Three-layer co-extrusion environment-friendly water-soluble film extrusion die head

Abstract

The utility model provides a three-layer co-extrusion environment-friendly water-soluble film extrusion die head. A feeding seat of the extrusion die head is provided with a first feeding hole, a second feeding hole and a third feeding hole; a fusion mold is arranged above the feeding seat, the fusion mold is provided with an annular first flow channel, an annular second flow channel and an annular third flow channel, the fusion flow channel and the first flow channel are communicated with the first feeding port, the second flow channel is communicated with the second feeding port, the third flow channel is communicated with the third feeding port, and the upper portions of the first flow channel, the second flow channel and the third flow channel are communicated with the fusion flow channel; the extrusion die is arranged above the fusion die, the extrusion die is provided with a fusion cavity and an extrusion runner communicated with the fusion cavity, the fusion cavity is communicated with a fusion runner, and as the first runner, the second runner, the third runner and the fusion runner are in annular design, the paths of extrusion stock solution in the first runner, the second runner, the third runner and the fusion runner are not bent and changed; the extrusion of uniform materials and the production of uniform three-layer co-extrusion water-soluble films are facilitated.

Description

Technical Field

[0001] The present application relates to an extrusion die, and more specifically, to a three-layer co-extruded environmentally friendly water-soluble film extrusion die. Background Art

[0002] Plastic packaging film is one of the important packaging materials. Common ones include polyethylene PE, polypropylene PP, nylon, polyester, etc. Because of their low price, good performance and wide application, they are obviously "irreplaceable". However, due to the long degradation cycle of plastic film, it is extremely difficult to be degraded by the natural environment after being discarded, which in turn causes environmental pollution. The degradable plastic packaging film currently on the market is difficult to promote due to problems such as low load-bearing capacity, poor barrier properties, low transparency, and unclear degradation effect. The prospects are not optimistic.

[0003] The hydrogen bonding between the molecular chains of polyvinyl alcohol is strong, the melting point is high, and the decomposition temperature of polyvinyl alcohol is low, resulting in the decomposition temperature and melting temperature of polyvinyl alcohol being close, making the melting processing temperature range of polyvinyl alcohol very narrow, and there are problems such as difficult to control the molding process, unstable film-forming performance, uneven film thickness, and incomplete water solubility. For this reason, the applicant proposed a method of preparing a polyvinyl alcohol water-soluble film by a three-layer co-extrusion method, but the flow path of the prior art varies greatly, and it is impossible to produce a uniform three-layer co-extruded polyvinyl alcohol water-soluble film. Utility Model Content

[0004] The technical problem to be solved by the present application is to provide a three-layer co-extruded water-soluble film extrusion die head to solve the problem in the prior art that a uniform three-layer co-extruded polyvinyl alcohol water-soluble film cannot be produced due to large changes in the flow path.

[0005] In order to solve the above problems, the present application provides a three-layer co-extruded environmentally friendly water-soluble film extrusion die head, including: a feed seat, on which a first feed port, a second feed port, and a third feed port are arranged; a fusion mold located above the feed seat, the fusion mold is provided with an annular first flow channel, a second flow channel, a third flow channel, and a fusion flow channel, the first flow channel is connected to the first feed port, the second flow channel is connected to the second feed port, the third flow channel is connected to the third feed port, and the upper parts of the first flow channel, the second flow channel, and the third flow channel are connected to the fusion flow channel; an extrusion mold located on the fusion mold, a fusion cavity and an extrusion flow channel connected to the fusion cavity are arranged on the extrusion mold, and the fusion cavity is connected to the fusion flow channel; the width of the fusion flow channel is greater than any of the first flow channel, the second flow channel, and the third flow channel, and the width of the extrusion flow channel is less than any of the first flow channel, the second flow channel, and the third flow channel; the first flow channel, the second flow channel, and the third flow channel are arranged in sequence from the inside to the outside in the fusion mold; the heights of the first feed port, the second feed port, and the third feed port are increased in sequence.

