A film stretching roller

Abstract

The utility model provides a kind of film stretching roller, it is related to film production technical field, including outer tube, inner tube, heat uniform layer, built-in piece and flow channel assembly, inner tube is arranged in the inside of outer tube, and with outer tube coaxial fixed, the accommodation gap between the outer wall of inner tube and the inner wall of outer tube is formed;Heat uniform layer is set in the accommodation gap, and the outer wall of inner tube and the inner wall of outer tube are adhered, to evenly conduct the heat on inner tube to outer tube.The utility model sets up inner tube and outer tube, and sets up inner flow channel in the inside of built-in piece, outer flow channel is set between built-in piece and inner tube, while outer flow channel is set as parallel with inner tube, to reduce the length of heat medium heat exchange as far as possible, and heat uniform layer is set between inner tube and outer tube, and the heat of heat medium transmission is evenly conducted, to effectively reduce the temperature difference of outer tube surface, improve the forming quality of film, avoid appearing wrinkle and other defects.

Description

Technical Field

[0001] This utility model relates to the field of film production technology, and in particular to a film stretching roller. Background Technology

[0002] With the rapid development of electronic information technology and the new energy industry, BOPP (biaxially oriented polypropylene) capacitor film, as a key electronic material, plays an increasingly important role in the capacitor manufacturing field. In the electronics industry, BOPP capacitor film is mainly used to manufacture film capacitors. These capacitors, due to their good stability and long lifespan, are widely used in home appliances, communication equipment, new energy vehicles, photovoltaic power generation, and other fields. Especially in new energy vehicles and renewable energy systems, high-performance film capacitors play a crucial role in power quality regulation and energy storage, further driving the market demand for BOPP capacitor film. The stretching roller is a core component in the BOPP capacitor film production line, mainly responsible for the precise longitudinal and transverse stretching of the polypropylene film during the biaxial stretching process. For example, a stretching roller for preparing biaxially oriented film, disclosed in CN117048034A, uses an electric heating wire to heat the roller body, providing the heat for film stretching.

[0003] However, heating with electric heating wires cannot guarantee the uniformity of heat conduction, and there is a significant delay in temperature adjustment, which can easily cause temperature fluctuations and affect the quality of film stretching production. In some solutions, heat is supplied by a heat medium, especially to avoid local temperature differences, using a spiral flow channel for heat medium circulation. However, this solution significantly increases the distance for heat exchange by the spiral flow channel, which can easily lead to a certain temperature difference between the two ends of the flow channel, affecting the quality of film stretching. Utility Model Content

[0004] In view of this, the present invention proposes a film stretching roller, which sets up an inner cylinder and an outer cylinder, with the inner flow channel set inside the inner component and the outer flow channel set between the inner component and the inner cylinder, and the outer flow channel set parallel to the inner cylinder, so as to minimize the length of heat exchange of the heat medium. A heat homogenizing layer is set between the inner cylinder and the outer cylinder to uniformly conduct the heat transferred by the heat medium, thereby effectively reducing the temperature difference on the surface of the outer cylinder, improving the forming quality of the film, and avoiding defects such as wrinkles.

[0005] The technical solution of this utility model is achieved as follows: This utility model provides a film stretching roller, including an outer cylinder, an inner cylinder, a heat equalization layer, built-in components, and a flow channel assembly, wherein, The inner cylinder is disposed inside the outer cylinder and is fixed coaxially with the outer cylinder, and an accommodating gap is formed between the outer wall of the inner cylinder and the inner wall of the outer cylinder; The heat spreader is set in the accommodating gap and is attached to the outer wall of the inner cylinder and the inner wall of the outer cylinder to evenly conduct the heat on the inner cylinder to the outer cylinder. The built-in component is fixed inside the inner cylinder, and the outside of the built-in component is provided with multiple external flow channels parallel to the axis of the inner cylinder. The external flow channels are used to supply the heating medium to conduct heat to the inner cylinder. The flow channel assembly is disposed inside the built-in component, and the flow channel assembly forms an inner flow channel inside the built-in component, one end of which is connected to the outer flow channel.

[0006] Based on the above technical solutions, preferably, it also includes a first shaft member, which is disposed on the same end of the outer cylinder and the inner cylinder and is coaxial with the outer cylinder. The first shaft member closes the ends of the outer cylinder and the inner cylinder and connects the outer flow channel with the inner flow channel.

