Downward film blowing equipment with film diameter adjusting and secondary stretching functions

Abstract

The invention discloses lower film blowing equipment with film diameter adjusting and secondary stretching functions. The feeding mechanism feeds molten plastic flow into the film blowing head to blow out an annular film, the annular film is cooled and shaped by the cooling ring and then enters the reducing assembly, and the annular film is flattened and passes through the reducing feeding clamping roller and then passes through the film reducing through hole of the heating cylinder and the reducing discharging clamping roller. Due to the fact that the heating cylinder can heat the annular membrane for the second time, the annular membrane can be deformed, the air injection and exhaust mechanism can inject air into or exhaust air out of the inner space of the annular membrane in the membrane reducing through hole, and the amount of air in the annular membrane between the reducing feeding clamping roller and the reducing discharging clamping roller can be adjusted. The larger the air amount is, the larger the diameter expansion amount of the annular diaphragm is, so that the diameter of the annular diaphragm is adjustable, the final diaphragm width can meet the requirement, diaphragms of various widths can be continuously produced, the cooling ring does not need to be replaced, the influence on the production efficiency is reduced, and the material loss is reduced.

Description

Technical Field

[0001] The present invention relates to a blown film machine, and particularly to a down-blown film device with a film diameter adjustment and secondary stretching function. Background Art

[0002] Some existing down-blown film devices include a blown film assembly and a control module. The blown film assembly includes a blown film head, a feeding mechanism, and a cooling ring. After the feeding mechanism feeds the molten plastic flow into the blown film head, the blown film head blows out an annular film, and then the annular film passes through the cooling ring for cooling and shaping, and then is flattened and post-processed to obtain a plastic film. However, currently, the diameter of the annular film is basically the same as the inner diameter of the cooling ring. When a small adjustment of the diameter of the annular film is required, it is necessary to stop the machine to replace the cooling rings of different specifications, and a part of the length of the annular film needs to be wasted, which affects the production efficiency and production material loss of the down-blown film device. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. For this purpose, the present invention provides a down-blown film device with a film diameter adjustment and secondary stretching function, which can reduce the impact on production efficiency and reduce material loss.

[0004] The down-blown film device with a film diameter adjustment and secondary stretching function according to an embodiment of the present invention includes a frame, a blown film assembly, and a diameter-changing assembly. The blown film assembly is arranged on the frame. The blown film assembly includes a blown film head, a feeding mechanism, and a cooling ring. The feeding mechanism is connected to the blown film head. The blown film head is provided with an annular film outlet. The cooling ring is located on the discharging side of the annular film outlet. The diameter-changing assembly is arranged on the frame. The diameter-changing assembly includes a heating cylinder, a diameter-changing feeding pinch roller, a diameter-changing discharging pinch roller, and an injection and exhaust mechanism. The heating cylinder is provided with a film diameter-changing through hole. The film diameter-changing through hole is provided with a feeding end and a discharging end. The diameter-changing feeding pinch roller is arranged corresponding to the feeding end of the film diameter-changing through hole. The diameter-changing discharging pinch roller is arranged corresponding to the discharging end of the film diameter-changing through hole. The injection and exhaust mechanism is located between the diameter-changing feeding pinch roller and the diameter-changing discharging pinch roller and can inject gas or exhaust gas into the inner space of the annular film.

[0005] The downblowing film equipment with the functions of film diameter adjustment and secondary stretching according to the embodiments of the present invention has at least the following beneficial effects: The feeding mechanism feeds the molten plastic flow into the film blowing head to blow out an annular film sheet. After the annular film sheet is cooled and shaped by the cooling ring, it enters the variable diameter assembly. The annular film sheet is flattened and passes through the variable diameter feeding pinch rolls, and then passes through the variable diameter through hole of the heating cylinder and the variable diameter discharging pinch rolls. Since the heating cylinder can reheat the annular film sheet, the annular film sheet can be deformed. The air injection and exhaust mechanism can inject air into or exhaust air from the internal space of the annular film sheet in the variable diameter through hole of the film sheet, that is, the internal air volume of the annular film sheet between the variable diameter feeding pinch rolls and the variable diameter discharging pinch rolls can be adjusted. The larger the air volume, the larger the diameter expansion amount of the annular film sheet, so that the diameter of the annular film sheet can be adjusted, and the width of the final film sheet can meet the requirements, continuously producing film sheets of multiple widths without replacing the cooling ring, thereby reducing the impact on production efficiency and reducing material loss.

