Film blowing device

Abstract

The invention relates to a film blowing device, comprising a shell, an inner rotating core mold, an outer rotating mold, an inner rotating core mold driving component, an outer rotating mold driving component and a main driving component. The inner rotating core mold, the outer rotating mold, the inner rotating core mold driving component and the outer rotating mold driving component are all arranged inside the shell. The outer rotating mold is sleeved on the outer side of the inner rotating core mold. A cylindrical gap is arranged between the outer rotating mold and the inner rotating core mold for forming a melt channel. A feed port is opened on the shell. The melt channel is connected to the feed port. An air channel is arranged in the inner rotating core mold. The inner rotating core mold driving component is connected to the inner rotating core mold and drives it to rotate. The outer rotating mold driving component is connected to the outer rotating mold and drives it to rotate. The inner rotating core mold driving component and the outer rotating mold driving component are both connected to the main driving component and rotate synchronously. The rotating axes of the inner rotating core mold, the outer rotating mold, the inner rotating core mold driving component and the outer rotating mold driving component are located on the same straight line.

Description

Technical Field

[0001] The invention relates to the technical field of polymer material processing and molding devices, in particular to a film blowing device. Background Art

[0002] Blow molding is the third most commonly used plastic processing method after extrusion molding and injection molding. Among them, film blow molding is to press the viscous melt from the front end of the screw extruder into the die head, so that the melt is extruded into a tube embryo through the die head, and the compressed air introduced from the bottom of the die head is used to blow the tube embryo evenly and freely into a film with a larger diameter. At the same time, the tubular film is longitudinally stretched in the process of upward traction, and then flattened by a herringbone plate, pulled by a traction roller, and finally rolled into a tube.

[0003] However, when this traditional film blow molding equipment processes plastics with a high degree of orientation, the blown film is anisotropic (such as thermotropic liquid crystal polymers, LCP for short), resulting in large differences in the film's anisotropic properties, which often cannot meet the actual engineering application. In addition, the gap between the melt flow channel of the blown film forming die is unstable, resulting in uneven film thickness, and even affecting the stability or continuity of production. Summary of the invention

[0004] Based on this, the utility model proposes a new film blowing device, and by optimizing and improving its structure, the anisotropy of the blown film obtained by the film blowing device converges, thereby meeting the needs of actual engineering applications.

[0005] The specific technical solution of the film blowing device of the present invention is as follows:

[0006] A film blowing device comprises a shell, an inner rotating core mold, an outer rotating mold, an inner rotating core mold driving assembly, an outer rotating mold driving assembly and a main driving assembly, wherein the inner rotating core mold, the outer rotating mold, the inner rotating core mold driving assembly and the outer rotating mold driving assembly are all arranged inside the shell, the outer rotating mold is sleeved on the outside of the inner rotating core mold, a cylindrical gap is arranged between the outer rotating mold and the inner rotating core mold for forming a melt channel, a feed port is opened on the shell, the melt channel is connected to the feed port, an air channel is arranged in the inner rotating core mold, the inner rotating core mold driving assembly is connected to the inner rotating core mold and drives it to rotate, the outer rotating mold driving assembly is connected to the outer rotating mold and drives it to rotate, the inner rotating core mold driving assembly and the outer rotating mold driving assembly are both connected to the main driving assembly and rotate synchronously, and the rotating axes of the inner rotating core mold, the outer rotating mold, the inner rotating core mold driving assembly and the outer rotating mold driving assembly are located on the same straight line.

[0007] In one of the embodiments, a joint is provided at the other end of the inner rotating mandrel away from the extrusion end, and the joint is used to connect the inner rotating mandrel driving assembly.

[0008] In one of the embodiments, the film blowing device further comprises an outer rotary die transmission assembly, and the outer rotary die is connected to the outer rotary die driving assembly via the outer rotary die transmission assembly.

[0009] In one embodiment, the external rotary mold transmission assembly includes a transition connection sleeve and an external rotary mold transmission sleeve, the transition connection sleeve and the external rotary mold transmission sleeve are connected to each other, one of the transition connection sleeve and the external rotary mold transmission sleeve is connected to the external rotary mold, and the other is connected to the external rotary mold drive assembly.

[0010] In one embodiment, the film blowing device further comprises a bearing, wherein the bearing is located between the inner rotating core mold and the outer rotating mold, and / or between the outer rotating mold and the shell, and / or between the outer rotating mold transmission assembly and the shell.

