A polyimide film annealing method

Abstract

The present invention discloses a polyimide film annealing method, comprising: pulling a polyimide film at a preset tension level; continuously blowing a first high-temperature carrier gas having a first preset temperature from a first gas outlet to an upper surface of the polyimide film at a preset air pressure upstream of the active direction of the polyimide film; extracting the first high-temperature carrier gas blown from the first gas outlet and heating it to a second high-temperature carrier gas having a second preset temperature, wherein the second preset temperature is higher than the first preset temperature; continuously blowing a second high-temperature carrier gas from a second gas outlet to a surface of the polyimide film at a preset air pressure midstream in the pulling direction of the polyimide film; extracting the second high-temperature carrier gas blown from the second gas outlet, mixing it with a normal-temperature carrier gas, heating it to the first preset temperature, and then circulating it to the first gas outlet for blowing.

Description

Technical Field

[0001] The invention relates to the technical field of polyimide film preparation, in particular to a polyimide film annealing method. Background Art

[0002] In the production process of polyimide film, in order to improve the performance of the film, the polyimide film needs to be annealed before shipment to eliminate the internal stress of the film formed in the previous process. The existing annealing treatment uses an annealing furnace, and the existing annealing furnace mostly uses electric heating. However, due to the fact that the heating components of the annealing furnace cannot be arranged completely evenly during the design process, it will always lead to uneven temperatures in various parts of the annealing furnace, and heat is easy to overflow, resulting in large energy losses, indirectly leading to increased costs, and is not friendly to the environment. In addition, the film product is relatively fragile and sensitive to temperature. It is extremely difficult to achieve precise temperature control in the existing annealing furnace, which easily leads to a decrease in the yield rate. Summary of the invention

[0003] In order to solve the technical problems existing in the background technology, the present invention provides a polyimide film annealing method.

[0004] The present invention provides a polyimide film annealing method, comprising:

[0005] pulling the polyimide film at a preset tension level;

[0006] Continuously blowing a first high-temperature carrier gas having a first preset temperature from a first gas outlet toward an upper surface of the polyimide film at a preset gas pressure upstream of the polyimide film in a moving direction;

[0007] Extracting the first high-temperature carrier gas blown out from the first gas outlet and heating it to form a second high-temperature carrier gas with a second preset temperature, wherein the second preset temperature is higher than the first preset temperature;

[0008] In the middle of the pulling direction of the polyimide film, a second high-temperature carrier gas is continuously blown from a second gas outlet toward the surface of the polyimide film at a preset gas pressure;

[0009] The second high-temperature carrier gas blown out from the second gas outlet is extracted and mixed with the normal-temperature carrier gas and auxiliary-heated to the first preset temperature, and then circulated to the first gas outlet for blowing out.

[0010] Furthermore, it also includes:

[0011] A third high-temperature carrier gas having a first preset temperature is continuously blown from a third gas outlet toward the lower surface of the polyimide film at a preset gas pressure upstream of the moving direction of the polyimide film;

[0012] Extracting the third high-temperature carrier gas blown out from the third gas outlet and heating it to form a fourth high-temperature carrier gas having a second preset temperature, wherein the fourth preset temperature is higher than the third preset temperature;

[0013] In the middle of the direction in which the polyimide film is pulled, a fourth high-temperature carrier gas is continuously blown from a fourth gas outlet toward the surface of the polyimide film at a preset gas pressure;

[0014] The fourth high-temperature carrier gas blown out from the fourth gas outlet is extracted and mixed with the second normal-temperature carrier gas and auxiliary-heated to a first preset temperature, and then circulated to the third gas outlet for blowing out.

[0015] Furthermore, it also includes:

[0016] Downstream of the polyimide film's moving direction, a normal temperature carrier gas for heat exchange with the polyimide film is continuously blown out from the fifth air outlet at a preset air pressure toward the upper surface of the polyimide film, and is assisted to heat to a first preset temperature before circulating to the first air outlet for blowing out.

