Casting machine with multiple temperature zones

Abstract

The invention discloses a casting machine with multiple temperature zones, which is characterized in that a plurality of temperature zones are divided in an upper drying tunnel, a passive rotary drum chamber and a lower drying tunnel, and the temperature zones at least comprise a first temperature zone, a curve temperature zone and a lower drying tunnel temperature zone; at least one first temperature zone is arranged in the upper drying tunnel, and the first temperature zone is close to an inlet of the upper drying tunnel; a parallel air circulation treatment device is arranged in the first temperature zone, the parallel air circulation treatment device comprises a parallel air duct air inlet part and a parallel air duct air outlet part which are oppositely arranged, and the parallel air duct air inlet part and the parallel air duct air outlet part are at least arranged above the steel belt; at least one curve temperature zone is arranged in the driven rotary drum chamber; a curve section temperature control device is arranged in the curve temperature zone or on the outer side of the passive rotary drum chamber; and at least one lower drying tunnel temperature zone is arranged in the lower drying tunnel. According to the scheme, the process time of the film material, the temperature in the hardening state, the drying mode and the like are controlled more accurately, temperature change is continuously avoided from sudden change, the film quality is effectively improved, and the solvent evaporation efficiency is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of film manufacturing equipment, and in particular relates to a multi-temperature zone casting machine. Background Art

[0002] Casting machine, also known as steel belt casting machine, is one of the key equipment for producing film by cast film method. Existing casting machine, such as the Chinese invention patent with application publication number CN109968575A, has less division of temperature zones, so there is a lack of accurate and staged temperature control in each stage of surface hardening of cast film; in particular, the tail mechanism (passive drum chamber) of such existing casting machine is located between the upper and lower drying tunnels, and there is no heating mechanism in the passive drum chamber, relying only on the insulation structure of the box body. The temperature of the film will decrease after passing through the passive drum chamber, which is not conducive to entering the lower drying tunnel for higher temperature drying, and will experience a sudden change in temperature when entering the lower drying tunnel, which will affect the process quality of the film, 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 to solve the problem of inaccurate temperature control in existing equipment, and to achieve a more continuous temperature transition, thereby helping to achieve a better cast film hardening 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, a steel belt connected to the active drum and the passive drum by transmission, and also includes an upper drying tunnel, a passive drum chamber and a lower drying tunnel connected in sequence along the conveying direction of the steel belt, and multiple temperature zones are divided and formed in the upper drying tunnel, the passive drum chamber and the lower drying tunnel, and the temperature zones at least include a first temperature zone, a curved temperature zone, and a lower drying tunnel temperature zone; each temperature zone is an adjustable temperature zone with adjustable temperature; there is at least one first temperature zone in the upper drying tunnel. A temperature zone, the first temperature zone is close to the entrance of the upper drying tunnel; a parallel wind circulation processing device is arranged in the first temperature zone, and the parallel wind circulation processing device includes a parallel wind channel air inlet and a parallel wind channel air outlet which are arranged oppositely, and the parallel wind channel air inlet and the parallel wind channel air outlet are arranged above and below the steel belt, or are only arranged above the steel belt separately; there is at least one bend temperature zone in the passive drum chamber; a bend section temperature control device is arranged in the bend 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 arranged at adjacent positions of the two temperature zones and at the entrances and exits of the upper drying tunnel and the lower drying tunnel; the negative pressure air curtain device includes a first exhaust part and a second exhaust part which are arranged opposite to each other, the first exhaust part and the second exhaust part are respectively 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 part and the second exhaust part, and the channel space is adapted to the width of the steel belt.

[0006] Furthermore, a wind curtain flow equalizing plate and / or an air regulating plate are arranged on the first exhaust part and the second exhaust part; the wind curtain flow equalizing plate is arranged parallel to or inclined along the film conveying direction, and has a plurality of wind holes or a plurality of slit holes on the wind curtain flow equalizing plate; the wind curtain flow equalizing plate is a single-layer structure, or the wind curtain flow equalizing plate is arranged in multiple layers and the wind holes or slit holes on each layer are arranged relatively or staggered.

[0007] Furthermore, an adjustable wind shielding mechanism is provided at the inlet and / or outlet of the channel space, so that the inlet and / or outlet of the channel space is adapted to the thickness of the steel belt carrying the film.

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

[0009] Further, the parallel air duct outlet is arranged close to the entrance of the upper drying channel, and the parallel air duct inlet is arranged on the opposite side of the parallel air duct outlet.

[0010] Furthermore, there is at least one upper drying tunnel temperature zone in the upper drying tunnel, and the upper drying tunnel temperature zone is located between the first temperature zone and the passive drum chamber; an upper drying tunnel longitudinal wind circulation processing device is arranged in the upper drying tunnel temperature zone at least above the steel belt, and the nozzle of the upper drying tunnel longitudinal wind circulation processing device is facing or tilted toward the steel belt or the direction of the nozzle is adjustable.