[0006] According to some embodiments of the present invention, the air injection and exhaust mechanism includes a ventilation needle, an air pump, and a first moving driver. The air pump is connected to the ventilation needle. The ventilation needle is movably arranged on the frame and can pierce into or disengage from the annular film sheet. The first rotation driver is used to drive the ventilation needle to insert into or disengage from the annular film sheet.

[0007] According to some embodiments of the present invention, the air injection and exhaust mechanism further includes a second moving driver. The ventilation needle is movably arranged on the frame and can move along the hole axis direction of the variable diameter through hole of the film sheet. The second moving driver is used to drive the ventilation needle to move along the hole axis direction of the variable diameter through hole of the film sheet.

[0008] According to some embodiments of the present invention, the rotation speed of the variable diameter feeding pinch rolls and / or the variable diameter discharging pinch rolls can be adjusted.

[0009] According to some embodiments of the present invention, the machine base is provided with a control module. The variable diameter assembly further includes a first rotation driver and a second rotation driver. The first rotation driver is used to drive the variable diameter feeding pinch rolls to rotate, and the second rotation driver is used to drive the variable diameter discharging pinch rolls to rotate. The first rotation driver and the second rotation driver are both electrically connected to the control module, and the control module can control the rotation speeds of the first rotation driver and the second rotation driver.

[0010] According to some embodiments of the present invention, the heating cylinder is provided with a variable diameter heater, and the heating temperature of the variable diameter heater can be adjusted.

[0011] According to some embodiments of the present invention, the film blowing assembly further includes a first flattening mechanism located between the cooling ring and the diameter-changing assembly. The first flattening mechanism includes two guiding plates arranged oppositely, and the distance between the two guiding plates gradually decreases along the advancing direction of the annular film.

[0012] According to some embodiments of the present invention, at least two feeding mechanisms are provided, and all the feeding mechanisms are respectively communicated with the film blowing head, and the film blowing head is a co-extrusion film blowing head.

[0013] According to some embodiments of the present invention, a heat setting assembly is further included. The heat setting assembly is arranged on the frame and is located in the discharging direction of the diameter-changing assembly. The heat setting assembly includes a heating chamber and a plurality of setting rollers. The setting rollers are rotatably arranged in the heating chamber, and the annular film sequentially bypasses each of the setting rollers.

[0014] According to some embodiments of the present invention, the setting rollers are arranged alternately up and down along the direction from left to right.

[0015] The additional aspects and advantages of the present invention will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, wherein:

[0017] Figure 1 is a schematic diagram of the film blowing assembly of the down-film blowing device according to an embodiment of the present invention;

[0018] Figure 2 is a schematic diagram of the diameter-changing assembly and the heat setting assembly of the down-film blowing device according to an embodiment of the present invention;

[0019] Figure 3 is a schematic diagram of the principle of the down-film blowing device according to an embodiment of the present invention.

[0020] Reference numerals:

[0021] Frame 100;

[0022] Film blowing assembly 200, film blowing head 210, feeding mechanism 220, cooling ring 230, first flattening mechanism 240, guiding plate 241;

[0023] Diameter-changing assembly 300, heating cylinder 310, film diameter-changing through hole 311, diameter-changing feeding pinch roller 320, diameter-changing discharging pinch roller 330, injection and exhaust mechanism 340, second flattening mechanism 350;

[0024] Thermal forming assembly 400, heating chamber 410, forming roller 420;

[0025] Traction roller 510, rotary guiding device 520;

[0026] Annular diaphragm 600. Specific embodiments

[0027] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

[0028] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as up, down, etc. is based on the orientation or positional relationship shown in the drawings, and is only for facilitating the description of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

[0029] In the description of the present invention, "a plurality" means more than two. If there is a description of first and second, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or the sequence of the indicated technical features.