[0006] In this scheme, since the first flow channel, the second flow channel, the third flow channel, and the fusion flow channel are designed in an annular manner, the paths of the extruded stock solution in the first flow channel, the second flow channel, the third flow channel, and the fusion flow channel have no bending changes, which is conducive to extruding uniform materials and producing uniform three-layer co-extruded water-soluble films. The heights of the first feed port, the second feed port, and the third feed port are successively increased, which can prevent the three feed channels from interfering with each other and improve the stability of the three-layer feed.

[0007] According to the above solution provided in the present application, a thermal insulation interlayer is further provided on the outer layer of the fusion mold, a medium inlet is provided below the thermal insulation interlayer, and a medium outlet is provided above the thermal insulation interlayer.

[0008] The insulation interlayer can significantly reduce the heat exchange between the inside of the die and the external environment, thereby maintaining a stable temperature of the material in the flow channel and helping to improve the uniformity of the film.

[0009] According to the above solution provided in the present application, the widths of the first flow channel, the second flow channel, and the third flow channel become narrower from bottom to top.

[0010] As the flow channel width gradually narrows, the material will be subjected to gradually increasing pressure during the flow process, which helps to accelerate the flow rate of the material, reduce the residence time in the flow channel, and promote uniform distribution of the material on the cross section.

[0011] In order to facilitate the manufacture and installation of the film extrusion die, according to the above scheme provided in the present application, the fusion mold is sequentially arranged from the inside to the outside including a first mold core, a second mold core, a third mold core, and a fourth mold core, the first flow channel is an annular cavity formed by the gap between the first mold core and the second mold core, the second flow channel is an annular cavity formed by the gap between the second mold core and the third mold core, and the third flow channel is an annular cavity formed by the gap between the third mold core and the fourth mold core.

[0012] In order to facilitate the manufacture and installation of the film extrusion die head, according to the above-mentioned scheme provided in the present application, a first feed channel, a second feed channel, and a third feed channel are arranged in an annular manner from the inside to the outside in the feed seat, the first feed port is connected to the first feed channel, the second feed port is connected to the second feed channel, and the third feed port is connected to the third feed channel.

[0013] In order to facilitate the manufacture and installation of the film extrusion die head, according to the above scheme provided in the present application, the first seat core, the second seat core, the third seat core, and the fourth seat core are arranged in sequence from the inside to the outside in the feed seat, the first feed channel is an annular cavity formed by the gap between the first seat core and the second seat core, the second feed channel is an annular cavity formed by the gap between the second seat core and the third seat core, and the third feed channel is an annular cavity formed by the gap between the third seat core and the fourth seat core.

[0014] In order to facilitate the manufacture and installation of the film extrusion die head, according to the above scheme provided in the present application, the first seat core and the second seat core, the second seat core and the third seat core, and the third seat core and the fourth seat core are all connected by plug-in fitting, and the first seat core is located above the bottom of the second seat core.

[0015] In order to facilitate the manufacture and installation of the film extrusion die head, according to the above scheme provided in the present application, the first seat core and the first mold core, the second seat core and the second mold core, the third seat core and the third mold core, and the fourth seat core and the fourth mold core are all connected by plug-in fitting.

[0016] Furthermore, according to the above solution provided in the present application, the feed seat, the fusion mold and the extrusion mold are connected by flanges.

[0017] In addition, according to the above solution provided in the present application, the axis of the fusion mold and the extrusion mold is a fixed cavity for connecting the film fixing frame.

[0018] The beneficial effects of this application are:

[0019] Since the first flow channel, the second flow channel, the third flow channel and the fusion flow channel are designed in an annular manner, the paths of the extruded stock solution in the first flow channel, the second flow channel, the third flow channel and the fusion flow channel have no bending changes, which is conducive to extruding uniform materials and producing uniform three-layer co-extruded water-soluble films. The heights of the first feed port, the second feed port and the third feed port are successively increased to prevent mutual interference of the three feed channels.

