Plastic extrusion device for multi-layer co-extruded film

Abstract

The present invention discloses a plastic extrusion device for multi-layer co-extruded film, comprising a feed mechanism, a melt mechanism, a co-extrusion compound distributor, a co-extrusion die head, a frame platform and a gantry frame; by sliding a base on the frame platform, the melt mechanism can slide relatively on the frame platform, so that when the entire melt mechanism expands and contracts with heat, it can expand and contract on the frame platform to reduce the stress of the melt mechanism. The output end of the melt mechanism is connected to the feed end of the co-extrusion compound distributor by a metal hose, so that the distance between the co-extrusion compound distributor and the melt mechanism is variable, effectively preventing the stress of the melt mechanism from expanding and contracting with heat to the co-extrusion compound distributor. In addition, since the distance between the co-extrusion compound distributor and the melt mechanism is variable, the co-extrusion die head is suspended in front of the frame platform by a linearly movable suspension arm, so that the co-extrusion die head can move back and forth relative to the frame platform to facilitate adjustment of the position of the co-extrusion die head extruding raw materials.

Description

Technical Field

[0001] The invention relates to the technical field of film production equipment, in particular to a plastic extrusion device for multi-layer co-extruded films. Background Art

[0002] In a multi-layer co-extrusion film production line, plastic pellets are first fed into a melter via a feed mechanism. The plastic pellets are then melted into a plastic slurry in the melter. The slurry then flows from the melter to a co-extrusion compounding distributor, compounding it into a composite melt with a multi-layer structure before being extruded from a co-extrusion die. However, in existing technologies, the fixed positional relationship between the mechanisms makes it difficult for the melter to expand and contract with heat during operation. This can easily lead to excessive stress and deformation in the melter, affecting the normal operation of the multi-layer co-extrusion film production line and hindering the ability to adjust the position of the co-extrusion die when extruding the raw materials. Summary of the Invention

[0003] In view of the above-mentioned defects, the purpose of the present invention is to provide a plastic extrusion device for multi-layer co-extruded films to solve the technical problems of excessive stress in existing plastic extrusion devices and difficulty in adjusting the position of the co-extrusion die to extrude raw materials.

[0004] To achieve this object, the present invention adopts the following technical scheme: a plastic extrusion device for multi-layer co-extruded film, comprising a blanking mechanism, a melting mechanism, a co-extrusion composite distributor, a co-extrusion die head, a frame platform and a gantry frame; the melting mechanism has a base; the gantry frame is provided with a linear movable boom that slides back and forth; the base is slidably arranged on the frame platform, and the sliding direction of the base is parallel to the length direction of the melting mechanism; the gantry frame is arranged in front of the frame platform, the co-extrusion die head is fixedly connected to the linear movable boom, and the co-extrusion composite distributor is installed on the co-extrusion die head; the discharge end of the blanking mechanism is connected to the feed end of the melting mechanism to form a raw material melting unit, and the output ends of the melting mechanisms in multiple raw material melting units are respectively connected to the feed ends of the co-extrusion composite distributor through metal hoses, and the discharge end of the co-extrusion composite distributor is connected to the feed end of the co-extrusion die head.

[0005] Furthermore, the linear movable boom includes a slide, an adjustment frame and a hanging plate; the slide is linearly slidably arranged on the gantry frame; the adjustment frame is connected to the bottom pin of the slide for sliding left and right; the hanging plate is slidably arranged at the bottom of the adjustment frame for sliding up and down; the hanging plates in the two linear movable booms are respectively fixedly connected to the two ends of the co-extrusion die head.

[0006] Furthermore, the adjustment frame is provided with an adjustment hole and an adjustment nut, and the adjustment nut is located in the adjustment hole; an adjustment stud is provided on the top of the hanging plate, and the top end of the adjustment stud is passed from the bottom of the adjustment frame into the adjustment hole and cooperates with the adjustment nut thread.

[0007] Furthermore, the metal hose is provided with a heating element and a heat-insulating cover. The heating element is arranged around the outer periphery of the metal hose, and a plurality of heat-insulating covers are arranged in sections around the outer periphery of the heating element.

