A film cast sheet forming and cooling device and process method

Abstract

The application discloses a film casting sheet forming and cooling device and a process method, which comprises a die head, a quenching assembly, a cooling assembly and an adjusting assembly. The quenching assembly comprises a hollow quenching roller and a quenching water circulation system communicated with both ends of the quenching roller. The cooling assembly comprises a hollow cooling roller, a cooling water circulation system communicated with both ends of the cooling roller, and the cooling roller is coaxially arranged on the side of the outer periphery of the quenching roller to form a cooling module. The die head is arranged above the quenching roller and the cooling roller. The adjusting assembly is used for adjusting the spacing between the quenching roller and the cooling roller in the cooling module and adjusting the relative position of the cooling module and the die head in the transverse direction. Through the adjustment of the quenching water circulation system and the cooling water circulation system, the cooling effects of both sides of the casting sheet are consistent, the crystallinity of both sides of the film casting sheet is as close as possible, and the film edge lifting problem generated in the existing film casting sheet process can be better solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high polymer film production, in particular to a film casting sheet forming and cooling device and process. BACKGROUND

[0002] There are two main ways of film extrusion casting sheet process: water cooling and air cooling. The air cooling method is to extrude the sheet onto the chill roller, one surface is in contact with the air for natural cooling, and the other surface is attached to the chill roller for heat exchange cooling. This method is generally used to produce cast film. The water cooling method is to make the film sheet adhere to the surface of the chill roller through the film solidification air knife, and then make the sheet enter the water bath cooling. Both of these two casting methods have a defect in the process: when the sheet is cast from the die to the chill roller, it will immediately change from viscous flow to elastomer. In this process, due to the difference in cooling medium of the two surfaces of the sheet, the thermal conductivity of the medium is quite different (in the water cooling and air cooling methods, the thermal conductivities of the two surfaces of the sheet are air and metal, which differ by more than 100 times), which will cause the cooling rate of the two surfaces of the sheet to differ greatly, and the final result is that the crystallinity of the two surfaces of the film sheet differs greatly, and the final product is prone to edge curling. The film casting process of the present application is an improvement on the basis of the existing casting process, which can avoid the edge curling problem caused by the difference in crystallinity of the two surfaces of the film during film casting. SUMMARY

[0003] The present application aims to provide a film casting sheet forming and cooling device and process to solve one or more technical problems in the prior art, at least to provide a beneficial choice or create conditions.

[0004] To solve the above technical problems, the technical scheme adopted by the present application is:

[0005] Firstly, the present application provides a film casting sheet forming and cooling device, which comprises a die head, a chilling assembly, a cooling assembly and an adjusting assembly. The chilling assembly comprises a hollow chill roller and a chilling water circulation system communicating with both ends of the chill roller. The cooling assembly comprises a hollow cooling roller and a cooling water circulation system communicating with both ends of the cooling roller. The cooling roller is coaxially arranged on the side of the outer periphery of the chill roller to form a cooling module. The die head is arranged above the chill roller and the cooling roller. The adjusting assembly is used to adjust the distance between the chill roller and the cooling roller in the cooling module, and adjust the relative position of the cooling module and the die head in the transverse direction.

[0006] The film casting sheet forming and cooling device has the following beneficial effects: in use, the film coming out of the die head enters the quenching roller and the cooling roller to be solidified and cooled, the sheet is in contact with the quenching roller and the cooling roller when it is in a viscous flow state, the traditional film solidification air knife is abandoned and the cooling roller is used instead to play a role in solidifying the film, the cooling effect of the film sheet is improved, the quenching water circulation system is separately arranged on the quenching roller, the cooling water circulation system is separately arranged on the cooling roller, the cooling effect of the two sides of the casting sheet can be made consistent by adjusting the quenching water circulation system and the cooling water circulation system, the crystallinity of the two sides of the casting sheet is as close as possible, and the film edge lifting problem caused by the existing film casting sheet process can be better solved; in addition, the relative position of the cooling die set and the die head can be adjusted by adjusting the adjusting assembly, that is, the relative position of the casting sheet and the cooling die set can be adjusted to change the contact angle and the contact area, the cooling effect of the film can be controlled, and the relative position between the cooling roller and the quenching roller in the cooling die set can be adjusted to adapt to the production of casting sheets with different materials and thicknesses.