[0020] The insulating interlayer can significantly reduce the heat exchange between the inside of the die and the external environment, thereby maintaining a stable temperature of the material in the flow channel, which helps to improve the uniformity and performance of the film.

[0021] The first, second and third flow channels are designed to be gradually narrowed from bottom to top, which can further optimize the flow and mixing process of the material. As the width of the flow channel gradually narrows, the material will be subjected to gradually increasing pressure during the flow process, which helps to accelerate the flow speed of the material and reduce the residence time in the flow channel, thereby reducing the possibility of stratification or precipitation of the material during the flow process. The gradually narrowing flow channel design can promote the uniform distribution of the material on the cross section. When the material flows from a wider flow channel to a narrower flow channel, due to the reduction of the flow channel area, the material is forced to disperse in a smaller area, thereby achieving more uniform flow and distribution.

[0022] In addition to the technical problems solved by the present application, the technical features that constitute the technical scheme, and the advantages brought by the technical features of these technical schemes described above, other technical problems that can be solved by the three-layer co-extrusion environmentally friendly water-soluble film extrusion die head of the present application, other technical features included in the technical scheme, and the advantages brought by these technical features will be further described in detail in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a front cross-sectional schematic diagram of a three-layer co-extruded environmentally friendly water-soluble film extrusion die head in an embodiment of the present application;

[0024] Description of reference numerals:

[0025] 1. Feeding seat; 1011. First feeding port; 1021. Second feeding port; 1031. Third feeding port;

[0026] 2. Fusion mold; 201. First flow channel; 202. Second flow channel; 203. Third flow channel; 204. Fusion flow channel;

[0027] 3. Extrusion die; 301. Fusion cavity; 302. Extrusion flow channel; 205. Insulation interlayer; 2051. Medium inlet; 2052. Medium outlet; 21. First mold core; 22. Second mold core; 23. Third mold core; 24. Fourth mold core; 101. First feed channel; 102. Second feed channel; 103. Third feed channel;

[0028] 4. Bolts;

[0029] 5. Flange;

[0030] 6. Fixed cavity. DETAILED DESCRIPTION

[0031] The embodiments of the technical solution of the present application will be described in detail below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0032] The technical problem to be solved by the present application is to provide a three-layer co-extruded water-soluble film extrusion die head to solve the problem in the prior art that a uniform three-layer co-extruded polyvinyl alcohol water-soluble film cannot be produced due to large changes in the flow path.

[0033] In order to solve the above problems, Figure 1An embodiment of a three-layer co-extruded environmentally friendly water-soluble film extrusion die head provided by the present application is illustrated, and the water-soluble film extrusion die head comprises: a feed seat 1, on which a first feed port 1011, a second feed port 1021, and a third feed port 1031 are arranged; a fusion mold 2 is located above the feed seat 1, and the fusion mold 2 is provided with an annular first flow channel 201, a second flow channel 202, a third flow channel 203, and a fusion flow channel 204, the first flow channel 201 is connected to the first feed port 1011, the second flow channel 202 is connected to the second feed port 1021, the third flow channel 203 is connected to the third feed port 1031, and the upper parts of the first flow channel 201, the second flow channel 202, and the third flow channel 203 are connected to the The fusion channel 204 is connected; the extrusion die 3 is located on the fusion die 2, and a fusion cavity 301 and an extrusion channel 302 connected to the fusion cavity 301 are arranged on the extrusion die 3, and the fusion cavity 301 is connected to the fusion channel 204; the width of the fusion channel 204 is greater than any of the first channel 201, the second channel 202, and the third channel 203, and the width of the extrusion channel 302 is less than any of the first channel 201, the second channel 202, and the third channel 203; the first channel 201, the second channel 202, and the third channel 203 are arranged in sequence from the inside to the outside in the fusion die 2; the heights of the first feed port 1011, the second feed port 1021, and the third feed port 1031 are increased in sequence.

