A multi-temperature zone casting machine

Abstract

The application discloses a multi-temperature-zone casting machine, a plurality of temperature zones are formed in an upper drying channel, a passive drum chamber and a lower drying channel, and the temperature zones at least include a first temperature zone, a curved channel temperature zone and a lower drying channel temperature zone; the first temperature zone is arranged at least in the upper drying channel and is close to an inlet of the upper drying channel; a parallel air circulation treatment device is arranged in the first temperature zone, the parallel air circulation treatment device includes oppositely arranged parallel air duct air inlet parts and parallel air duct air outlet parts, and the parallel air duct air inlet parts and the parallel air duct air outlet parts are arranged at least above a steel belt; the curved channel temperature zone is arranged at least in the passive drum chamber; a curved channel section temperature control device is arranged in the curved channel temperature zone or outside the passive drum chamber; and the lower drying channel temperature zone is arranged at least in the lower drying channel. According to the scheme, the film material process time, the temperature in the hardened state and the drying mode and the like can be respectively controlled more accurately, the temperature change is continuous and sudden change is avoided, the film quality is effectively improved, and the solvent evaporation efficiency is ensured.

Description

Technical Field

[0001] This invention belongs to the field of thin film manufacturing equipment technology, and specifically relates to a multi-temperature zone casting machine. Background Technology

[0002] Casting machines, also known as steel strip casting machines, are one of the key pieces of equipment in the cast film production process. Existing casting machines, such as the Chinese invention patent with publication number CN109968575A, have limited temperature zone divisions, resulting in a lack of accurate, staged temperature control during the various stages of surface hardening of the cast film. In particular, the tail mechanism (passive drum chamber) of such existing casting machines is located between the upper and lower drying tunnels. The passive drum chamber lacks a heating mechanism and relies solely on the insulation structure of the chamber. This causes the film temperature to drop after passing through the passive drum chamber, hindering its entry into the lower drying tunnel for higher-temperature drying. Furthermore, the sudden temperature change upon entering the lower drying tunnel affects the film's processing quality, especially for high-end films such as polyimide films. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a multi-temperature zone casting machine, which solves the problem of insufficient temperature control in existing equipment, and enables more continuous temperature transition, thereby helping to achieve better casting film curing effect.

[0004] According to the technical solution of the present invention, the present invention provides a multi-temperature zone casting machine, which includes an active drum, a passive drum, and a steel belt drivenly connected to the active drum and the passive drum. It also includes an upper drying tunnel, a passive drum chamber, and a lower drying tunnel sequentially connected along the steel belt conveying direction. Multiple temperature zones are formed in the upper drying tunnel, the passive drum chamber, and the lower drying tunnel, and each temperature zone includes at least a first temperature zone, a bend temperature zone, and a lower drying tunnel temperature zone. Each temperature zone is an adjustable temperature zone. The upper drying tunnel has at least one first temperature zone. The first temperature zone is located near the entrance of the upper drying tunnel. A parallel air circulation treatment device is installed in the first temperature zone. The parallel air circulation treatment device includes a parallel air duct inlet and a parallel air duct outlet arranged opposite each other. The parallel air duct inlet and outlet are located above and below the steel belt, or only above the steel belt. There is at least one curved temperature zone in the passive drum chamber. A curved section temperature control device is installed in the curved temperature zone or on the outside of the passive drum chamber. There is at least one lower drying tunnel temperature zone in the lower drying tunnel.

[0005] Furthermore, negative pressure air curtain devices are installed at the adjacent locations of the two temperature zones and at the entrances and exits of the upper and lower drying tunnels. The negative pressure air curtain device includes a first exhaust section and a second exhaust section arranged opposite to each other. The first exhaust section and the second exhaust section are located on both sides of the steel belt, and a channel space for the steel belt to pass through is formed between the first exhaust section and the second exhaust section. The channel space is adapted to the width of the steel belt.

[0006] Furthermore, both the first and second exhaust sections are provided with air curtain equalization plates and / or air regulating plates; the air curtain equalization plates are arranged parallel or inclined along the film conveying direction, and have a number of air holes or a number of slit holes; the air curtain equalization plates are single-layer structures, or the air curtain equalization plates are multi-layered and the air holes or slit holes in each layer are arranged oppositely or staggered.

[0007] Furthermore, the entrance and / or exit of the passage space are equipped with an adjustable windbreak mechanism to adapt the entrance and / or exit of the passage space to the thickness of the steel strip carrying the membrane.

[0008] Furthermore, parallel air duct flow equalization plates and / or air regulating plates are provided at both the air inlet and air outlet of the parallel air duct.

[0009] Furthermore, the air outlet of the parallel air duct is located near the entrance of the upper drying duct, and the air inlet of the parallel air duct is located on the opposite side of the air outlet of the parallel air duct.

[0010] Furthermore, the upper drying tunnel also has at least one upper drying tunnel temperature zone, which is located between the first temperature zone and the passive rotating drum chamber; the upper drying tunnel temperature zone is provided with an upper drying tunnel longitudinal air circulation treatment device above the steel belt, and the nozzle of the upper drying tunnel longitudinal air circulation treatment device is facing or tilted toward the steel belt or the direction of the nozzle is adjustable.

