Automatic film blowing machine for plastic production

Abstract

The invention relates to the technical field of film blowing, in particular to an automatic film blowing machine for plastic production, which comprises an extruder, a die head, a traction device, an outer air ring, an inner air ring, an air extracting pump and an air feeding pump, the traction device stretches raw materials extruded by the die head into film bubbles, the outer air ring comprises a ring body and a partition plate, the ring body and the die head are coaxially mounted, and the partition plate is arranged on the ring body. The partition plate is inserted into the ring body and divides the interior of the ring body into an upper cavity and a lower cavity, an upper air opening and a lower air opening are sequentially formed in the inner circumferential face of the ring body from top to bottom, the inner air ring comprises a short pipe and a long pipe, and the long pipe and the short pipe are both located in the film bubble; according to the air ring, air is independently supplied to the upper air opening and the lower air opening in the air ring, and warm air generated in the production process is circulated to the lower air opening, so that a small-thickness thin film passes through the lower air opening in an unformed state, and the thickness of the thin film is adjusted at the upper air opening, so that the purpose of improving the thickness uniformity of the thin film is achieved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of film blowing, and particularly relates to an automatic film blowing machine for plastic production. BACKGROUND

[0002] Plastic is a material that can be recycled and has excellent plasticity, and according to different manufacturing processes, the plastic has excellent application value in many industries. For example, the plastic film obtained through the film blowing process is not only the base material of a packaging bag, but also can be used as a mulch film for agricultural planting.

[0003] The commonly used equipment for the film blowing process is a film blowing machine. The effective structure of the film blowing machine comprises an extruder, a die head, an air ring and a traction device. The extruder fully mixes and plasticizes the input raw material particles and then pushes the raw material particles into the die head. The molten raw material is extruded from the annular gap at the top of the die head. The traction device is located above the film blowing machine and simultaneously stretches the raw material extruded from the annular gap and winds the film formed by stretching. The air ring is installed above the die head and is used to cool the raw material extruded from the die head, so that the raw material is cooled and formed. The core factor for measuring the advantages and disadvantages of the film blowing process is the uniformity of the film thickness, and this performance is directly affected by the structure of the air ring. The traditional air ring is provided with an array of air ports on the circumferential surface of the inner ring (and thus this kind of arrangement is called a single-air-port type), and a valve is arranged in each air port channel to independently control the cooling gas flow of each air port, so that the gas flow is adjusted in real time according to the detection of the film thickness, so as to ensure the uniformity of the film thickness. However, under the action of only one annular air flow, in order to ensure the cooling effect, the direction of the air port is made to be as perpendicular to the film as possible, which will cause the impact force of the air flow on the film to increase, and thus the instability of the film is caused, thereby affecting the uniformity of the film thickness.

[0004] Therefore, the prior art usually adopts a double-air-port arrangement, that is, a circle of lower air ports is arranged at equal intervals below the air ports of the traditional air ring. For example, the high-efficiency double-air-port air ring disclosed in the patent with the publication number CN213321698U. In this way, the air flow sprayed from the upper air ports and the air flow sprayed from the lower air ports do not directly shoot towards the film after the two air flows intersect, so that the cooling effect is ensured while the impact force of the cooling air flow on the film is reduced, thereby improving the uniformity of the film thickness.

[0005] The prior art can improve the stability of the film by the double air port setting of the air ring, thereby improving the uniformity of the film thickness, but there is still room for further improvement when producing a film with small thickness, such as a mulch film, because the air flows of the two air ports in the air ring are both from the air ring cavity, so the temperatures of the two air flows are the same, and the air flow of the lower air port is mainly auxiliary, without complex settings inside, while the air flow of the upper air port is adjusted in real time to ensure the uniformity of the film thickness, when producing a small-thickness film represented by a mulch film, the film is prone to be cooled and formed, and the forming process is often completed when passing through the lower air port, so the film thickness cannot be adjusted by the subsequent upper air port, thereby still causing the problem of uneven film thickness.

[0006] Therefore, an automatic film blowing machine for plastic production is provided. SUMMARY

[0007] The automatic film blowing machine for plastic production solves the problem of premature cooling and forming of the film when the film blowing machine blows a small-thickness film, and realizes that the small-thickness film passes through the lower air port in an unformed state by independently supplying air to the upper air port and the lower air port in the air ring and circulating the warm air generated during production to the lower air port, so that the film thickness is adjusted at the upper air port, thereby improving the uniformity of the film thickness.