[0034] In a specific embodiment, the feed seat includes three feed ports 1011, 1021, and 1031, which are respectively used to introduce extrusion solutions. The fusion mold is provided with three annular flow channels 201, 202, and 203, which are respectively connected to the three feed ports for introducing different extrusion solutions into the die head. The fusion mold is provided with a fusion flow channel 204, which is located above the three annular flow channels 201, 202, and 203, and is used to mix the three extrusion solutions together. The width of the fusion flow channel 204 is greater than that of the other three flow channels, which helps the materials to be better mixed in the fusion flow channel. The extrusion die is provided with a fusion chamber 301, which is connected to the fusion flow channel 204 and is used to further mix and prepare the extruded film material stock solution. The extrusion die is provided with an extrusion flow channel 302, which guides the mixed film material stock solution to the die outlet to form a film. Since the width of the extrusion flow channel 302 is smaller than that of the other flow channels, this helps to maintain the uniformity and stability of the material during the extrusion process. The heights of the first feed port 1011 , the second feed port 1012 , and the third feed port 1013 are sequentially increased to prevent interference between the three feed ports during feeding.

[0035] Since the first flow channel 201, the second flow channel 202, the third flow channel 203, and the fusion flow channel 204 are of annular design, the path of the extruded raw liquid in the first flow channel 201, the second flow channel 202, the third flow channel 203, and the fusion flow channel 204 has no bending changes, which is conducive to extruding uniform materials and producing uniform three-layer co-extruded water-soluble films.

[0036] In an optional embodiment, the outer layer of the fusion mold 2 is also provided with an insulating interlayer 205, a medium inlet 2051 is provided below the insulating interlayer 205, and a medium outlet 2052 is provided above the insulating interlayer 205. The introduction of the insulating interlayer 205 can effectively maintain the temperature stability in the die head, which is crucial to ensure the fluidity and stability of the extruded stock solution and the uniformity of the final film. The insulating interlayer 205 is located in the outer layer of the fusion mold 2, which means that it wraps the internal flow channel to ensure that the material in the flow channel is maintained in a relatively stable temperature range throughout the extrusion process. The medium inlet 2051 is used to introduce an insulating medium, such as hot oil, hot water or other heating fluid, into the insulating interlayer 205. By controlling the temperature and flow rate of the medium, the temperature in the die head can be effectively adjusted. The medium outlet 2052 is used to discharge the insulating medium from the insulating interlayer 205 to ensure that the medium can circulate, thereby maintaining a uniform and stable temperature in the die head. The insulating interlayer 205 can significantly reduce the heat exchange between the inside of the die head and the external environment, thereby maintaining the temperature of the material in the flow channel stable. This helps improve film uniformity and performance.

[0037] In an optional embodiment, the widths of the first flow channel 201 , the second flow channel 202 , and the third flow channel 203 narrow from bottom to top.

[0038] In an optional embodiment, the first flow channel 201, the second flow channel 202, and the third flow channel 203 are designed to be a structure that gradually narrows from bottom to top, which is a very beneficial design improvement. This design can help optimize the flow and mixing process of the material. As the flow channel width gradually narrows, the material will be subjected to gradually increasing pressure during the flow process, which helps to accelerate the flow rate of the material and reduce the residence time in the flow channel, thereby reducing the possibility of stratification or precipitation of the material during the flow process. The gradually narrowing flow channel design can promote the uniform distribution of the material in the cross section. When the material flows from a wider flow channel into a narrower flow channel, due to the reduction in the flow channel area, the material is forced to disperse in a smaller area, thereby achieving a more uniform flow and distribution.

[0039] In one embodiment, the fusion mold 2 includes a first mold core 21, a second mold core 22, a third mold core 23, and a fourth mold core 24, which are sequentially arranged from the inside to the outside. The first flow channel 201 is an annular cavity formed by the gap between the first mold core 21 and the second mold core 22, the second flow channel 202 is an annular cavity formed by the gap between the second mold core 22 and the third mold core 23, and the third flow channel 203 is an annular cavity formed by the gap between the third mold core 23 and the fourth mold core 24. By arranging multiple mold cores (the first mold core 21, the second mold core 22, the third mold core 23, and the fourth mold core 24) in the fusion mold 2, and using the gaps between them to form the first flow channel 201, the second flow channel 202, and the third flow channel 203, it is convenient to manufacture and install the fusion mold 2.