[0017] Furthermore, it also includes:

[0018] Downstream of the polyimide film's moving direction, the sixth air outlet continuously blows out a normal temperature carrier gas for heat exchange with the polyimide film at a preset air pressure toward the lower surface of the polyimide film, and then circulates to the third air outlet for blowing after auxiliary heating to the first preset temperature.

[0019] Furthermore, a first wind curtain is provided at the upstream starting point, and a second wind curtain is provided at the downstream ending point.

[0020] Further, the upstream, the midstream, and the downstream are all located in the annealing chamber, the starting point is located at the inlet of the annealing chamber, and the ending point is located at the outlet of the annealing chamber.

[0021] Furthermore, a horizontally arranged first upper guide roller is provided at the connection between the upstream and the midstream along the width direction of the polyimide film, the top of the first upper guide roller is close to the top wall of the annealing chamber, and the bottom is close to the upper surface of the polyimide film along the width direction of the polyimide film.

[0022] Furthermore, a first lower guide roller is horizontally arranged along the width direction of the polyimide film at the junction of the upstream and the midstream, the bottom of the first lower guide roller is close to the bottom wall of the annealing chamber, and the top is close to the lower surface of the polyimide film along the width direction of the polyimide film.

[0023] Furthermore, a second upper guide roller is horizontally arranged at the junction of the midstream and the downstream along the width direction of the polyimide film, the top of the second upper guide roller is close to the top wall of the annealing chamber, and the bottom is close to the upper surface of the polyimide film along the width direction of the polyimide film.

[0024] Furthermore, a second lower guide roller is horizontally arranged along the width direction of the polyimide film at the junction of the midstream and the downstream, the bottom of the second lower guide roller is close to the bottom wall of the annealing chamber, and the top is close to the lower surface of the polyimide film along the width direction of the polyimide film.

[0025] The polyimide film annealing method proposed in the present invention is not only energy-saving, but also can realize segmented processing of preheating, annealing and cooling, and can realize more accurate temperature control in the whole process, thereby improving the yield rate. DETAILED DESCRIPTION

[0026] The present invention provides a polyimide film annealing method, comprising:

[0027] pulling the polyimide film at a preset tension level;

[0028] Continuously blowing a first high-temperature carrier gas having a first preset temperature from a first gas outlet toward an upper surface of the polyimide film at a preset gas pressure upstream of the polyimide film in a moving direction;

[0029] Extracting the first high-temperature carrier gas blown out from the first gas outlet and heating it to form a second high-temperature carrier gas with a second preset temperature, wherein the second preset temperature is higher than the first preset temperature;

[0030] In the middle of the pulling direction of the polyimide film, a second high-temperature carrier gas is continuously blown from a second gas outlet toward the surface of the polyimide film at a preset gas pressure;

[0031] The second high-temperature carrier gas blown out from the second gas outlet is extracted and mixed with the normal-temperature carrier gas and auxiliary-heated to the first preset temperature, and then circulated to the first gas outlet for blowing out.

[0032] The upstream belongs to the preheating area, by continuously blowing the first high-temperature carrier gas with the first preset temperature to the upper surface of the pulled polyimide film, and at the same time quickly extracting the first high-temperature carrier gas that has contacted the upper surface of the polyimide film, the polyimide film will always be in contact with the first high-temperature carrier gas with a constant first preset temperature, thereby achieving precise control of the heating temperature of the upper surface of the polyimide film, and directly auxiliary heating the extracted first high-temperature carrier gas to the second high-temperature carrier gas with a second preset temperature, thereby achieving maximum capacity recycling, and the midstream belongs to the constant temperature annealing area, similarly, by continuously blowing the second high-temperature carrier gas with the second preset temperature to the upper surface of the pulled polyimide film, and at the same time quickly extracting the second high-temperature carrier gas that has contacted the upper surface of the polyimide film, the polyimide film will always be in contact with the second high-temperature carrier gas with a constant second preset temperature, thereby achieving precise control of the heating temperature of the upper surface of the polyimide film in the constant temperature annealing area.

