Insulation board unit of polyimide film production line and box body formed by insulation board units

Abstract

The invention provides insulation board units of a polyimide film production line and a box body formed by the insulation board units. The insulation board units comprise upper and lower sides of the box body formed by main bearing insulation board units and side surfaces of the box body formed by side surface insulation units. Each heat preservation plate unit is of a hollow cavity structure formed by at least two layers of supporting frames and at least one heat insulation layer arranged between the supporting frames, single-layer sealing plates (side plates) are arranged on the two open sides of each hollow cavity, and therefore a heat preservation and insulation mode similar to a broken bridge heat insulation mode is formed. The cavity is filled with heat preservation materials or provided with at least multiple heat preservation layers, so that the good heat preservation performance of the whole cavity is achieved. The sealing plates (side plates) can also adopt sandwich heat insulation plates with heat insulation plates as middle interlayers, a two-stage broken bridge heat insulation mode is formed, internal heat is prevented from being transmitted to the outside to cause overheating of the outer surface of the box body, effective heat preservation and heat insulation are achieved, the mechanical property is better, and the cost is lower. And meanwhile, the functional requirements of sealing performance and the like of the box body of the casting machine or the transverse drawing machine are met.

Description

Technical Field

[0001] The invention belongs to the technical field of film manufacturing equipment, and specifically relates to a main load-bearing heat-insulating unit for a polyimide film production line, which is suitable for the box structure of a casting machine or a horizontal stretching machine. Background Art

[0002] Cast-film machines and horizontal stretching machines are both necessary equipment used in polyimide film production lines. Based on the needs of chemical film making, the outside of the machine body needs to have good thermal insulation and sealing functions. Both cast-film machines and horizontal stretching boxes need to be made of insulation panels for effective heat insulation and heat preservation.

[0003] In the prior art, steel plates or other metal plates attached with high-efficiency thermal insulation materials are mostly used as the side walls of the box, which are usually set as an integrated unit. Since the steel strip casting machine equipment is large and heavy, it not only requires a larger space for installation, but also if the equipment is partially damaged, the entire side wall has to be replaced, or other costly designs have to be adopted, which is not conducive to the current market promotion and application. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an insulation board unit structure for a polyimide film production line and a box composed of insulation board units, which can achieve high-performance modular design, factory prefabrication, on-site assembly, on-site replacement, no site restrictions, convenient maintenance and adjustment.

[0005] The present invention provides a polyimide film production line insulation board unit and a box body composed of the insulation board unit, including upper and lower sides of the box body composed of main load-bearing insulation board units and the side of the box body composed of side insulation units. The insulation board unit is a hollow cavity structure formed by at least two layers of support frames and at least one layer of insulation layer arranged therebetween, and single-layer sealing plates (side plates) are arranged on both sides of the open hollow cavity, thereby forming a thermal insulation method similar to thermal insulation of broken bridges. Thermal insulation material is filled in the cavity or at least multiple insulation layers are arranged to achieve good thermal insulation performance of the entire cavity. The sealing plate (side plate) can also adopt a sandwich insulation board with an intermediate layer as an insulation board to form a double-stage thermal insulation method to achieve the purpose of thermal insulation.

[0006] The present invention first provides a main load-bearing unit, and the main load-bearing insulation unit includes a main support frame, and the main support frame includes an outer frame, an inner frame, and a main support frame connecting the inner and outer frames. The outer frame and / or the inner frame are composed of an outer sealing plate, an insulation plate and an inner sealing plate, and at least one insulation layer is filled in the hollow cavity of the main frame. The inner and outer panels adopt a three-layer insulation method, and the entire frame adopts a three-layer insulation method to achieve a double-stage thermal insulation method. An internal support beam is arranged in the hollow cavity of the main frame, and the internal support beam is arranged on one side of the inner frame, or on one side of the outer frame, or on both sides. Interval support frames are arranged in the hollow cavity of the main frame to support the main support frame at intervals.

[0007] The main support frame is provided with a reserved opening, the reserved opening is composed of a support frame, a reinforcement piece is provided on one side of the reserved opening support frame located at the inner frame or / and the outer frame, and the reinforcement piece is connected to the inner side plate of the inner frame or / and the outer frame. The reserved opening is extended to the outside with an external connection part, and an insulation layer or a coating of insulation material is provided between the external connection part and the outer frame.