[0008] Furthermore, the base is provided with rollers, the frame platform is provided with guide rails, the slide rails extend along the length direction of the melting mechanism, and the rollers are slidably matched with the guide rails.

[0009] Furthermore, the melting mechanism includes a heating pipe, the heating pipe is provided with a feed port, a water-cooled hopper seat is provided on the outer periphery of the heating pipe, and the discharge mechanism is installed on the water-cooled hopper seat; the water-cooled hopper seat has a discharge port, an installation cavity and a cold water chamber; the discharge port is connected to the interior of the installation cavity; the installation cavity is arranged on the outer periphery of the heating pipe, and the discharge port is connected to the feed port; the cold water chamber is arranged around the outer periphery of the installation cavity; the discharge end of the discharge mechanism is connected to the discharge port.

[0010] Furthermore, the unloading mechanism includes an outer hopper assembly for feeding plastic particles and an inner hopper assembly for feeding plastic film edge materials, the outer hopper assembly includes a suction hopper and an outer hopper; the inner hopper assembly includes a cyclone separator, a unloading screw and an inner hopper; the inner hopper is arranged inside the outer hopper; the suction hopper is used to suck the plastic particles into the inside of the outer hopper; the cyclone separator is used to introduce the cast film edge materials into the inside of the inner hopper; the unloading screw is rotatably arranged inside the inner hopper; the discharge end of the outer hopper is connected to the installation cavity through the unloading port, and the discharge end of the inner hopper passes through the discharge end of the outer hopper and is connected to the installation cavity.

[0011] Furthermore, the outer hopper assembly also includes a forked hopper; the forked hopper has several discharge ends; the discharge end of the suction hopper is connected to the feed end of the forked hopper; the several discharge ends of the forked hopper are evenly arranged on the outer wall of the outer hopper and connected to the interior of the outer hopper.

[0012] Furthermore, the melting mechanism also includes a pushing screw, which is rotatably arranged inside the heating pipe, and the pushing screw is sequentially provided with a feeding section, a compression section and a metering section along the axial direction; the feeding section has a first thread and a first spiral groove; the compression section has a second thread and a second spiral groove, and the second thread is provided with a third spiral groove; the metering section has a third thread and a fourth spiral groove; the first thread, the second thread and the third thread have the same rotation direction, the end of the first thread is connected to the starting end of the second thread, and the end of the second thread is connected to the starting end of the third thread; the end of the first spiral groove is connected to the starting end of the second spiral groove, and the end of the third spiral groove is connected to the starting end of the fourth spiral groove; the rod body of the compression section has a taper, the rod body diameter at the starting end of the compression section is smaller than the rod body diameter at the end of the compression section, the groove width of the second spiral groove gradually changes to zero from the starting end to the end of the compression section, and the groove depth of the second spiral groove gradually changes to zero from the starting end to the end of the compression section.

[0013] Furthermore, a barrier portion is provided in the middle of the metering section, and the barrier portion is provided with multiple fourth threads, feed spiral grooves and discharge spiral grooves. The fourth thread has the same rotation direction as the first thread. The groove depth of the feed spiral groove gradually changes to zero from the feed end to the discharge end, and the groove depth of the discharge spiral groove gradually changes to zero from the discharge end to the feed end.

[0014] In the present invention, the base is slidably arranged on the frame platform so that the melting mechanism can slide relatively on the frame platform. Therefore, when the entire melting mechanism expands and contracts due to heat or cold, it can expand and contract on the frame platform to reduce the stress of the melting mechanism. Furthermore, the output end of the melting mechanism is connected to the feed end of the co-extrusion composite distributor by a metal hose. Utilizing the deformable characteristics of the metal hose, when the melting mechanism is in the process of thermal expansion, the metal hose can bend, thereby reducing the distance between the co-extrusion composite distributor and the melting mechanism. When the melting mechanism is in the process of cold contraction, the metal hose can open, thereby increasing the distance between the co-extrusion composite distributor and the melting mechanism. That is, the metal hose can make corresponding deformations according to actual conditions, so that the distance between the co-extrusion composite distributor and the melting mechanism is variable, effectively preventing the stress of the thermal expansion and contraction of the melting mechanism from being transferred to the co-extrusion composite distributor. In addition, since the distance between the co-extrusion composite distributor and the melt mechanism is variable, the co-extrusion die head is suspended in front of the frame platform by a linearly movable boom, so that the co-extrusion die head can move back and forth relative to the frame platform to facilitate adjustment of the position of the co-extrusion die head extruding the raw material. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of an embodiment of the present invention;