[0011] Furthermore, a longitudinal air circulation treatment device for the lower drying tunnel is provided at least below the steel belt in the lower drying tunnel temperature zone, and the nozzles of the longitudinal air circulation treatment device for the lower drying tunnel are facing the steel belt directly or at an angle, or the direction of the nozzles is adjustable.

[0012] Furthermore, in the lower drying tunnel, a longitudinal air circulation treatment device is also provided above the steel belt, and the longitudinal air circulation treatment device is corresponding to the upper and lower sides of the steel belt; and / or, in the first temperature zone, a parallel air duct inlet and a parallel air duct outlet are also provided below the steel belt, and the parallel air circulation treatment device is corresponding to the upper and lower sides of the steel belt.

[0013] Furthermore, an active drum chamber is located on the outside of the active drum, which is connected to the upper and lower drying tunnels. A temperature control device for the feed section is installed in the active drum chamber.

[0014] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0015] The multi-temperature zone casting machine of this invention is divided into multiple adjustable temperature zones within the oven, enabling more precise control of the various process times, temperatures during the hardening state, and drying methods of the film material. Specifically, it employs a parallel airflow method to blow preheating air into the first temperature zone when the film slurry first enters the drying tunnel. This allows the surface of the film slurry to begin hardening while ensuring airflow, preventing hot air from directly blowing onto the film surface and affecting film quality. Furthermore, a curved temperature zone is provided at the passive drum to continue heating the film or more effectively maintain its temperature, avoiding the natural temperature drop that occurs with existing equipment. Consequently, as the film continues into the next drying tunnel, the temperature change is essentially continuous without significant abrupt fluctuations. After passing through the first temperature zone, the film surface is hard enough to withstand the hot air, allowing subsequent hot air to be blown generally directly onto the film surface for more direct and efficient heat transfer and accelerated solvent evaporation. Furthermore, this solution preferably incorporates a negative pressure air curtain device, where two opposing exhaust units simultaneously draw air, forming a negative pressure air curtain within the channel space between the two exhaust units. The membrane can then be transported between the two spaces through this channel space. Because of the negative pressure air curtain between these two spaces, issues such as temperature and gas interaction (e.g., escape / cross-contamination of gases with different temperatures and compositions) are avoided, effectively ensuring the accuracy and stability of process environment control for high-end processes. Simultaneously, since the airflow from adjacent temperature zones is drawn towards the center, a certain temperature transition zone is formed between adjacent temperature zones, further preventing sudden changes in ambient temperature when the membrane enters or exits the temperature zone. Attached Figure Description

[0016] Figure 1 This is a cross-sectional structural schematic diagram of a casting machine according to an embodiment of the present invention.

[0017] Figure 2 yes Figure 1 The diagram shows a top view of the casting machine.

[0018] Figure 3 This is a cross-sectional structural schematic diagram of a casting machine according to another embodiment of the present invention.

[0019] Figure 4 This is a cross-sectional structural schematic diagram of a casting machine according to another embodiment of the present invention.

[0020] Figure 5 This is a three-dimensional structural diagram of a negative pressure air curtain device according to an embodiment of the present invention.

[0021] Figure 6 yes Figure 5 The diagram shows a rear view of the negative pressure air curtain device.

[0022] Figure 7 yes Figure 5 The diagram shows a left-side view of the negative pressure air curtain device.

[0023] Figure 8 This is a schematic diagram of a negative pressure air curtain device according to another embodiment of the present invention.

[0024] Explanation of reference numerals in the attached figures:

[0025] 1. Upper drying tunnel; 2. Lower drying tunnel; 3. Parallel air circulation treatment device; 32. Parallel air duct air inlet; 31. Parallel air duct air outlet; 41. Upper drying tunnel longitudinal air circulation treatment device; 42. Lower drying tunnel longitudinal air circulation treatment device; 5. Negative pressure air curtain device; 51. First exhaust section; 52. Second exhaust section; 53. Air curtain flow equalization plate; 54. Channel space; 55. Channel side plate; 56. Slit baffle; 57. First airtight air... 58. Second airtight air box; 59. First exhaust duct; 510. Second exhaust duct; 511. Wind speed acquisition device; 512. Wind speed adjustment mechanism; 61. Oven exhaust port; 62. Oven inlet; 63. Explosion vent; 71. Active rotating drum; 72. Passive rotating drum; 81. Active rotating drum chamber; 82. Passive rotating drum chamber; 91. First temperature zone; 92. Upper drying tunnel temperature zone; 93. Curved tunnel temperature zone; 94. Lower drying tunnel temperature zone. Detailed Implementation

[0026] This invention provides a multi-temperature zone casting machine to solve the problem of insufficient temperature control in existing equipment. This solution can more accurately control the process time of each process of the film material, the temperature in the hardening state, and the drying method, and make the temperature change continuous to avoid abrupt changes, thereby helping to achieve a better casting film hardening effect, effectively improving film quality, and ensuring solvent evaporation efficiency.