[0008] The main support frame is a channel steel or an I-beam, and / or the internal support beam and the reserved opening reinforcement are an I-beam, a channel steel or an angle iron, and / or the outer plate is a stainless steel plate, and / or the inner plate is an iron plate or a stainless steel plate, and the insulation board is a calcium silicon board.

[0009] The present invention also provides a side insulation board unit, including a main support frame, which includes a first support frame and a second support frame, with a first insulation layer arranged therebetween, the first support frame and the second support frame are connected to form a three-dimensional bracket with open inner and outer sides, the first support frame is directly or indirectly connected to an inner panel, the second support frame is directly or indirectly connected to an outer panel, and a hollow cavity structure is formed as a whole, and the thickness of the hollow cavity can be extended by a third support frame, and an insulation layer can be arranged in the hollow cavity to provide a highly strong thermal insulation board material with a strong expansion function.

[0010] The present invention also provides a side insulation unit with a reserved opening on the main support frame, the crane reserved opening includes a reserved opening support frame, and a heat insulation layer is provided between the reserved opening support frame and the outer plate. An insulation door is installed in the reserved opening, and the insulation door includes a door outer peripheral plate, a door inner plate and a door outer plate; a heat insulation layer is provided between the door outer peripheral plate and the door inner plate, and / or between the door outer peripheral plate and the door outer plate. An observation window is provided in the insulation door, and the observation window includes an inner frame and an outer frame, and a heat insulation layer is provided between the two. A double-layer glass window is provided on the outer frame, and a heat insulation layer is provided between the double-layer glass window and the door outer plate.

[0011] Compared with the prior art, the beneficial technical effects of the present invention are as follows: The insulation board unit for polyimide film production line is generally used on the four sides of the box of cast film machine or horizontal stretching machine, and cooperates with the upper and lower load-bearing units to form the whole box. The main load-bearing insulation board unit adopts a double-stage thermal insulation method, and fills the cavity formed by the board with insulation cotton, so that the inner and outer sides of the box wall are not in direct contact and are divided into at least two different temperature sections to prevent the internal heat from being transferred to the outside and causing the outer surface of the box to overheat. The inner and outer panels simultaneously adopt a sandwich insulation method containing an insulation layer, bipolar insulation, and better overall mechanical properties, lower cost, and faster and more convenient operation, installation and replacement.

[0012] Unlike the main load-bearing unit, the side insulation board unit does not require a high-strength counterweight frame such as channel steel. It only needs to use angle iron to make at least two layers of frames. An insulation layer is set between each layer of the frame. The hollow cavity formed by the frame is filled with insulation cotton or other insulation materials, or insulated in a layered manner, forming a similar thermal insulation method. One of the inner and outer panels, or both, can form a sandwich insulation method by setting only insulation panels in the middle interlayer. The entire main support frame adopts a three-layer thermal insulation method, plus the board to achieve a three-layer insulation method, forming a double-stage thermal insulation method. The cavity of the main support frame is filled with insulation cotton, so that the inner and outer walls of the box wall are not in direct contact. Based on the principle of thermal insulation, the internal heat is prevented from being transferred to the outside, causing the outer surface of the box to overheat; and compared with the existing structure, this solution has better mechanical properties and lower cost, while also ensuring the functional requirements of the casting machine box such as sealing.

[0013] The main load-bearing unit constitutes the upper and lower sides of the box body, and the side insulation board unit constitutes the side of the box body. The main support frame of the main load-bearing unit is made of materials with strong load-bearing capacity such as channel steel or I-beam, and this part can be directly covered by the side insulation unit of the thermal insulation bipolar thermal insulation method without being provided with insulation material, so as to achieve high performance of overall insulation.

[0014] The side insulation unit has both maintenance and observation functions, so the reserved space is relatively large for installing an inspection door or an observation door. The reserved opening is formed by a plate or a bracket, and an insulation layer is also required between the inner plate or the outer plate in contact with it. The reserved opening is provided with a cavity structure composed of a multi-layer insulation plate of the same similar structure, and the cavity is filled with insulation material or an insulation layer is provided, which can play the role of overall insulation and heat insulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the main load-bearing thermal insulation unit in the present invention.

[0016] Figure 2 yes Figure 1Schematic diagram of the cross-sectional structure of the main load-bearing insulation unit.

[0017] Figure 3 yes Figure 1 A schematic cross-sectional structure diagram of another main load-bearing insulation unit is shown.

