A silicone paper and its manufacturing process

Abstract

The application belongs to the technical field of paper manufacturing, and particularly relates to a silicone oil paper, which comprises a center base paper layer, the center base paper layer being kraft paper; further comprises a composite filling layer, the composite filling layer comprising a hot melt adhesive layer and a grid layer; and an outer base paper layer, the outer base paper layer being arranged on both sides of the center base paper layer, and the outer surface of the outer base paper layer being provided with a coating layer; wherein the composite filling layer is arranged between the outer base paper layer and the center base paper layer, the center base paper layer, the composite filling layer and the outer base paper layer are fixedly connected with each other, the setting of the composite filling layer can effectively improve the high-temperature resistance and structural strength of the silicone oil paper, the silicone oil paper is not prone to damage and can be repeatedly used, the service life of the silicone oil paper is improved, and the production, transportation and use requirements of the silicone oil paper are met.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of paper manufacturing, and particularly relates to a silicone oil paper and a production process thereof. BACKGROUND

[0002] The silicone oil paper is a kind of paper treated specially, and is named because of the silicone oil coated on the surface. It is usually composed of a base paper and a silicone oil coating layer. The silicone oil paper is widely used because of its excellent performance in specific applications. For example, a silicone oil paper disclosed in a patent with the application number CN201220220025.9 comprises a base material, i.e. a base paper, a silicone oil film and a silicone coating layer coated on the surface of the base material, and a non-dry adhesive provided on the back surface of the base paper.

[0003] The existing silicone oil paper has poor high-temperature resistance and structural strength due to the single-layer base material, and cannot meet the production, transportation and use requirements. Therefore, it is necessary to make improvements. SUMMARY

[0004] The present application aims to provide a silicone oil paper and a production process thereof to effectively improve the performance of the silicone oil paper and meet the production, transportation and use requirements of the silicone oil paper.

[0005] Therefore, the present application provides a silicone oil paper, which comprises:

[0006] a center base paper layer, which is kraft paper;

[0007] and further comprises:

[0008] a composite filling layer, which comprises a hot melt adhesive layer and a mesh layer;

[0009] an outer base paper layer, which is provided on both sides of the center base paper layer, and the outer surface of the outer base paper layer is provided with a coating layer;

[0010] wherein the composite filling layer is provided between the outer base paper layer and the center base paper layer, and the center base paper layer, the composite filling layer and the outer base paper layer are fixedly connected with each other.

[0011] In the technical solution, the composite filling layer can effectively improve the high-temperature resistance and structural strength of the silicone oil paper, so that the silicone oil paper is not easy to be damaged and can be repeatedly used, the service life of the silicone oil paper is improved, and the production, transportation and use requirements of the silicone oil paper are met.

[0012] In the above technical solution, further, the outer base paper layer is kraft paper.

[0013] In the above technical solution, further, the mesh layer is a nylon woven mesh.

[0014] In the above technical solution, the present invention further discloses a process for producing silicone paper, including the following steps:

[0015] S1 base paper preparation: After rehydration, the base paper is dried in an oven.

[0016] The S2 base paper body is made by dividing the prepared base paper into a central base paper layer and an outer base paper layer. After covering both sides of the central base paper layer with a composite filler layer, the outer base paper layer is covered on the outer surface of the composite filler layer to finally complete the production of the base paper body.

[0017] S3 coating material preparation involves mixing silicone oil and catalyst in a specific ratio and then heating and maintaining the temperature of the coating material.

[0018] S4 coating involves feeding the completed base paper into the coating machine, where the coating zone of the coating machine coats the base paper with coating material. The coating amount is 0.8–1.6 g / m², the paper winding tension is 30–35 N, and the machine speed is 80–120 m / min.

[0019] S5 drying: After the base paper is coated with the coating material in the coating area of ​​the coating machine, it is moved to the drying area of ​​the coating machine for rapid drying. The drying temperature is controlled between 60 and 130°C.

[0020] S6 calendering: After drying, the base paper is moved to a calender for calendering to form a complete silicone paper.

[0021] S7 rewinding involves rewinding the formed silicone paper and storing it.

