the cooling roller (2); the first mounting ring (14) is fixed with the end of the water storage cavity (13) through a plurality of second connecting rods.
8. A cast film production apparatus according to claim 7, characterized in that One side of the cooling roller (2) away from the rotating motor (17) is provided with a third supporting rod (20), the third supporting rod (20) is provided with a second mounting ring (22), the second mounting ring (22) is coaxially arranged with the cooling roller (2), and the outer edge of the end of the cooling roller (2) is rotatably connected with the second mounting ring (22) through a second bearing. One end of the water storage pipe (11) close to the second mounting ring (22) is provided with a fourth supporting rod (21).
9. A method of producing a cast film, characterized by, The method comprises the following steps: Step 1: start the extruder (1) and the feeding system, the cooling roller (2) starts to rotate, adjust the rotating speed to match the preset production line speed, start the first water pump, pump the external cooling water into the water storage pipe (11), start the second water pump, start to pump water from the water storage cavity (13), and establish a cooling water circulation; Step 2: The cooling water temperature is initially set to the range required by the process; Step 3: After the melt curtain is running stably, the vacuum pump is started, and the vacuum degree in the sealed assembly is adjusted to the optimal value required by the process; Step 4: The air and heated volatilized substances between the melt curtain and the cooling roller (2) are rapidly extracted by the vacuum pump, filtered through the filter, and then discharged. The cooling water in the water storage pipe (11) is sprayed into the corresponding first chamber of the cooling roller (2) through the partition nozzles (1103), and the roller surface is cooled. The cooled water flows to the openings (10) at the edge of each first chamber under the action of gravity, collects in the water storage cavity (13), and is pumped away by the second water pump to complete the circulation.
10. A cast film production method according to claim 9, characterized in that, In Step 2, the cooling water temperature is initially set to the range required by the process: the cooling roller (2) surface temperature after the film runs to the middle and later stages of the cooling roller (2) is higher than the cooling roller (2) surface temperature when the film contacts the cooling roller (2).