[0007] As a further improvement of the above technical solution, the number of cooling rollers is multiple, and the multiple cooling rollers are arranged in a ring shape and spaced apart from each other outside the periphery of the quenching roller.

[0008] The present scheme cools and solidifies the film casting sheet through multiple cooling rollers, and a channel for cooling and solidifying the film casting sheet is formed between the multiple cooling rollers and the quenching roller, so that the film casting sheet is cooled more uniformly, and the film edge lifting problem caused by the existing film casting sheet process is further solved.

[0009] As a further improvement of the above technical solution, each cooling roller is provided with an independent cooling water circulation system. According to actual needs, the cooling effect of each cooling water circulation system is controlled, and the cooling temperature of the cooling roller is adjusted to meet different casting sheet production.

[0010] As a further improvement of the above technical solution, the cooling roller and the quenching roller each include a hollow roller body and a circulation heat conduction pipe penetrating through both ends of the roller body, the circulation heat conduction pipe and the inner peripheral wall of the roller body form a heat conduction cavity, both ends of the heat conduction cavity are sealed, and the heat conduction cavity is filled with heat conduction liquid.

[0011] When the cooling liquid in the water circulation system passes through the circulation heat conduction pipe, heat exchange is performed between the pipe wall of the circulation heat conduction pipe and the heat conduction liquid in the heat conduction cavity, and heat exchange is performed between the heat conduction liquid and the wall of the roller body, so that the cooling temperature of the outer peripheral wall of the roller body is uniformly distributed, and the phenomenon of local uneven cooling of the casting sheet is avoided.

[0012] As a further improvement of the above technical solution, the circulation heat conduction pipe is in a spiral pipe shape or a straight pipe shape.

[0013] The spiral pipe-shaped circulating heat conduction pipe can make the cooling liquid stay in the circulating heat conduction pipe for a longer time, and the heat exchange time between the cooling liquid and the heat conduction liquid in the heat conduction cavity is longer, and the heat exchange effect is better, and the straight-through pipe-shaped circulating heat conduction pipe has smaller flow resistance to the cooling liquid, and the flow resistance of the water circulation system is reduced.

[0014] As a further improvement of the above technical solution, the quenching water circulation system and the cooling water circulation system each comprise a water storage tank, a circulating pump, a refrigerating machine and a heating machine connected with each other.

[0015] The circulating pump is arranged to drive the cooling water to flow between the roller body and the water storage tank, and the refrigerating machine and the heating machine are arranged to respectively cool and heat the cooling water, so that the water temperature can be flexibly controlled.

[0016] As a further improvement of the above technical solution, the cooling water tank filled with deionized water is further arranged, and a part of the plurality of cooling rollers is immersed in the cooling water tank.

[0017] In use, the deionized water is filled in the cooling water tank, and the film cast piece is formed after being immersed in the deionized water, thereby achieving the cleaning effect.

[0018] As a further improvement of the above technical solution, the machine frame is further arranged, the adjusting assembly comprises a sliding frame slidingly installed on the machine frame, a total adjusting member driving the sliding frame to move transversely, a cooling adjusting member and a quenching adjusting member installed on the sliding frame, the quenching roller and the cooling roller are slidingly installed on the sliding frame, the cooling adjusting member is in transmission connection with the cooling roller, and the quenching adjusting member is in transmission connection with the quenching roller.

[0019] The total adjusting member is arranged to drive the sliding frame to move transversely relative to the machine frame, and the relative position between the cooling module installed on the sliding frame and the die head is adjusted, so that the relative position between the cast piece and the cooling module is adjusted and the contact angle is changed without changing the position of the die head; and the cooling adjusting member is arranged to drive the cooling roller to move transversely, and the quenching adjusting member is arranged to drive the quenching roller to move transversely, so as to adapt to the production of cast pieces with different materials and thicknesses.

[0020] As a further improvement of the above technical solution, the quenching roller and the cooling roller are both metal members. The heat conduction effect of the metal member is better, the cooling medium of the two surfaces is metal in the process of changing the film piece into an elastomer, the cooling rate is similar, the crystallinity of the finished product is similar, and the problem of film edge curling in the existing film cast piece process can be better solved.