[0022] In the above technical solution, the coating machine further includes:

[0023] The main body is equipped with an unwinding roller and a guide roller.

[0024] A coating box is installed on the main body and located above the unwinding roller, and a coating material conveying pipe is provided in the coating box;

[0025] A coating nozzle, wherein there are several coating nozzles arranged in a coating box;

[0026] A coating material bucket is located on the rear side of the main body;

[0027] A coating and drying oven is located on the left side of the main machine.

[0028] The coating nozzle is connected to the coating material conveying pipe, and the coating material conveying pipe is connected to the coating material tank.

[0029] In the above technical solution, the coating raw material bucket further includes:

[0030] A heating element is disposed in the wall of the coating raw material barrel;

[0031] A stirring mechanism is disposed in a coating material tank;

[0032] The stirring mechanism can uniformly stir the coating material in the coating material tank and make the coating material uniformly heated by the heating element.

[0033] In the above technical solution, the stirring mechanism further includes:

[0034] A stirring shaft is rotatably mounted in the coating raw material tank and driven to rotate by a stirring motor.

[0035] A stirring rod, wherein the stirring rod has several rods and is evenly distributed along the axial and circumferential directions of the stirring shaft;

[0036] A flow-blocking groove is disposed on the inner side of the stirring rod;

[0037] A flow guiding channel is provided in the stirring rod;

[0038] The inner end of the flow guiding channel is connected to the flow blocking groove, and the outer end of the flow guiding channel extends along the axial direction of the stirring rod to the outer end of the stirring rod.

[0039] In the above technical solution, the coating drying oven further includes:

[0040] A hot air mechanism is installed on a coating drying box, and the hot air mechanism includes an air outlet pipe that communicates with the inside of the coating drying box;

[0041] The uniformly distributed exhaust head is installed in the coating drying box and connected to the exhaust duct.

[0042] In the above technical solution, the evenly distributed exhaust fan further includes:

[0043] A connecting pipe section, which is movably connected to the air outlet pipe in the circumferential direction;

[0044] Several air guide hoods are arranged inside the connecting pipe section. The air guide hoods are evenly spaced from top to bottom and can guide the hot air flow to distribute in all directions.

[0045] Several air ducts are connected to several air guide hoods, and the air ducts are nested from the inside out.

[0046] A spoiler is disposed on the bottom surface of the air guide shroud;

[0047] The connecting pipe section and the air duct, as well as the several air ducts, have gaps through which the heated airflow passes. The air duct located in the center of the several air ducts can directly discharge the heated airflow downwards. The connecting pipe section can be driven to rotate.

[0048] The beneficial effects of this invention are:

[0049] 1. The composite filler layer effectively improves the high temperature resistance and structural strength of silicone paper, making it less prone to damage and reusable, thus extending its service life and meeting the production, transportation and use requirements of silicone paper.

[0050] 2. By controlling the moisture content in the base paper, the coating material can adhere better to the surface of the base paper, thus improving the finished quality of the silicone paper.

[0051] 3. By maintaining the temperature of the coating material within a suitable range and controlling the viscosity of the coating material, problems such as poor coating uniformity, poor flowability, or premature drying caused by excessively high or low viscosity of the coating material are prevented, thereby further improving the finished quality of silicone paper.

[0052] 4. By evenly distributing the hot airflow in the coating and drying chamber through the uniform exhaust heads, the drying process is maintained to ensure sufficient drying and consistent drying speed. This prevents coating adhesion, stickiness, or uneven drying, further improving the finished quality of the silicone paper. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 This is a schematic diagram of a specific embodiment of the present invention.

[0055] Figure 2 This is a schematic diagram of the main body structure of the present invention.

[0056] Figure 3 This is a schematic diagram of the back structure of the main body of the present invention.

[0057] Figure 4 This is a schematic diagram of the internal structure of the coating box of the present invention.

[0058] Figure 5 This is a schematic diagram of the coating raw material bucket structure of the present invention.

[0059] Figure 6This is a schematic diagram of the flow-blocking groove structure of the present invention.