[0008] To achieve the above object, the present application provides the following technical scheme:

[0009] An automatic film blowing machine for plastic production, comprising an extruder, a die head and a traction device, the die head is in communication with the inside of the extruder, the traction device is located above the die head, and the traction device stretches the raw material extruded by the die head into a film bubble, further comprising an outer air ring, an inner air ring, a gas extraction pump and a gas supply pump, the outer air ring comprises a ring body and a partition plate, the ring body is coaxially installed with the die head, and the ring body is located outside the film bubble, the partition plate is inserted into the inside of the ring body, and the partition plate divides the inside of the ring body into an upper cavity and a lower cavity, the inner circumferential surface of the ring body is sequentially provided with an upper air port and a lower air port from top to bottom, the upper air port and the lower air port are respectively in communication with the upper cavity and the lower cavity, the inner air ring comprises a short pipe and a long pipe, the long pipe and the short pipe are both located inside the film bubble, and the long pipe is in communication with the lower cavity, the gas extraction pump is installed on the long pipe which is in communication with the lower cavity, and the gas supply pump is in communication with the short pipe.

[0010] The gas extraction pump extracts the warm flow gathered above the film bubble to the lower cavity of the ring body through the long pipe, and the lower air port discharges the warm air in the lower cavity to avoid premature cooling and forming of the film bubble.

[0011] The initial film blowing machine is without inner air ring. With the increasing requirement of the industry on the film blowing quality, the design requirement of the inner air ring gradually becomes a necessity. The design purposes are to accelerate the cooling forming of the film and to form the pressure difference between the inside and outside of the bubble. The thickness of the bubble can be more accurately controlled by adjusting the pressure difference. That is, the inner air ring supplies air to the bubble while keeping the air pressure in the bubble stable. However, the volume of the bubble is constant after the cooling forming. Therefore, the air supply mode of the inner air ring in the prior art is roughly as follows: one is to continuously or stop supplying air according to the real-time feedback of the air pressure in the bubble; the other is to use a double air pump system to supply air to the bubble through the inner air ring while pumping out the air in the inner air ring to complete the alternation of hot and cold by the circulation of the air. The first mode can be completed by using only one air blower, which has a low cost, but the corresponding function is also lacking. First, the air supply of the inner air ring is intermittent, which affects the cooling effect of the bubble and the uniformity of the thickness of the bubble. Second, this setting can only supply air to the inside of the bubble. Once the air pressure in the bubble rises, there is no reliable measure to reduce the pressure, and the air pressure in the bubble can only be naturally reduced, which also affects the uniformity of the thickness of the bubble. Therefore, the present scheme improves the second mode. When the second mode is applied to the prior art, the air outlet and the air inlet of the inner air ring are usually arranged close to each other. However, the position of the same kind of air is positively correlated with the temperature of itself. The high-temperature air gathered in the bubble will continue to float upwards, and the air outlet located below cannot timely discharge them, which continuously increases the temperature of the upper bubble and increases the risk of film adhesion.

[0012] Preferably, the long pipe and the short pipe are coaxially installed with the die head, and the long pipe is located inside the short pipe.

[0013] In the above scheme, the long pipe is used to extract the high-temperature air above the bubble, and the air extraction of the long pipe will accelerate the contraction of the upper part of the bubble, and then make the bubble more smoothly complete the winding. The long pipe and the short pipe are coaxially arranged with the die head, so that the air flow can uniformly act on the bubble during air extraction and exhaust, thereby ensuring the stability of the bubble and improving the uniformity of the thickness of the bubble.

[0014] Preferably, the opening of the short pipe has an inward flange, and the opening of the long pipe has an outward flange.

[0015] In the above scheme, the short pipe is used to supply air to the inside of the bubble. The inward flange design makes the sprayed air gather towards the peripheral surface of the long pipe, thereby avoiding the impact of high-pressure air on the bubble. This setting makes the air gather in one place, thereby increasing the rising height of the air. The falling air after rising increases the cooling area, thereby improving the refrigeration efficiency (for reference, the fan blades are upward in air conditioning refrigeration). The long pipe is used to extract the high-temperature air in the bubble. The outward flange design has a flow guiding effect, thereby making the air flow more smoothly into the long pipe to promote the air extraction work.

[0016] Compared with the upper air vent, which can adjust its own air outlet through the flow control device to change the thickness of the film bubble at the corresponding position, thereby controlling the uniformity of the film bubble thickness as a whole, the lower air vent plays a more auxiliary role to make the effect of the upper air vent better. The design of the upper air vent in the existing technology is sufficiently sophisticated, so this solution focuses on the design around the lower air vent to enhance its functionality. The main functions of the lower air vent are three: First, to form an air gap between the film bubble and the inner ring of the outer air ring, thereby avoiding the adhesion of the film bubble that has not yet been cooled and formed on the outer air ring; second, Buffering the airflow ejected from the upwind vent to reduce the impact on the film bubble, thereby ensuring the stability of the film bubble and improving the uniformity of the film bubble thickness; thirdly, cooling the film bubble; when producing thicker films with slower cooling and forming speeds, the cooling effect of the downwind vent is negligible, but as the thickness of the film decreases, the cooling effect of the downwind vent becomes gradually more significant, and may even cause the film to cool and form before passing through the upwind vent; therefore, when producing thin films, the cooling effect of the downwind vent should be reduced or eliminated, while maintaining the air gap and buffering effect;