[0016] Figure 2 1 is a schematic structural diagram of a linear movable boom according to an embodiment of the present invention;

[0017] Figure 3 It is a structural schematic diagram of a melting mechanism in one embodiment of the present invention;

[0018] Figure 4 This is a schematic structural diagram of a water-cooled hopper seat according to an embodiment of the present invention;

[0019] Figure 5 1 is a schematic cross-sectional view of a water-cooling hopper seat according to an embodiment of the present invention;

[0020] Figure 6 This is a schematic diagram of the cross-section structure of a blanking mechanism in one embodiment of the present invention;

[0021] Figure 7 It is a schematic structural diagram of a push screw in one embodiment of the present invention. DETAILED DESCRIPTION

[0022] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0023] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "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, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" or "second" may explicitly or implicitly include one or more of the features, and are used to distinguish and describe features, without distinction of order or importance. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0024] Reference Figure 1-7 A plastic extrusion device for multi-layer co-extruded film includes a feeding mechanism 100, a melting mechanism 200, a co-extrusion compound distributor 300, a co-extrusion die head 400, a frame platform 500 and a gantry frame 600. The melting mechanism 200 has a base 210. Specifically, the base 210 is used to support the remaining components of the melting mechanism 200. The gantry frame 600 is provided with a linear movable boom 610 that slides back and forth. The base 210 is slidably set on the frame platform 500, and the sliding direction of the base 210 is parallel to the length direction of the melting mechanism 200. The gantry frame 600 is set in front of the frame platform 500, the co-extrusion die head 400 is fixedly connected to the linear movable boom 610, and the co-extrusion compound distributor 300 is installed on the co-extrusion die head 400. The discharge end of the blanking mechanism 100 is connected to the feed end of the melting mechanism 200 to form a raw material melting unit. The output ends of the melting mechanisms 200 in the multiple raw material melting units are respectively connected to the feed end of the co-extrusion composite distributor 300 through metal hoses 310. The discharge end of the co-extrusion composite distributor 300 is connected to the feed end of the co-extrusion die 400. Specifically, after the blanking mechanism 100 feeds the material into the melting mechanism 200, the melting mechanism 200 melts the material and conveys it to the co-extrusion composite distributor 300. The co-extrusion composite distributor 300 composites the molten material into a composite melt with a multi-layer structure and conveys it to the co-extrusion die 400 for extrusion.

[0025] In the present invention, by slidably positioning the base 210 on the frame platform 500, the melt mechanism 200 can slide relatively on the frame platform 500. Therefore, when the entire melt mechanism 200 expands and contracts due to heat or cold, it can expand and contract on the frame platform 500, thereby reducing stress on the melt mechanism 200. Furthermore, the output end of the melt mechanism 200 is connected to the feed end of the co-extrusion composite distributor 300 via a metal hose 310. Utilizing the deformable nature of the metal hose 310, when the melt mechanism 200 expands due to heat, the metal hose 310 can bend, thereby reducing the distance between the co-extrusion composite distributor 300 and the melt mechanism 200. When the melt mechanism 200 contracts due to cold, the metal hose 310 can expand, thereby increasing the distance between the co-extrusion composite distributor 300 and the melt mechanism 200. That is, the metal hose 310 can be deformed according to actual conditions, making the distance between the co-extrusion compound distributor 300 and the melt mechanism 200 variable, effectively preventing the stress caused by thermal expansion and contraction of the melt mechanism 200 from being transmitted to the co-extrusion compound distributor 300. In addition, because the distance between the co-extrusion compound distributor 300 and the melt mechanism 200 is variable, the co-extrusion die 400 is suspended in front of the frame platform 500 by a linearly movable suspension arm 610, allowing the co-extrusion die 400 to move forward and backward relative to the frame platform 500, thereby facilitating adjustment of the position of the co-extrusion die 400 in extruding the raw materials.