[0021] In addition, the present application also provides a film cast piece forming and cooling process method, which adopts the film cast piece forming and cooling device, and the specific method is as follows:

[0022] First, according to the material and thickness of the pre-made film cast sheet, the relative positions of the chill roller, the cooling roller and the die head are adjusted by adjusting the assembly;

[0023] Then, the chill water circulation system and the cooling water circulation system are run;

[0024] After the film is cast through the die head, the circulating water flow rate and temperature are adjusted, and the fluid is cooled and formed between the chill roller and the cooling roller.

[0025] By controlling the circulating water flow rate and temperature in the chill roller and the cooling roller, the heat exchange rate of the two surfaces of the film sheet when contacting the two rollers is indirectly controlled, and the crystallinity of the two surfaces of the film sheet is indirectly controlled. BRIEF DESCRIPTION OF DRAWINGS

[0026] The present application will be further described below in conjunction with the drawings and examples.

[0027] Fig. 1 is a film cast sheet forming and cooling device provided by the present application, and a film cast sheet forming schematic diagram of an embodiment thereof;

[0028] Fig. 2 is a water circulation system provided by the present application, and a schematic diagram of an embodiment thereof;

[0029] Fig. 3 is a circulating heat conduction pipe in the chill roller or the cooling roller provided by the present application, and a cross-sectional view of an embodiment thereof, wherein the circulating heat conduction pipe is a straight pipe;

[0030] Fig. 4 is a circulating heat conduction pipe in the chill roller or the cooling roller provided by the present application, and a cross-sectional view of an embodiment thereof, wherein the circulating heat conduction pipe is a spiral pipe. DETAILED DESCRIPTION

[0031] This part will describe the specific embodiments of the present application in detail, and the preferred embodiments of the present application are shown in the drawings. The drawings serve to supplement the description in the text part of the specification, so that people can intuitively and visually understand each technical feature and the overall technical scheme of the present application. However, it cannot be understood as a limitation on the protection scope of the present application.

[0032] In the description of the present application, it should be understood that the orientation description, such as the orientation or position relationship indicated by up, down, front, back, left, right, etc., is based on the orientation or position relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0033] In the description of the present application, if the word such as "several" is described, its meaning is one or more, the meaning of more than two is more than two, greater than, less than, more than, etc. Understand as not including the number, above, below, within, etc. Understand as including the number.

[0034] In the description of the present application, unless otherwise explicitly limited, the words such as setting, installation, connection, etc. Should be understood broadly, and those skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical scheme.

[0035] Reference Figs. 1 to 4 The film casting sheet forming and cooling device of the present application is as follows:

[0036] The film casting sheet forming and cooling device of the present application includes a rack 700, a die head 100, a chilling assembly, a cooling assembly and an adjusting assembly.

[0037] The die head 100 is fixedly installed on the rack 700, and the die head 100 is arranged downwardly, and the chilling assembly includes a chilling roller 200 and a chilling water circulating system, wherein the axis of the chilling roller 200 is arranged in front and back, the chilling roller 200 is a hollow structure, and the chilling water circulating system is communicated with both ends of the chilling roller 200.

[0038] The chilling water circulating system of the present embodiment includes a water storage tank 500 and a circulating pump 510, and a refrigerator 520 and a heating machine 530 connected between the water storage tank 500 and the circulating pump 510, and the water storage tank 500, the refrigerator 520, the heating machine 530 and the circulating pump 510 are sequentially connected by a pipeline closed loop with the chilling roller 200, wherein the water storage tank 500 and the pipeline are wrapped with heat insulation cotton for heat insulation.

[0039] And the cooling assembly includes a cooling roller 300 and a cooling water circulating system, wherein the axis of the cooling roller 300 is arranged in front and back, the cooling roller 300 is a hollow structure, and the cooling water circulating system is communicated with both ends of the cooling roller 300.