[0017] Preferably, the ring body comprises an upper ring and a lower ring, the lower ring is mounted on the die head, the upper ring is mounted on the lower ring, a pressure block is arranged in a circumferential array on the upper cavity side wall of the upper ring, the pressure block coincides with the position of the upper air outlet, and one end of the pressure block is communicated with the upper air outlet, and the other end of the pressure block is connected to a flow control device, the lower ring has a support block arranged in a circumferential array on the lower cavity side wall, the partition is located between the pressure block and the support block, a cold air cavity is opened inside the lower ring, the cold air cavity is located outside the upper cavity and the lower cavity, and the flow control device is installed between the cold air cavity and the upper cavity;

[0018] In the above scheme, after the upper ring and the lower ring are assembled, the pressure block and the support block form a space for the installation of the partition; when the partition is installed, the upper cavity and the lower cavity are independent, and the cold air cavity supplies cooling gas to the upwind port through the flow control device and the pressure block, while the high-temperature gas extracted by the long tube is discharged to the lower cavity and discharged from the downwind port, thereby reducing the cooling effect of the downwind port on the membrane bubble while still retaining its function of forming an air gap and buffering the airflow at the upwind port.

[0019] If the outer air ring remains in the above configuration, it will obviously be disadvantageous for the production of thick films. In this case, the manufacturer will need to purchase additional outer air rings for the production of thick films, which will not only increase the purchase cost but also add the process of replacing the outer air rings.

[0020] Preferably, the lower ring is provided with a cold flow hole, the cold flow hole is located on the side wall of the lower cavity of the lower ring, and the opening position of the cold flow hole on the side wall of the lower cavity coincides with the support block, the interior of the support block is communicated with the cold flow hole, and the internal channel opening of the support block faces upward, and the cold air cavity is communicated with the cold flow hole;

[0021] With this solution, after the baffle is removed, the lower chamber connects to the cold air chamber, allowing the upper and lower air outlets to inlet air from the same source, restoring the cooling function of the lower air outlet and enabling the production of thicker films. Furthermore, after the baffle is removed, the lower chamber merges with the upper chamber, expanding the volume of the cold air chamber, thereby ensuring a more uniform and stable air supply to the upper and lower air outlets.

[0022] Preferably, the upper and lower sides of the partition are both provided with stoppers, the stoppers on the lower side of the partition are of different heights, and a through slot is provided on the stopper with the larger height, the through slot is located on the side where the stopper is connected to the partition, and the protruding end of the stopper is in clearance with the bottom wall of the lower cavity;

[0023] In the above scheme, a block is set above the partition to facilitate the extraction of the partition when disassembling and assembling the partition; blocks of different heights are set below the partition to form a maze structure, so that the air pressure in the lower cavity is more uniform and stable, so that the air outlet of each lower air outlet is consistent, so as to ensure the stability of the membrane bubble and thus improve the uniformity of the membrane bubble thickness.

[0024] The air pump's air volume will be adjusted in real time according to the air pressure inside the bubble. If the air pump is directly discharged into the lower cavity, the air pressure inside the lower cavity will fluctuate, which will in turn cause fluctuations in the jet airflow at the lower air outlet, resulting in uneven bubble thickness.

[0025] Preferably, a cold port and a warm port are opened below the lower ring, the cold port and the warm port are communicated with the cold air cavity and the lower cavity respectively, the cold port is communicated with the air supply pump, an overflow throttle valve is installed between the air extraction pump and the warm port, and the inlet and outlet of the overflow throttle valve are connected to the air extraction pump and the warm port respectively;

[0026] In the above scheme, an overflow throttle valve is set between the warming port and the vacuum pump, and then by adjusting the throttling pressure of the overflow throttle valve, the gas flow into the lower cavity is stabilized, so that the gas output of the lower air port at each moment is consistent, so as to ensure the uniformity of the film bubble thickness;

[0027] When producing thick films, close the main channel of the overflow throttle valve so that all the extracted gas is discharged from the overflow port, and the vacuum pump no longer supplies air to the lower cavity, so as to restore the cooling function of the lower air port on the film bubble, thereby better producing thick films.

[0028] In addition to the air volume type improved by the present invention, the film blowing machine also has an air temperature type. The air temperature type arranges a heating rod in the flow channel of each upwind port, thereby controlling the thickness of the film bubble by adjusting the temperature of the exhaust gas from the upwind port. It can be seen that the so-called cooling gas injected from the upwind port is only relative to the solidification temperature of the film material. In other words, the gas discharged from the overflow port of the overflow throttle valve may be further utilized by the air pump.