[0027] Please see Figure 1 An embodiment of the present invention provides a multi-temperature zone casting machine, comprising a transversely distributed active drum 71 and a passive drum 72, and a steel belt drively connected to the active drum 71 and the passive drum 72. The active drum 71, the passive drum 72, and the steel belt are located within an insulated oven of the casting machine. The oven includes an upper drying tunnel 1, a passive drum chamber 82, and a lower drying tunnel 2 sequentially connected along the steel belt conveying direction. The upper drying tunnel 1 and the lower drying tunnel 2 correspond to the upper and lower straight sections of the steel belt, respectively. The passive drum 72 is housed within the passive drum chamber 82. The oven is a sealed and insulated chamber with an inspection door and ventilation system inlets and outlets. One of the main improvements of the present invention is that multiple temperature zones are formed in the upper drying tunnel 1, the passive drum chamber 82, and the lower drying tunnel 2, each temperature zone including at least a first temperature zone 91, a curved temperature zone 93, and a lower drying tunnel temperature zone 94. Each temperature zone is an adjustable temperature zone.

[0028] The first temperature zone 91 is a preheating and pre-evaporation temperature zone with parallel air ducts. There is at least one first temperature zone 91 in the upper drying tunnel 1, and the first temperature zone 91 is close to the entrance of the upper drying tunnel 1. Figure 1 (The right end of the upper drying tunnel 1). A parallel air circulation treatment device 3 is provided in the first temperature zone 91. The parallel air circulation treatment device 3 includes a parallel air duct inlet 32 ​​and a parallel air duct outlet 31 arranged opposite to each other. The parallel air duct inlet 32 ​​and the parallel air duct outlet 31 are arranged above and below the steel belt, or only arranged above the steel belt (the cast film slurry is also located above the steel belt in this area). The parallel air circulation treatment device 3 blows preheating air in a direction generally parallel to the steel belt, forming an airflow in this direction.

[0029] The curved temperature zone 93 serves as a transitional temperature zone between the upper drying tunnel 1 and the lower drying tunnel 2. At least one curved temperature zone 93 is present within the passive drum chamber 82; for example, the internal space of the passive drum chamber 82 may constitute a curved temperature zone 93, or the internal space of the passive drum chamber 82 may be further divided, for example, into upper and lower temperature zones that can be set to the same or different temperatures. A curved section temperature control device, such as a far-infrared heating device or a ceramic heating device, is provided in the curved temperature zone 93 or on the outside of the passive drum chamber 82 to control the temperature within the curved temperature zone 93. According to some embodiments, the curved section temperature control device may be, for example, a heating device such as a heating plate located on the outside of the passive drum chamber 82, and / or heating may be achieved by delivering hot air, for example, by using pipelines or longitudinal air circulation devices to blow hot air into the curved temperature zone 93 or toward the steel belt.

[0030] The lower drying tunnel temperature zone 94 is a temperature zone for further heating. There is at least one lower drying tunnel temperature zone 94 in the lower drying tunnel 2. At this time, the film surface has been initially hardened, so existing or feasible air supply methods can be used for heating. For example, in a specific embodiment, a hot air blowing method that is basically facing the film surface is used.

[0031] Taking polyimide film as an example, a mixer is used to uniformly mix the main material, polyamic acid resin, and the auxiliary material, imidizing agent. Then, the mixed slurry is output from the mold at the discharge end of the mixer onto the steel belt at the active drum 71 of the casting machine. The slurry moves, heats, evaporates the solvent, and gradually begins to solidify into a film as the steel belt rotates. Finally, after nearly one revolution, it is peeled off from the steel belt at the active drum 71 by a peeling roller; this process continues. Specifically, using… Figure 1For example, the film slurry first drips onto the upper right position of the annular steel belt. Then, as the steel belt moves counterclockwise, it first enters the first temperature zone 91 of the parallel air circulation treatment device 3. This zone is used for preheating and pre-evaporation, and to give the film surface a certain hardness. The parallel air duct method is used to ensure airflow in this zone, so that the surface of the film slurry (wet film) begins to harden, while avoiding hot air blowing directly onto the film surface. After passing through the first temperature zone 91, the film surface hardness is sufficient to withstand conventional hot air. Subsequently, hot air can be blown roughly directly onto the film surface to transfer heat more directly and efficiently and accelerate solvent evaporation. On the other hand, after passing through the upper drying tunnel 1, the film enters the passive rotating drum chamber 82, i.e., the curved temperature zone 93, to continue heating or heat preservation of the film. This avoids the situation where the film temperature naturally decreases in this area when using existing equipment. As a result, when the film continues to enter the lower drying tunnel 2, the temperature change is basically continuous without large abrupt fluctuations.

[0032] More specifically, in the first temperature zone 91, the parallel air circulation treatment device preferably adopts a structure similar to a static pressure box. The parallel air duct inlet 32 ​​and the parallel air duct outlet 31 are both located on the corresponding static pressure box. Parallel air duct flow equalization plates and / or air regulating plates are provided at both the parallel air duct inlet 32 ​​and the parallel air duct outlet 31 to ensure the uniformity of the parallel airflow and preheating effect. Furthermore, it is optional to allow adjustment of wind speed or direction. The parallel air duct flow equalization plate is, for example, a porous flat plate, and the air regulating plate is, for example, a grid. The parallel air duct flow equalization plate is provided with several air holes or several slits. The parallel air duct flow equalization plate can be configured as multiple layers, with the air holes or slits in each layer arranged opposite to or staggered. In some embodiments, the air vents are, for example, small holes arranged closely on the flow equalization plate; in other embodiments, the air vents are arranged strip-shaped holes, or the flow equalization plate is grid-shaped or mesh-shaped; or it is a combination of multiple hole types; the slit hole is a long and narrow slit-shaped hole, for example, one or more slit holes, and the length direction of the slit hole is, for example, parallel to the width direction of the film or inclined at a certain angle.