[0011] In one embodiment, the air channel runs through the length direction of the inner rotating core mold.

[0012] In one embodiment, the main driving component is a gear shaft, the outer rotating mold driving component and the inner rotating core mold driving component are both transmission gears, and the gear shaft is meshed with the outer rotating mold driving component and the inner rotating core mold driving component at the same time.

[0013] In one embodiment, the gears of the gear shaft of the main drive assembly are double gears.

[0014] In one embodiment, there is more than one feed inlet.

[0015] In one of the embodiments, a mixing groove is provided between the shell and the outer rotating mold, the mixing groove is communicated with the feed port, and the mixing groove is communicated with the melt channel.

[0016] Beneficial Effects

[0017] The film blowing device described in the present invention simultaneously drives the inner rotating core mold and the outer rotating mold through the main driving assembly, and the rotating axes of the inner rotating core mold, the outer rotating mold, the inner rotating core mold driving assembly, and the outer rotating mold driving assembly are arranged on the same straight line, so that the changes of the inner rotating core mold and the outer rotating mold are adjusted to be the same both in time dimension and space dimension. Therefore, the film blowing device described in the present invention has very good structural stability. Even if the rotation speed of the inner rotating core mold and the outer rotating mold is greatly increased, the morphology of the melt channel will not change, so that the blown film prepared by the film blowing device described in the present invention has similar anisotropy and uniform thickness. Compared with the blown film prepared by the film blowing device of the prior art, the product prepared by the present invention has a higher yield rate and better production efficiency, which can better meet the actual needs of users. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of a film blowing device according to one embodiment of the present invention;

[0019] Figure 2 A schematic diagram of a driving assembly of a film blowing device according to one embodiment of the present invention;

[0020] Figure 3 A cross-sectional view of a feeding port of a film blowing device according to one embodiment of the present invention;

[0021] Among them, 1 is the inner rotating core mold, 2 is the outer rotating mold, 3 is the melt channel, 4 is the shell, 5 is the outer rotating mold transmission sleeve, 6 is the transition connecting sleeve, 7 is the main driving assembly, 8 is the inner rotating core mold driving assembly, 9 is the outer rotating mold driving assembly, 21 is the connecting channel, 41 is the feed port, 42 is the feed channel, and 43 is the mixing tank. DETAILED DESCRIPTION

[0022] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0023] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0024] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0025] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0027] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0028] Combination Figure 1 ,like Figure 1 The film blowing device of the present invention is shown, comprising a shell 4, an inner rotating core mold 1, an outer rotating mold 2, an inner rotating core mold driving assembly 8, an outer rotating mold driving assembly 9 and a main driving assembly 7. The inner rotating core mold 1, the outer rotating mold 2, the inner rotating core mold driving assembly 8 and the outer rotating mold driving assembly 9 are all arranged inside the shell 4. The outer rotating mold 2 is sleeved on the outside of the inner rotating core mold 1. A cylindrical gap is arranged between the outer rotating mold 2 and the inner rotating core mold 1 to form a melt channel 3. A feed port 41 is opened on the shell 4. The melt channel 3 is connected to the feed port 41, an air channel is provided in the inner rotating core mold 1, the inner rotating core mold driving assembly 8 is connected to the inner rotating core mold 1 and drives it to rotate, the outer rotating mold driving assembly 9 is connected to the outer rotating mold 2 and drives it to rotate, the inner rotating core mold driving assembly 8 and the outer rotating mold driving assembly 9 are both connected to the main driving assembly 7 and rotate synchronously, and the rotation axes of the inner rotating core mold 1, the outer rotating mold 2, the inner rotating core mold driving assembly 8, and the outer rotating mold driving assembly 9 are located on the same straight line.

[0029] The rotary film blowing device in the prior art usually uses two driving devices to drive the inner rotating core mold and the outer rotating mold respectively from the perspective of simplifying the structure and being the easiest to implement. This technical solution uses different driving devices to drive the rotation of the inner and outer molds, which causes the inner and outer molds to vibrate and deflect in different patterns during rotation, resulting in irregular changes in the gap between the inner rotating core mold and the outer rotating film. Therefore, the stability of the melt channel formed by the gap will also be affected, resulting in large differences in the performance of the film extruded from the melt channel and blown in various directions, which cannot meet the needs of actual engineering applications.