[0029] Preferably, a mask and an escutcheon are respectively arranged on the drainage side of the air suction pump and the air supply pump, the mask is communicated with the inlet of the overflow throttle valve, the escutcheon is communicated with the overflow port of the overflow throttle valve, the mask surface has no openings, and the escutcheon surface has multiple openings;

[0030] Through the above scheme, the recycling of gas is achieved. On the one hand, the vacuum pump extracts the high-temperature gas accumulated above the film bubble, and discharges the high-temperature gas into the lower cavity through the seal of the mask, so as to realize the heat preservation effect of the lower air outlet on the film bubble during the production of small thickness films; on the other hand, the overflow valve discharges the gas that cannot be used by the lower cavity into the hole cover, thereby reducing the power consumption of the air pump and saving production costs.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. The present invention divides the interior of the outer air ring into an upper chamber and a lower chamber by setting a partition, and the upper air port in the upper chamber is supplied with air by an air supply pump, while the lower chamber receives the high-temperature gas extracted from above the film bubble by the air extraction pump and discharges it from the lower air port. Therefore, when producing thin films with small thickness, the high-temperature gas from the lower air port is used to keep the film bubble warm to avoid premature cooling and molding of the film bubble, so that the air flow from the upper air port can regulate the thickness of the film bubble in real time to improve the uniformity of the film bubble thickness.

[0033] 2. The present invention facilitates the disassembly and assembly of the partition inside the outer air ring through the design of the pressure block and the support block; when the partition is installed, the lower cavity is isolated and used for the production of small thickness films, and with the help of the maze structure formed by the block below the partition, the air pressure inside the lower cavity can be made uniform and stable, and the air outlet of each lower air outlet is made consistent, thereby improving the uniformity of the film thickness; after the partition is removed, the cold air cavity, the lower cavity, and the upper cavity are connected, and the cold air cavity supplies air to the upper air outlet and the lower air outlet at the same time, which is used for the production of large thickness films. At this time, the volume of the cold air cavity is expanded, so its air supply to each air outlet is more stable, thereby further improving the uniformity of the film thickness.

[0034] 3. The present invention installs an overflow throttle valve between the lower chamber and the vacuum pump. The inlet and outlet of the overflow throttle valve are connected to the vacuum pump and the lower chamber respectively, so that the airflow entering the lower chamber is stabilized by adjusting the throttling pressure of the overflow throttle valve to make the thickness of the film bubble uniform, and the overflow port of the overflow throttle valve is connected to the air pump, and then the gas that cannot be used in the lower chamber is discharged to the air pump, so as to reduce the power consumption of the air pump, thereby reducing the production cost of the blown film. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the overall isometric structure of the present invention;

[0036] Figure 2 Schematic diagram of gas flow of the present invention;

[0037] Figure 3 A partial left view schematic diagram of the present application;

[0038] Figure 4 A partial left view schematic diagram of the present application; Figure 2 A partial left view schematic diagram of the present application;

[0039] Figure 5 A partial left view schematic diagram of the present application;

[0040] Figure 6 A partial left view schematic diagram of the present application;

[0041] Figure 7 A partial left view schematic diagram of the present application; Figure 2 A partial left view schematic diagram of the present application;

[0042] Figure 8 A partial left view schematic diagram of the present application.

[0043] In the figure: 1, extruder; 2, die head; 3, traction device; 4, bubble; 5, outer air ring; 51, ring body; 511, upper cavity; 512, lower cavity; 513, upper air port; 514, lower air port; 515, upper ring; 5151, pressing block; 516, lower ring; 5161, supporting block; 5162, cold air cavity; 5163, cold flow hole; 5164, cold port; 5165, warm port; 52, partition plate; 521, stop block; 5211, through slot; 53, flow control device; 6, inner air ring; 61, short pipe; 62, long pipe; 7, air extraction pump; 71, face shield; 8, air supply pump; 81, hole cover; 9, overflow throttle valve. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the protection scope of the present application.

[0045] Please refer to Figures 1 to 8 The present application provides an automatic film blowing machine for plastic production, and the technical solutions are as follows:

[0046] An automatic film blowing machine for plastic production, comprising an extruder 1, a die head 2 and a traction device 3, referring to Figure 1, the die 2 is arranged at the left side of the extruder 1, and the die 2 is communicated with the inside of the extruder 1, the traction device 3 is located above the die 2, and the traction device 3 draws the raw material extruded by the die 2 into a film bubble 4; during production, the raw material (such as resin particles) is put into from the material port above the extruder 1, and the machine is used instead of manual feeding, so that the feeding amount can be more accurately controlled, thereby making the production of the film more stable, the extruder 1 plasticizes and mixes the raw material through the internal screw, and then extrudes the molten raw material from the upper annular gap of the die 2 to form the initial state of the film bubble 4; when starting a new round of production, usually multiple people are needed to complete the winding work of the film, and the specific process is as follows: several people first stand at the corresponding positions of the stairs (note to wear gloves to block the high temperature on the surface of the film), then one person gathers and pulls up the film extruded by the die 2, and then sequentially transmits the gathered film end to the uppermost person, and after receiving the film, the film is sequentially wound on each roller group of the traction device 3 to complete the winding work; in order to make the automatic process of the film blowing machine smooth, the traction device 3 with automatic roll changing function can be used, and the traction device 3 further comprises an outer air ring 5, an inner air ring 6, a suction pump 7 and a gas sending pump 8; the outer air ring 5 comprises a ring body 51 and a partition plate 52, the ring body 51 is coaxially installed with the die 2, and the ring body 51 is located outside the film bubble 4, the partition plate 52 is inserted into the ring body 51, and the partition plate 52 divides the inside of the ring body 51 into an upper cavity 511 and a lower cavity 512, the inner circumferential surface of the ring body 51 is sequentially provided with an upper air port 513 and a lower air port 514 from top to bottom, and the upper air port 513 and the lower air port 514 are communicated with the upper cavity 511 and the lower cavity 512 respectively; the inner air ring 6 comprises a short pipe 61 and a long pipe 62, the long pipe 62 and the short pipe 61 are located inside the film bubble 4, and the long pipe 62 is communicated with the lower cavity 512; the suction pump 7 is installed on the long pipe 62 communicated with the lower cavity 512, and the gas sending pump 8 is communicated with the short pipe 61 to send cooling air into the film bubble 4 through the short pipe 61.