[0040] The cooling water circulating system of the present embodiment also includes a water storage tank 500 and a circulating pump 510, and a refrigerator 520 and a heating machine 530 connected between the water storage tank 500 and the circulating pump 510, and the water storage tank 500, the refrigerator 520, the heating machine 530 and the circulating pump 510 are sequentially connected by a pipeline closed loop with the cooling roller 300, and the cooling roller 300 is arranged at the side of the outer periphery of the chilling roller 200 to form a cooling module, and at this time the die head 100 is located above the chilling roller 200 and the cooling roller 300.

[0041] The diameter of the cooling roller 300 of the embodiment is smaller than that of the chilling roller 200. For example, in the case of producing bidirectional-stretching polypropylene film and polypropylene casting film, the diameter of the chilling roller 200 is 2500mm-3500mm, the wall thickness is ≥100mm, the surface is plated with chromium and mirror polished to 50±25nm according to the measurement method of GB / T 2523-2008, the diameter of the cooling roller 300 is preferably 600mm-700mm, the wall thickness is 20mm-35mm, and the surface is plated with chromium and mirror polished to 50±25nm according to the measurement method of GB / T 2523-2008.

[0042] The chilling roller 200 and the cooling roller 300 of the embodiment have the same structure, both of which include a roller body 400 and a circulating heat conduction pipe 410. The roller body 400 is a hollow structure, the circulating heat conduction pipe 410 penetrates through both ends of the roller body 400, and a heat conduction cavity 420 is formed between the outer peripheral wall of the circulating heat conduction pipe 410 and the inner peripheral wall of the roller body 400. Both ends of the heat conduction cavity 420 are in a sealed arrangement. The circulating heat conduction pipe 410 is an SU304 stainless steel pipe, the roller body 400 is a metal member, and the roller body 400 and the circulating heat conduction pipe 410 have good heat conduction performance.

[0043] The circulating heat conduction pipe 410 can have a spiral pipe structure. The spiral pipe structure of the circulating heat conduction pipe 410 can make the cooling liquid stay in the circulating heat conduction pipe 410 for a longer time, so that the cooling liquid and the heat conduction liquid in the heat conduction cavity 420 have a longer heat exchange time and a better heat exchange effect.

[0044] In other embodiments, the circulating heat conduction pipe 410 can have a straight pipe structure. The straight pipe structure of the circulating heat conduction pipe 410 has smaller flow resistance to the cooling liquid, thereby reducing the flow resistance of the water circulation system.

[0045] The water circulation system is connected to both ends of the circulating heat conduction pipe 410.

[0046] The heat conduction cavity 420 is filled with heat conduction liquid. The heat conduction liquid of the embodiment is low-viscosity (≤250 centipoise) heat conduction oil.

[0047] When the cooling liquid in the water circulation system passes through the circulating heat conduction pipe 410, the cooling liquid exchanges heat with the heat conduction liquid in the heat conduction cavity 420 through the pipe wall of the circulating heat conduction pipe 410, and the heat conduction liquid exchanges heat with the wall of the roller body 400. In this way, the cooling temperature of the outer peripheral wall of the roller body 400 is uniformly distributed, and the phenomenon of local uneven cooling of the cast piece is avoided.

[0048] The circulating pump 510 is used to drive the cooling water to flow between the circulating heat conduction pipe 410 and the water storage tank 500. The refrigerating machine 520 and the heating machine 530 are arranged to respectively cool and heat the cooling water, so that the water temperature can be flexibly controlled.

[0049] The water temperature in the cooling roller 300 is generally controlled in the range of 2-60°C, and the pure water medium temperature of the quenching roller 200 is generally set between 25-65°C.

[0050] Further, the cooling roller 300 of the embodiment is two, and the two cooling rollers 300 are sequentially and spacedly arranged on the outer periphery of the quenching roller 200. Each cooling roller 300 is provided with a separate cooling water circulation system. Thus, according to the actual needs, the cooling effect of each cooling water circulation system is controlled, and the cooling temperature of the cooling roller 300 is adjusted to meet different casting sheet production.

[0051] Meanwhile, the quenching roller 200 and the cooling roller 300 are not metal components. The heat conduction effect of the metal component is better. In the process of transforming the contact film sheet into an elastomer, the cooling medium of the two surfaces is metal, the cooling rate is similar, the crystallinity of the finished product is similar, and the film edge lifting problem generated in the existing film casting sheet process can be better solved.