[0033] In a preferred embodiment, in the parallel air circulation processing device, the parallel air duct outlet 31 is relatively close to the inlet of the upper drying tunnel 1, and the parallel air duct inlet 32 ​​is located on the opposite side of the parallel air duct outlet 31, relatively far from the inlet of the upper drying tunnel 1. The direction of the parallel air is towards the inlet of the upper drying tunnel 1, opposite to the direction of movement of the film slurry, ensuring the airflow velocity above the film slurry in a relatively gentle and stable manner, which helps the film surface to harden.

[0034] For ease of description, a pair of parallel air duct inlets 32 and parallel air duct outlets 31 arranged opposite each other are considered as a set of parallel air circulation treatment devices. Here, "matching" means that a pair of inlets and outlets are directly opposite each other, and the air path between them is directly connected; in other words, they are the closest pair of inlets and outlets facing opposite directions. In such cases... Figure 3 In the illustrated embodiment, only one set of parallel air circulation processing devices is provided in the upper drying tunnel 1, allowing the parallel air to cover the entire length of the upper drying tunnel 1. In such a case... Figure 4 In the embodiment shown, two or more sets of parallel air circulation processing devices are arranged sequentially along the length direction in the upper drying tunnel 1, and two or more first temperature zones 91 are divided.

[0035] In such Figure 1 In the illustrated embodiment, the upper drying tunnel 1 also includes at least one upper drying tunnel temperature zone 92, which is located between the first temperature zone 91 and the passive rotating drum chamber 82. The film passes through the first temperature zone 91 and enters the upper drying tunnel temperature zone 92, and then enters the curved tunnel temperature zone 93. It is understood that the temperature zones in this scheme are adjacent and continuously connected. For example, in a scheme without an upper drying tunnel temperature zone 92, the first temperature zone 91 and the curved tunnel temperature zone 93 are directly adjacent; while in a scheme with an upper drying tunnel temperature zone 92, the first temperature zone 91, the upper drying tunnel temperature zone 92, and the curved tunnel temperature zone 93 are sequentially adjacent. Figure 1 The illustration shows a typical embodiment with a total of seven temperature zones. At least above the steel belt, in the upper drying tunnel temperature zone 92, there is an upper drying tunnel longitudinal air circulation treatment device 41, specifically, for example, a nozzle-type static pressure box. The nozzles of the upper drying tunnel longitudinal air circulation treatment device 41 are either directly facing or tilted towards the steel belt, or the nozzle orientation is adjustable. The tilting refers to the option, as needed, to employ a blowing method that is not completely directly facing the film surface, but rather has a certain tilt angle, making the hot air blowing and impact on the film surface relatively gentler.

[0036] In the lower drying tunnel temperature zone 94, at least below the steel belt, there is a lower drying tunnel longitudinal air circulation treatment device 42, specifically, for example, a nozzle-type static pressure box, and the nozzle of the lower drying tunnel longitudinal air circulation treatment device 42 is facing the steel belt directly or tilted, or the direction of the nozzle is adjustable; wherein, tilting means that, as needed, at least in some areas, the blowing method is not completely facing the film surface, but has a certain tilt angle, so that the blowing of hot air and the impact on the film surface are relatively gentler.

[0037] Preferably, in the lower drying tunnel 2, a lower drying tunnel longitudinal air circulation treatment device 42 is also provided above the steel strip, and the lower drying tunnel longitudinal air circulation treatment device 42 is corresponding to the upper and lower sides of the steel strip; the nozzle-type longitudinal air circulation treatment devices on the inner and outer sides of the steel strip are arranged in groups opposite to each other, so that the impact of hot air on the upper and lower sides is basically offset, avoiding the problem that the nozzle-type longitudinal air circulation treatment device blows directly on the steel strip on only one side and the steel strip is obviously bent and deformed by force. Similarly, preferably in the first temperature zone 91, a parallel air duct inlet 32 ​​and a parallel air duct outlet 31 are also provided below the steel belt, and the parallel air circulation treatment device 3 is corresponding to the upper and lower sides of the steel belt. It can be optionally configured so that the flow rate, flow direction and other parameters of the parallel air on the upper and lower sides are consistent, so as to avoid uneven force on both sides of the steel belt and heat the other side of the steel belt and the film, thereby improving temperature uniformity and heating efficiency; and in the upper drying tunnel temperature zone 92, an upper drying tunnel longitudinal air circulation treatment device 41 is also provided below the steel belt, and the upper drying tunnel longitudinal air circulation treatment device 41 is corresponding to the upper and lower sides of the steel belt.

[0038] Understandably, this solution primarily emphasizes improvements to the airflow pattern along the movement direction of the film and steel belt. Parallel air circulation devices and longitudinal air circulation devices along the width of the steel belt can be arranged in a single row or multiple rows side-by-side, depending on the specific requirements. Of course, the oven or temperature zone typically also includes temperature measurement devices, etc., to achieve the necessary functionalities.