[0030] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

[0031] Some existing downblown film equipment includes a film blowing assembly and a control module. The film blowing assembly includes a film blowing head, a feeding mechanism, and a cooling ring. After the feeding mechanism sends the molten plastic flow into the film blowing head, the film blowing head blows out an annular diaphragm, and then the annular diaphragm passes through the cooling ring for cooling and shaping, and then undergoes flattening and post-treatment to obtain a plastic film sheet. Currently, the diameter of the annular diaphragm is basically the same as the inner diameter of the cooling ring. When it is necessary to slightly adjust the diameter of the annular diaphragm, it is necessary to stop the machine to replace the cooling ring of different specifications, and a part of the length of the annular diaphragm needs to be wasted, which affects the production efficiency and production material loss of the downblown film equipment. Some existing downblown film equipment can also cut off a part of the film edge material through a cutting mechanism to obtain a film finished product with a specified width. However, this method wastes more materials.

[0032] Refer to Figures 1 to 3, is a downblown film equipment with film diameter adjustment and secondary stretching functions according to an embodiment of the present invention, including a frame 100, a film blowing assembly 200, and a diameter-changing assembly 300. The film blowing assembly 200 is arranged on the frame 100. The film blowing assembly 200 includes a film blowing head 210, a feeding mechanism 220, and a cooling ring 230. The feeding mechanism 220 is connected to the film blowing head 210. The film blowing head 210 is provided with an annular film outlet. The cooling ring 230 is located on the discharging side of the annular film outlet. The diameter-changing assembly 300 is arranged on the frame 100. The diameter-changing assembly 300 includes a heating cylinder 310, a diameter-changing feeding pinch roller 320, a diameter-changing discharging pinch roller 330, and an air injection and exhaust mechanism 340. The heating cylinder 310 is provided with a film diameter-changing through hole 311. The film diameter-changing through hole 311 is provided with a feeding end and a discharging end. The diameter-changing feeding pinch roller 320 is arranged corresponding to the feeding end of the film diameter-changing through hole 311. The diameter-changing discharging pinch roller 330 is arranged corresponding to the discharging end of the film diameter-changing through hole 311. The air injection and exhaust mechanism 340 is located between the diameter-changing feeding pinch roller 320 and the diameter-changing discharging pinch roller 330 and can inject air or exhaust air into the internal space of the annular film.

[0033] The feeding mechanism 220 sends the molten plastic flow into the film blowing head 210 to blow out the annular film. After the annular film is cooled and shaped by the cooling ring 230, it enters the diameter-changing assembly 300. The annular film is flattened and passes through the diameter-changing feeding pinch roller 320, and then passes through the film diameter-changing through hole 311 of the heating cylinder 310 and the diameter-changing discharging pinch roller 330. Since the heating cylinder 310 can reheat the annular film, the annular film can be deformed. The air injection and exhaust mechanism 340 can inject air into or exhaust air from the internal space of the annular film in the film diameter-changing through hole 311, that is, the internal air volume of the annular film between the diameter-changing feeding pinch roller 320 and the diameter-changing discharging pinch roller 330 can be adjusted. The larger the air volume, the larger the diameter expansion amount of the annular film. Thus, the diameter of the annular film can be adjusted, so that the final film width can meet the requirements, and films of multiple widths can be continuously produced without replacing the cooling ring 230, thereby reducing the impact on production efficiency and reducing material loss.

[0034] Specifically, in this embodiment, the discharging direction refers to the moving forward direction of the film and does not represent the spatial orientation of the equipment.

[0035] It should be understood that the air inside the annular film will expand in the heating cylinder 310. Under the action of the internal and external pressure difference, it promotes the diameter expansion of the annular film until the deformation resistance of the annular film and the internal and external air pressure difference reach equilibrium.

[0036] Specifically, the heating cylinder 310 reheats the annular film. In addition to restoring the deformation ability of the annular film so that the diameter of the annular film can change, it can also play a certain heat setting role on the annular film, making the annular film stronger.

[0037] In an embodiment, the air injection and exhaust mechanism 340 includes an air venting needle, an air pump, and a first moving driver. The air pump is in communication with the air venting needle. The air venting needle is movably disposed on the frame 100 and can pierce or disengage from the annular diaphragm. The first rotating driver is used to drive the air venting needle to insert into or disengage from the annular diaphragm.

[0038] In the initial state, there is a certain amount of air inside the annular diaphragm in the diaphragm variable diameter through hole 311. When it is necessary to inject air into the annular diaphragm, the first moving driver can drive the air venting needle to insert into the annular diaphragm, and the air pump injects air into the annular diaphragm through the air venting needle. Then, the air venting needle is pulled out, thereby increasing the internal air volume of the annular diaphragm. At this time, the diameter expansion amount of the annular diaphragm can be increased, that is, the width of the flattened diaphragm is ultimately increased.