[0011] Furthermore, a lower drying tunnel longitudinal wind circulation processing device is provided at least below the steel belt in the lower drying tunnel temperature zone, and the nozzle of the lower drying tunnel longitudinal wind circulation processing device is directly facing or tilted toward the steel belt or the direction of the nozzle is adjustable.

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

[0013] Furthermore, an active drum chamber is provided on the outer side of the active drum, the active drum chamber is connected with the upper drying channel and the lower drying channel, and a temperature control device for the feeding section is arranged in the active drum chamber.

[0014] Compared with the prior art, the beneficial technical effects of the present invention are as follows: The multi-temperature zone casting machine of the present invention is divided into a plurality of adjustable temperature zones in the oven, which can more accurately control the various process times of the film material, the temperature in the hardened state, the drying method, etc., and especially adopts a parallel air duct method to blow preheated air for the first temperature zone when the film slurry just enters the drying tunnel, so that the surface of the film slurry begins to harden and ensures air flow, while avoiding the hot air blowing directly to the film surface of the film slurry and affecting the film quality; and a curved temperature zone is provided at the passive drum to continue to heat the film or to keep it warm more effectively, avoiding the situation where the film temperature here will naturally decrease when the existing equipment is used, and then when the film continues to enter the lower drying tunnel, the temperature change is basically continuous without large sudden fluctuations; the hardness of the film surface after passing through the first temperature zone can withstand hot air, and hot air can be blown in a manner generally facing the film surface in the future, so as to transfer heat more directly and efficiently and accelerate the evaporation of the solvent. In addition, the present scheme preferably has a negative pressure wind curtain device, in which two relatively arranged exhaust parts simultaneously exhaust air, forming a negative pressure wind curtain in the channel space between the two exhaust parts, and the film can be transmitted in the front and rear spaces through the channel space. Since there is a negative pressure wind curtain between the two spaces, the mutual influence of temperature and gas between the two spaces (such as the escape / interconnection of gases with different temperatures and different component contents) is avoided, thereby effectively ensuring the accuracy and stability of the process environment control of high-end processes; at the same time, since the airflows in adjacent temperature zones are sucked toward the middle, a certain temperature transition area will be formed between adjacent temperature zones, which can further avoid sudden changes in ambient temperature when the film enters and exits the temperature zone. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic cross-sectional structural diagram of a tape casting machine according to an embodiment of the present invention.

[0016] Figure 2 yes Figure 1 The schematic diagram of the structure of the casting machine from top view is shown.

[0017] Figure 3 It is a schematic cross-sectional structural diagram of a tape casting machine according to another embodiment of the present invention.

[0018] Figure 4 It is a schematic cross-sectional structural diagram of a tape casting machine according to another embodiment of the present invention.

[0019] Figure 5 2 is a schematic diagram of the three-dimensional structure of a negative pressure air curtain device according to an embodiment of the present invention.

[0020] Figure 6 yes Figure 5 A schematic diagram of the rear structure of the negative pressure air curtain device shown.

[0021] Figure 7 yes Figure 5 The left side structural schematic diagram of the negative pressure air curtain device is shown.

[0022] Figure 8 2 is a schematic structural diagram of a negative pressure air curtain device according to yet another embodiment of the present invention.

[0023] Description of reference numerals in the accompanying drawings: 1. Upper drying channel; 2. Lower drying channel; 3. Parallel air circulation treatment device; 32. Parallel air channel air inlet; 31. Parallel air channel air outlet; 41. Upper drying channel longitudinal air circulation treatment device; 42. Lower drying channel longitudinal air circulation treatment device; 5. Negative pressure air curtain device; 51. First exhaust part; 52. Second exhaust part; 53. Air curtain flow plate; 54. Channel space; 55. Channel side plate; 56. Slit baffle; 57. First airtight air curtain Box; 58, second airtight bellows; 59, first exhaust duct; 510, second exhaust duct; 511, wind speed collection device; 512, wind speed adjustment mechanism; 61, oven exhaust port; 62, oven air inlet; 63, explosion vent; 71, active drum; 72, passive drum; 81, active drum chamber; 82, passive drum chamber; 91, first temperature zone; 92, upper drying tunnel temperature zone; 93, bend temperature zone; 94, lower drying tunnel temperature zone. DETAILED DESCRIPTION

[0024] The present invention provides a multi-temperature zone casting machine to solve the problem of inaccurate temperature control in existing equipment. The present invention can more accurately control the various process times of the film material, the temperature in the hardening state, the drying method, etc., and make the temperature change continuously to avoid sudden changes, thereby helping to achieve a better cast film hardening effect, effectively improve the film quality, and ensure the solvent evaporation efficiency.