[0047] The suction pump 7 draws the warm air gathered above the film bubble 4 to the lower cavity 512 of the ring body 51 through the long pipe 62, and the lower air port 514 discharges the warm air in the lower cavity 512 to avoid premature cooling and forming of the film bubble 4.

[0048] As an embodiment of the present application, referring to Figure 2 and Figure 3 , the long pipe 62 and the short pipe 61 are coaxially installed with the die 2, and the long pipe 62 is located inside the short pipe 61; the opening of the short pipe 61 has an inward folding edge, and the opening of the long pipe 62 has an outward folding edge;

[0049] The long pipe 62 and the short pipe 61 are both made of heat-insulating material (such as ceramic fiber plate) to avoid heat exchange of the gas inside the long pipe 62 and the short pipe 61, so as to ensure that the high-temperature gas is sprayed from the upper blowhole 514 and the low-temperature gas is sprayed from the lower blowhole 513 when the small-thickness film is produced, to respectively complete the heat preservation and cooling and shaping of the film bubble 4; the short pipe 61 is a bent pipe, the long pipe 62 is a straight pipe, a through hole in the up-down direction is formed at the bending position of the short pipe 61, during installation, the long pipe 62 is first inserted into the upper end of the short pipe 61, then is inserted out of the through hole at the bending position of the short pipe 61, and finally the adhesion between the long pipe 62 and the short pipe 61 is completed at the through hole (high-temperature adhesive is used), after the adhesion, the sealing property is checked to prevent the short pipe 61 from leaking to the outside through the through hole when the film blowing machine is working, so as to make the gas supply to the inside of the film bubble 4 unstable, and further cause the fluctuation of the film bubble 4, thereby affecting the uniformity of the thickness of the film bubble 4; during the manufacturing of the short pipe 61, the interference with the long pipe 62 should be avoided.

[0050] As an embodiment of the present application, referring to Figure 4 The ring body 51 includes an upper ring 515 and a lower ring 516, the lower ring 516 is installed on the die head 2, the upper ring 515 is installed on the lower ring 516, the upper wall of the upper cavity 511 of the upper ring 515 is circumferentially provided with a plurality of pressing blocks 5151, the pressing blocks 5151 are coincided with the positions of the upper blowholes 513, one end of the pressing blocks 5151 is communicated with the upper blowholes 513, the other end of the pressing blocks 5151 is connected with the flow control device 53, the lower wall of the lower cavity 512 of the lower ring 516 is circumferentially provided with a plurality of supporting blocks 5161, the partition plate 52 is located between the pressing blocks 5151 and the supporting blocks 5161, the cold air cavity 5162 is formed in the inside of the lower ring 516, the cold air cavity 5162 is located outside the upper cavity 511 and the lower cavity 512, and the flow control device 53 is installed between the cold air cavity 5162 and the upper cavity 511;

[0051] During the production stage, after the holes and grooves inside the upper ring 515 and the lower ring 516 are opened, the pressure block 5151 and the support block 5161 are welded (or glued) to the upper ring 515 and the lower ring 516 respectively. When welding (or gluing), pay attention to the coincidence of the port of the internal channel of the pressure block 5151 and the contour of the upper air outlet 513 on the inner wall of the upper cavity 511; when installing the ring body 51, first install each flow control device 53 at the corresponding position of the lower ring 516, and then install the lower ring 516 on the die head 2. Bolt connection can be used. When it is suitable for the production of thin films with small thickness, the partition 52 is placed in the lower ring 516 and placed on the support plate. Then the upper ring 515 is placed above the lower ring 516. Pay attention to aligning the pressure block 5151 with the flow control device 53. Finally, use bolts to complete the fixation between the upper ring 515 and the lower ring 516. In this way, the lower cavity 512 is divided into independent areas, so that the lower cavity 512 can be By independently receiving air supply, the lower air port 514 connected to the lower chamber 512 can discharge the independently supplied gas (high-temperature gas) in the lower chamber 512 to keep the film bubble 4 initially extruded from the die head 2 warm and prevent the film bubble 4 from cooling and forming prematurely. The upper air port 513 receives air supply from the cold air chamber 5162. When the cold air chamber 5162 supplies air to the upper air port 513, the gas first passes through the flow control device 53 (the common flow control device 53 is a combination of a motor and a valve. Through real-time detection of the thickness of the film bubble 4, the corresponding data is transmitted to the motor. The motor drives the opening and closing of the valve through rotation, thereby controlling the amount of gas passing through the cold air chamber 5162). The airflow controlled by the flow control device 53 then passes through the inside of the pressing block 5151 (the path of the gas inside the pressing block 5151 can be specially designed to enhance the stability of gas transmission). After that, the gas is discharged from the upper air port 513 to cool and shape the film bubble 4.