[0039] When it is necessary to reduce the internal air volume of the annular diaphragm, the air venting needle can be directly used to pierce the annular diaphragm, and the internal air of the annular diaphragm is slowly discharged through the pierced hole. Or the air injection and exhaust mechanism 340 further includes an exhaust tool. The production personnel can manually operate the exhaust tool to make small holes in the annular diaphragm to release the internal air, or the air venting needle can also be inserted into the annular diaphragm, and the internal air of the annular diaphragm is suctioned through the air pump and the air venting needle, thereby reducing the internal air volume of the annular diaphragm. Then, the air venting needle is pulled out.

[0040] It can be understood that in other embodiments, the air injection and exhaust mechanism 340 can also separately set an air injection needle, an air pump, and an exhaust needle. The air injection needle is in communication with the air pump, and air is injected into the annular diaphragm through the air injection needle. The internal air is discharged by piercing the annular diaphragm through the exhaust needle; or the exhaust needle can also be replaced with a hole-punching tool; the air injection and exhaust mechanism 340 can also manually move the air injection needle and the exhaust needle by the production personnel to perform injection or piercing exhaust.

[0041] In an embodiment, the air injection and exhaust mechanism 340 further includes a second moving driver. The air venting needle is movably disposed on the frame 100 and can move along the hole axis direction of the diaphragm variable diameter through hole 311. The second moving driver is used to drive the air venting needle to move along the hole axis direction of the diaphragm variable diameter through hole 311. Since the annular diaphragm is moving during the production process of the down-blown film equipment, the air injection and exhaust mechanism 340 is provided with a second moving driver to drive the air venting needle to move along the hole axis direction of the diaphragm variable diameter through hole 311, which can make the air venting needle move at the same speed and synchronously with the annular diaphragm, avoiding the air venting needle staying in place for air injection or exhaust. When the air venting needle inserts into the annular diaphragm, the air venting needle moves synchronously with the annular diaphragm; when the air venting needle is pulled out, the air venting needle moves back to its original position to wait for the next insertion into the annular diaphragm.

[0042] Specifically, the venting needle can be slidably arranged on the moving table along the radial direction of the variable-diameter through-hole 311 of the diaphragm by means of a guide post and guide sleeve structure or a slide rail and slider structure. The moving table is slidably arranged in the heating cylinder 310 along the hole axis direction of the variable-diameter through-hole 311 of the diaphragm, so as to enable the venting needle to insert into or disengage from the annular diaphragm, and to enable the venting needle to move along the hole axis direction of the variable-diameter through-hole 311 of the diaphragm.

[0043] Specifically, the first moving driver can adopt structures such as a cylinder, an oil cylinder or an electric cylinder, etc., to drive the venting needle to insert into or disengage from the annular diaphragm. The second moving driver can adopt a structure such as a motor cooperating with a lead screw and a lead screw nut to drive the moving table to move synchronously with the annular diaphragm, or adopt a linear driver with a controllable speed such as a linear motor.

[0044] It can be understood that the first moving driver and the second moving driver can also adopt a three-axis manipulator, or the production personnel can manually control the venting needle to insert into or pull out of the annular diaphragm, and manually control the venting needle to move at the same speed as the annular diaphragm.

[0045] Since the variable-diameter feed pinch rolls 320 and the variable-diameter discharge pinch rolls 330 can clamp the annular diaphragm, when the injection and exhaust mechanism 340 is not used, the air volume in the annular diaphragm between the variable-diameter feed pinch rolls 320 and the variable-diameter discharge pinch rolls 330 basically remains unchanged, so that the diameter of the produced annular diaphragm remains stable.

[0046] In the embodiment, the rotation speeds of the variable-diameter feed pinch rolls 320 and the variable-diameter discharge pinch rolls 330 can be adjusted. When the air volume in the annular diaphragm between the variable-diameter feed pinch rolls 320 and the variable-diameter discharge pinch rolls 330 remains basically unchanged, when the speed of the variable-diameter discharge pinch rolls 330 is greater than the speed of the variable-diameter feed pinch rolls 320, a stretching phenomenon can occur to the annular cylindrical film, that is, the diameter of the annular diaphragm is reduced, so as to reduce the width of the finally produced diaphragm; in this case, if a part of the gas in the annular diaphragm is discharged by using the injection and exhaust mechanism 340, the diameter of the annular diaphragm can be quickly reduced. When the speed of the variable-diameter discharge pinch rolls 330 is less than or equal to the speed of the variable-diameter feed pinch rolls 320, the diameter of the annular diaphragm can be increased.