[0030] The rotary film blowing device described in the present invention drives the outer rotary mold driving assembly 9 for driving the outer rotary mold 2 and the inner rotary core mold driving assembly 8 for driving the inner rotary core mold 1 using the same main driving assembly 7, so that even if the outer rotary mold 2 and the inner rotary core mold 1 vibrate and deflect during the rotation process, the vibration and deflection also occur simultaneously. Moreover, since the present invention specifically sets the rotation axes of the inner rotary core mold 1, the outer rotary mold 2, the inner rotary core mold driving assembly 8, and the outer rotary mold driving assembly 9 on the same straight line, even if the inner rotary core mold 1 and the outer rotary mold 2 vibrate and deflect during the rotation process, the vibration and deflection are of the same degree. In summary, the present invention adjusts the changes of the inner rotating core mold 1 and the outer rotating mold 2 to be the same in both time and space dimensions, so that the gap between the inner rotating core mold 1 and the outer rotating mold 2 can always remain stable, so that the film obtained by the rotary film blowing device of the present invention has high thickness consistency, good production stability and continuity, and the performance of the film in all directions tends to be the same, which can meet the needs of practical engineering applications. In addition, the rotary film blowing device of the present invention uses a main drive component 7 to drive the rotation of the inner rotating core mold 1 and the outer rotating mold 2, which reduces the number of drive components and reduces the cost of use compared to the prior art.

[0031] The film blowing device of the present invention, when in use, delivers the molten material to the melt channel through the feed port, starts the main drive assembly 7, and the main drive assembly 7 drives the inner rotating core mold drive assembly 8 and the outer rotating mold drive assembly 9 to move at the same time, and the inner rotating core mold drive assembly 8 and the outer rotating mold drive assembly 9 respectively drive the inner rotating core mold 1 and the outer rotating mold 2 to rotate, and the melt is extruded upward along the melt channel into a tube shape. Compressed air passes through the air channel of the inner rotating core mold 1 and blows out from the inside of the tube, so that the tube is evenly and freely inflated into a film of a predetermined diameter. The film is pulled upward by the traction device and stretched longitudinally, then flattened by the herringbone plate, pulled by the traction roller, and finally rolled into a tube.

[0032] Specifically, if Figure 1 As shown, in some embodiments, a joint is provided at the other end of the inner rotating core mold 1 away from the extrusion end, and the joint is used to connect the inner rotating core mold driving component 8. Such a setting can form a distance between the driven rotating part and the extrusion end to avoid affecting the extrusion end. It is easy to understand that the joint can be an independent component connected to the inner rotating core mold 1 by any common connection method. Of course, the joint can also be directly the other end of the inner rotating core mold 1 away from the extrusion end, thereby further reducing the structural complexity of the film blowing device described in the present invention.

[0033] Specifically, in some embodiments, in order to reduce the difficulty of processing and installing the outer rotating mold 2, the film blowing device of the present invention may further include an outer rotating mold transmission component, and the outer rotating mold 2 is connected to the outer rotating mold driving component 9 through the outer rotating mold transmission component. Figure 1 In some embodiments shown, the outer rotary mold transmission assembly includes a transition connection sleeve 6 and an outer rotary mold transmission sleeve 5, the transition connection sleeve 6 and the outer rotary mold transmission sleeve 5 are connected to each other, one of the transition connection sleeve 6 and the outer rotary mold transmission sleeve 5 is connected to the outer rotary mold 2, and the other is connected to the outer rotary mold driving assembly 9. With such an arrangement, the existing outer rotary mold 2 can be further used without redesigning the outer rotary mold 2, and only needs to be connected in sequence during assembly, and the method for realizing the technical solution described in the present invention is simple and effective.

[0034] Further preferably, the film blowing device of the present invention further comprises a bearing, and the bearing is located between the inner rotating core mold 1 and the outer rotating mold 2, and / or between the outer rotating mold 2 and the shell 4, and / or between the outer rotating mold transmission assembly and the shell 4. By setting the bearing, the relative positions between the inner rotating core mold 1, the outer rotating mold 2, the outer rotating mold transmission assembly and the shell 4 can be made more compact and fixed. In conjunction with the above-mentioned technical solution, even if the film blowing device of the present invention greatly increases the rotation speed of the inner rotating core mold 1 and the outer rotating mold 2 relative to the prior art, the stability of the melt channel between the inner rotating core mold 1 and the outer rotating mold 2 will not be affected, and the increase in the rotation speed of the inner rotating core mold 1 and the outer rotating mold 2 can make the anisotropy of the blown film more similar, and the thickness of the film at various locations is further consistent, so that the blown film obtained by using the film blowing device of the present invention has better performance than the film of the prior art, and can meet the higher requirements of customers.