[0052] As an embodiment of the present invention, refer to Figure 5 The lower ring 516 is provided with a cold flow hole 5163, which is located on the side wall of the lower cavity 512 of the lower ring 516, and the opening position of the cold flow hole 5163 on the side wall of the lower cavity 512 coincides with the support block 5161. The interior of the support block 5161 is connected to the cold flow hole 5163, and the internal channel opening of the support block 5161 faces upward, and the cold air cavity 5162 is connected to the cold flow hole 5163;

[0053] When producing thick films, the installation of the partition 52 can be omitted in the above-mentioned installation steps of the ring body 51. In this way, the lower cavity 512 is connected to the cold air cavity 5162 through the hollow support block 5161 and the cold flow hole 5163, so that the upper air port 513 and the lower air port 514 are supplied with air from the same source, thereby quickly cooling and shaping the film bubble 4; before welding (or bonding) the support block 5161 to the lower ring 516, the channel inside the support block 5161 is first processed, and Figure 5For the convenience of display, the welding position of the support block 5161 and the installation position of the flow control device 53 are arranged on the same radial direction of the lower ring 516, but in actual manufacturing, it is not necessary to do so, and instead, the welding position of the support block 5161 and the installation position of the flow control device 53 are staggered. When producing a large-thickness film, the path of the gas discharged from the support block 5161 to the lower air outlet 514 is lengthened, so that the gas can be discharged more smoothly from the lower air outlet 514, thereby improving the uniformity of the thickness of the film bubble 4.

[0054] As an embodiment of the present application, refer to Figure 6 The upper and lower sides of the partition plate 52 are provided with stop blocks 521, and the stop blocks 521 on the lower side of the partition plate 52 are not of the same height, and a through slot 5211 is formed on the stop block 521 with a larger height, the through slot 5211 is located on the side of the stop block 521 connected to the partition plate 52, and the gap between the extended end of the stop block 521 and the bottom wall of the lower cavity 512 is matched; Figure 6 The stop blocks 521 below the partition plate 52 are arranged in an array, and the gap between the two groups of stop blocks 521 is for the accommodation of the support block 5161. In actual production, if the space of the lower cavity 512 is large enough, and the support block 5161 does not interfere with the stop block 521, the array of stop blocks 521 can also be arranged as a unit, so that the labyrinth structure formed by the stop blocks 521 is more compact, thereby further improving the stability of the gas discharged from the lower air outlet 514 when producing a large-thickness film, and improving the uniformity of the thickness of the film bubble 4.

[0055] As an embodiment of the present application, refer to Figure 2 , Figure 7 and Figure 8 A cold port 5164 and a warm port 5165 are formed below the lower ring 516, the cold port 5164 and the warm port 5165 are respectively communicated with the cold air cavity 5162 and the lower cavity 512, the cold port 5164 is communicated with the gas sending pump 8, the overflow throttle valve 9 is installed between the gas extraction pump 7 and the warm port 5165, and the inlet and outlet of the overflow throttle valve 9 are respectively connected with the gas extraction pump 7 and the warm port 5165; the above-mentioned communication relationship is realized through the connection of an additional heat preservation pipeline; the overflow throttle valve 9 is usually composed of a throttle valve and an overflow valve in parallel; when producing a small-thickness film, by setting the throttling pressure of the overflow throttle valve 9, the high-temperature gas extracted from the top of the film bubble 4 by the gas extraction pump 7 is quantitatively introduced into the lower cavity 512 from the warm port 5165; in order to ensure the constant temperature of the gas introduced from the warm port 5165, a constant temperature device can be arranged on the pipeline connected with the warm port 5165 and the overflow throttle valve 9; when producing a large-thickness film, the main channel of the overflow throttle valve 9 is closed, thereby cutting off the gas supply channel of the gas extraction pump 7 to the lower cavity 512, so that the cold air cavity 5162 is normally communicated with the lower cavity 512, thereby supplying the same source gas to the upper air outlet 513 and the lower air outlet 514.