[0060] Figure 7 This is a schematic diagram of the coating drying oven structure of the present invention.

[0061] Figure 8 This is a schematic diagram of the uniformly distributed exhaust fan structure of the present invention.

[0062] Figure 9 This is a top view structural diagram of the uniformly distributed exhaust fan head of the present invention.

[0063] Figure 10 This is a schematic cross-sectional view of the uniformly distributed exhaust fan head of the present invention.

[0064] The markings in the diagram are as follows:

[0065] 1. Central base paper layer; 2. Composite filler layer; 3. Outer base paper layer; 4. Main body; 40. Unwinding roller; 41. Guide roller; 5. Coating box; 50. Coating material conveying pipe; 51. Coating nozzle; 6. Coating material bucket; 60. Heating element; 61. Stirring mechanism; 610. Stirring shaft; 611. Stirring motor; 612. Stirring rod; 613. Baffle groove; 614. Guide channel; 7. Coating drying box; 70. Hot air mechanism; 71. Air outlet pipe; 72. Uniformly distributed exhaust head; 8. Connecting pipe section; 9. Guide hood; 10. Air guide pipe; 11. Baffle plate. Detailed Implementation

[0066] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0067] In the description of this application, it should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. For ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0068] Example 1:

[0069] This application provides a silicone paper, including: a central base paper layer 1, wherein the central base paper layer 1 is kraft paper;

[0070] It also includes: a composite filler layer 2, which includes a hot melt adhesive layer and a mesh layer; and an outer base paper layer 3, which is disposed on both sides of the central base paper layer 1, and the outer surface of the outer base paper layer 3 is provided with a coating layer.

[0071] The composite filler layer 2 is disposed between the outer base paper layer 3 and the central base paper layer 1, and the central base paper layer 1, the composite filler layer 2 and the outer base paper layer 3 are fixedly connected to each other.

[0072] The outer base paper layer 3 is kraft paper.

[0073] The mesh layer is made of nylon woven mesh.

[0074] Moreover, the main body 4 has a conventional machine structure. The unwinding roller 40 and the guide roller 41 are rotatably mounted on the main body 4. The unwinding roller 40 can be driven by a rotating motor. The coating box 5 has a feed port and a discharge port on both sides. The coating material conveying pipe 50 is distributed on the upper and lower sides inside the coating box 5. The material can pass through the middle of the coating material conveying pipe 50 on the upper and lower sides. The bottom of the coating box 5 is also equipped with a coating material recovery tank. The coating material recovery tank is connected to the coating material bucket 6. The coating material bucket 6 and the coating material conveying pipe 50 are connected in series, as are the coating material bucket 6 and the coating material recovery tank. The coating drying box 7 also has a feed port and a discharge port on both sides.

[0075] In this embodiment, the addition of composite filler layer 2 effectively improves the high temperature resistance and structural strength of silicone paper, making it less prone to damage and reusable, thus extending its service life and meeting the production, transportation, and usage requirements of silicone paper.

[0076] Example 2:

[0077] This embodiment provides a process for producing silicone paper, which, in addition to the technical solutions of the above embodiments, also has the following technical features, including the following steps:

[0078] S1 base paper preparation: After rehydration, the base paper is dried in an oven.

[0079] The S2 base paper body is made by dividing the prepared base paper into a central base paper layer 1 and an outer base paper layer 3. After covering both sides of the central base paper layer 1 with a composite filler layer 2, the outer base paper layer 3 is covered on the outer surface of the composite filler layer 2 to finally complete the production of the base paper body.

[0080] S3 coating material preparation involves mixing silicone oil and catalyst in a specific ratio and then heating and maintaining the temperature of the coating material.

[0081] S4 coating involves feeding the completed base paper into the coating machine, where the coating zone of the coating machine coats the base paper with coating material. The coating amount is 0.8–1.6 g / m², the paper winding tension is 30–35 N, and the machine speed is 80–120 m / min.

[0082] S5 drying: After the base paper is coated with the coating material in the coating area of ​​the coating machine, it is moved to the drying area of ​​the coating machine for rapid drying. The drying temperature is controlled between 60 and 130°C.