[0047] In an embodiment, the machine base is provided with a control module. The variable-diameter assembly 300 further includes a first rotation driver and a second rotation driver. The first rotation driver is used to drive the variable-diameter feed pinch rolls 320 to rotate, and the second rotation driver is used to drive the variable-diameter discharge pinch rolls 330 to rotate. The first rotation driver and the second rotation driver are both electrically connected to the control module through a PLC program. The control module can control the rotation speeds of the first rotation driver and the second rotation driver. By controlling the running speeds of the first rotation driver and the second rotation driver respectively through the control module, the speeds of the variable-diameter feed pinch rolls 320 and the variable-diameter discharge pinch rolls 330 are respectively controlled, so as to realize the adjustment of the speed difference between the variable-diameter discharge pinch rolls 330 and the variable-diameter feed pinch rolls 320. The structure is relatively simple and easy to implement.

[0048] Specifically, the first rotation driver and the second rotation driver can adopt, for example, a servo motor or other structures that output rotational power, and the rotation speed can be adjusted relatively accurately through the control module.

[0049] It can be imagined that in some embodiments, it can also be that the rotation speed of the variable-diameter feed pinch rolls 320 is adjustable and the speed of the variable-diameter discharge pinch rolls 330 is not adjustable; or the speed of the variable-diameter feed pinch rolls 320 is not adjustable and the speed of the variable-diameter discharge pinch rolls 330 is adjustable, and a speed difference between the variable-diameter discharge pinch rolls 330 and the variable-diameter feed pinch rolls 320 can also be formed. Those skilled in the art can specifically select according to actual needs. Specifically, as the speed difference between the variable-diameter discharge pinch rolls 330 and the variable-diameter feed pinch rolls 320 increases, the diameter of the annular diaphragm will gradually decrease.

[0050] In an embodiment, the heating cylinder 310 is provided with a variable-diameter heater, and the heating temperature of the variable-diameter heater can be adjusted. When the temperature of the variable-diameter heater rises, the temperature inside the heating cylinder 310 can be increased, reducing the deformation impedance of the annular diaphragm, so that the diameter of the annular diaphragm can be increased when the air volume inside the annular diaphragm remains unchanged; when the temperature of the variable-diameter heater drops, the temperature inside the heating cylinder 310 can be decreased, thereby increasing the deformation impedance of the annular diaphragm, so that the diameter of the annular diaphragm can be reduced when the air volume inside the annular diaphragm remains unchanged.

[0051] Specifically, the variable-diameter assembly 300 can have several effects on the annular diaphragm:

[0052] When other parameters remain unchanged, when the speed of the variable-diameter discharge pinch rolls 330 is greater than the speed of the variable-diameter feed pinch rolls 320, the diameter of the annular diaphragm can be shrunk; when the speed of the variable-diameter discharge pinch rolls 330 is the same as the speed of the variable-diameter feed pinch rolls 320, the diameter of the annular diaphragm remains basically unchanged, which is equivalent to performing a heat setting on the annular diaphragm one more time; when the speed of the variable-diameter discharge pinch rolls 330 is less than the speed of the variable-diameter feed pinch rolls 320, the diameter of the annular diaphragm can be increased.

[0053] When other parameters remain unchanged, when the air injection and exhaust mechanism 340 is used to inject air into the annular diaphragm, the diameter of the cylindrical film can be increased; when the air injection and exhaust mechanism 340 is used to exhaust the air in the annular diaphragm, the diameter of the cylindrical film can be reduced.

[0054] When other parameters remain unchanged, when the temperature of the heating cylinder 310 is increased, the diameter of the annular diaphragm can be increased; when the temperature of the heating cylinder 310 is decreased, the diameter of the annular diaphragm can be reduced.

[0055] It should be understood that when the diameter of the annular diaphragm increases, the thickness of the annular diaphragm also decreases. Therefore, through the above structure, a diaphragm thickness that cannot be formed by the conventional film blowing method can be produced, and the same amount of material can be made into a larger area of the diaphragm, improving economic benefits.