[0039] In a more preferred embodiment, negative pressure air curtain devices 5 are provided at the adjacent locations of the two temperature zones and at the inlet and outlet of the upper drying tunnel 1 and the lower drying tunnel 2 (in other words, at the boundaries connecting the various temperature zones within the oven). The function of the negative pressure air curtain devices 5 is to create a temperature and air barrier between the various temperature zones, preventing uncontrollable mutual interference caused by gas diffusion and escape between the temperature zones. The negative pressure air curtain devices 5 include a first exhaust section 51 and a second exhaust section 52 arranged vertically opposite each other. The first exhaust section 51 and the second exhaust section 52 are located on both sides of the steel belt, and a channel space 54 is formed between the first exhaust section 51 and the second exhaust section 52 for the steel belt to pass through. It should be noted that the "opposite" of the first exhaust section 51 and the second exhaust section 52 refers to the opposite of the exhaust ports. In other words, both have through holes (which can be called air holes) on the side facing the steel belt for air passage. The air holes can be directly opened on the exhaust section (such as the bellows) or located on the flow equalization plate. To ensure the effect of the negative pressure air curtain, this solution further limits the exhaust section on at least one side to use a flow equalization plate. The flow equalization plate can be one or more pieces or multiple layers, which will be further introduced later. The channel space 54 is adapted to the width of the membrane, i.e., the steel belt, which can better ensure the formation of a relatively closed partition on both sides of the negative pressure air curtain device. Specifically, the width covers the membrane and is generally greater than or equal to the width.

[0040] More specifically, the temperature zones are divided within the upper / lower drying tunnels by structures such as partitions. Each partition has a central opening for the passage of steel strips (and films), and a negative pressure air curtain device 5 is sealed at the opening. A transversely sealed partition connects the upper drying tunnel 1 and the lower drying tunnel 2. The adjacent sides of each temperature zone within the oven are only connected by a passage space 54 (the opening) through which the steel strip can pass; the rest is sealed. During operation, the first exhaust unit 51 and the second exhaust unit 52 simultaneously exhaust air. When the airflow reaches the partition between adjacent temperature zones, it is drawn away by the first and second exhaust units 51 and 52 on both sides, thus preventing airflow from entering adjacent spaces. Especially for polyimide films, it is necessary to ensure that the evaporated solvent (flammable gas) is promptly discharged from the oven to guarantee solvent evaporation efficiency and to prevent solvent gas from escaping into other temperature zones or spaces, for example, to prevent excessive solvent content in high-temperature zones from causing combustion or explosion. In this scheme, since hot air cannot be exchanged between spaces, the temperature also cannot be exchanged. Therefore, the temperature and solvent gas content of each temperature zone are well controllable. Furthermore, since the airflow in adjacent spaces is drawn towards the center, a certain temperature transition zone is formed between adjacent spaces, which can prevent sudden changes in ambient temperature when the film enters or exits the temperature zone.

[0041] Please see Figures 5 to 8 The negative pressure air curtain device 5 preferably adopts a structure similar to a static pressure box. The first exhaust section 51 and the second exhaust section 52 are both located on the static pressure box. Air curtain flow equalization plates 53 and / or air regulating plates are provided at both the first exhaust section 51 and the second exhaust section 52 to ensure the uniformity of air extraction. Furthermore, the airflow speed or direction can be adjusted. The air curtain flow equalization plate 53 ensures uniform airflow speed. Without the equalization plate, problems such as higher airflow speeds closer to the exhaust port (exhaust duct) and insufficient airflow further away from the exhaust port (exhaust duct) will occur. The membrane will not be subjected to strong airflow impact when passing through, further ensuring the ventilation effect within the space. The air regulating plate is, for example, a grid pattern. It should be noted that the main ventilation and timely solvent removal effects are still achieved by other ventilation systems; the negative pressure air curtain device 5 mainly serves as a temperature zone barrier.

[0042] Preferably, the inlet and / or outlet of the channel space 54 has an adjustable baffle mechanism to adapt the inlet and / or outlet of the channel space 54 to the thickness of the steel strip carrying the membrane. The adjustable baffle mechanism includes, for example, the aforementioned partition. The adjustable baffle mechanism is used to further reduce the inlet / outlet. For example, if the thickness of the membrane (and steel strip) is about 1.2 mm to 1.5 mm, the adjustable baffle mechanism reduces the inlet / outlet to close to this thickness value, thereby better separating the spaces before and after the negative pressure air curtain device and preventing the inlet / outlet from being too large, allowing gas to escape. Preferably, for example, the adjustable baffle mechanism includes at least one slit baffle 56 located on the first exhaust section 51 and / or the second exhaust section 52. The slit baffle 56 is two upper and lower baffles that are sealed and fixed to the outside. The slit baffle 56 forms a slit at the inlet and / or outlet of the channel space 54, and the size of the slit is smaller than the channel space 54. The distance between the first exhaust section 51 and the second exhaust section 52 should not be too close. Therefore, the size of the inlet and / or outlet of the channel space 54 can be further defined by the slit baffle 56, and preferably the position and size of the slit are adjustable (e.g., the slit is formed by two detachable / adjustable baffles, the slit baffle 56 being independent of the aforementioned partition). More specifically, for example, the slit is located in a central position between the first exhaust section 51 and the second exhaust section 52, so that the distance between the film and the first exhaust section 51 and the second exhaust section 52 is substantially the same. The slit baffle 56 allows a thinner film to pass through while more effectively preventing gas in the oven from escaping from the oven or a certain process space of the oven. It is conceivable that in other feasible embodiments, the adjustable baffle mechanism is a plate with a slit, or a pipe-like structure, or further provided with a flow guiding / filtering structure, etc., all of which are intended to serve as a barrier and do not depart from the concept of this solution.