[0083] S6 calendering: After drying, the base paper is moved to a calender for calendering to form a complete silicone paper.

[0084] S7 rewinding involves rewinding the formed silicone paper and storing it.

[0085] In this embodiment, by controlling the moisture content in the base paper, the coating material can better adhere to the surface of the base paper, thus improving the finished quality of the silicone paper. At the same time, the coating material can be evenly distributed on the surface of the base paper, further improving the finished quality of the silicone paper. Furthermore, the base paper can continuously enter the drying process after coating, effectively improving work efficiency.

[0086] Example 3:

[0087] This embodiment provides a process for producing silicone paper. In addition to the technical solutions of the above embodiments, it also has the following technical features: the coating machine further includes: a main body 4, on which an unwinding roller 40 and a guide roller 41 are arranged; a coating box 5, which is arranged on the main body 4 and located above the unwinding roller 40, and a coating material conveying pipe 50 is arranged in the coating box 5; a coating nozzle 51, which has several coating nozzles and is arranged in the coating box 5; a coating material tank 6, which is arranged on the rear side of the main body 4; and a coating drying box 7, which is arranged on the left side of the main body.

[0088] The coating nozzle 51 is connected to the coating material conveying pipe 50, and the coating material conveying pipe 50 is connected to the coating material tank 6.

[0089] A conventional winding mechanism is also installed on the discharge side of the coating drying oven 7.

[0090] In this embodiment, the base paper body is placed on the unwinding roller 40. As the base paper body moves, it passes through the coating box 5. The coating material conveying pipe 50 conveys the coating material in the coating material bucket 6 to the coating nozzle 51. The coating nozzle 51 sprays the material evenly on the surface of the base paper body. Then, the base paper body moves to the coating drying box 7 for drying. After coating, the base paper can continuously enter the drying process, which effectively improves the work efficiency.

[0091] Example 4:

[0092] This embodiment provides a process for producing silicone paper. In addition to the technical solutions of the above embodiments, it also has the following technical features: the coating raw material tank 6 further includes: a heating element 60, which is disposed in the tank wall of the coating raw material tank 6; and a stirring mechanism 61, which is disposed in the coating raw material tank 6.

[0093] The stirring mechanism 61 can uniformly stir the coating material in the coating material tank 6 and make the coating material uniformly heated by the heating element 60.

[0094] The stirring mechanism 61 further includes: a stirring shaft 610, which is rotatably disposed in the coating raw material tank 6 and driven to rotate by a stirring motor 611; a stirring rod 612, which has several rods and is evenly distributed along the axial and circumferential directions of the stirring shaft 610; a baffle groove 613, which is disposed on the inner side of the stirring rod 612; and a guide channel 614, which is disposed in the stirring rod 612.

[0095] The inner end of the flow guiding channel 614 is connected to the flow blocking groove 613, and the outer end of the flow guiding channel 614 extends along the axial direction of the stirring rod 612 to the outer end of the stirring rod 612.

[0096] The top of the coating material tank 6 also has a coating material addition port, and the heating element 60 can be a conventional electric heating element 60, such as electric heating wires distributed in the tank wall of the coating material tank 6.

[0097] In this embodiment, the heating element 60 in the coating material tank 6 can heat and keep the coating material in the coating material tank 6 at a suitable temperature, thereby maintaining the temperature of the coating material within a suitable range and controlling the viscosity of the coating material. During the operation of the heating element 60, the stirring shaft 610 of the stirring mechanism 61 rotates under the drive of the stirring motor 611, thereby driving the stirring rod 612 to stir the coating material, so that the coating material can be heated evenly and fully. At the same time, during the stirring process, the baffle groove 613 collides with the coating material as the stirring rod 612 rotates. After entering the baffle groove 613, the coating material flows into the guide channel 614 under pressure and moves with the guide channel 614. Finally, the coating material flows to the edge of the coating material tank 6 through the guide channel and contacts the tank wall of the coating material tank 6, so that the coating material in the center of the coating material tank 6 can also be fully heated and kept at a suitable temperature, further maintaining the temperature of the coating material within a suitable range and controlling the viscosity of the coating material.