[0025] See also Figure 1 A multi-temperature zone casting machine according to an embodiment of the present invention comprises a transversely distributed active drum 71 and a passive drum 72, and a steel belt connected to the active drum 71 and the passive drum 72 by transmission. The active drum 71, the passive drum 72 and the steel belt are located in a heat-insulating box (oven) of the casting machine. The oven comprises an upper drying tunnel 1, a passive drum chamber 82 and a lower drying tunnel 2 which are sequentially connected along the conveying direction of the steel belt. The upper drying tunnel 1 and the lower drying tunnel 2 correspond to the upper straight section and the lower straight section of the steel belt respectively. The passive drum chamber 82 accommodates the passive drum 72. The oven is a sealed and heat-insulating box with an inspection door and an air inlet and outlet of a ventilation system. One of the main improvements of the present invention is that a plurality of temperature zones are divided and formed in the upper drying tunnel 1, the passive drum chamber 82 and the lower drying tunnel 2. The temperature zones at least include a first temperature zone 91, a bend temperature zone 93 and a lower drying tunnel temperature zone 94. Each temperature zone is an adjustable temperature zone with adjustable temperature.

[0026] 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 first temperature zone 91 is provided with a parallel wind circulation treatment device 3, which includes a parallel wind channel air inlet 32 ​​and a parallel wind channel air outlet 31 which are arranged opposite to each other. The parallel wind channel air inlet 32 ​​and the parallel wind channel air outlet 31 are arranged above and below the steel belt, or are only arranged above the steel belt (the cast film slurry is also located above the steel belt in this area). The parallel wind circulation treatment device 3 blows preheated air in a direction substantially parallel to the steel belt to form air flow in this direction.

[0027] The bend temperature zone 93 is a transition temperature zone between the upper drying tunnel 1 and the lower drying tunnel 2, and there is at least one bend temperature zone 93 in the passive drum chamber 82; for example, the internal space of the passive drum chamber 82 constitutes a bend temperature zone 93, or there is also a division in the internal space of the passive drum chamber 82, for example, it is further divided into two upper and lower temperature zones, and the same or different temperatures can be set. A bend section temperature control device, such as a far infrared heating device or a ceramic heating device, is provided in the bend temperature zone 93 or on the outside of the passive drum chamber 82 to control the temperature in the bend temperature zone 93. According to some embodiments, the bend section temperature control device is, for example, a heating device such as a heating plate provided on the outside of the passive drum chamber 82, and / or, heating is performed by conveying hot air, for example, using a pipeline or a longitudinal wind circulation processing device to blow hot air into the bend temperature zone 93 or toward the steel strip.

[0028] 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 surface of the film has been preliminarily hardened, so the existing or feasible air supply method can be used for heating. For example, in a specific embodiment, a hot air blowing method basically facing the film surface is used.

[0029] Taking polyimide film as an example, a mixer is used to evenly mix the main material polyamic acid resin and the auxiliary material imidization agent, and then the mixed slurry is output from the mold at the discharge end of the mixer to the steel belt at the active drum 71 of the casting machine. The slurry moves with the rotation of the steel belt, heats, evaporates the solvent, and gradually forms a preliminary film. Finally, after rotating for nearly a week, it is peeled off from the steel belt at the active drum 71 by the peeling roller; this process continues. Figure 1For example, the film slurry first drips on the upper right position of the annular steel belt, and then moves counterclockwise with the steel belt, first entering the first temperature zone 91 where the parallel wind circulation treatment device 3 is located. This area is used for preheating, pre-evaporation, and to make the film surface have a certain hardness. The role of using the parallel air duct method is to make a certain amount of air flow in this area, so that the surface of the film slurry (wet film) begins to harden, and avoid hot air blowing directly on the film slurry. The hardness of the film surface after passing through the first temperature zone 91 can withstand conventional hot air, and hot air can be blown in a manner that is generally facing the film surface to transfer heat more directly and efficiently and accelerate the evaporation of the solvent. On the other hand, after the film passes through the entire upper drying tunnel 1, it enters the passive drum chamber 82, that is, the bend temperature zone 93, and continues to heat or keep the film warm, avoiding the situation where the film temperature here will naturally decrease when using existing equipment, and then when the film continues to enter the lower drying tunnel 2, the temperature change is basically continuous without large sudden fluctuations.

[0030] More specifically, in the first temperature zone 91, the parallel air circulation processing device preferably adopts a structure similar to a static pressure box, and the parallel air duct air inlet 32 ​​and the parallel air duct air outlet 31 are both located on the corresponding static pressure box, and parallel air duct air inlet 32 ​​and parallel air duct air outlet 31 are provided with parallel air duct flow equalizing plates and / or air regulating plates, so as to ensure the uniformity of parallel wind and preheating effect, and further optionally can adjust wind speed or wind direction, etc. The parallel air duct flow equalizing plate is, for example, a porous flat plate, and the air regulating plate is, for example, a grid shape. A plurality of air holes or a plurality of slit holes are arranged on the parallel air duct flow equalizing plate, and the parallel air duct flow equalizing plate can be optionally provided in multiple layers, and the air holes or slit holes of each layer are relatively arranged or staggered. In some embodiments, the air holes are, for example, small holes, closely arranged on the flow equalizing plate; in other embodiments, the air holes are arranged in strip-shaped holes, or the flow equalizing plate is in a grid or mesh shape; or a combination of multiple hole types; slit holes are elongated slit-shaped holes, and the slit holes are, for example, one or more, and the length direction of the slit holes is, for example, parallel to the width direction of the film or inclined at a certain angle.