[0040] In one embodiment, a first annular feed channel 101, a second feed channel 102, and a third feed channel 103 are sequentially arranged in the feed seat 1 from the inside to the outside, the first feed port 1011 is connected to the first feed channel 101, the second feed port 1021 is connected to the second feed channel 102, and the third feed port 1031 is connected to the third feed channel 103.

[0041] In one embodiment, the first seat core 11, the second seat core 12, the third seat core 13, and the fourth seat core 14 are sequentially arranged in the feed seat 1 from the inside to the outside, the first feed channel 101 is an annular cavity formed by the gap between the first seat core 11 and the second seat core 12, the second feed channel 102 is an annular cavity formed by the gap between the second seat core 12 and the third seat core 13, and the third feed channel 103 is an annular cavity formed by the gap between the third seat core 13 and the fourth seat core 14. This is conducive to the manufacture and installation of the feed seat 1.

[0042] In one embodiment, the first seat core 11 and the first mold core 21 , the second seat core 12 and the second mold core 22 , the third seat core 13 and the third mold core 23 , and the fourth seat core 14 and the fourth mold core 24 are all connected by plug-fitting.

[0043] like Figure 1 In one embodiment, the first seat core 11 and the second seat core 12, the second seat core 12 and the third seat core 13, and the third seat core 13 and the fourth seat core 14 are all connected by plug-in fitting, and the first seat core 11 is located above the bottom of the second seat core 12. Figure 1In the illustrated feed seat 1, a first seat core groove is provided at the bottom of the first seat core 11, a first seat core protrusion 111 is provided at the top of the first seat core 11, a second seat core lower protrusion 122 is provided at the connection between the second seat core 12 and the first seat core 11, a second seat core upper protrusion 121 is provided at the top of the second seat core 12, a third seat core groove is provided at the bottom of the third seat core 13, a third seat core protrusion 131 is provided at the top of the third seat core 13, a fourth seat core groove is provided at the bottom of the fourth seat core 14, and a fourth seat core protrusion 141 is provided at the top of the fourth seat core 14. A groove matching with the first seat core protrusion 111 is provided at the bottom of the first mold core 21, a groove matching with the second seat core upper protrusion 121 is provided at the bottom of the second mold core 22, a groove matching with the third seat core protrusion 131 is provided at the bottom of the third mold core 23, and a groove matching with the fourth seat core protrusion 141 is provided at the bottom of the fourth mold core 24. The installation and positioning of the seat core and the mold core are realized by the above-mentioned protrusions and grooves.

[0044] like Figure 1 In one embodiment, the feed seat 1, the fusion die 2, and the extrusion die 3 are connected by a flange 5. The flanges between the feed seat 1 and the fusion die 2 are fastened by bolts 4 after being matched, and the flanges between the fusion die 2 and the extrusion die 3 are fastened by bolts 4 after being matched.

[0045] In one embodiment, the axis of the fusion die and the extrusion die is a fixing cavity 6 for connecting the film fixing frame.

[0046] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0047] In the description of the embodiments of the present application, the orientations or positional relationships indicated by technical terms such as "upper", "lower", "inside" and "outside" are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the embodiments of the present application and simplifying the description. They 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 a limitation on the embodiments of the present application.