[0033] A third high-temperature carrier gas having a first preset temperature is continuously blown from a third gas outlet toward the lower surface of the polyimide film at a preset gas pressure upstream of the moving direction of the polyimide film;

[0034] Extracting the third high-temperature carrier gas blown out from the third gas outlet and heating it to form a fourth high-temperature carrier gas having a second preset temperature, wherein the fourth preset temperature is higher than the third preset temperature;

[0035] In the middle of the direction in which the polyimide film is pulled, a fourth high-temperature carrier gas is continuously blown from a fourth gas outlet toward the surface of the polyimide film at a preset gas pressure;

[0036] The fourth high-temperature carrier gas blown out from the fourth gas outlet is extracted and mixed with the second normal-temperature carrier gas and auxiliary-heated to a first preset temperature, and then circulated to the third gas outlet for blowing out.

[0037] Similarly, the lower surface of the polyimide film can be subjected to a precise temperature preheating treatment in the upstream preheating area, and the lower surface of the polyimide film can be subjected to a precise temperature constant temperature annealing treatment in the midstream constant temperature annealing area.

[0038] Moreover, heating the upper and lower surfaces of the polyimide film can accelerate heat transfer and speed up the processing process.

[0039] Downstream of the polyimide film's moving direction, a normal temperature carrier gas for heat exchange with the polyimide film is continuously blown out from the fifth air outlet at a preset air pressure toward the upper surface of the polyimide film, and is assisted to heat to a first preset temperature before circulating to the first air outlet for blowing out.

[0040] Downstream of the polyimide film's moving direction, the sixth air outlet continuously blows out a normal temperature carrier gas for heat exchange with the polyimide film at a preset air pressure toward the lower surface of the polyimide film, and then circulates to the third air outlet for blowing after auxiliary heating to the first preset temperature.

[0041] The downstream is a cooling area, where after cooling the upper and lower surfaces of the polyimide film, auxiliary heating is performed to recover heat and realize the recycling of the carrier gas.

[0042] A first wind curtain is provided at the upstream starting point, and a second wind curtain is provided at the downstream ending point.

[0043] The upstream, the midstream, and the downstream are all located in the annealing chamber, the starting point is located at the inlet of the annealing chamber, and the ending point is located at the outlet of the annealing chamber.

[0044] The annealing furnace is isolated from the outside to minimize the escape of heat and carrier gas.

[0045] A first upper guide roller is horizontally arranged at the connection between the upstream and midstream along the width direction of the polyimide film, the top of the first upper guide roller is close to the top wall of the annealing chamber, and the bottom is close to the upper surface of the polyimide film along the width direction of the polyimide film.

[0046] A first lower guide roller is horizontally arranged at the junction of the upstream and the midstream along the width direction of the polyimide film, the bottom of the first lower guide roller is close to the bottom wall of the annealing chamber, and the top is close to the lower surface of the polyimide film along the width direction of the polyimide film.

[0047] A second upper guide roller arranged horizontally is provided at the junction of the midstream and the downstream along the width direction of the polyimide film, the top of the second upper guide roller is close to the top wall of the annealing chamber, and the bottom is close to the upper surface of the polyimide film along the width direction of the polyimide film.

[0048] A second lower guide roller is horizontally arranged at the junction of the midstream and the downstream along the width direction of the polyimide film, the bottom of the second lower guide roller is close to the bottom wall of the annealing chamber, and the top is close to the lower surface of the polyimide film along the width direction of the polyimide film.

[0049] The first upper guide roller, the first lower guide roller, the second upper guide roller, the second lower guide roller, the first air curtain, the second air curtain and the annealing furnace wall together spatially divide the annealing chamber into upstream, midstream and downstream isolated from the outside world, thereby avoiding heat exchange between upstream preheating, midstream constant temperature auxiliary heating and downstream cooling to a certain extent, thereby improving the accuracy of heat exchange temperature control between the carrier gas and the polyimide film and, at the same time, achieving a better heat energy recycling effect.