[0031] In a preferred embodiment, in the parallel air circulation treatment device, the parallel air duct outlet 31 is relatively close to the inlet of the upper drying channel 1, and the parallel air duct inlet 32 ​​is arranged on the opposite side of the parallel air duct outlet 31, and the parallel air duct inlet 32 ​​is relatively far away from the inlet of the upper drying channel 1. The direction of the parallel wind is toward the inlet of the upper drying channel 1, which is opposite to the direction of movement of the film slurry, and the air flow rate above the film slurry is ensured in a relatively gentle and stable manner, which is conducive to the hardening of the film surface.

[0032] For ease of description, a pair of parallel air duct inlet 32 ​​and parallel air duct outlet 31 arranged in a coordinated manner are referred to as a set of parallel air circulation processing devices, wherein coordinated means that a pair of air inlets and outlets are directly opposite to each other and the air path between the two is directly connected, in other words, a pair of air inlets and outlets that are closest to each other and face opposite to each other. Figure 3 In the embodiment shown, only one set of parallel wind circulation processing devices is provided in the upper drying tunnel 1, so that the parallel wind can cover the entire upper drying tunnel 1. Figure 4 In the illustrated embodiment, more than two groups of parallel air circulation processing devices are sequentially arranged along the length direction in the upper drying tunnel 1 , and more than two first temperature zones 91 are divided.

[0033] In such Figure 1 In the embodiment shown, the upper drying tunnel 1 further has at least one upper drying tunnel temperature zone 92, which is located between the first temperature zone 91 and the passive drum chamber 82; the film enters the upper drying tunnel temperature zone 92 after passing through the first temperature zone 91, and then enters the bend temperature zone 93. It can be understood that the temperature zones in this solution are adjacent and continuously connected, for example, for a solution without the upper drying tunnel temperature zone 92, the first temperature zone 91 and the bend temperature zone 93 are directly adjacent; and for a solution with the upper drying tunnel temperature zone 92, the first temperature zone 91, the upper drying tunnel temperature zone 92, and the bend temperature zone 93 are adjacent in sequence. Figure 1 The figure shows a typical embodiment, which has seven temperature zones in total. In the upper drying tunnel temperature zone 92, at least above the steel belt, an upper drying tunnel longitudinal wind circulation treatment device 41 is provided, specifically, for example, a nozzle-type static pressure box, and the nozzle of the upper drying tunnel longitudinal wind circulation treatment device 41 is facing or tilted toward the steel belt, or the direction of the nozzle is adjustable; wherein, tilt means that, according to needs, at least partially, a blowing method that is not completely facing the membrane surface can be selected, but has a certain tilt angle, so that the hot air is blown and the impact on the membrane surface is relatively softer.

[0034] In the lower drying tunnel temperature zone 94, a lower drying tunnel longitudinal wind circulation processing device 42 is provided at least below the steel belt, specifically, for example, a nozzle-type static pressure box, and the nozzle of the lower drying tunnel longitudinal wind circulation processing device 42 is facing or tilted toward the steel belt, or the direction of the nozzle is adjustable; wherein, tilt means that, according to needs, a blowing method that is not completely facing the membrane surface can be selected at least partially, but has a certain tilt angle, so that the blowing of hot air and the impact on the membrane surface are relatively softer.

[0035] Preferably, in the lower drying tunnel 2, a lower drying tunnel longitudinal wind circulation processing device 42 is also provided above the steel belt, and the lower drying tunnel longitudinal wind circulation processing device 42 corresponds to the upper and lower sides of the steel belt; the nozzle-type longitudinal wind circulation processing devices on the inner and outer sides of the steel belt are arranged in groups relatively to each other, so that the impact of the hot air on the upper and lower sides is basically offset, avoiding the problem that the nozzle-type longitudinal wind circulation processing device directly blows the steel belt only on one side, resulting in obvious bending and deformation of the steel belt. 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 processing device 3 is provided at the upper and lower sides of the steel belt correspondingly. It can be optionally arranged that the flow velocity, flow direction and other parameters of the parallel wind on the upper and lower sides are consistent, so as to avoid inconsistent force on both sides of the steel belt while also heating 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 processing device 41 is also provided below the steel belt, and the upper drying tunnel longitudinal air circulation processing device 41 is provided at the upper and lower sides of the steel belt correspondingly.

[0036] It is understandable that this solution mainly emphasizes the improvement of the airflow mode in the direction of the film and the steel strip movement. The parallel air circulation processing device and the longitudinal air circulation processing device in the width direction of the steel strip can be one row or multiple rows arranged side by side, and can be designed and selected according to specific circumstances. Of course, the oven or temperature zone generally also has a device for measuring temperature, etc., to achieve the required corresponding functions.