[0056] As an embodiment of the present application, refer to Figure 2The drainage sides of the air extraction pump 7 and the air supply pump 8 are respectively arranged with a mask 71 and a hole cover 81, the mask 71 is communicated with the inlet of the overflow throttle valve 9, the hole cover 81 is communicated with the overflow port of the overflow throttle valve 9, the surface of the mask 71 is free of openings, the surface of the hole cover 81 is provided with a plurality of openings to additionally inhale ambient gas, the temperature of the gas discharged from the overflow port of the overflow throttle valve 9 is reduced after being combined with the ambient gas, thereby becoming cooling gas, and the cooling gas is sent into the cold hole 5164 and the short pipe 61 by the air supply pump 8.

[0057] Working principle: in the production of small thickness film, in order to avoid the lower air port 514 of the outer wind ring 5 to cool and form the film bubble 4 too early, thereby causing the upper air port 513 to be unable to control the thickness of the film bubble 4, so that the thickness of the film bubble 4 is not uniform, the present application wants to make the lower air port 514 of the outer wind ring 5 spray high temperature gas to perform initial heat preservation on the film bubble 4 extruded by the die head 2; in addition, considering that the high temperature gas is gathered on the top of the film bubble 4, and the high temperature effect of the gas will cause the film bubble 4 to be adhered during the winding process, therefore, the present application extracts the gas from above the film bubble 4 through the setting of the long pipe 62 and the air extraction pump 7, and sends the extracted gas into the outer wind ring 5 to be sprayed from the lower air port 514, thereby completing the heat preservation work and avoiding the energy consumption caused by additional heating gas, thereby reducing the production cost;

[0058] Specifically, in order to extract the high temperature gas above the film bubble 4, the short pipe 61 and the long pipe 62 are installed in the die head 2, the short pipe 61 and the long pipe 62 are respectively used for discharging and extracting gas into the film bubble 4 to maintain the stability of the air pressure in the film bubble 4, thereby ensuring the uniformity of the thickness of the film bubble 4; in order to make the air flow driven by the short pipe 61 and the long pipe 62 uniformly act on the film bubble 4, thereby maintaining the stability of the film bubble 4, the long pipe 62 and the short pipe 61 are coaxially installed with the die head 2, and the long pipe 62 is located inside the short pipe 61; in order to reduce the impact of the air flow discharged by the short pipe 61 on the film bubble 4 to maintain the stability of the film bubble 4, an inward folding edge is arranged at the opening of the short pipe 61, so that the gas sprayed by the short pipe 61 is gathered towards the peripheral surface of the long pipe 62, and because of the gathering, the rising height of the gas is lifted, thereby increasing the cooling area of the gas after falling, thereby improving the refrigeration efficiency; at the same time, an outward folding edge is arranged at the opening of the long pipe 62 to make the high temperature gas flow more smoothly into the long pipe 62, thereby reducing the power consumption of the air extraction pump 7;

[0059] In order to separate the space inside the outer wind ring 5, so that the gas extracted from the film bubble 4 can be stored independently in the outer wind ring 5, thereby stabilizing the exhaust from each downwind port 514, the ring body 51 is designed in two parts, into an upper ring 515 and a lower ring 516, and the pressure block 5151 and the support block 5161 are arranged on the upper ring 515 and the lower ring 516 respectively, for positioning the partition plate 52. After the partition plate 52 is installed, the ring body 51 is divided into an upper cavity 511 and a lower cavity 512, and the gas extracted by the air pump 7 is discharged into the lower cavity 512 for storage and discharged from the downwind port 514; and the baffles 521 of different heights are arranged below the partition plate 52 to form a labyrinth structure, so that the air pressure of the lower cavity 512 is more uniform and stable, thereby making the air output of each downwind port 514 consistent, to ensure the stability of the film bubble 4, thereby improving the uniformity of the thickness of the film bubble 4.

[0060] In order to enhance the applicability of the outer wind ring 5, so that it can produce films of various thicknesses, the support block 5161 is communicated with the cold flow hole 5163, so that when the partition plate 52 is removed, the lower cavity 512 is communicated with the cold air cavity 5162, thereby making the upper air port 513 and the lower air port 514 both take in air from the cold air cavity 5162 when producing thick films, to restore the cooling function of the lower air port 514 to the film bubble 4, and after the partition plate 52 is removed, the lower cavity 512 is combined with the upper cavity 511, the volume of the cold air cavity 5162 is expanded, thereby making the air supply to the upper air port 513 and the lower air port 514 more stable, thereby making the thickness of the film bubble 4 more uniform;

[0061] In order to make the flow of high-temperature gas from the air pump 7 to the lower cavity 512 not fluctuate, so that the air output of each downwind port 514 is stable, the overflow throttle valve 9 is installed between the air pump 7 and the warm port 5165, thereby adjusting the throttle pressure of the overflow throttle valve 9 to stabilize the gas flow into the lower cavity 512, thereby making the air output of the lower air port 514 consistent at all times, to ensure the uniformity of the thickness of the film bubble 4, and the hole cover 81 is communicated with the overflow port of the overflow throttle valve 9, thereby making the overflow valve discharge the gas that cannot be used by the lower cavity 512 into the hole cover 81, thereby reducing the power consumption of the air pump 8, to save production cost.