[0043] Preferably, the system further includes channel side plates 55 disposed on the outer sides of the first exhaust section 51 and the second exhaust section 52. The channel side plates 55, together with the air curtain equalization plates 53 of the first exhaust section 51 and the second exhaust section 52, form the four side walls of the channel space 54. Therefore, in practical applications, the position and size of the channel space 54 are no larger than the connection opening between the two spaces, and it is sealed to the connection opening, ensuring that the airflow at the connection opening can only flow to the first exhaust section 51 and the second exhaust section 52, and cannot escape from other places around the connection opening. It is understood that for cases where the process space is small or the first exhaust section 51 and the second exhaust section 52 are large, the side walls of the process space can be equivalent to the side walls of the channel space, effectively achieving the desired effect, thus eliminating the need for channel side plates 55 (and other structures restricting the connection opening).

[0044] In some embodiments, both the first exhaust section 51 and the second exhaust section 52 are strip-shaped to adapt to the width of the spatial connection opening; the air curtain equalization plate 53 is a porous strip-shaped flat plate, and the air curtain equalization plates 53 of the first exhaust section 51 and the second exhaust section 52 are parallel. This solution is small in size while achieving the required functions, making it convenient for production and use. For example, the oven also has a longitudinal air circulation treatment device for blowing out hot air, so the air curtain device should not be too large to ensure the uniformity and efficiency of the main heating effect. In addition, if the air curtain device is too large, it will affect the overall size of the equipment box, resulting in increased costs, low heating efficiency, and poor heat preservation. The first exhaust section 51 and the second exhaust section 52 are arranged vertically to adapt to the transversely conveyed film.

[0045] More specifically, the negative pressure air curtain device includes a first airtight air box 57 and a second airtight air box 58; the first airtight air box 57 is connected to a first exhaust pipe 59, and has a first exhaust section 51 on the side facing the second airtight air box 58; the second airtight air box 58 is connected to a second exhaust pipe 510, and has a second exhaust section 52 on the side facing the first airtight air box 57. The air curtain flow equalization plate 53 matches the first airtight air box 57 and the second airtight air box 58 to ensure airflow uniformity. A channel side plate 55 and a slit baffle 56 (if present) are provided on the first airtight air box 57 and the second airtight air box 58. Preferably, the first exhaust pipe 59 is provided on both sides of the first airtight air box 57, and the second exhaust pipe is provided on both sides of the second airtight air box 58; this method of connecting exhaust pipes on both sides further helps to ensure uniform airflow throughout the air curtain flow equalization plate 53.

[0046] Further, please refer to Figure 8 A wind speed acquisition device 511 (such as an anemometer) is installed at the air curtain flow equalization plate 53. A wind speed adjustment mechanism 512 (such as a speed-regulating fan, or an independent air-regulating valve, etc.) is connected to the outside of the first exhaust section 51 and / or the second exhaust section 52 via exhaust ducts, thereby enabling the monitoring and adjustment of wind speed. Specifically, the first exhaust section 51 and / or the second exhaust section 52 are connected to exhaust ducts, which include, for example, a first exhaust pipe 59 and a second exhaust pipe 510. The wind speed adjustment mechanism 512 is located at the outer end of the exhaust ducts. Preferably, the wind speed acquisition device 511 is also electrically connected to the wind speed adjustment mechanism 512, enabling signal transmission and thus achieving automatic adjustment and control based on wind speed. More specifically, the ends of the first exhaust pipe 59 and the second exhaust pipe 510 may converge into a single pipe, connecting to a wind speed adjustment mechanism 512, or the first exhaust pipe 59 and the second exhaust pipe 510 may be respectively connected to their respective wind speed adjustment mechanisms.

[0047] In some embodiments, the air curtain equalization plate 53 is a single-layer structure; preferably, the air curtain equalization plate 53 inside the first exhaust section 51 and / or the second exhaust section 52 is multi-layered (e.g., two or more layers) to improve the equalization effect. The multi-layered air curtain equalization plate 53 is arranged parallel to the film conveying direction or inclined to the film conveying direction; for example... Figure 8 In the illustrated embodiment, the air curtain equalization plate 53 consists of two layers arranged parallel to (horizontally) along the film conveying direction. In other embodiments, the air curtain equalization plate 53 is not parallel to the film conveying direction but at a certain angle, i.e., it is inclined. The air curtain equalization plate 53 has air holes, and the air holes in each layer are arranged oppositely or staggered. Relative arrangement means that the air holes are corresponding in the wind speed direction, and the line connecting several corresponding air holes is consistent with the wind speed direction. Staggered arrangement means that the air holes are staggered in the wind speed direction. In some embodiments, the air holes are, for example, small holes, closely arranged on the air curtain equalization plate 53. In other embodiments, the air holes are arranged strip-shaped holes, or the air curtain equalization plate 53 is grid-like or mesh-like; or it is a combination of various hole types. Slit holes are elongated slit-shaped holes, for example, one or more slit holes, and the length direction of the slit holes is, for example, parallel to or inclined at a certain angle to the film width direction.