[0037] As a more preferred embodiment, negative pressure air curtain devices 5 are provided at the adjacent parts of the two temperature zones and at the entrances and exits of the upper drying tunnel 1 and the lower drying tunnel 2 (in other words, at the boundaries where the temperature zones in the oven are connected). The function of the negative pressure air curtain device 5 is to form a temperature and air barrier between the temperature zones to avoid uncontrollable mutual influence caused by the diffusion and escape of gas between the temperature zones. The negative pressure air curtain device 5 includes a first exhaust part 51 and a second exhaust part 52 arranged opposite to each other up and down, and the first exhaust part 51 and the second exhaust part 52 are respectively 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 part 51 and the second exhaust part 52. It should be noted that the first exhaust part 51 and the second exhaust part 52 are relative to each other in that the exhaust ports are relative to each other. In other words, both of them have through holes (which may be called air holes) for air to pass through on the side facing the steel belt. The air holes are, for example, directly opened on the exhaust part (such as a bellows), or the air holes are located on the flow equalizer plate. To ensure the negative pressure wind curtain effect, this solution further stipulates that the exhaust part on at least one side adopts a flow equalizer plate. The flow equalizer plate may be one or more pieces or a multi-layer structure, which will be further introduced later. The channel space 54 is adapted to the width of the film, i.e., the steel belt, which can better ensure that a relatively closed partition is formed on both sides of the negative pressure wind curtain device. Specifically, the width covers the film, which is generally greater than or equal to the width.

[0038] More specifically, the temperature zones are divided by structures such as partitions in the upper / lower drying tunnels. The middle of the partition has a connecting port for the steel strip (and film) to pass through, and a negative pressure air curtain device 5 is sealed and connected at the connecting port. A transverse sealed partition is provided between the upper drying tunnel 1 and the lower drying tunnel 2. The adjacent sides of each temperature zone in the oven only allow the steel strip to pass through the channel space 54 (connecting port), and the rest of the parts are sealed. When working, the first exhaust part 51 and the second exhaust part 52 are exhausted at the same time. When the airflow flows to the partition between the adjacent temperature zones, the airflow will be sucked away by the first exhaust part 51 and the second exhaust part 52 on the upper and lower sides, thereby preventing the airflow from entering the adjacent space. Especially for polyimide film, it is necessary to discharge the evaporated solvent (flammable gas) out of the oven in time, ensure the solvent evaporation efficiency, and prevent the solvent gas from escaping into other temperature zones or spaces, for example, to prevent the solvent content in the high temperature zone from being too high and causing combustion and explosion. In this solution, since the hot air cannot flow between the spaces, the temperatures cannot flow between each other either. Therefore, the temperature and solvent gas content in each temperature zone are better controllable. Moreover, since the airflows in adjacent spaces are sucked toward the middle, a certain temperature transition zone will be formed between the adjacent spaces, which can avoid sudden changes in ambient temperature when the film enters and exits the temperature zone.

[0039] See also Figures 5 to 8 The negative pressure air curtain device 5 preferably adopts a structure similar to a static pressure box, and the first exhaust part 51 and the second exhaust part 52 are both located on the static pressure box. The first exhaust part 51 and the second exhaust part 52 are both provided with an air curtain flow equalizing plate 53 and / or an air regulating plate, so as to ensure the uniformity of the exhaust, and further optionally can adjust the wind speed or wind direction, etc. The air curtain flow equalizing plate 53 can make the wind speed uniform. If there is no flow equalizing plate, the wind speed will be higher closer to the exhaust port (exhaust pipe), and the wind speed will not be exhausted far away from the exhaust port (exhaust pipe). The film will not be impacted by strong airflow when passing through, and the ventilation effect in the space is further guaranteed. The air regulating plate is, for example, in the shape of a grid. It should be noted that the main ventilation and timely discharge of the solvent are still achieved by other ventilation systems, and the negative pressure air curtain device 5 mainly serves to act as a partition between temperature ranges.

[0040] Preferably, the entrance and / or exit of the channel space 54 is provided with an adjustable wind shielding mechanism, so that the entrance and / or exit of the channel space 54 is adapted to the thickness of the steel strip carrying the film. The adjustable wind shielding mechanism, for example, includes the aforementioned partition. The adjustable wind shielding mechanism is used to further reduce the entrance / exit. For example, if the thickness of the film (and the steel strip) is about 1.2 mm to 1.5 mm, the adjustable wind shielding mechanism reduces the entrance / exit to a value close to this thickness, thereby better separating the front and rear spaces of the negative pressure air curtain device, and avoiding the entrance / exit being too large and gas still being able to escape. Preferably, for example, the adjustable wind shielding mechanism includes at least one slit baffle 56 located on the first exhaust part 51 and / or the second exhaust part 52, and the slit baffle 56 is an upper and lower baffle that is sealed and fixed to the outside; the slit baffle 56 forms a slit at the entrance and / or exit 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 cannot be too close, so the size of the entrance and / or exit of the channel space 54 can be further limited by the slit baffle 56, and the position and size of the slit can be adjusted (for example, the slit is formed by two detachable / adjustable baffles, and the slit baffle 56 is independent of the aforementioned partition). More specifically, for example, the slit is located in the center 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 basically the same. The slit baffle 56 can allow thinner films to pass through, while more effectively preventing the gas in the oven from escaping from the oven or a process space of the oven. It can be imagined that in other feasible embodiments, the adjustable windshield mechanism is a plate with a slit, or a pipe-like structure, or is further provided with a guide / filter structure, etc., all of which are intended to play a partition role and do not deviate from the concept of this solution.