[0056] In the embodiment, the film blowing assembly 200 further includes a first flattening mechanism 240. The first flattening mechanism 240 is located between the cooling ring 230 and the diameter-changing assembly 300. The first flattening mechanism 240 includes two guiding plates 241 arranged oppositely, and the distance between the two guiding plates 241 gradually decreases along the advancing direction of the annular diaphragm. Since the diaphragm blown out by the film blowing head 210 is annular, after passing through the cooling ring 230, the annular diaphragm still remains annular, which is not conducive to guiding and transporting through the roller body and entering the diameter-changing assembly 300. Therefore, the first flattening mechanism 240 is provided. Through the two guiding plates 241 arranged oppositely, the distance of the guiding plates 241 gradually decreases along the advancing direction of the annular diaphragm, so that the annular diaphragm can be gradually flattened, facilitating guiding and transporting through the roller body. Specifically, air spray holes can be provided on the guiding plates 241 to reduce the direct contact between the diaphragm and the guiding plates 241.

[0057] In the embodiment, at least two feeding mechanisms 220 are provided. All the feeding mechanisms 220 are respectively communicated with the film blowing head 210, and the film blowing head 210 is a co-extrusion film blowing head 210. Multiple feeding mechanisms 220 supply materials to the film blowing head 210 simultaneously, facilitating the production of co-extrusion films. Specifically, the number of the feeding mechanisms 220 can be set to two, three, four, five or more. Those skilled in the art can specifically select according to actual needs. For example, when the co-extrusion film blowing head is a (2N + 1)-layer co-extrusion, N feeding mechanisms 220 are required to correspond to it.

[0058] In the embodiment, a shaping assembly is further included. The heat shaping assembly 400 is arranged on the frame 100 and is located in the discharging direction of the diameter-changing assembly 300. The heat shaping assembly 400 includes a heating chamber 410 and a plurality of shaping rollers 420. The shaping rollers 420 are rotatably arranged in the heating chamber 410, and the annular diaphragm sequentially bypasses each shaping roller 420. The annular diaphragm sequentially bypasses a plurality of shaping rollers 420, and the heating chamber 410 can perform heat shaping on the annular diaphragm passing through it, thereby improving the thermal stability of the annular diaphragm.

[0059] In an embodiment, along the direction from left to right, the shaping rollers 420 are arranged alternately up and down, so that each shaping roller 420 can be arranged relatively compactly in the heating chamber 410, with a high space utilization rate, and the length of the annular diaphragm in the heating chamber 410 is increased as much as possible to improve the heat setting effect. Traction rollers 510 are provided on both the inlet side and the outlet side of the heating chamber 410 to facilitate the traction of the diaphragm into and out of the heating chamber 410. The heating chamber 410 can be heated by means of hot air circulation, so as to maintain a suitable heating temperature in the heating chamber 410 and save energy.

[0060] Specifically, the cooling ring 230 is cooled by means of cold water circulation in cooperation with vacuum sizing.

[0061] Specifically, a traction roller 510 and a rotary guiding device 520 are arranged in the discharging direction of the first flattening mechanism 240. The rotary guiding device 520 can perform rotary guiding on the diaphragm, reduce the phenomenon of unevenness or wrinkles after the winding of the diaphragm finished product, and improve the strength and appearance quality of the diaphragm.

[0062] Specifically, a variable diameter assembly 300 is arranged in the discharging direction of the rotary guiding device 520. A second flattening mechanism 350 is also arranged between the heating cylinder 310 and the variable diameter discharging pinch rollers 330 of the variable diameter assembly 300 to assist in flattening the annular diaphragm after variable diameter.

[0063] Specifically, a heat setting assembly 400 is arranged in the discharging direction of the variable diameter assembly 300, and a cooling device is arranged in the discharging direction of the heat setting assembly 400, which can cool the diaphragm. A thickness measuring device is arranged in the discharging direction of the cooling device, which can detect the thickness of the diaphragm.

[0064] Specifically, a traction device and a corona device are arranged in the discharging direction of the thickness measuring device. The corona device can improve the surface adhesion of the diaphragm and facilitate use. A winding device is arranged in the discharging direction of the corona device, which can wind the diaphragm to obtain a diaphragm finished product.