[0007] More preferably, the first shaft member is provided with an extension cavity, the extension cavity communicating with an outer flow channel, and the flow channel assembly includes a first fixing member and an extension tube, wherein, The first fixing member is located inside the inner cylinder and at one end of the inner cylinder near the first shaft member; One end of the extension tube is mounted on the first fixing member, and the other end extends into the extension cavity. The inner flow channel is connected to the extension cavity through the extension tube.

[0008] Based on the above technical solution, preferably, it also includes a second shaft member, which is disposed on the same end of the outer cylinder and the inner cylinder and is coaxial with the outer cylinder. The second shaft member closes the ends of the outer cylinder and the inner cylinder. The second shaft member is hollow inside and has an opening at its end. The opening end of the second shaft member is used for introducing and discharging heat medium.

[0009] More preferably, the flow channel assembly includes a second fixing member and a heat medium inlet pipe, wherein, The second fastener is fixed inside the inner cylinder and is located at one end of the inner cylinder near the second shaft member; One end of the heat medium inlet pipe is mounted on the second fixing member, and the other end extends into the interior of the second shaft member. The heat medium inlet pipe is connected to the inner flow channel, and a return channel connecting the outer flow channel is formed between the heat medium inlet pipe and the inner wall of the second shaft member.

[0010] Based on the above technical solutions, preferably, the flow channel assembly includes a first fixing member, a second fixing member, and a conduit, wherein, Both the first and second fasteners are installed inside the inner cylinder and are located at both ends of the inner cylinder, respectively. The two ends of the conduit are fixed to the first fixing member and the second fixing member respectively, and the inner flow channel passes through the inside of the conduit.

[0011] More preferably, the conduit does not contact the inner cylinder, and a structural gap is formed between the outside of the conduit and the inner wall of the inner cylinder.

[0012] More preferably, it also includes a thermal insulation layer, which is disposed within the structural gap to prevent heat loss of the heat medium inside the duct.

[0013] The film stretching roller of this invention has the following advantages over the prior art: (1) By setting an inner cylinder and an outer cylinder, and setting the inner flow channel inside the inner component and the outer flow channel between the inner component and the inner cylinder, and setting the outer flow channel parallel to the inner cylinder, the length of heat exchange of the heat medium is minimized as much as possible. A heat homogenizing layer is set between the inner cylinder and the outer cylinder to conduct the heat transferred by the heat medium evenly, thereby effectively reducing the temperature difference on the surface of the outer cylinder, improving the forming quality of the film, and avoiding defects such as wrinkles. (2) An extension cavity is set up and an extension tube is used to allow the heat medium to enter the first shaft during the flow process, forming an extension flow channel for the heat medium. The first shaft serves as the end of the flow channel to avoid rapid heat loss at the end of the inner cylinder, which would cause a temperature difference between the end and the middle of the roller body in contact with the film, thereby improving the quality of film stretching and forming. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of the film stretching roller of this utility model; Figure 2 for Figure 1 Enlarged view of point A in the middle; Figure 3 This is a schematic diagram of the cross-section of the film stretching roller of this utility model perpendicular to the axis. Detailed Implementation

[0016] The technical solutions of this utility model will be clearly and completely described below with reference to the embodiments of this utility model. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0017] like Figure 1-3 As shown, the film stretching roller of this utility model includes an outer cylinder 1, an inner cylinder 2, a heat equalization layer 3, an internal component 4, and a flow channel assembly 5.

[0018] The outer cylinder 1 is a cylindrical component with chrome plating on the outside. The outer cylinder 1 will directly contact the film to be stretched. Its radial runout (≤0.01mm) and surface roughness (Ra≤0.1μm) are specified.

[0019] The inner cylinder 2 is set inside the outer cylinder 1 and is fixed coaxially with the outer cylinder 1. A receiving gap is formed between the outer wall of the inner cylinder 2 and the inner wall of the outer cylinder 1. The outer diameter of the inner cylinder 2 is smaller than the inner diameter of the outer cylinder 1 to form the receiving gap. The length of the inner cylinder 2 is equal to the length of the outer cylinder 1, so that when the entire roller is sealed from the outside of the outer cylinder 1, the receiving gap can be sealed synchronously.