[0062] Although embodiments of the present application have been shown and described, it is to be understood that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An automated film blowing machine for plastic production, comprising an extruder (1), a die head (2) and a traction device (3), wherein the traction device (3) stretches the raw material extruded by the die head (2) into a film bubble (4), characterized in that: It also includes an outer air ring (5), an inner air ring (6), an air pump (7) and an air supply pump (8), wherein the outer air ring (5) includes a ring body (51) and a partition (52), wherein the ring body (51) is coaxially mounted with the die head (2), and the ring body (51) is located outside the film bubble (4), and the partition (52) is plugged into the inside of the ring body (51), and the partition (52) divides the inside of the ring body (51) into an upper cavity (511) and a lower cavity (512), and the inner circumference of the ring body (51) is provided with upper air ports in sequence from top to bottom. (513) and a lower air outlet (514), the upper air outlet (513) and the lower air outlet (514) are respectively connected to the upper cavity (511) and the lower cavity (512), the inner air ring (6) includes a short tube (61) and a long tube (62), the long tube (62) and the short tube (61) are both located inside the membrane bubble (4), and the long tube (62) is connected to the lower cavity (512), the air extraction pump (7) is installed on the long tube (62) connected to the lower cavity (512), and the air supply pump (8) is connected to the short tube (61); The vacuum pump (7) draws the warm air gathered above the film bubble (4) to the lower cavity (512) of the ring body (51) through the long tube (62), and the lower air outlet (514) discharges the warm air in the lower cavity (512) to avoid premature cooling and molding of the film bubble (4).

2. The automatic film blowing machine for plastic production according to claim 1, characterized in that: The long tube (62) and the short tube (61) are both coaxially installed with the die head (2), and the long tube (62) is located inside the short tube (61).

3. The automatic film blowing machine for plastic production according to claim 2, characterized in that: The opening of the short tube (61) has an inward folded edge, and the opening of the long tube (62) has an outward folded edge.

4. The automatic film blowing machine for plastic production according to claim 1, characterized in that: The ring body (51) includes an upper ring (515) and a lower ring (516), wherein the lower ring (516) is mounted on the die head (2), and the upper ring (515) is mounted on the lower ring (516). A pressing block (5151) is arranged in a circumferential array on the side wall of the upper cavity (511) of the upper ring (515), wherein the position of the pressing block (5151) coincides with the position of the upper air outlet (513), and one end of the pressing block (5151) is connected to the upper air outlet (513), and the other end of the pressing block (5151) is connected to the upper air outlet (513). A flow control device (53) is connected, and a support block (5161) is arranged in a circumferential array on the side wall of the lower cavity (512) of the lower ring (516). The partition (52) is located between the pressure block (5151) and the support block (5161). A cold air cavity (5162) is provided inside the lower ring (516), and the cold air cavity (5162) is located outside the upper cavity (511) and the lower cavity (512). The flow control device (53) is installed between the cold air cavity (5162) and the upper cavity (511).

5. The automatic film blowing machine for plastic production according to claim 4, characterized in that: The lower ring (516) is provided with a cold flow hole (5163), and the cold flow hole (5163) is located on the side wall of the lower cavity (512) of the lower ring (516), and the opening position of the cold flow hole (5163) on the side wall of the lower cavity (512) coincides with the support block (5161), the interior of the support block (5161) is communicated with the cold flow hole (5163), and the internal channel opening of the support block (5161) faces upward, and the cold air cavity (5162) is communicated with the cold flow hole (5163).

6. The automatic film blowing machine for plastic production according to claim 5, characterized in that: Blocks (521) are provided on both the upper and lower sides of the partition (52). The block (521) on the lower side of the partition (52) has different heights, and a through groove (5211) is provided on the block (521) with a larger height. The through groove (5211) is located on the side where the block (521) is connected to the partition (52). The protruding end of the block (521) is in clearance with the bottom wall of the lower cavity (512).

7. The automatic film blowing machine for plastic production according to claim 4, characterized in that: A cold port (5164) and a warm port (5165) are provided below the lower ring (516). The cold port (5164) and the warm port (5165) are communicated with the cold air cavity (5162) and the lower cavity (512) respectively. The cold port (5164) is communicated with the air supply pump (8). An overflow throttle valve (9) is installed between the air extraction pump (7) and the warm port (5165). The inlet and outlet of the overflow throttle valve (9) are connected with the air extraction pump (7) and the warm port (5165) respectively.

8. The automatic film blowing machine for plastic production according to claim 7, characterized in that: A face mask (71) and an escutcheon (81) are respectively arranged on the drainage sides of the air extraction pump (7) and the air supply pump (8); the face mask (71) is communicated with the inlet of the overflow throttle valve (9); the escutcheon (81) is communicated with the overflow port of the overflow throttle valve (9); the face mask (71) has no openings on its surface, while the escutcheon (81) has a plurality of openings on its surface.

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