[0026] Specifically, the linear movable boom 610 includes a slide 611, an adjustment frame 612, and a hanging plate 613. The slide 611 is linearly slidably arranged on the gantry body 600. The adjustment frame 612 is connected to the bottom pin of the slide 611 in a left-right sliding manner. The hanging plate 613 is slidably arranged at the bottom of the adjustment frame 612 in an up-and-down manner. The hanging plates 613 in the two linear movable booms 610 are respectively fixedly connected to the two ends of the co-extrusion die 400. Figure 2 As shown, by setting the hanging plate 613 at the bottom of the adjustment frame 612 so as to slide up and down, the height of the co-extrusion die 400 can be adjusted up and down. The adjustment frame 612 is connected to the bottom pin of the slide 611 so as to slide left and right, so that the two ends of the co-extrusion die 400 can move left and right relative to each other. Therefore, when the co-extrusion die 400 expands and contracts due to heat and cold, the two ends of the co-extrusion die 400 can extend and retract respectively, so as to prevent the co-extrusion die 400 from being deformed due to excessive stress. It is worth noting that in some embodiments, the gantry body 600 is provided with a linear moving module, and the slide 611 is fixed to the moving end of the linear moving module, so that the linear moving arm 610 can slide linearly on the gantry body 600, thereby driving the co-extrusion die 400 to move forward and backward.

[0027] Furthermore, the adjustment frame 612 is provided with an adjustment hole 614 and an adjustment nut 615, and the adjustment nut 615 is located in the adjustment hole 614. The top of the hanging plate 613 is provided with an adjustment stud 616, and the top end of the adjustment stud 616 is passed from the bottom of the adjustment frame 612 into the adjustment hole 614 and is threadedly engaged with the adjustment nut 615. Figure 2 As shown, when the top of the adjustment stud 616 is inserted into the adjustment hole 614 and then threadedly engaged with the adjustment nut 615, the hanging plate 613 is clamped to the bottom of the adjustment frame 612. The adjustment hole 614 is used by a worker to screw the adjustment nut 615. By screwing the adjustment nut 615, the hanging plate 613 can be adjusted to rise or fall, thereby adjusting the height position of the front die assembly or the rear die assembly in the co-extrusion die 400.

[0028] Preferably, in some embodiments, the metal hose 310 is provided with a heating element and a thermal insulation cover, the heating element is arranged around the outer periphery of the metal hose 310, and a plurality of thermal insulation covers are arranged in sections around the outer periphery of the heating element. Specifically, in the process of the molten raw material entering the co-extrusion compounding distributor 300 through the metal hose 310, the temperature of the raw material is maintained by heat generated by the heating element, so that the temperature of the raw material remains unchanged, which is conducive to the compounding of the raw material in the co-extrusion compounding distributor 300. By covering the outer periphery of the heating element in sections with a plurality of thermal insulation covers, heat loss is reduced, and the thermal insulation covers are arranged in sections around the outer periphery of the metal hose 310 to avoid the thermal insulation covers from destroying the flexibility of the metal hose 310. The heating element can be a ceramic heating plate or an electric heating coil.

[0029] It is worth noting that the base 210 is equipped with rollers, and the frame platform 500 is equipped with guide rails. The guide rails extend along the length of the melting mechanism 200, and the rollers and guide rails slide in cooperation. This sliding cooperation between the rollers and guide rails enables the base 210 to slide on the frame platform 500. The use of rolling friction between the base 210 and the frame platform 500 significantly reduces friction between the base 210 and the frame platform 500, facilitating thermal expansion and contraction of the melting mechanism 200 on the frame platform 500 and reducing stress within the melting mechanism 200.