[0020] The heat spreader 3 is disposed within the accommodating gap and is attached to the outer wall of the inner cylinder 2 and the inner wall of the outer cylinder 1 to uniformly conduct the heat on the inner cylinder 2 to the outer cylinder 1. The heat spreader 3 needs to be made of filler, liquid, etc. with high thermal conductivity. In some embodiments, it can be a ternary low molten salt layer. The heat spreader 3 conducts the heat on the inner cylinder 2 to the outer cylinder 1 through diffusion, avoiding uneven heat distribution caused by the heat medium not being able to form a whole to conduct heat outward due to the flow channel setting.

[0021] The built-in component 4 is fixed inside the inner cylinder 2. The outside of the built-in component 4 is provided with a plurality of external flow channels 401 parallel to the axis of the inner cylinder 2. The external flow channels 401 are used to supply heating medium to conduct heat to the inner cylinder 2.

[0022] In this embodiment, the built-in component 4 is used to form the outer flow channel 401. Specifically, the built-in component 4 can be configured as a cylindrical structure with a length less than that of the inner cylinder 2 and a wall thickness greater than that of the inner cylinder 2, thereby setting the outer flow channel 401 outside the built-in component 4. Since connection stability, heat medium flow rate, pressure, etc. need to be considered, multiple outer flow channels 401 are set and distributed around the axis of the roller body in this embodiment. Specifically, rotational symmetry can be selected. The number of outer flow channels 401 needs to be selected according to the outer diameter of the built-in component 4 and the specifications of the outer flow channel 401 itself. In a specific embodiment, the number of outer flow channels 401 is set to sixteen.

[0023] Meanwhile, by setting the outer flow channel 401 parallel to the axis of the inner cylinder 2, the length of the outer flow channel is no greater than the entire roller body, and the time from one end of the roller body to the other end is short, so that no large temperature fluctuations will occur.

[0024] The flow channel assembly 5 is disposed inside the built-in component 4, and the flow channel assembly 5 forms an inner flow channel 501 inside the built-in component 4. One end of the inner flow channel 501 is connected to the outer flow channel 401. The flow channel assembly 5 is used to form an inner flow channel 501 inside the built-in component 4. Only one inner flow channel 501 is set, and it is not directly disposed inside the built-in component 4. The built-in component 4 is hollow inside, so as to install the flow channel assembly 5. In addition to forming the inner flow channel, the flow channel assembly 5 is also used to cooperate in the internal assembly of the entire roller body, as well as to connect the end structure, forming a communication structure between the inner flow channel 501 and the outer flow channel 401.

[0025] In this embodiment, by setting an inner cylinder 2 and an outer cylinder 1, and setting an inner flow channel 501 inside the built-in component 4, and setting an outer flow channel 401 between the built-in component 4 and the inner cylinder 2, and setting the outer flow channel 401 to be parallel to the inner cylinder 2, the length of heat exchange of the heat medium is minimized as much as possible. A heat equalization layer 3 is set between the inner cylinder 2 and the outer cylinder 1 to uniformly conduct the heat transferred by the heat medium, thereby effectively reducing the temperature difference on the surface of the outer cylinder, improving the forming quality of the film, and avoiding defects such as wrinkles.

[0026] In some embodiments, a first shaft 6 is also provided. The first shaft 6 is disposed on the same end of the outer cylinder 1 and the inner cylinder 2 and is coaxial with the outer cylinder 1. The first shaft 6 closes the ends of the outer cylinder 1 and the inner cylinder 2 and connects the outer flow channel 401 with the inner flow channel 501.

[0027] The first shaft 6 is used to seal one end of the inner cylinder 2 and the outer cylinder 1, and to connect it to the stretching forming equipment. The first shaft 6 is provided with a transmission structure such as a spline groove for external driving equipment to drive it. At the same time, by sealing the inner cylinder 2, the first shaft 6 forms a structure at its end that connects the outer flow channel 401 and the inner flow channel 501, so as to form a channel for the heat medium to circulate in the roller body. This allows the heat medium to enter from one end of the inner cylinder 2 and enter the outer flow channel 401 from the other end of the inner cylinder 2, and then exit from the end where the heat medium enters the inner cylinder 2, realizing one-sided entry and exit without affecting the transmission between the first shaft 6 and the external equipment.