[0065] Specifically, a deviation rectifying device can be arranged at the inlet position of some feeding rollers. For example, before the diaphragm enters the variable diameter assembly 300, it first passes through the deviation rectifying device for deviation rectification and then enters the variable diameter feeding pinch rollers 320, and before the diaphragm enters the heat setting assembly 400, it first passes through the deviation rectifying device for deviation rectification and then enters the heating chamber 410, etc. Those skilled in the art can specifically select according to actual needs.

[0066] In this embodiment, the film outlet of the film blowing head 210 is arranged downward, and the vertical height of the cooling ring 230 is adjustable, so that it can be applicable to film blowing heads 210 with different height dimensions, the universality of the cooling ring 230 is better, and the position of the cooling ring 230 can be adjusted according to the production process requirements of annular diaphragms made of different materials. Specifically, the cooling ring 230 is slidably connected to the frame 100, and the vertical height can be adjusted by a motor cooperating with a lead screw and a lead screw nut structure.

[0067] In the embodiment, the included angle and distance between the two guiding plates 241 of the first flattening mechanism 240 are adjustable to be applicable to diaphragms with different process requirements, and the effect of flattening the diaphragm can be reasonably adjusted. Specifically, the guiding plates 241 are arranged in the vertical direction. The upper part of the guiding plate 241 adjusts the left and right positions through a first left-right adjustment structure, and the lower part of the guiding plate 241 also adjusts the left and right positions through a second left-right adjustment mechanism, so that the inclination angle and position of the guiding plate 241 can be adjusted. The first left-right adjustment structure adopts a dial wheel cooperating with a lead screw and a lead screw nut structure, and the second left-right adjustment structure adopts a roller cooperating with a linear actuator. The lower part of the guiding plate 241 is slidably connected to the frame 100 in the left and right directions through the roller, and the linear actuator is pivotally connected to the roller and drives the roller to move left and right. It can be understood that in some other embodiments, both the first left-right adjustment structure and the second left-right adjustment structure can adopt electric cylinders, and one end of the electric cylinder is pivotally connected to the guiding plate 241.

[0068] Specifically, the first flattening mechanism 240 is installed on the rotary guiding device 520.

[0069] Specifically, the control module can be controlled by an equipment computer or other types of control systems.

[0070] Specifically, the production process of the down-blown film equipment in this embodiment is as follows: The feeding mechanism 220 mixes plastic particles according to the ratio and extrudes a molten material flow. The molten material flow passes through the film blowing head 210 to blow out an annular diaphragm. After being cooled by the cooling ring 230, it is flattened by the first flattening mechanism 240, and then enters the rotary guiding device 520 through the traction roller 510. Subsequently, it passes through the diameter-changing assembly 300 for diameter adjustment, and then passes through the deviation rectifying device for deviation rectification. Subsequently, the diaphragm passes through the heat setting assembly 400 for heat setting and is cooled by the cooling device, and then passes through the thickness measuring device to detect the thickness. When the thickness of the diaphragm meets the requirements, it is guided by the traction device to the corona device for corona treatment, and then is wound into a film roll by the winding device. When the thickness of the diaphragm does not meet the requirements, it is pulled by the traction device to the crushing device for waste crushing, and then the recycled raw materials are sent to the feeding mechanism 220 for reuse. The corona device can be divided into an inner corona part and an outer corona part, which perform corona treatment on the inner and outer sides of the diaphragm respectively.

[0071] Specifically, for the above-mentioned down-blown film equipment, the diameter-changing component (300) can process the annular film with a diameter reduction of no more than 30% or a diameter increase of no more than 10%. The process of the blowing head 210 blowing down the annular film controls the thickness uniformity of the annular film, and the diameter-changing component (300) can adjust the folding diameter of the annular film, that is, adjust the width of the flattened film.

[0072] Specifically, the change in barrel diameter is positively correlated with the heating temperature T of the diameter-changing component 300 and the internal air pressure P of the annular film, and negatively correlated with the speed difference ΔV between the diameter-changing discharge pinch roll 330 and the diameter-changing feed pinch roll 320. For example In the above formula, k1, k2, and k3 are the variable constants of temperature, pressure, and speed difference respectively, and m is a constant related to the film material.