[0098] Example 5:

[0099] This embodiment provides a process for producing silicone paper. In addition to the technical solutions of the above embodiments, it also has the following technical features: the coating drying box 7 further includes: a hot air mechanism 70, which is disposed on the coating drying box 7 and includes an air outlet pipe 71 communicating with the inner side of the coating drying box 7; and a uniformly distributed exhaust head 72, which is disposed in the coating drying box 7 and communicates with the air outlet pipe 71. In the above technical solution, the evenly distributed exhaust head 72 further includes: a connecting pipe section 8, which is movably connected to the exhaust pipe 71 in the circumferential direction; a plurality of air guide hoods 9, which are disposed inside the connecting pipe section 8 and are evenly spaced from top to bottom, and can guide the hot air flow to be distributed in all directions; a plurality of air guide pipes 10, which are correspondingly connected to the plurality of air guide hoods 9 and are nested from the inside to the outside; and a baffle plate 11, which is disposed on the bottom surface of the air guide hoods 9.

[0100] There are gaps between the connecting pipe section 8 and the air duct 10, as well as between each of the several air ducts 10, through which the heated airflow passes. The air duct 10 located in the center of the several air ducts 10 can directly discharge the heated airflow downwards, and the connecting pipe section 8 can be driven to rotate.

[0101] Furthermore, an electric heating tube can be installed in the coating drying oven 7. The hot air mechanism 70 is a conventional hot air generating mechanism. The hot air mechanism 70 can also be connected to the coating drying oven 7 through a return pipe to recover the residual heat of the hot airflow. The connection between the connecting pipe section 8 and the air outlet pipe 71 is movably connected in the circumferential direction and fixedly connected in the axial direction. The connecting pipe section 8 can be driven to rotate in a conventional way. For example, a toothed ring can be installed on the outside of the connecting pipe section 8. A rotating motor is installed on the coating drying oven 7. A gear that meshes with the toothed ring is installed on the drive end of the rotating motor. Several guide air hoods 9 can be connected and fixed to each other and to the connecting pipe section 8 through connecting rods. The edge of the guide air hood 9 extends horizontally in all directions.

[0102] In this embodiment, when the base paper body is moved to the coating drying box 7 for drying, the hot air mechanism 70 generates hot airflow and delivers the hot airflow to the uniformly distributed exhaust head 72 through the air outlet duct 71. After the hot airflow reaches the uniformly distributed exhaust head 72, the hot airflow flows through the gaps between the connecting pipe and the air guide duct 10 and the gaps between the several air guide ducts 10 to each air guide hood 9. Under the action of the air guide hood 9, the hot airflow is dispersed in all directions and dispersed at all heights. At the same time, the air guide duct 10 located in the center of the several air guide ducts 10 can directly discharge the hot airflow downwards, so that the hot airflow can be evenly distributed in various positions in the coating drying box 7, maintaining the temperature uniformity in the coating drying box 7. During the flow of hot airflow, the baffle 11 can also disturb the hot airflow with the rotation of the connecting pipe section 8, thereby further dispersing the hot airflow and improving the flow effect of the hot airflow in the coating drying box 7, effectively ensuring that the base paper body can be fully and evenly dried, thereby improving the finished quality of the silicone paper.

