A single-layer blown film extrusion die for producing high-barrier nylon films

Abstract

This invention provides a single-layer blown film extrusion die for producing high-barrier nylon films, comprising a die core, a die core outer sleeve, a die adjusting ring, and a die. A feed inlet is located at the center of the bottom surface of the die core. A series of inclined flow channels are radially distributed outwards from the center of the lower part of the die core at equal angles, connected to the feed inlet. The inclined flow channels gradually increase in height from the inside out, forming a conical radiating structure. An annular connecting portion extends outwards from the bottom of the die core, and an annular flow channel portion extends upwards from the top surface of the die core. A series of inclined spiral flow channels are arranged on the outer surface of the annular flow channel portion, with the bottom of each spiral flow channel corresponding to the top of an inclined flow channel and connected. The top surface of the annular connecting portion is connected to the die core outer sleeve, and the top surface of the annular flow channel portion is connected to the die. The top surface of the die core outer sleeve is connected to the die adjusting ring, forming an annular extrusion channel between the die and the die adjusting ring. The film extruded by this invention exhibits good uniformity.

Description

Technical Field

[0001] This invention relates to an extrusion die, and more particularly to a single-layer blown film extrusion die for producing high-barrier nylon films. Background Technology

[0002] Cooked and fresh foods need to be isolated from air and moisture during transportation to prevent spoilage. Therefore, food packaging bags must be able to block the influence of environmental factors such as air, moisture, and odors. Nylon film, due to its excellent ability to isolate gases and moisture, is widely used in the food packaging industry and is known in the industry as high-barrier nylon film. The main production methods for high-barrier films are blown film blowing, step-by-step stretching, and simultaneous biaxial stretching. Blown film blowing produces films with good uniformity, high crystallinity, simple equipment, small footprint, and low energy consumption. Step-by-step biaxial stretching technology inevitably produces a "bow effect" defect, limiting its application in areas with high flatness requirements. Simultaneous stretching technology avoids the "bow effect," but its equipment technology is highly complex and monopolized by a few leading companies. Therefore, blown film blowing accounts for a large proportion of nylon high-barrier film production in the industry. Summary of the Invention

[0003] To address the aforementioned problems, this invention aims to provide a single-layer blown film extrusion die for producing high-barrier nylon films. It features a novel structure, balanced feeding, and good uniformity in the extruded film.

[0004] The technical solution of this invention is a single-layer blown film extrusion die for producing high-barrier nylon films. Its features include: a die core, a die core outer sleeve, a die adjusting ring, and a die. A feed inlet is located at the center of the bottom surface of the die core. A series of inclined flow channels are radially distributed outwards at equal angles from the center of the lower part of the die core. These inclined flow channels are connected to the feed inlet. The height of the inclined flow channels gradually increases from the inside to the outside, and all inclined flow channels form a conical, radiating structure. An annular connecting portion extends outwards from the bottom of the die core, and a circular ring extends upwards from the top surface of the die core. The annular flow channel section has a series of inclined spiral flow channels on its outer side. The bottom of each spiral flow channel is connected to the top of an inclined flow channel. The top surface of the annular connecting part is connected to a die core outer sleeve. The top surface of the annular flow channel section is connected to a die. The top surface of the die core outer sleeve is connected to a die adjusting ring. An annular extrusion channel is formed between the die and the die adjusting ring. Molten raw material enters through the feed port, passes through a series of inclined flow channels to reach the spiral flow channel evenly, and then enters the annular extrusion channel through the gap between the die core and the die core outer sleeve for uniform extrusion.

[0005] Preferably, it also includes a plug, the plug comprising a connecting ring at the top and a cylindrical section at the bottom, a connecting channel is provided at the center of the top surface of the mold core, the cylindrical section is inserted into the connecting channel for sealing, the connecting ring is connected to the mold core by screws, the bottom surface of the plug is generally in the shape of an inwardly concave cone, and a series of guide grooves are provided on the bottom surface of the plug along the circumferential direction, each guide groove matching each inclined flow channel.

[0006] Preferably, the spiral flow channel gradually decreases in depth from bottom to top, the lower part of the outer side of the annular flow channel is in close contact with the inner side of the mold core outer sleeve, and the gap between the upper part of the outer side of the annular flow channel and the inner side of the mold core outer sleeve generally increases from bottom to top.

[0007] Preferably, the gap formed between the top region of the outer side of the annular flow channel and the inner side of the outer sleeve of the mold core corresponds to the gap size formed between the outer side of the bottom of the die and the inner side of the die adjustment ring.