[0052] In other embodiments, the number of cooling rollers 300 can be more, and a plurality of cooling rollers 300 are annularly and spacedly arranged on the outer periphery of the quenching roller 200. The film casting sheet is cooled and solidified by the plurality of cooling rollers 300, and a passage for the film casting sheet to pass through the cooling and solidification is formed between the plurality of cooling rollers 300 and the quenching roller 200, so that the film casting sheet is cooled more uniformly, and the film edge lifting problem generated in the existing film casting sheet process is further solved.

[0053] In addition, the embodiment also has a cooling water tank 600, which is filled with deionized water when in use. The cooling roller 300 downstream of the embodiment is immersed in the deionized water in the cooling water tank 600, and the lower part of the quenching roller 200 is also immersed in the deionized water. When in use, the cooling water tank 600 is filled with deionized water, and the film casting sheet is formed after being immersed in the deionized water, thereby achieving the cleaning effect.

[0054] The low-temperature water in the cooling roller 300 exchanges heat with the downstream cooling roller 300 immersed in the cooling water tank 600 to maintain the constant water temperature in the cooling water tank 600.

[0055] In use, the film coming out of the die head 100 enters between the quenching roller 200 and the cooling roller 300 for solidification and cooling. The sheet is in a viscous flow state when it contacts the quenching roller 200 and the cooling roller 300. The traditional film solidification air knife is abandoned, and the cooling roller 300 is used instead to play a role in film solidification. Meanwhile, the cooling effect of the film sheet is improved. The quenching roller 200 is separately provided with a quenching water circulation system, and the cooling roller 300 is separately provided with a cooling water circulation system. The quenching water circulation system and the cooling water circulation system can be adjusted to make the cooling effects of the two sides of the casting sheet consistent, so that the crystallinity of the two sides of the film casting sheet is as similar as possible, and the film edge lifting problem generated in the existing film casting sheet process can be better solved.

[0056] The function of the adjusting assembly is to adjust the distance between the cooling roller 300 and the chilling roller 200 in the cooling module, and to adjust the relative position of the cooling module and the die head 100. The adjusting direction of the adjusting assembly is mainly in the transverse direction.

[0057] That is, the relative position of the cast sheet and the cooling module can be adjusted to change the contact angle and the contact area, to control the cooling effect of the film, and to adjust the relative position of the cooling roller 300 and the chilling roller 200 in the cooling module to adapt to the production of cast sheets of different materials and thicknesses.

[0058] Specifically, the adjusting assembly includes a sliding frame 800, a general adjusting member 710, a cooling adjusting member 810, and a chilling adjusting member 820. The sliding frame 800 is transversely slidably mounted on the rack 700. The general adjusting member 710 is fixed to the rack 700 and is in transmission connection with the sliding frame 800. The chilling roller 200 and the cooling roller 300 are both transversely slidably mounted on the sliding frame 800. The cooling adjusting member 810 is in transmission connection with the cooling roller 300, and the chilling adjusting member 820 is in transmission connection with the chilling roller 200.

[0059] In the embodiment, the general adjusting member 710 drives the sliding frame 800 to move transversely relative to the rack 700 to adjust the relative position of the cooling module mounted on the sliding frame 800 and the die head 100. The relative position of the cast sheet and the cooling module is adjusted to change the contact angle when the position of the die head 100 is unchanged. The cooling adjusting member 810 drives the cooling roller 300 to move transversely, and the chilling adjusting member 820 drives the chilling roller 200 to move transversely to adapt to the production of cast sheets of different materials and thicknesses.

[0060] The general adjusting member 710, the cooling adjusting member 810, and the chilling adjusting member 820 all adopt a hydraulic screw driving structure with a self-locking function.

[0061] The embodiment also provides a film cast sheet forming and cooling process method. The specific method is as follows:

[0062] First, according to the material and thickness of the cast sheet to be prepared, the general adjusting member 710 drives the sliding frame 800 to move to a set position and is locked, that is, the cooling module is adjusted to a specified position. Then, the relative position of the chilling roller 200 and the cooling roller 300 is adjusted by the chilling adjusting member 820 and the cooling adjusting member 810, the contact angle and the contact area of the cast sheet and the chilling roller 200 and the cooling roller 300 are adjusted, and the cooling effect of the film is controlled.