[0050] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A polyimide film annealing method, characterized in that: include: pulling the polyimide film at a preset tension level; Continuously blowing a first high-temperature carrier gas having a first preset temperature from a first gas outlet toward an upper surface of the polyimide film at a preset gas pressure upstream of the polyimide film in a moving direction; Extracting the first high-temperature carrier gas blown out from the first gas outlet and heating it to form a second high-temperature carrier gas with a second preset temperature, wherein the second preset temperature is higher than the first preset temperature; In the middle of the pulling direction of the polyimide film, a second high-temperature carrier gas is continuously blown from a second gas outlet toward the surface of the polyimide film at a preset gas pressure; The second high-temperature carrier gas blown out from the second gas outlet is extracted and mixed with the normal-temperature carrier gas and auxiliary-heated to the first preset temperature, and then circulated to the first gas outlet for blowing out.

2. The polyimide film annealing method according to claim 1, characterized in that: Also includes: A third high-temperature carrier gas having a third preset temperature is continuously blown from a third gas outlet toward the lower surface of the polyimide film at a preset gas pressure upstream of the moving direction of the polyimide film; Extracting the third high-temperature carrier gas blown out from the third gas outlet and heating it to form a fourth high-temperature carrier gas with a fourth preset temperature, wherein the fourth preset temperature is higher than the third preset temperature; In the middle of the direction in which the polyimide film is pulled, a fourth high-temperature carrier gas is continuously blown from a fourth gas outlet toward the surface of the polyimide film at a preset gas pressure; The fourth high-temperature carrier gas blown out from the fourth gas outlet is extracted and mixed with the second normal-temperature carrier gas and auxiliary-heated to a first preset temperature, and then circulated to the third gas outlet for blowing out.

3. The polyimide film annealing method according to claim 1, characterized in that: Also includes: Downstream of the polyimide film's moving direction, a normal temperature carrier gas for heat exchange with the polyimide film is continuously blown out from the fifth air outlet at a preset air pressure toward the upper surface of the polyimide film, and is assisted to heat to a first preset temperature before circulating to the first air outlet for blowing out.

4. The polyimide film annealing method according to claim 2, characterized in that: Also includes: Downstream of the polyimide film's moving direction, the sixth air outlet continuously blows out a normal temperature carrier gas for heat exchange with the polyimide film at a preset air pressure toward the lower surface of the polyimide film, and then circulates to the third air outlet for blowing after auxiliary heating to the first preset temperature.

5. The polyimide film annealing method according to claim 3, characterized in that: A first wind curtain is provided at the upstream starting point, and a second wind curtain is provided at the downstream ending point.

6. The polyimide film annealing method according to claim 5, characterized in that: The upstream, the midstream, and the downstream are all located in the annealing chamber, the starting point is located at the inlet of the annealing chamber, and the ending point is located at the outlet of the annealing chamber.

7. The polyimide film annealing method according to claim 6, characterized in that: A first upper guide roller is horizontally arranged at the connection between the upstream and midstream along the width direction of the polyimide film, the top of the first upper guide roller is close to the top wall of the annealing chamber, and the bottom is close to the upper surface of the polyimide film along the width direction of the polyimide film.

8. The polyimide film annealing method according to claim 7, characterized in that: A first lower guide roller is horizontally arranged at the junction of the upstream and the midstream along the width direction of the polyimide film, the bottom of the first lower guide roller is close to the bottom wall of the annealing chamber, and the top is close to the lower surface of the polyimide film along the width direction of the polyimide film.

9. The polyimide film annealing method according to claim 8, characterized in that: A second upper guide roller arranged horizontally is provided at the junction of the midstream and the downstream along the width direction of the polyimide film, the top of the second upper guide roller is close to the top wall of the annealing chamber, and the bottom is close to the upper surface of the polyimide film along the width direction of the polyimide film.

10. The polyimide film annealing method according to claim 9, characterized in that: A second lower guide roller is horizontally arranged at the junction of the midstream and the downstream along the width direction of the polyimide film, the bottom of the second lower guide roller is close to the bottom wall of the annealing chamber, and the top is close to the lower surface of the polyimide film along the width direction of the polyimide film.