[0103] The embodiments of this application have been described above with reference to the accompanying drawings. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. This application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A silicone oil paper, comprising: a central base paper layer (1), which is kraft paper; characterized in that it further comprises: a composite filling layer (2) comprising a hot melt adhesive layer and a mesh layer; an outer base paper layer (3) arranged on both sides of the central base paper layer (1), the outer surface of the outer base paper layer (3) being provided with a coating layer; wherein the composite filling layer (2) is arranged between the outer base paper layer (3) and the central base paper layer (1), the central base paper layer (1), the composite filling layer (2) and the outer base paper layer (3) are fixedly connected to each other, the outer base paper layer (3) is kraft paper, and the mesh layer is a nylon woven mesh; and a production process for the above-mentioned silicone oil paper, comprising the following steps: S1. Base paper preparation: after rewetting the base paper, dry it in an oven; S2. Base paper body manufacturing: divide the prepared base paper into a central base paper layer (1) and an outer base paper layer (3), cover the composite filling layer (2) on both sides of the central base paper layer (1), and then cover the outer base paper layer (3) on the outer surface of the composite filling layer (2) to finally complete the manufacturing of the base paper body; S3. Coating raw material preparation: stir and mix the silicone oil and catalyst according to the proportion, and heat and keep the coating raw material; S4. Coating: introduce the completed base paper body into the coating machine, and coat the coating raw material on the base paper body in the coating area of the coating machine, the coating amount being 0.8-1.6 g / m2, the paper tension being 30-35 N, and the speed being 80-120 m / min; S5. Drying: after the coating of the coating raw material is completed in the coating area of the coating machine, move the base paper body to the drying area of the coating machine for rapid drying, and control the drying temperature at 60-130℃; S6. Calendering: after drying, move the base paper body to the calendering machine for calendering to form a complete silicone oil paper; S7. Rewinding: rewind the formed silicone oil paper and store it; the coating machine further comprises: a main body (4) provided with a unwinding roller (40) and a guide roller (41); a coating box (5) arranged on the main body (4) above the unwinding roller (40), and provided with a coating raw material conveying pipe (50) therein; a plurality of coating nozzles (51) arranged in the coating box (5); a coating raw material barrel (6) arranged on the rear side of the main body (4); a coating drying box (7) arranged on the left side of the main body; wherein the coating nozzles (51) are in communication with the coating raw material conveying pipe (50), and the coating raw material conveying pipe (50) is in communication with the coating raw material barrel (6); the coating raw material barrel (6) further comprises: a heating element (60) arranged in the barrel wall of the coating raw material barrel (6); a stirring mechanism (61) arranged in the coating raw material barrel (6); wherein the stirring mechanism (61) can uniformly stir the coating raw material in the coating raw material barrel (6) and make the coating raw material uniformly heated by the heating element (60). The stirring mechanism (61) further comprises: a stirring shaft (610) rotatably arranged in the coating raw material barrel (6) and driven to rotate by a stirring motor (611); a plurality of stirring rods (612) uniformly distributed along the axial and circumferential directions of the stirring shaft (610); a flow blocking groove (613) arranged on the inner side of the stirring rod (612); a flow guiding channel (614) arranged in the stirring rod (612); wherein the inner end of the flow guiding channel (614) is in communication with the flow blocking groove (613), and the outer end of the flow guiding channel (614) extends to the outer end of the stirring rod (612) along the axial direction of the stirring rod (612).

2. The paper of claim 1 wherein, The coating drying box (7) further comprises: a hot air mechanism (70) arranged on the coating drying box (7), the hot air mechanism (70) comprising an air outlet pipe (71) in communication with the inner side of the coating drying box (7); an air distribution head (72) arranged in the coating drying box (7) and in communication with the air outlet pipe (71).

3. A paper according to claim 2, wherein the silicone oil is a polyalkylsiloxane. The air distribution head (72) further comprises: a connecting pipe section (8) movably connected with the air outlet pipe (71) in the circumferential direction; a plurality of flow guiding hoods (9) arranged on the inner side of the connecting pipe section (8), the plurality of flow guiding hoods (9) being uniformly spaced from top to bottom, the flow guiding hoods (9) being capable of guiding the hot air flow to be distributed in all directions; a plurality of air guiding pipes (10) corresponding to the plurality of flow guiding hoods (9), the plurality of air guiding pipes (10) being sequentially nested from inside to outside; a spoiler (11) arranged on the bottom surface of the flow guiding hood (9); wherein the connecting pipe section (8) and the air guiding pipe (10) and the plurality of air guiding pipes (10) each have a gap for the hot air flow to pass through, the air guiding pipe (10) located at the center of the plurality of air guiding pipes (10) being capable of directly discharging the hot air flow downward, and the connecting pipe section (8) being capable of being driven to rotate.

Images