[0048] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "set", "provided with", "connected", "installed" and the like should be understood in a broad sense, for example, they can be fixedly connected, detachably connected, or integrated; they can be directly connected, or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A three-layer co-extruded environmentally friendly water-soluble film extrusion die head, characterized in that: include: A feed seat (1), wherein a first feed port (1011), a second feed port (1021), and a third feed port (1031) are provided on the feed seat; a fusion mold (2) located above the feed seat (1), the fusion mold (2) being provided with an annular first flow channel (201), a second flow channel (202), a third flow channel (203), and a fusion flow channel (204), the first flow channel (201) being in communication with the first feed port (1011), the second flow channel (202) being in communication with the second feed port (1021), the third flow channel (203) being in communication with the third feed port (1031), and the upper parts of the first flow channel (201), the second flow channel (202), and the third flow channel (203) being in communication with the fusion flow channel (204); an extrusion die (3) located on the fusion die (2), the extrusion die (3) being provided with a fusion cavity (301) and an extrusion flow channel (302) communicating with the fusion cavity (301), the fusion cavity (301) being communicated with the fusion flow channel (204); The width of the fusion channel (204) is greater than that of any of the first channel (201), the second channel (202), and the third channel (203); the width of the extrusion channel (302) is less than that of any of the first channel (201), the second channel (202), and the third channel (203); the widths of the first channel (201), the second channel (202), and the third channel (203) gradually narrow from bottom to top; The first flow channel (201), the second flow channel (202), and the third flow channel (203) are arranged in sequence from the inside to the outside in the fusion mold (2); The heights of the first feed port (1011), the second feed port (1021), and the third feed port (1031) are increased sequentially.

2. The extrusion die head according to claim 1, characterized in that: The outer layer of the fusion mold (2) is further provided with a heat-insulating interlayer (205), a medium inlet (2051) is provided below the heat-insulating interlayer (205), and a medium outlet (2052) is provided above the heat-insulating interlayer (205).

3. The extrusion die head according to claim 1, characterized in that: The widths of the first flow channel (201), the second flow channel (202), and the third flow channel (203) narrow from bottom to top.

4. The extrusion die head according to claim 1, characterized in that: The fusion mold (2) includes, from the inside to the outside, a first mold core (21), a second mold core (22), a third mold core (23), and a fourth mold core (24). The first flow channel (201) is an annular cavity formed by the gap between the first mold core (21) and the second mold core (22). The second flow channel (202) is an annular cavity formed by the gap between the second mold core (22) and the third mold core (23). The third flow channel (203) is an annular cavity formed by the gap between the third mold core (23) and the fourth mold core (24).

5. The extrusion die head according to claim 4, characterized in that: The feed seat (1) is provided with a first annular feed channel (101), a second feed channel (102), and a third feed channel (103) in sequence from the inside to the outside; the first feed port (1011) is connected to the first feed channel (101), the second feed port (1021) is connected to the second feed channel (102), and the third feed port (1031) is connected to the third feed channel (103).

6. The extrusion die head according to claim 5, characterized in that: The feed seat (1) is provided with a first seat core (11), a second seat core (12), a third seat core (13), and a fourth seat core (14) in sequence from the inside to the outside; the first feed channel (101) is an annular cavity formed by the gap between the first seat core (11) and the second seat core (12); the second feed channel (102) is an annular cavity formed by the gap between the second seat core (12) and the third seat core (13); and the third feed channel (103) is an annular cavity formed by the gap between the third seat core (13) and the fourth seat core (14).

7. The extrusion die head according to claim 6, characterized in that: The first seat core (11) and the second seat core (12), the second seat core (12) and the third seat core (13), and the third seat core (13) and the fourth seat core (14) are all connected by plug-in fitting, and the first seat core (11) is located above the bottom of the second seat core (12).

8. The extrusion die head according to claim 7, characterized in that: The first seat core (11) and the first mold core (21), the second seat core (12) and the second mold core (22), the third seat core (13) and the third mold core (23), and the fourth seat core (14) and the fourth mold core (24) are all connected by plug-in fitting.

9. The extrusion die head according to claim 1, characterized in that: The feed seat (1), the fusion die (2) and the extrusion die (3) are connected via a flange (5).

10. The extrusion die head according to claim 1, characterized in that: The axis of the fusion die and the extrusion die is a fixed cavity (6) used for connecting a film fixing frame.

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