[0063] Then, the circulating pump 510 is started to adjust the temperature and flow rate of the cooling water in each water circulation system through the refrigerating machine 520 and the heating machine 530, so as to control the cooling temperature of the outer peripheral wall of the chill roll 200 and the cooling roll 300;

[0064] After that, the film is cast from the die of the die head 100, and flows between the chill roll 200 and the cooling roll 300, and is cooled and solidified between the chill roll 200 and the cooling roll 300.

[0065] The above describes the preferred embodiments of the present application, but the present application is not limited to the above-mentioned embodiments. Those skilled in the art can make various equivalent modifications or replacements without departing from the spirit of the present application, and these equivalent modifications or replacements are all included in the scope defined by the claims of the present application.

Claims

1. A thin-film casting cooling device, characterized in that: It includes: Mold head (100); The quenching assembly includes a hollow quenching roller (200) and a quenching water circulation system connected to both ends of the quenching roller (200); The cooling assembly includes a hollow cooling roller (300) and a cooling water circulation system connected to both ends of the cooling roller (300). The cooling roller (300) is coaxially arranged on the side of the outer periphery of the quenching roller (200) to form a cooling module. The die head (100) is arranged above the quenching roller (200) and the cooling roller (300). The adjustment component is used to adjust the distance between the chilling roller (200) and the cooling roller (300) in the module, and to adjust the relative position of the cooling module and the die head (100) in the lateral direction, thereby changing the contact angle and contact area. The cooling rollers (300) are multiple in number, and the multiple cooling rollers (300) are arranged in annular intervals on the outer periphery of the quenching roller (200); Each of the cooling rollers (300) is equipped with an independent cooling water circulation system; Both the cooling roller (300) and the chilling roller (200) include a hollow roller body (400) and a circulating heat conduction pipe (410) that runs through both ends of the roller body (400). The circulating heat conduction pipe (410) and the inner peripheral wall of the roller body (400) form a heat conduction cavity (420). The two ends of the heat conduction cavity (420) are sealed and filled with heat conduction liquid. It also includes a frame (700), the adjustment assembly includes a sliding frame (800) slidably mounted on the frame (700), a general adjustment component (710) for driving the sliding frame (800) to move laterally, a cooling adjustment component (810) and a quenching adjustment component (820) mounted on the sliding frame (800), the quenching roller (200) and the cooling roller (300) are slidably mounted on the sliding frame (800), the cooling adjustment component (810) is drivenly connected to the cooling roller (300), and the quenching adjustment component (820) is drivenly connected to the quenching roller (200); The sliding frame (800) is moved laterally relative to the frame (700) by the main adjustment component (710), and the relative position of the cooling module and the die head (100) installed on the sliding frame (800) is adjusted. The contact angle is changed by adjusting the relative position of the casting and the cooling module while the position of the die head (100) remains unchanged.

2. The thin film casting cooling device according to claim 1, characterized in that: The circulating heat pipe (410) is either a spiral tube or a straight tube.

3. The thin film casting cooling device according to claim 1, characterized in that: Both the chilled water circulation system and the cooling water circulation system include interconnected water storage tanks (500), circulation pumps (510), chillers (520), and heaters (530).

4. The thin film casting cooling device according to claim 1, characterized in that: It also includes a cooling water tank (600) filled with deionized water, and a portion of the multiple cooling rollers (300) are immersed in the cooling water tank (600).

5. The thin film casting cooling device according to claim 1, characterized in that: Both the quenching roller (200) and the cooling roller (300) are metal components.

6. A method for cooling thin-film casting, characterized in that: It employs the thin-film casting cooling device as described in any one of claims 1 to 5, and the specific method is as follows: First, based on the material and thickness of the pre-cast thin film, the relative positions of the chilling roller (200), cooling roller (300), and die head (100) are adjusted by adjusting the components; Then, the quench water circulation system and the cooling water circulation system are operated; After the film is cast through the die head (100), the flow rate and temperature of the circulating water are adjusted, and the fluid is cooled and formed between the chill roller (200) and the cooling roller (300).

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