[0048] It should be noted that existing air curtain devices generally form an air curtain by blowing out a strong airflow, and are usually not set up opposite each other on both sides. Furthermore, they cannot be used in casting machines. The film slurry or the partially hardened wet film cannot be impacted by a strong airflow, otherwise it will affect the film quality. Therefore, the existing casting machine oven does not have an air curtain and is a directly connected structure. Although there is a ventilation system to provide negative pressure, there will still be gas escape.

[0049] Please see again Figure 1 , Figure 2 In the preferred ventilation system, each temperature zone has a main exhaust vent (a structure independent of the negative pressure air curtain device 5), used to cooperate with the air inlet to form an overall airflow within the temperature zone, thereby expelling the solvent. The main exhaust vent is located on the oven body; after the hot air enters, it carries the evaporated solvent out through the main exhaust vent. Preferably, the oven body has an oven exhaust vent 61 near the edge of the temperature zone (such as on both sides of the negative pressure air curtain device or partition), and / or, the oven body has an oven exhaust vent 61 near the passive rotating drum 72 (such as next to the passive rotating drum 72, on the side wall of the passive rotating drum chamber 82). This design places the oven exhaust vent in the dead corners of the oven, i.e., where the evaporated solvent is prone to stagnation and accumulation, thus focusing on exhausting from these solvent-prone areas, ensuring airflow in the dead corners, and improving the efficiency and effectiveness of solvent removal.

[0050] The oven air inlet 62 is related to the setting of the static pressure chamber. For example, an air inlet is provided on the side wall of the chamber perpendicular to the partition (i.e., on both sides of the chamber's length). Specifically, for example, the oven air inlet 62 corresponding to the nozzle-type static pressure chamber 4 is located in the middle of the temperature zone, on both sides of the oven body; the air inlet position corresponding to the parallel air circulation treatment device corresponds to the parallel air duct air inlet 32. For the upper drying duct, the air inlet and exhaust port can also be opened at the top of the oven body; for the lower drying duct, the situation and setting principle of the air inlet and exhaust port can be similar to that of the upper drying duct, the difference being that they are opened on the left and right sides of the oven body. The oven exhaust port 61 is sealed to the chamber body and is connected to a negative pressure fan and exhaust gas treatment system, etc. The relevant required components / systems are existing technology and will not be described in detail here.

[0051] Preferably, explosion vents 63 are provided in the first temperature zone and / or other temperature zones in the upper drying tunnel (such as the second and third temperature zones downstream of the first temperature zone). Explosion vents 63 are preferably located at least in the first temperature zone and the second temperature zone downstream of it, where the solvent concentration is high, allowing for pressure relief in extreme conditions. Explosion vents 63 are, for example, located at the top of the chamber. More preferably, each temperature zone is also equipped with monitoring devices for temperature, air pressure, and other conditions, facilitating timely intervention or explosion relief in extreme situations, thereby protecting equipment and personnel safety.

[0052] An active drum chamber 81 is located outside the active drum 71. The active drum chamber 81 is connected to the upper drying tunnel 1 and the lower drying tunnel 2. Preferably, the active drum chamber 81 is equipped with a temperature control device for the feed section, such as a pipe or air box for blowing cooling air, or contact cooling of the steel strip, to ensure that the temperature in the active drum chamber 81 is not too high and can be maintained at, for example, room temperature or slightly below room temperature. This is because the temperature of the mixed film raw material slurry is generally lower than room temperature. If the ambient temperature is high when the slurry is fed into the steel strip of the active drum 71, solvent will evaporate into the outside space after the slurry is fed in. This solution ensures that the film material has virtually no volatile solvent in the active drum chamber 81 (especially the upper feed side), and is gradually heated after entering the upper drying tunnel.

[0053] Preferably, such as Figure 2 As shown, the bearings, bearing housings, motors, and steel belt correction devices of the active drum 71 and the passive drum 72 are located on the outside of the oven body to avoid long-term operation in a high-temperature environment, thereby effectively improving their service life.