[0028] In one specific embodiment, the first shaft member 6 is provided with an extension cavity 601, the extension cavity 601 is connected to the outer flow channel 401, the flow channel assembly 5 includes a first fixing member 51 and an extension tube 52, the first fixing member 51 is disposed inside the inner cylinder 2 and is located at one end of the inner cylinder 2 near the first shaft member 6, one end of the extension tube 52 is disposed on the first fixing member 51, and the other end extends into the extension cavity 601, the inner flow channel 501 is connected to the extension cavity 601 through the extension tube 52.

[0029] Considering that the heat dissipation rate of the heat medium at the end of the roller is greater than that in the middle, which may cause the temperature at the end to be slightly lower than that in the middle, an extension cavity 601 is added, along with an extension tube 52, so that the heat medium enters the first shaft member 6 during the flow process, forming an extended flow channel for the heat medium. The first shaft member 6 serves as the end of the flow channel to avoid rapid heat loss at the end of the inner cylinder 2, which would cause a temperature difference between the end of the roller that contacts the film and the middle, thereby improving the quality of film stretching and forming.

[0030] Correspondingly, in addition to the first shaft member 6, a second shaft member 7 is also provided. The second shaft member 7 is located on the same end of the outer cylinder 1 and the inner cylinder 2 and is coaxial with the outer cylinder 1. The second shaft member 7 closes the ends of the outer cylinder 1 and the inner cylinder 2. The second shaft member 7 is hollow inside and has an opening at its end. The opening end of the second shaft member 7 is used for introducing and discharging heat medium.

[0031] Unlike the first shaft 6, the second shaft 7 is only used for mounting on the equipment and is not connected to the external drive equipment for transmission. Therefore, the second shaft 7 can be used as one end for the heat medium to enter and exit.

[0032] In some specific embodiments, the flow channel assembly 5 includes a second fixing member 53 and a heat medium inlet pipe 54. The second fixing member 53 is fixed inside the inner cylinder 2 and is located at one end of the inner cylinder 2 near the second shaft member 7. One end of the heat medium inlet pipe 54 is disposed on the second fixing member 53, and the other end extends into the interior of the second shaft member 7. The heat medium inlet pipe 54 communicates with the inner flow channel 501, and a return channel communicating with the outer flow channel 401 is formed between the heat medium inlet pipe 54 and the inner wall of the second shaft member 7.

[0033] Since the heat medium inlet pipe 54 is located inside the second shaft member 7 and a return channel is formed inside the second shaft member 7, a flow channel extension structure similar to that of the first shaft member 6 is formed at this end, which can prevent the heat loss at this end from being too fast, thus avoiding the formation of a temperature difference on the surface of the roller body and the film in contact.

[0034] In some embodiments, the flow channel assembly 5 specifically includes a first fixing member 51, an extension tube 52, a second fixing member 53, a heat medium inlet tube 54, and a conduit 55. The first fixing member 51 and the second fixing member 53 are both disposed inside the inner cylinder 2 and are located at both ends of the inner cylinder 2, respectively. The two ends of the conduit 55 are respectively fixed to the first fixing member 51 and the second fixing member 53. The inner flow channel 501 passes through the interior of the conduit 55. The extension tube 51 is disposed on the first fixing member 51 and extends into the first shaft member 6. The heat medium inlet tube 54 is disposed on the second fixing member 53 and extends into the second shaft member 7. The interiors of the extension tube 52, the conduit 55, and the heat medium inlet tube 54 form a continuous inner flow channel 501.

[0035] This configuration allows for the assembly of the various parts of the flow channel assembly 5 during the assembly process. The assembly is then placed into the built-in component 4 and fixed into the inner cylinder 2. The inner cylinder 2 is then placed into the outer cylinder 1, thereby completing the assembly of all components except for the first shaft component 6 and the second shaft component 7. The first shaft component 6 and the second shaft component 7 can be installed during the installation process of each part or at the end.

[0036] In some embodiments, in order to avoid or reduce the radiation of heat from the heat medium in the inner flow channel 501 to the outside, the conduit 55 does not contact the inner cylinder 2, and a structural gap is formed between the outside of the conduit 55 and the inner wall of the inner cylinder 2. In this structural gap, heat insulation can be achieved by means of vacuuming, etc. At the same time, this setting can reduce the production cost and overall quality of the entire roller.