[0041] Preferably, it also includes channel side panels 55 arranged on both sides of the outside of the first exhaust section 51 and the second exhaust section 52. The channel side panels 55 and the wind curtain flow equalizing plates 53 of the first exhaust section 51 and the second exhaust section 52 together form the four side walls of the channel space 54; further, in actual application, the position and size of the channel space 54 are not larger than the connecting port of the front and rear spaces, and it is sealed with the connecting port to ensure that the airflow at the connecting port can only flow to the first exhaust section 51 and the second exhaust section 52, and cannot escape from other places around the connecting port. It can be understood that for situations 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, which can effectively achieve the desired effect, and then there is no need to set the channel side panels 55 (and other structures that limit the connecting port).

[0042] In some embodiments, the first exhaust section 51 and the second exhaust section 52 are both strip-shaped so as to match the width of the space connection port; the wind curtain flow equalizing plate 53 is a porous strip-shaped flat plate, and the wind curtain flow equalizing plates 53 of the first exhaust section 51 and the second exhaust section 52 are parallel. This solution is small in size and easy to produce and use while being able to achieve the required functions. For example, the oven also has a longitudinal wind circulation processing device for blowing out hot air, etc. Therefore, the wind curtain device should not be too large to ensure the uniformity and efficiency of the main heating effect. In addition, if the wind curtain device is too large, it will also affect the size of the overall equipment box, resulting in increased costs, low heating efficiency, poor insulation effect, etc. The first exhaust section 51 and the second exhaust section 52 are arranged in correspondence with each other up and down to match the horizontally conveyed film.

[0043] More specifically, the negative pressure wind curtain device includes a first airtight wind box 57 and a second airtight wind box 58; the first airtight wind box 57 is connected to a first exhaust pipe 59, and the first airtight wind box 57 has a first exhaust part 51 on the side facing the second airtight wind box 58; the second airtight wind box 58 is connected to a second exhaust pipe 510, and the second airtight wind box 58 has a second exhaust part 52 on the side facing the first airtight wind box 57. The wind curtain flow equalizer 53 matches the first airtight wind box 57 and the second airtight wind box 58 to ensure the uniformity of the air flow. The channel side plate 55 and the slit baffle 56 (if any) are arranged on the first airtight wind box 57 and the second airtight wind box 58. Preferably, the first exhaust pipe 59 is arranged on both sides of the first airtight wind box 57, and the second exhaust pipe is arranged on both sides of the second airtight wind box 58; this method of connecting the exhaust pipes on both sides is more conducive to making the air flow uniform at all parts of the wind curtain flow equalizer 53.

[0044] For further information, see Figure 8 , a wind speed collection device 511 (such as an anemometer) is provided at the wind curtain flow plate 53, and a wind speed regulating mechanism 512 (such as a speed regulating fan, or an air regulating valve independent of the fan, etc.) is connected to the outside of the first exhaust part 51 and / or the second exhaust part 52 through an exhaust duct, so that the wind speed can be monitored and adjusted. Specifically, the first exhaust part 51 and / or the second exhaust part 52 are connected to an exhaust duct, and the exhaust duct includes, for example, a first exhaust duct 59 and a second exhaust duct 510, and the wind speed regulating mechanism 512 is arranged at the outer end of the exhaust duct. Preferably, the wind speed collection device 511 is also electrically connected to the wind speed regulating mechanism 512, and can transmit signals, so as to realize automatic adjustment and control according to the wind speed. More specifically, the ends of the first exhaust duct 59 and the second exhaust duct 510, for example, converge into one pipeline, connected to a wind speed regulating mechanism 512, or the first exhaust duct 59 and the second exhaust duct 510 are respectively connected to their respective wind speed regulating mechanisms.

[0045] In some embodiments, the wind curtain flow equalizer 53 is a single-layer structure; preferably, the wind curtain flow equalizer 53 inside the first exhaust part 51 and / or the second exhaust part 52 is multi-layered (such as two or more layers) to achieve a better flow equalization effect. The multi-layer wind curtain flow equalizer 53 is arranged parallel to the film conveying direction or inclined along the film conveying direction; for example Figure 8 In the illustrated embodiment, the wind curtain flow equalizing plate 53 is two layers arranged in parallel (transversely arranged) along the film conveying direction; in other embodiments, the wind curtain flow equalizing plate 53 is not parallel to the film conveying direction, but is at a certain angle, which is the inclined arrangement. The wind curtain flow equalizing plate 53 has air holes, and the air holes of each layer are relatively arranged or staggered; wherein, the relative arrangement means that the air holes are corresponding in the wind speed direction, and the connecting line of the corresponding air holes is consistent with the wind speed direction; and the 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, which are closely arranged on the wind curtain flow equalizing plate 53; in other embodiments, the air holes are arranged in strip-shaped holes, or the wind curtain flow equalizing plate 53 is in a grid or mesh shape; or it is a combination of multiple hole types; the slit hole is a slender slit-shaped hole, and the slit hole is, for example, one or more, 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.