[0018] Figure 4 It is a schematic diagram of the insulation board structure including two insulation board units.

[0019] Figure 5 It is a schematic diagram of the structure at the junction of two insulation board units.

[0020] Figure 6 It is a structural schematic diagram of the extra-long insulation board unit.

[0021] Figure 7 for Figure 6 Schematic diagram of the structure of the internal reinforcement ribs of the extra-long insulation board unit.

[0022] Figure 8 It is the front view of the insulation board unit.

[0023] Fig. 9 is along Figure 8 Cross-sectional view along the LL direction. Fig.10 This is a side view of a side insulation board unit for a polyimide film production line.

[0024] Fig.11 yes Fig. 9 A partial enlarged schematic diagram of point C in the middle.

[0025] Fig.12 yes Fig. 9 A schematic structural diagram of another embodiment at C in FIG.

[0026] Fig.13 It is a schematic structural diagram of the heat insulation door of the present invention.

[0027] Fig.14 This is one of the structural schematic diagrams of the insulation box for the polyimide film production line.

[0028] Fig.15 This is the second structural schematic diagram of the heat preservation box for the polyimide film production line. DETAILED DESCRIPTION

[0029] The present invention provides an insulation board unit for a polyimide film production line and a box body composed of the insulation unit, which solves the problems of high cost or poor insulation effect of the existing technical solutions, and achieves better insulation effect through structural improvement design. At the same time, the structure is relatively simple and the cost is relatively low.

[0030] See also Figures 1 to 3The present invention first provides a main load-bearing insulation unit 1, which includes a main support frame 10. The main support frame 10 is provided with a reserved opening 2 for convenient installation of auxiliary components. The main support frame 10 is a three-dimensional structure, and a hollow cavity 100 is formed inside it. The hollow cavity 100 is filled with an insulation layer 20 or other insulation structures are arranged.

[0031] See also Figure 2 , which is an embodiment of a main support frame 10, the main support frame 10 includes an outer frame 11 and an inner frame 12, the inner and outer frames are connected by a main support connector 13, the main support connector 13 is arranged around the frame to form a hollow cavity 100, and a multi-layer insulation layer 20 can be arranged inside the hollow cavity, the insulation layer can be insulation cotton or other insulation materials, preferably aluminum silicate insulation cotton, the thermal conductivity of the insulation cotton is smaller than that of air; and, more than two sections of broken bridge structure can be formed by adding insulation boards in the hollow cavity, the insulation layer can be arranged on both sides of the insulation board, and the structural members are not in direct contact with each other, which effectively blocks the transfer of heat; in this way, better insulation effect can be achieved, and the relevant materials and processes are relatively mature, so that the manufacturing cost of this scheme is relatively low.

[0032] The hollow cavity of the main support frame 10 is provided with an internal support beam 14 to form a load-bearing frame with the main support frame. The reserved openings are provided for installing different external components. The internal support beam 14 needs to consider the overall layout and weight of these reserved external components. It can be provided on one side of the inner frame, or on one side of the outer frame, or on both sides at the same time. The internal support beam 14 is lower than the main support connector 13 in terms of the usual height, which can effectively reduce the overall weight and cost while meeting the support requirements. A support beam or support frame with the same load-bearing capacity as the main support connector 13 can also be used as needed.

[0033] The reserved opening 2 may be a plurality of air outlets / inlets, or may be used to set other external devices, and is composed of a support frame 21 or a support rod or a support plate. The reserved opening support frame 21 is provided with a reinforcement member 22 located on one side of the inner frame or / and the outer frame, and is shown as an angle iron. In order to avoid heat conduction of the reinforcement member 22 and the reserved opening support frame 21, when it is connected to the inner frame 11 or / and the outer frame, an insulation measure is provided in the middle, such as an insulation board or insulation layer 25, or an insulation gap is reserved in the middle. The reserved opening 2 is usually extended outward, and has an external connection portion 23, i.e., an outer support frame. Considering the insulation measures when extending to the outside, insulation measures are provided between the external connection portion 23 and the outer frame 11, such as an insulation layer or a coating with insulation material. In this embodiment, the main support connector 13 is a channel steel, and the internal support beam and the reserved opening reinforcement can be an I-beam, a channel steel or an angle iron. The entire main support frame 10 is a three-dimensional frame composed of these components. The main support connector 13 is arranged around the frame to form a sturdy support load-bearing mechanism.