[0008] Preferably, the annular extrusion channel forms a diameter reduction compression flow channel section and a thin-walled annular shaping extrusion section in the upper region, and the gap of the diameter reduction compression flow channel section gradually decreases from bottom to top.

[0009] Preferably, the outer sleeve of the mold core is connected to the mold core body by screws, the die adjusting ring is connected to the top surface of the outer sleeve of the mold core body by screws, and the die is connected to the top surface of the annular flow channel by screws.

[0010] This invention provides uniform feeding, resulting in well-uniform extruded films and ensuring high-quality film extrusion. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a structural schematic diagram from another perspective of the present invention; Figure 3 This is a cross-sectional view of the present invention; Figure 4 This is an exploded view of the present invention; Figure 5 for Figure 4 A structural diagram from another perspective; Figure 6 This is a schematic diagram of the core structure in this invention; Figure 7 This is a schematic diagram of the plug structure in this utility model; Wherein: 1—Die core; 11—Feed inlet; 12—Inclined flow channel; 13—Annular connecting part; 14—Annular flow channel part; 141—Spiral flow channel; 2—Die core outer sleeve; 3—Die adjusting ring; 4—Die; 5—Annular extrusion channel; 51—Between diameter compression flow channel section; 52—Thin-walled annular shaping extrusion section; 6—Plug; 61—Connecting ring; 62—Columnar section; 621—Guide groove. Detailed Implementation

[0012] The present invention will now be described in further detail with reference to the accompanying drawings.

[0013] like Figures 1 to 6 As shown, this invention provides a single-layer blown film extrusion die for producing high-barrier nylon films, comprising a die core 1, a die core outer sleeve 2, a die adjusting ring 3, and a die 4. A feed inlet 11 is located at the center of the bottom surface of the die core 1. A series of inclined flow channels 12 are radially distributed outwards at equal angles from the lower center of the die core 1. The inclined flow channels 12 are connected to the feed inlet 11. The height of the inclined flow channels 12 gradually increases from the inside to the outside, and all inclined flow channels 12 form a conical radiating structure. An annular connecting portion 13 extends outwards from the bottom of the die core 1, and an annular flow channel portion 14 extends upwards from the top surface of the die core 1. A series of inclined spiral channels 141 are provided on the outer side of the annular flow channel 14. The bottom of each spiral channel 141 corresponds to the top of an inclined channel 12 and is connected. The top surface of the annular connecting part 13 is connected to the die core body sleeve 2. The top surface of the annular flow channel 14 is connected to the die 4. The top surface of the die core body sleeve 2 is connected to the die adjusting ring 3. An annular extrusion channel 5 is formed between the die 4 and the die adjusting ring 3. The molten raw material enters through the feed port 11, passes through a series of inclined channels 12 and reaches the spiral channel 141 evenly, and then enters the annular extrusion channel 5 through the gap between the die core body 1 and the die core body sleeve 2 for uniform extrusion.

[0014] Based on the above scheme, a plug 6 is also included. The plug 6 includes a connecting ring 61 at the top and a cylindrical section 62 at the bottom. A connecting channel is provided at the center of the top surface of the mold core 1. The cylindrical section 62 is inserted into the connecting channel for sealing. The connecting ring 61 is connected to the mold core 1 by screws. The bottom surface of the plug 6 is generally a concave conical structure. A series of guide grooves 621 are provided on the bottom surface of the plug 6 along the circumferential direction. Each guide groove 621 is guided and matched with each inclined flow channel 12.

[0015] Furthermore, the depth of the spiral flow channel 141 gradually decreases from bottom to top, the lower part of the outer side of the annular flow channel portion 14 is in close contact with the inner side of the mold core outer sleeve 2, and the gap between the upper part of the outer side of the annular flow channel portion 14 and the inner side of the mold core outer sleeve 2 generally increases from bottom to top.

[0016] In addition, the gap formed between the top area of ​​the outer side of the annular flow channel 14 and the inner side of the mold core body jacket 2 corresponds to the gap size formed between the bottom outer side of the die 4 and the inner side of the die adjusting ring 3.

[0017] Specifically, the annular extrusion channel 5 forms a diameter reduction compression flow channel section 51 and a thin-walled annular shaping extrusion section 52 in the upper region, and the gap of the diameter reduction compression flow channel section 51 gradually decreases from bottom to top.