[0046] It should be noted that the existing air curtain device generally forms an air curtain by blowing out a strong airflow, and is usually not set up on both sides. Moreover, it cannot be used in a casting machine. The film slurry or the initially hardened wet film cannot be impacted by a strong airflow, otherwise it will affect the film quality. Therefore, the existing casting machine oven is not equipped with an air curtain and is a directly connected structure. Although there is a ventilation system to provide negative pressure, there will be gas leakage.

[0047] Please see again Figure 1 , Figure 2 In the preferred ventilation system, each temperature zone has a main exhaust port (a structure independent of the negative pressure air curtain device 5), which is used to cooperate with the air intake to form an overall air flow in the temperature zone, thereby discharging the solvent. The main exhaust port is arranged on the oven body, and the hot air enters and is discharged from the main exhaust port with the evaporated solvent. Preferably, the oven body is provided with an oven exhaust port 61 near the edge of the temperature zone (such as the positions on both sides of the negative pressure air curtain device and the partition), and / or the oven body is provided with an oven exhaust port 61 near the passive drum 72 (such as the side wall of the passive drum chamber 82 next to the passive drum 72). This scheme is designed to set the oven exhaust port in the dead corner of the oven, that is, the position where the evaporated solvent is easy to stagnate and gather, so as to focus on exhausting from these positions where the solvent is easy to be retained, ensure the air flow in the dead corner, and improve the efficiency and effect of solvent discharge.

[0048] The oven air inlet 62 is related to the setting of the static pressure box. For example, an air inlet is provided at the side wall of the box body perpendicular to the partition (i.e., the side walls on both sides of the length direction of the box body). For example, the oven air inlet 62 corresponding to the nozzle static pressure box 4 is located in the middle of the temperature zone and 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 the air exhaust port can also be optionally opened at the top of the oven body; for the lower drying duct, the situation and setting principle of the air inlet and the air exhaust port can be selected to be similar to those of the upper drying duct, except that they are opened on the left and right sides of the oven body. The oven exhaust port 61 is sealed and connected to the box body, and is connected to a negative pressure fan and an exhaust gas treatment system, etc. The relevant required components / systems are existing technologies and will not be elaborated here.

[0049] Preferably, an explosion vent 63 is provided in the first temperature zone and / or other temperature zones of the upper drying tunnel (such as the second and third temperature zones on the downstream side of the first temperature zone). The explosion vent 63 is preferably provided at least in the first temperature zone and the second temperature zone on the downstream side thereof. The solvent concentration in these areas is relatively high, and the explosion vent can release pressure in extreme cases. The explosion vent 63 is provided, for example, at the top of the box. Further preferably, each temperature zone is also provided with a monitoring device for temperature, air pressure and other states, so that timely measures or explosion relief can be taken in extreme cases, thereby protecting the safety of equipment and personnel.

[0050] An active drum chamber 81 is provided on the outside of the active drum 71, and the active drum chamber 81 is connected to the upper drying tunnel 1 and the lower drying tunnel 2. Preferably, a temperature control device for the feeding section is provided in the active drum chamber 81, such as a pipe or bellows for blowing cooling air, or a contact cooling of the steel belt, 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 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 very high when feeding the material at the steel belt of the active drum 71, the solvent will evaporate into the external space after the slurry is fed. This solution ensures that the film material is basically free of volatile solvents in the active drum chamber 81 (especially the upper feeding side), and is gradually heated after entering the upper drying tunnel.

[0051] Preferably, if Figure 2 As shown, the bearings, bearing seats, motors, steel belt deviation correcting devices, etc. of the active drum 71 and the passive drum 72 are arranged on the outside of the oven body to avoid long-term operation in a high-temperature environment, thereby effectively improving the service life.