[0034] See also Figure 3 As shown, it is another preferred embodiment of the present invention, which is embodied in that the outer frame 11 and / or the inner frame 12 are a heat-insulating multi-layer structure. The outer frame 11 and / or the inner frame 12 are composed of an outer sealing plate 101, a heat insulation plate 102 and an inner sealing plate (103). The heat insulation plate 102 can be made of calcium silicate board or other heat-insulating materials. Other structures are the same as above. Figure 2 The embodiments shown are basically the same, and the reinforcing member 22 of the reserved opening support frame 21 can be directly connected to the inner side plate, and the purpose of heat insulation can be achieved without adding additional heat preservation measures.

[0035] Inventions such as Figure 4 As shown, it is an insulation board composed of insulation board units, which includes two insulation board units 1 connected to each other, and combined with Figure 5 As shown, a buffer plate 15 is provided on adjacent sides of two mutually connected heat preservation board units 1, that is, they are separated by non-metallic plates, so as to achieve a buffer function and a certain degree of heat insulation and reinforcement function.

[0036] See also Figure 6 As shown, it is a structural diagram of an extra-long insulation board unit. When extra-long materials are used, a spacing support frame 16 with the same structure as the main supporting connector 13 is provided in the middle position or the position that needs to bear weight to ensure that the whole has the strongest load-bearing effect. Figure 7 The figure shows the arrangement of the spacer support frame 16.

[0037] like Figure 8As shown, it is a side insulation board unit, which is mainly used for the box body of a cast-film machine or a horizontal stretching machine. The side insulation board unit 3 is composed of an insulation structure, and a reserved opening 4 is provided on it for installing external equipment, or an inspection door or an observation window, etc.

[0038] like Fig. 9 and Fig.10 As shown, the side insulation panel unit 3 includes a main support frame 30, which includes a first support frame 31 and a second support frame 32, with a first insulation layer 33 arranged therebetween, the first support frame 31 and the second support frame 32 are connected to form a three-dimensional bracket with open inner and outer sides, the first support frame 31 is directly or indirectly connected to an inner plate 301, and the second support frame 32 is directly or indirectly connected to an outer plate 302, forming a hollow cavity structure as a whole.

[0039] Please combine Fig.12 As shown, the first support frame 31 and the second support frame 32 can be surrounded by angle irons to form a square or rectangular frame, and the two frames are connected by one side of the angle iron, and the first heat insulation layer 33 is arranged between the two frames. The other side of the angle iron is used as a side edge connected and fixed to the inner plate 301 and the outer plate 302. At the same time, in addition to the plate surface that shields the open area, the inner plate 301 and the outer plate 302 are provided with a connecting edge that matches the side edge of the angle iron. It is better that the connecting edge has the same width as the side edge of the angle iron, which can improve the overall aesthetics of the appearance.

[0040] like Fig.11 As shown, due to Fig.12 In the embodiment, the thickness of the hollow cavity structure formed by the two angle iron frames interlocking with each other is limited, and a third support frame 34 can be added, which is connected to one side of the inner plate 301 or the outer plate 302 to expand the space of the hollow cavity. As shown in the figure, the third support frame 34 is surrounded by a longitudinal plate with a slightly bent portion on one side to form a square or rectangular frame, one side of which is connected to one side of the angle iron of the second support frame 32, and the other side is connected to the connecting edge of the outer plate 302 from the inner side of the frame through the bent portion. In order to further insulate, the surface of the third support frame 34 in contact with the outer plate 302 is provided with a second insulation layer 35. The addition of the third support frame 34 can expand the overall thickness of the side insulation unit and further increase the insulation performance.

[0041] Look again Fig.10 and Fig.13 , which reflects the overall structure of the side insulation unit, which is composed of the inner plate 301, the first support frame 31, the insulation layer 33, the second support frame 32, the third support frame 34, the insulation layer 35 and the outer plate 302 from the inside to the outside, and the insulation layer is filled inside. Figure 4 Embodiment, or adopt Figure 5 In the embodiment, a heat-insulating layer is provided in the hollow cavity, and the heat-insulating layer can be a heat-insulating material that fills the entire space, or can be a heat-insulating board that is provided in multiple layers. The side heat-insulating unit is not a load-bearing unit, and has a heat-insulating layer provided inside from the inside to the outside, and a heat-insulating layer is provided between the outer plate 302 and the frame that contacts it, so that there is a very strong heat-insulating function between the inside and the outside. Generally speaking, the inner plate 301 and / or the outer plate 302 can achieve a very good heat-insulating method by being a single-layer plate. If you want to reduce the thickness of the cavity, or pursue the ultimate heat-insulating effect, the inner plate 301 and / or the outer plate 302, including a heat-insulating multi-layer plate composed of an outer sealing plate, a heat-insulating plate and an inner sealing plate, can also be placed with multiple layers of heat-insulating plates.