[0018] Furthermore, the outer sleeve 2 of the mold core body is connected to the mold core body 1 by screws, the die adjusting ring 3 is connected to the top surface of the outer sleeve 2 of the mold core body by screws, and the die 4 is connected to the top surface of the annular flow channel 14 by screws.

[0019] In this invention, the raw material enters from the feed inlet 11, and the internal temperature of the die head is maintained at 260-270°C. Guided by the guide groove 621, the raw material smoothly enters each inclined flow channel 12. The raw material flows out radially outward and upward, and enters each spiral flow channel 141 evenly. The raw material flows upward in a spiral shape. In the upper region of the annular flow channel 14, the raw material is evenly extruded upward through the spiral flow channel 141 and the gap between the annular flow channel 14 and the die core body outer sleeve 2. The raw material enters the annular extrusion channel 5 and continues to flow upward. It is compressed through the diameter reduction compression flow channel section 51 and finally shaped and extruded through the thin-walled annular shaping extrusion section 52 to form a cylindrical film.

[0020] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, equivalent changes, or alterations made to the above embodiments based on the technical principles of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A single layer blown film extrusion die for producing a nylon high barrier film, characterized by: The mold includes a core body (1), a core body outer sleeve (2), a die adjusting ring (3), and a die (4). The core body (1) has a feed inlet (11) at the center of its bottom surface. A series of inclined flow channels (12) are radially distributed outward from the center of the lower part of the core body (1) at equal angles. The inclined flow channels (12) are connected to the feed inlet (11). The inclined flow channels (12) gradually increase in height from the inside to the outside. All the inclined flow channels (12) form a cone-shaped radiating structure. A ring-shaped connecting part (13) extends outward from the bottom of the core body (1). A circular flow channel part (14) extends upward from the top surface of the core body (1). A series of... The spiral flow channels (141) are arranged at an incline. The bottom of each spiral flow channel (141) corresponds to the top of an inclined flow channel (12) and they are connected. The top surface of the annular connecting part (13) is connected to the mold core body outer sleeve (2). The top surface of the annular flow channel part (14) is connected to the die (4). The top surface of the mold core body outer sleeve (2) is connected to the die adjusting ring (3). An annular extrusion channel (5) is formed between the die (4) and the die adjusting ring (3). The molten raw material enters through the feed port (11), passes through a series of inclined flow channels (12) and reaches the spiral flow channel (141) evenly. Then, it enters the annular extrusion channel (5) through the gap between the mold core body (1) and the mold core body outer sleeve (2) and is evenly extruded.

2. A single layer blown film extrusion die for producing a nylon high barrier film according to claim 1, characterized in that: It also includes a plug (6), which includes a connecting ring (61) at the top and a cylindrical section (62) at the bottom. A connecting channel is provided at the center of the top surface of the mold core (1). The cylindrical section (62) is inserted into the connecting channel for sealing. The connecting ring (61) is connected to the mold core (1) by screws. The bottom surface of the plug (6) is a concave cone structure. A series of guide grooves (621) are provided on the bottom surface of the plug (6) along the circumferential direction. Each guide groove (621) is guided and matched with each inclined flow channel (12).

3. A single layer blown film extrusion die for producing a nylon high barrier film according to claim 1, characterized in that: The spiral flow channel (141) gradually decreases in depth from bottom to top. The lower part of the outer side of the annular flow channel (14) is closely fitted with the inner side of the mold core outer sleeve (2). The gap between the upper part of the outer side of the annular flow channel (14) and the inner side of the mold core outer sleeve (2) generally increases from bottom to top.

4. A single layer blown film extrusion die for producing a nylon high barrier film according to claim 3, characterized in that: The gap formed between the top area of ​​the outer side of the annular flow channel (14) and the inner side of the outer sleeve (2) of the mold core body corresponds to the gap size formed between the outer side of the bottom of the die (4) and the inner side of the die adjustment ring (3).

5. A single layer blown film extrusion die for producing a nylon high barrier film according to claim 1, characterized in that: The annular extrusion channel (5) forms a diameter reduction compression flow channel section (51) and a thin-walled annular shaping extrusion section (52) in the upper region, respectively, and the gap of the diameter reduction compression flow channel section (51) gradually decreases from bottom to top.

6. A single layer blown film extrusion die for producing a nylon high barrier film according to claim 1, characterized in that: The outer sleeve (2) of the mold core body is connected to the mold core body (1) by screws, the die adjusting ring (3) is connected to the top surface of the outer sleeve (2) of the mold core body by screws, and the die (4) is connected to the top surface of the annular flow channel (14) by screws.

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