[0073] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0074] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and purposes of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A bottom blowing film equipment with film diameter adjustment and secondary stretching functions, characterized in that: include: Rack(100); A film blowing assembly (200) is arranged on the frame (100), the film blowing assembly (200) comprises a film blowing head (210), a feeding mechanism (220) and a cooling ring (230), the feeding mechanism (220) is connected to the film blowing head (210), the film blowing head (210) is provided with an annular film outlet, and the cooling ring (230) is located on the discharge side of the annular film outlet; A variable diameter assembly (300) is arranged on the frame (100), and the variable diameter assembly (300) comprises a heating cylinder (310), a variable diameter feed roller (320), a variable diameter discharge roller (330) and an air injection and exhaust mechanism (340). The heating cylinder (310) is provided with a diaphragm variable diameter through hole (311), and the diaphragm variable diameter through hole (311) is provided with a feed end and a discharge end. The variable diameter feed roller (320) is arranged corresponding to the feed end of the diaphragm variable diameter through hole (311), and the variable diameter discharge roller (330) is arranged corresponding to the discharge end of the diaphragm variable diameter through hole (311). The air injection and exhaust mechanism (340) is located between the variable diameter feed roller (320) and the variable diameter discharge roller (330) and can inject or exhaust air into the internal space of the annular diaphragm.

2. The bottom blowing film equipment with film diameter adjustment and secondary stretching functions according to claim 1, characterized in that: The air injection and exhaust mechanism (340) comprises a ventilation needle, an air pump and a first movable driver, the air pump is connected to the ventilation needle, the ventilation needle is movably arranged on the frame (100) and can penetrate into or detach from the annular diaphragm, and the first rotating driver is used to drive the ventilation needle to penetrate into or detach from the annular diaphragm.

3. The bottom blowing film equipment with film diameter adjustment and secondary stretching functions according to claim 2 is characterized in that: The injection and exhaust mechanism (340) further comprises a second movable driver, wherein the ventilation needle is movably arranged on the frame (100) and can move along the hole axis direction of the diaphragm variable diameter through hole (311), and the second movable driver is used for driving the ventilation needle to move along the hole axis direction of the diaphragm variable diameter through hole (311).

4. The bottom blowing film equipment with film diameter adjustment and secondary stretching functions according to claim 1 is characterized in that: The rotation speed of the variable diameter feeding clamp roller (320) and / or the variable diameter discharging clamp roller (330) can be adjusted.

5. The bottom blowing film equipment with film diameter adjustment and secondary stretching functions according to claim 4 is characterized in that: The machine base is provided with a control module, and the variable diameter assembly (300) also includes a first rotation driver and a second rotation driver, the first rotation driver is used to drive the variable diameter feed clamp roller (320) to rotate, and the second rotation driver is used to drive the variable diameter discharge clamp roller (330) to rotate, the first rotation driver and the second rotation driver are both electrically connected to the control module, and the control module can control the rotation speed of the first rotation driver and the second rotation driver.

6. The bottom blowing film equipment with film diameter adjustment and secondary stretching functions according to claim 1, characterized in that: The heating cylinder (310) is provided with a variable-diameter heater, and the heating temperature of the variable-diameter heater can be adjusted.

7. The bottom blowing film equipment with film diameter adjustment and secondary stretching functions according to claim 1, characterized in that: The film blowing assembly (200) further includes a first flattening mechanism (240), which is located between the cooling ring (230) and the diameter-changing assembly (300). The first flattening mechanism (240) includes two guide plates (241) arranged opposite to each other, and the distance between the two guide plates (241) gradually decreases along the forward direction of the annular diaphragm.

8. The bottom blowing film equipment with film diameter adjustment and secondary stretching functions according to claim 1, characterized in that: At least two of the feeding mechanisms (220) are provided, and all of the feeding mechanisms (220) are respectively connected to the film blowing head (210), and the film blowing head (210) is a co-extrusion film blowing head (210).

9. The bottom blowing film equipment with film diameter adjustment and secondary stretching functions according to claim 1, characterized in that: The invention also comprises a heat setting component (400), wherein the heat setting component (400) is arranged on the frame (100) and is located in the discharge direction of the diameter reducing component (300), and the heat setting component (400) comprises a heating chamber (410) and a plurality of setting rollers (420), wherein the setting rollers (420) are rotatably arranged on the heating chamber (410), and the annular diaphragm passes around each of the setting rollers (420) in sequence.

10. The bottom blowing film equipment with film diameter adjustment and secondary stretching functions according to claim 9, characterized in that: From left to right, the shaping rollers (420) are arranged alternately up and down.

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