[0054] In summary, the multi-temperature zone casting machine of this invention divides the oven into multiple temperature zones, enabling more precise control of the various process times, temperatures during the hardening state, and drying methods of the film material. Specifically, it employs a parallel airflow method to blow preheating air into the first temperature zone when the film slurry first enters the drying tunnel, allowing the surface of the film slurry to begin hardening and ensuring airflow, thus preventing hot air from directly blowing onto the film surface and affecting film quality. Furthermore, a curved temperature zone is provided at the passive drum to continue heating the film or more effectively maintain its temperature, avoiding the natural temperature drop that occurs with existing equipment. Consequently, as the film continues into the next drying tunnel, the temperature change is essentially continuous without significant abrupt fluctuations. After passing through the first temperature zone, the film surface hardens sufficiently to withstand conventional hot air, allowing subsequent hot air to be blown generally directly onto the film surface for more direct and efficient heat transfer and accelerated solvent evaporation. Furthermore, this solution preferably incorporates a negative pressure air curtain device, where two opposing exhaust units simultaneously draw air, forming a negative pressure air curtain within the channel space between the two exhaust units. The membrane can then be transported between the two spaces through this channel space. Because of the negative pressure air curtain between these two spaces, issues such as temperature and gas interaction (e.g., escape / cross-contamination of gases with different temperatures and compositions) are avoided, effectively ensuring the accuracy and stability of process environment control for high-end processes. Simultaneously, since the airflow from adjacent temperature zones is drawn towards the center, a certain temperature transition zone is formed between adjacent temperature zones, further preventing sudden changes in ambient temperature when the membrane enters or exits the temperature zone.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention; for ease of description, only the parts related to the invention are shown in the accompanying drawings. In the absence of conflict, the embodiments and features in the embodiments of the present invention can be combined with each other; modifications to the technical solutions described in the foregoing embodiments, or equivalent substitutions for some of the technical features, do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-temperature zone casting machine, comprising an active drum (71), a passive drum (72), a steel belt drively connected to the active drum (71) and the passive drum (72), and further comprising an upper drying tunnel (1), a passive drum chamber (82), and a lower drying tunnel (2) sequentially connected along the conveying direction of the steel belt, characterized in that, Multiple temperature zones are formed in the upper drying tunnel (1), the passive rotating drum chamber (82) and the lower drying tunnel (2). The temperature zones include at least the first temperature zone (91), the curved temperature zone (93) and the lower drying tunnel temperature zone (94); each temperature zone is an adjustable temperature zone with adjustable temperature. The upper drying tunnel (1) has at least one first temperature zone (91) which is close to the entrance of the upper drying tunnel (1); a parallel air circulation treatment device (3) is provided in the first temperature zone (91), which includes a parallel air duct inlet (32) and a parallel air duct outlet (31) arranged opposite to each other. The parallel air duct inlet (32) and the parallel air duct outlet (31) are arranged above and below the steel belt, or are arranged only above the steel belt. The passive drum chamber (82) has at least one bend temperature zone (93); a bend section temperature control device is provided in the bend temperature zone (93) or on the outside of the passive drum chamber (82); There is at least one lower drying chamber temperature zone (94) in the lower drying chamber (2); Negative pressure air curtain devices (5) are provided at the adjacent locations of the two temperature zones and at the entrance and exit of the upper drying tunnel (1) and the lower drying tunnel (2). The negative pressure air curtain device (5) includes a first exhaust section (51) and a second exhaust section (52) arranged opposite to each other. The first exhaust section (51) and the second exhaust section (52) are located on both sides of the steel belt, and a channel space (54) for the steel belt to pass through is formed between the first exhaust section (51) and the second exhaust section (52). The channel space (54) is adapted to the width of the steel belt.

2. The multi-temperature zone casting machine according to claim 1, characterized in that, An air curtain equalization plate (53) and / or an air regulating plate are provided on both the first exhaust section (51) and the second exhaust section (52); the air curtain equalization plate (53) is arranged parallel or inclined along the film conveying direction, and the air curtain equalization plate (53) has a number of air holes or a number of slit holes; the air curtain equalization plate (53) is a single-layer structure, or the air curtain equalization plate (53) is arranged in multiple layers and the air holes or slit holes of each layer are arranged oppositely or staggered.

3. The multi-temperature zone casting machine according to claim 1, characterized in that, The entrance and / or exit of the passage space (54) are provided with an adjustable windbreak mechanism so that the entrance and / or exit of the passage space (54) are adapted to the thickness of the steel strip carrying the membrane.

4. The multi-temperature zone casting machine according to any one of claims 1-3, characterized in that, Parallel air duct flow equalization plate and / or air regulating plate are provided at both the air inlet (32) and air outlet (31) of the parallel air duct.

5. The multi-temperature zone casting machine according to any one of claims 1-3, characterized in that, The parallel air duct outlet (31) is located near the entrance of the upper drying duct (1), and the parallel air duct inlet (32) is located on the opposite side of the parallel air duct outlet (31).

6. The multi-temperature zone casting machine according to any one of claims 1-3, characterized in that, The upper drying tunnel (1) also has at least one upper drying tunnel temperature zone (92), which is located between the first temperature zone (91) and the passive rotating drum chamber (82); the upper drying tunnel temperature zone (92) is provided with an upper drying tunnel longitudinal air circulation treatment device (41) at least above the steel belt, and the nozzle of the upper drying tunnel longitudinal air circulation treatment device (41) is facing or tilted toward the steel belt or the direction of the nozzle is adjustable.

7. The multi-temperature zone casting machine according to any one of claims 1-3, characterized in that, The lower drying tunnel temperature zone (94) is provided with a lower drying tunnel longitudinal air circulation treatment device (42) at least below the steel belt, and the nozzle of the lower drying tunnel longitudinal air circulation treatment device (42) is facing or tilted toward the steel belt or the direction of the nozzle is adjustable.

8. The multi-temperature zone casting machine according to claim 7, characterized in that, In the lower drying tunnel (2), a longitudinal air circulation treatment device (42) is also provided above the steel belt, and the longitudinal air circulation treatment device (42) is corresponding to the upper and lower sides of the steel belt; and / or, in the first temperature zone (91), a parallel air duct inlet (32) and a parallel air duct outlet (31) are also provided below the steel belt, and the parallel air circulation treatment device (3) is corresponding to the upper and lower sides of the steel belt.

9. The multi-temperature zone casting machine according to any one of claims 1-3, characterized in that, An active drum chamber (81) is located on the outside of the active drum (71). The active drum chamber (81) is connected to the upper drying tunnel (1) and the lower drying tunnel (2). A temperature control device for the feed section is installed in the active drum chamber (81).

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