[0052] In summary, the multi-temperature zone casting machine of the present invention is divided into multiple temperature zones in the oven, which can more accurately control the various process times of the film material, the temperature in the hardened state, the drying method, etc., and especially adopts a parallel air duct method to blow preheated air in the first temperature zone when the film slurry just enters the drying tunnel, so that the surface of the film slurry begins to harden and ensure air flow, while avoiding hot air blowing directly on the film surface of the film slurry and affecting the quality of the film; and a curved temperature zone is provided at the passive drum to continue to heat the film or keep it warm more effectively, avoiding the situation where the film temperature here will naturally decrease when using existing equipment, and then when the film continues to enter the lower drying tunnel, the temperature change is basically continuous without large sudden fluctuations; the hardness of the film surface after passing through the first temperature zone can withstand conventional hot air, and hot air can be blown in a manner generally facing the film surface in the future, so as to transfer heat more directly and efficiently and accelerate the evaporation of solvent. In addition, the present scheme preferably has a negative pressure wind curtain device, in which two relatively arranged exhaust parts simultaneously exhaust air, forming a negative pressure wind curtain in the channel space between the two exhaust parts, and the film can be transmitted in the front and rear spaces through the channel space. Since there is a negative pressure wind curtain between the two spaces, the mutual influence of temperature and gas between the two spaces (such as the escape / interconnection of gases with different temperatures and different component contents) is avoided, thereby effectively ensuring the accuracy and stability of the process environment control of high-end processes; at the same time, since the airflows in adjacent temperature zones are sucked toward the middle, a certain temperature transition area will be formed between adjacent temperature zones, which can further avoid sudden changes in ambient temperature when the film enters and exits the temperature zone.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention; for ease of description, only the parts related to the relevant inventions are shown in the accompanying drawings. In the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other; modifying the technical solutions recorded in the aforementioned embodiments, or replacing some of the technical features therein by equivalents, does not deviate the essence of the corresponding technical solutions 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 drivingly connected to the active drum (71) and the passive drum (72), and 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: A plurality of temperature zones are formed in the upper drying tunnel (1), the passive drum chamber (82) and the lower drying tunnel (2), the temperature zones at least comprising a first temperature zone (91), a bend temperature zone (93) and a lower drying tunnel temperature zone (94); each temperature zone is an adjustable temperature zone with adjustable temperature; At least one first temperature zone (91) is provided in the upper drying tunnel (1), and the first temperature zone (91) is close to the entrance of the upper drying tunnel (1); a parallel air circulation processing device (3) is provided in the first temperature zone (91), and the parallel air circulation processing device (3) comprises a parallel air duct air inlet (32) and a parallel air duct air outlet (31) which are arranged opposite to each other, and the parallel air duct air inlet (32) and the parallel air duct air outlet (31) are arranged above and below the steel strip, or are only arranged above the steel strip; At least one bend temperature zone (93) is provided in the passive drum chamber (82); a bend temperature control device is provided in the bend temperature zone (93) or on the outside of the passive drum chamber (82); At least one lower drying tunnel temperature zone (94) is provided in the lower drying tunnel (2).

2. The multi-temperature zone tape casting machine according to claim 1, characterized in that: Negative pressure air curtain devices (5) are arranged at adjacent locations of the two temperature zones and at the entrances and exits of the upper drying tunnel (1) and the lower drying tunnel (2); the negative pressure air curtain device (5) comprises a first air exhaust portion (51) and a second air exhaust portion (52) which are arranged opposite to each other, the first air exhaust portion (51) and the second air exhaust portion (52) are respectively located on both sides of the steel strip, a passage space (54) for the steel strip to pass through is formed between the first air exhaust portion (51) and the second air exhaust portion (52), and the passage space (54) is adapted to the width of the steel strip.

3. The multi-temperature zone casting machine according to claim 2, characterized in that: A wind curtain flow balancing plate (53) and / or an air regulating plate are arranged on the first air exhaust section (51) and the second air exhaust section (52); the wind curtain flow balancing plate (53) is arranged parallel to or inclined along the film conveying direction, and has a plurality of air holes or a plurality of slit holes on the wind curtain flow balancing plate (53); the wind curtain flow balancing plate (53) is a single-layer structure, or the wind curtain flow balancing plate (53) is a multi-layer structure and the air holes or slit holes on each layer are arranged relatively or staggered.

4. The multi-temperature zone tape casting machine according to claim 2, characterized in that: An adjustable wind shielding mechanism is provided at the inlet and / or outlet of the channel space (54), so that the inlet and / or outlet of the channel space (54) is adapted to the thickness of the steel belt carrying the film.

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

6. The multi-temperature zone tape casting machine according to any one of claims 1 to 4, characterized in that: The parallel air duct outlet portion (31) is arranged close to the entrance of the upper drying channel (1), and the parallel air duct inlet portion (32) is arranged on the opposite side of the parallel air duct outlet portion (31).

7. The multi-temperature zone tape casting machine according to any one of claims 1 to 4, characterized in that: The upper drying tunnel (1) also has at least one upper drying tunnel temperature zone (92), and the upper drying tunnel temperature zone (92) is located between the first temperature zone (91) and the passive drum chamber (82); an upper drying tunnel longitudinal air circulation processing device (41) is provided in the upper drying tunnel temperature zone (92) at least above the steel belt, and the nozzle of the upper drying tunnel longitudinal air circulation processing device (41) is directly facing or tilted toward the steel belt, or the direction of the nozzle is adjustable.

8. The multi-temperature zone tape casting machine according to any one of claims 1 to 4, characterized in that: A lower drying tunnel longitudinal air circulation processing device (42) is provided in the lower drying tunnel temperature zone (94) at least below the steel belt, and the nozzle of the lower drying tunnel longitudinal air circulation processing device (42) is directly facing or tilted toward the steel belt, or the direction of the nozzle is adjustable.

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

10. The multi-temperature zone tape casting machine according to any one of claims 1 to 4, characterized in that: An active drum chamber (81) is provided on the outside of the active drum (71). The active drum chamber (81) is connected to the upper drying channel (1) and the lower drying channel (2). A material inlet section temperature control device is provided in the active drum chamber (81).

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