[0035] Specifically, if Figure 1 In some embodiments, the air passage runs through the length direction of the inner rotating core mold 1. With such a configuration, the internal structure of the film blowing device of the present invention is further simplified, and the film blowing device of the present invention is easier to operate, whether in the early assembly process, the mid-term use process, or the later maintenance process.

[0036] It is understandable that the film blowing device of the present invention has no particular limitation on the specific forms of the inner rotating core mold driving assembly 8, the outer rotating mold driving assembly 9 and the main driving assembly 7, as long as the main driving assembly 7 can synchronously drive the inner rotating core mold driving assembly 8 and the outer rotating mold driving assembly 9. For example, in some embodiments, Figure 2 As shown, the main drive assembly 7 is a gear shaft, which is connected to the external motor drive, and the outer rotating mold drive assembly 9 and the inner rotating core mold drive assembly 8 are both transmission gears. The gear shaft is meshed with the outer rotating mold drive assembly 9 and the inner rotating core mold drive assembly 8 at the same time. Specifically, the transmission gear of the inner rotating core mold drive assembly 8 is arranged on the inner rotating core mold 1, so that when the main drive assembly 7 drives the transmission gear, the inner rotating core mold 1 can rotate synchronously. The transmission gear of the inner rotating core mold drive assembly 8 can be fixedly connected to the inner rotating core mold 1, such as welding, or can be detachably connected, such as key connection. In this embodiment, the transmission gear of the inner rotating core mold driving assembly 8 is located on one side of the gear shaft of the main driving assembly 7, and the transmission gear of the outer rotating mold driving assembly 9 is located on the other side opposite to the gear shaft of the main driving assembly 7, so that the rotation direction of the transmission gear of the inner rotating core mold driving assembly 8 is opposite to the rotation direction of the transmission gear of the outer rotating mold driving assembly 9, that is, the rotation direction of the inner rotating core mold 1 is opposite to the rotation direction of the outer rotating mold 2, and the film blowing device described in the present invention is a counter-rotating film blowing device.

[0037] In such Figure 2 In the embodiment shown, the gear shaft of the main drive assembly 7 is a single-layer gear. Under the condition of ensuring the same modulus and pressure angle, the rotation speed of the inner rotating core mold 1 and the outer rotating mold 2 can be adjusted by adjusting other parameters such as the number of teeth of the inner rotating core mold drive assembly 8 and the outer rotating mold drive assembly 9. Optionally, in some other embodiments, the gear shaft of the main drive assembly 7 is a double gear, and the modulus and pressure angle of the double gear can be different. The large and small gears are respectively connected to the inner rotating core mold drive assembly 8 and the outer rotating mold drive assembly 9, so that the rotation state of the inner rotating core mold 1 and the outer rotating mold 2 can be adjusted more flexibly according to needs.

[0038] It is worth noting that the film blowing device of the present invention may have more than one feed inlet. By adding feed inlets, the feed amount can be increased, or different melts can be mixed to prepare a composite film. Figure 1 , Figure 3 As shown, Figure 3The film blowing device of the present invention is a radial cross-sectional view at the feed port 41. In some embodiments, there are three feed ports 41 on the shell 4. Preferably, a mixing groove 43 is provided between the shell 4 and the outer rotating mold 2, and a feed channel 42 connected to the feed port 41 is provided on the shell 4. The mixing groove 43 is connected to the feed port 41 through the feed channel 42. The outer rotating mold 2 is provided with a connecting channel 21, and the mixing groove 43 is connected to the melt channel 3 through the connecting channel 21. Multiple melts enter the feed channel 42 from multiple feed ports 41 respectively, and enter the mixing groove 43 through the feed channel 42. The multiple melts are mixed in the mixing groove 43 to form a composite melt. The composite melt enters the melt channel 3 between the outer rotating mold 2 and the inner rotating core mold 1 through the connecting channel 21, and is extruded from the melt channel 3 to form a composite tube blank, and after being blown, a composite film is formed. The film blowing device of the present invention realizes one-time blow molding of the composite film by arranging multiple feed inlets, thereby reducing the complexity of the process.