[0042] Next, the main support frame 30 is provided with a reserved opening 4 for installing external equipment or installing an inspection door, etc. Fig. 9 As shown, in order to ensure the heat preservation and heat insulation function of the reserved opening position, the reserved opening 4 includes a reserved opening support frame 41, and a heat insulation layer is arranged between the reserved opening support frame 41 and the outer plate 302, so as to achieve heat insulation between the reserved opening support frame 41 and the outer side. Of course, a heat insulation layer can also be arranged at the inner side plate to further enhance the heat preservation and heat insulation effect of the frame body in contact with the outside at the reserved opening position.

[0043] Please combine Fig.13 As shown, an insulating door 5 is installed in the reserved opening, and the insulating door 5 includes a door outer peripheral plate 51, a door inner plate 51 and a door outer plate 53; the door outer peripheral plate 51 includes the plate surfaces on both sides and the upper end of the door body to form a frame, and a support plate 55 can be arranged inside, and an insulating layer 54 is arranged between the door outer peripheral plate 51 and the door inner plate 51, and / or between the door outer peripheral plate 51 and the door outer plate 53. A thermal insulation layer is arranged at the position where the insulating door 5 contacts the reserved opening 4 to block heat conduction. An observation window 6 is arranged in the insulating door 5, and the observation window 6 includes an inner frame 61 and an outer frame 62, and an insulating layer is arranged between the two. A double-layer glass window is arranged on the outer frame, and an insulating layer is arranged between the double-layer glass window and the door outer plate 53.

[0044] like Fig.14As shown, it is a structural schematic diagram of a cast film machine for a polyimide film production line, including the upper and lower sides of the box body formed by the main load-bearing insulation board unit and the side of the box body formed by the side insulation unit. The insulation board unit is a hollow cavity structure formed by at least two layers of support frames and at least one layer of insulation layer arranged therebetween, and a single-layer sealing plate (side plate) is arranged on both sides of the open hollow cavity, thereby forming a thermal insulation method similar to thermal insulation of broken bridges. Fill the cavity with insulation material or set at least multiple insulation layers to achieve good thermal insulation performance of the entire cavity. The main support frame of the main load-bearing unit is made of materials with strong bearing capacity such as channel steel or I-beam, and this part does not need to be coated with insulation material, but is directly coated with the side insulation unit of the thermal insulation bipolar broken bridge insulation method, thereby achieving high performance of overall insulation.

[0045] like Fig.15 As shown, it is a structural schematic diagram of a horizontal stretching machine for a polyimide film production line. Unlike a cast film machine, the positions and numbers of the reserved openings are different, and the functions of the components installed in the reserved openings are different.

[0046] The present invention adopts a modular construction method and a double-stage thermal insulation method, which can ensure remote production and remote assembly, high-strength thermal insulation functions, and convenient disassembly and installation.

[0047] 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; although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention. The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A heat preservation board unit for a polyimide film production line, characterized in that: The invention comprises a main support frame (10, 30), which comprises an open three-dimensional support frame composed of a single-layer main support frame (13) or a double-layer support frame (31, 32) including at least one layer of heat insulation layer (32), and the two open sides are directly or indirectly connected to a single-layer sealing plate, or at least one side adopts a multi-layer sealing plate with at least one layer of heat insulation plate, so that a hollow cavity structure is formed as a whole.

2. The heat preservation board unit for a polyimide film production line according to claim 1, characterized in that: The hollow cavity is filled with a heat-insulating material or is provided with at least one heat-insulating layer.

3. The heat preservation board unit for a polyimide film production line according to claim 2, characterized in that: At least one internal support frame is arranged in the hollow cavity.