[0037] Correspondingly, a heat insulation layer 8 is also provided. The heat insulation layer 8 is set in the structural gap to prevent the heat loss of the heat medium in the conduit 55. The heat insulation layer 8 can be a vacuum layer or other heat insulation filler, etc. It can have a certain heat conduction effect and can conduct heat to the heat medium flowing back to the second shaft 7 to slightly compensate for the temperature loss of the heat medium. The heat conducted by the heat insulation layer 8 is the heat conducted by the heat medium that initially enters the conduit 55.

[0038] Alternatively, heat transfer oil can be used as the heat transfer medium.

[0039] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A film stretching roller, characterized in that: It includes an outer cylinder (1), an inner cylinder (2), a heat spreader (3), internal components (4), and a flow channel assembly (5), wherein, The inner cylinder (2) is set inside the outer cylinder (1) and is fixed coaxially with the outer cylinder (1). An accommodating gap is formed between the outer wall of the inner cylinder (2) and the inner wall of the outer cylinder (1). The heat spreader (3) is set in the accommodating gap and is attached to the outer wall of the inner cylinder (2) and the inner wall of the outer cylinder (1) so as to evenly conduct the heat on the inner cylinder (2) to the outer cylinder (1). The built-in component (4) is fixed inside the inner cylinder (2). The outside of the built-in component (4) is provided with multiple external flow channels (401) parallel to the axis of the inner cylinder (2). The external flow channels (401) are used to supply the heating medium to conduct heat to the inner cylinder (2). The flow channel assembly (5) is disposed inside the built-in member (4), and the flow channel assembly (5) forms an inner flow channel (501) inside the built-in member (4), one end of the inner flow channel (501) being connected to the outer flow channel (401).

2. The film stretching roller as described in claim 1, characterized in that: It also includes a first shaft (6), which is disposed on the same end of the outer cylinder (1) and the inner cylinder (2) and is coaxial with the outer cylinder (1). The first shaft (6) closes the ends of the outer cylinder (1) and the inner cylinder (2) and connects the outer flow channel (401) with the inner flow channel (501).

3. The film stretching roller as described in claim 2, characterized in that: The first shaft (6) is provided with an extension cavity (601), the extension cavity (601) is connected to the outer flow channel (401), and the flow channel assembly (5) includes a first fixing member (51) and an extension tube (52), wherein, The first fixing member (51) is located inside the inner cylinder (2) and at one end of the inner cylinder (2) near the first shaft member (6); One end of the extension tube (52) is disposed on the first fixing member (51), and the other end extends into the extension cavity (601). The inner flow channel (501) is connected to the extension cavity (601) through the extension tube (52).

4. The film stretching roller as described in claim 1, characterized in that: It also includes a second shaft (7), which is disposed on the same end of the outer cylinder (1) and the inner cylinder (2) and is coaxial with the outer cylinder (1). The second shaft (7) closes the ends of the outer cylinder (1) and the inner cylinder (2). The second shaft (7) is hollow inside and has an opening at its end. The opening end of the second shaft (7) is used to introduce and discharge the heat medium.

5. The film stretching roller as described in claim 4, characterized in that: The flow channel assembly (5) includes a second fixing member (53) and a heat medium inlet pipe (54), wherein, The second fastener (53) is fixed inside the inner cylinder (2) and is located at one end of the inner cylinder (2) near the second shaft (7); One end of the heat medium inlet pipe (54) is set on the second fixing member (53), and the other end extends into the interior of the second shaft member (7). The heat medium inlet pipe (54) is connected to the inner flow channel (501), and a return channel connecting the outer flow channel (401) is formed between the heat medium inlet pipe (54) and the inner wall of the second shaft member (7).

6. The film stretching roller as described in claim 1, characterized in that: The flow channel assembly (5) includes a first fixing member (51), a second fixing member (53), and a conduit (55), wherein, The first fixing member (51) and the second fixing member (53) are both installed inside the inner cylinder (2) and are located at both ends of the inner cylinder (2); The two ends of the conduit (55) are fixed to the first fixing member (51) and the second fixing member (53) respectively, and the inner flow channel (501) passes through the interior of the conduit (55).

7. The film stretching roller as described in claim 6, characterized in that: The conduit (55) does not contact the inner cylinder (2) and forms a structural gap between the outside of the conduit (55) and the inner wall of the inner cylinder (2).

8. The film stretching roller as described in claim 7, characterized in that: It also includes a thermal insulation layer (8), which is disposed within the structural gap to prevent heat loss of the heat medium inside the conduit (55).

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