[0039] Specifically, the film blowing device of the present invention further comprises an upper cover and a lower cover, wherein the upper cover is arranged at the extrusion end of the shell 4 at the film blowing device, and the lower cover is arranged at the other end of the shell 4 relative to the upper cover. Specifically, the shell 4 can also be divided into an upper shell and a lower shell, and the upper shell and the lower shell are connected. By disassembling and assembling the shell 4, the installation of the components inside it can be facilitated. A heater is also arranged on the periphery of the melt channel 3 to keep the melt in the melt channel 3 in a molten state.

[0040] To sum up, the film blowing device described in the present invention drives the inner rotating core mold 1 and the outer rotating mold 2 simultaneously through the main driving component 7, and the rotating axes of the inner rotating core mold 1, the outer rotating mold 2, the inner rotating core mold driving component 8, and the outer rotating mold driving component 9 are arranged on the same straight line, so that the changes of the inner rotating core mold 1 and the outer rotating mold 2 are adjusted to be the same both in time dimension and space dimension. Therefore, the film blowing device described in the present invention has very good structural stability. Even if the rotation speed of the inner rotating core mold 1 and the outer rotating mold 2 is greatly increased, the shape of the melt channel 3 will not change, so that the anisotropy of the blown film prepared by the film blowing device described in the present invention is similar and the thickness is uniform. Compared with the blown film prepared by the film blowing device of the prior art, the product prepared by the present invention has a higher yield rate and better production efficiency, which can better meet the actual needs of users.

[0041] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0042] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A film blowing device, characterized in that: It includes a shell, an inner rotating core mold, an outer rotating mold, an inner rotating core mold driving assembly, an outer rotating mold driving assembly and a main driving assembly, wherein the inner rotating core mold, the outer rotating mold, the inner rotating core mold driving assembly and the outer rotating mold driving assembly are all arranged inside the shell, the outer rotating mold is sleeved on the outside of the inner rotating core mold, a cylindrical gap is arranged between the outer rotating mold and the inner rotating core mold for forming a melt channel, a feed port is opened on the shell, the melt channel is communicated with the feed port, an air channel is arranged in the inner rotating core mold, and the air channel runs through the length direction of the inner rotating core mold, the inner rotating core mold driving assembly is connected to the inner rotating core mold and drives it to rotate, the outer rotating mold driving assembly is connected to the outer rotating mold and drives it to rotate, the inner rotating core mold driving assembly and the outer rotating mold driving assembly are all connected to the main driving assembly and rotate synchronously, and the rotating axes of the inner rotating core mold, the outer rotating mold, the inner rotating core mold driving assembly and the outer rotating mold driving assembly are located on the same straight line; The main drive assembly is a gear shaft, the outer rotating mold drive assembly and the inner rotating core mold drive assembly are both transmission gears, and the gear shaft is meshed with the outer rotating mold drive assembly and the inner rotating core mold drive assembly at the same time; The gears of the gear shaft of the main driving assembly are double gears.

2. The film blowing device according to claim 1, characterized in that: The other end of the inner rotating core mold away from the extrusion end is provided with a joint, and the joint is used to connect the inner rotating core mold driving component.

3. The film blowing device according to claim 1, characterized in that: It also includes an outer rotary die transmission assembly, and the outer rotary die is connected to the outer rotary die drive assembly through the outer rotary die transmission assembly.

4. The film blowing device according to claim 3, characterized in that: The outer rotary mold transmission assembly includes a transition connection sleeve and an outer rotary mold transmission sleeve, the transition connection sleeve and the outer rotary mold transmission sleeve are connected to each other, one of the transition connection sleeve and the outer rotary mold transmission sleeve is connected to the outer rotary mold, and the other is connected to the outer rotary mold drive assembly.

5. The film blowing device according to claim 3, characterized in that: It also includes a bearing, which is located between the inner rotating core mold and the outer rotating mold, and / or between the outer rotating mold and the shell, and / or between the outer rotating mold transmission assembly and the shell.

6. A film blowing device according to claim 1, characterized in that: A heater is arranged on the periphery of the melt channel.

7. The film blowing device according to claim 1, characterized in that: There is more than one feed inlet.

8. The film blowing device according to claim 7, characterized in that: A mixing groove is provided between the shell and the outer rotating die, the mixing groove is communicated with the feed port, and the mixing groove is communicated with the melt channel.

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