4. The heat preservation board unit for a polyimide film production line according to any one of claims 1 to 3, characterized in that: A reserved opening (21, 4) is provided on the main support frame body (10, 30), the reserved opening (21, 4) includes a reserved opening support frame (21, 41), and a heat insulation layer is provided between the reserved opening support frame (21, 41) and at least the outer plate (302).

5. A heat preservation box for a polyimide film production line, characterized in that: The side of the box body comprises the upper and lower sides of the box body formed by the main load-bearing insulation board unit and the side insulation unit; The main load-bearing heat-insulating unit (1) comprises a main support frame (10), the main support frame (10) comprises a hollow frame formed by a main support frame (13), an outer frame (11) and an inner frame (12) are arranged on both sides of the hollow frame, and the outer frame (11) and / or the inner frame (12) of the main support frame are not single-layer plates or are formed by an outer sealing plate (101), a heat insulation plate (102) and an inner sealing plate (103), forming a hollow cavity (100) structure as a whole; The side heat-insulating unit (3) comprises a first support frame (31) and a second support frame (32), a first heat-insulating layer (33) being arranged between the first support frame (31) and the second support frame (32), the first support frame (31) and the second support frame (32) being connected to form a three-dimensional support frame with an inner side and an outer side open, the first support frame (31) being directly or indirectly connected to an inner side plate (301), and the second support frame (32) being directly or indirectly connected to an outer side plate (302), so that a hollow cavity structure is formed as a whole.

6. The heat preservation box for a polyimide film production line according to claim 5, characterized in that: An internal support beam (14) is arranged in the hollow cavity (100) of the main frame, and the internal support beam (14) is arranged on one side of the inner frame (12), or on one side of the outer frame (11), or on both sides; and / or a spacing support frame (16) is arranged in the hollow cavity (100) of the main frame to support the main support frame (10) at intervals.

7. A heat preservation box for a polyimide film production line as claimed in claim 5 or 6, characterized in that: The first support frame (31) and / or the second support frame (32) are connected to at least one third support frame (34), and are connected to the inner plate (301) or the outer plate (302) via the third support frame (34) to expand the space of the hollow cavity, and a second heat insulation layer (35) is provided between the third support frame (34) and the inner plate (301) or the outer plate (302).

8. The heat preservation box for a polyimide film production line according to claim 7, characterized in that: A heat-insulating layer is arranged in the hollow cavity.

9. The heat preservation box for a polyimide film production line according to claim 8, characterized in that: A reserved opening (2) is provided on the main load-bearing heat-insulating unit (1), the reserved opening (2) is formed by a support frame (21), the reinforcement member (22) is connected to an inner side plate (103) of an inner frame or / and an outer frame, a reinforcement member (22) is provided on one side of the reserved opening support frame (21) located on the inner frame or / and the outer frame, an external connection portion (23) extends outward from the reserved opening, and a heat-insulating layer is provided or coated with a heat-insulating material between the external connection portion (23) and the outer frame (11); The side heat-insulating unit (3) is provided with a reserved opening (4), the reserved opening (4) comprises a reserved opening support frame (41), and a heat-insulating layer is provided between the reserved opening support frame (41) and the outer plate (302).

10. The heat preservation box for a polyimide film production line according to claim 9, characterized in that: An insulating door (5) is installed in the reserved opening, and the insulating door (5) comprises a door outer peripheral plate (51), a door inner plate (51) and a door outer plate (53); a heat insulating layer (54) is provided between the door outer peripheral plate (51) and the door inner plate (51), and / or between the door outer peripheral plate (51) and the door outer plate (53).

11. The heat preservation box for a polyimide film production line according to claim 10, characterized in that: An observation window (6) is arranged inside the heat-insulating door (5), the observation window (6) comprising an inner frame (61) and an outer frame (62), a heat-insulating layer being arranged between the inner frame and the outer frame, a double-layer glass window being arranged on the outer frame, a heat-insulating layer being arranged between the double-layer glass window and the door outer panel (53); and a heat-insulating layer being arranged between the heat-insulating door (5) and the reserved opening (4).

12. The heat preservation box for a polyimide film production line according to claim 11, characterized in that: The main support frame (13) is a channel steel or an I-beam, and / or the internal support beam (14) and the reserved opening reinforcement member (22) are an I-beam, a channel steel or an angle iron, and / or the outer plate (101) is a stainless steel plate, and / or the inner plate (103) is an iron plate or a stainless steel plate, and the heat insulation board is a calcium silicon board.

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