[0030] Specifically, refer to Figure 3-5The melting mechanism 200 includes a heating pipe 220, which is provided with a feed port 221. A water-cooled hopper seat 230 is provided on the periphery of the heating pipe 220, and the unloading mechanism 100 is installed on the water-cooled hopper seat 230. The water-cooled hopper seat 230 has a feed port 231, an installation cavity 232 and a cold water chamber 233. The feed port 231 is connected to the interior of the installation cavity 232. The installation cavity 232 is sleeved on the periphery of the heating pipe 220 to realize the installation and fixation of the water-cooled hopper seat 230, and the feed port 231 is connected to the feed port 221 to enable the material of the unloading mechanism 100 to be put into the heating pipe 220. The cold water chamber 233 is arranged around the periphery of the installation cavity 232. The discharge end of the unloading mechanism 100 is connected to the feed port 231. By surrounding the installation cavity 232 with a cold water chamber 233, the installation cavity 232 is wrapped. The cold water chamber 233 is loaded with cold water to reduce the heat transfer from the heating pipe 220 to the unloading mechanism 100, thereby preventing the material in the unloading mechanism 100 from melting and generating adhesion resistance, thereby reducing the unloading efficiency. Furthermore, the water-cooled hopper seat 230 includes a first hollow shell 234 and a second hollow shell 235. The first hollow shell 234 is covered on the second hollow shell 235 to form a cylindrical water-cooled hopper seat 230. Figure 4 and Figure 5 As shown, the first hollow shell 234 and the second hollow shell 235 are each semicircular in shape. The first hollow shell 234 is placed on the second hollow shell 235 to form a cylindrical water-cooling hopper seat 230. The hollow portions of the first hollow shell 234 and the second hollow shell 235 form a cold water chamber 233, and the hollow portion of the water-cooling hopper seat 230 forms a mounting cavity 232. By configuring the water-cooling hopper seat 230 into a cylindrical shape, corners are reduced, thereby facilitating the flow of cold water in the cold water chamber 233. Furthermore, the first hollow shell 234 is provided with a first cold water inlet 2341 and a first cold water outlet 2342, and the second hollow shell 235 is provided with a second cold water inlet 2351 and a second cold water outlet 2352. The first cold water inlet 2341 is used to introduce cold water into the interior of the first hollow shell 234. The first cold water outlet 2342 is connected to the second cold water inlet 2351 via a connecting hose, thereby connecting the first hollow shell 234 with the second hollow shell 235. The second cold water outlet 2352 is used to draw cold water out of the second hollow shell 235. In the water-cooled hopper seat 230, external cold water flows from the first cold water inlet 2341 into the hollow portion of the first hollow shell 234, then flows from the first cold water inlet 2341 to the second cold water inlet 2351, allowing the cold water to flow into the hollow portion of the second hollow shell 235. The cold water is then discharged from the second cold water outlet 2352, allowing the cold water in the cold water chamber 233 to remove some heat, thereby reducing the heat transferred from the melting mechanism 200 to the discharge mechanism 100.

[0031] It is worth noting that the unloading mechanism 100 includes an outer hopper assembly 110 for dispensing plastic pellets and an inner hopper assembly 120 for dispensing plastic film scraps. The outer hopper assembly 110 includes a suction hopper 111 and an outer hopper 112. The inner hopper assembly 120 includes a cyclone separator 121, a unloading screw 122, and an inner hopper 123. The inner hopper 123 is arranged inside the outer hopper 112. The suction hopper 111 is used to suck the plastic pellets into the interior of the outer hopper 112. Specifically, the feed end of the suction hopper 111 is connected to a material pool for storing plastic pellets, and the discharge end of the suction hopper 111 is connected to the interior of the outer hopper 112. The suction hopper 111 can be a device that generates negative pressure through a high-pressure blower to suck the raw materials into the interior of the outer hopper 112. The cyclone separator 121 is used to introduce the cast film scraps into the interior of the inner hopper 123. Specifically, the feed end of the cyclone separator 121 is connected to a pool for storing the crushed edge materials, and the discharge end of the cyclone separator 121 is connected to the interior of the inner hopper 123. The cyclone separator 121 introduces the edge materials of the cast film through its own rotating structure. The discharge screw 122 is rotatably arranged inside the inner hopper 123. The discharge end of the outer hopper 112 is connected to the installation cavity 232 through the discharge port 231, and the discharge end of the inner hopper 123 passes through the discharge end of the outer hopper 112 and is connected to the installation cavity 232. Specifically, as Figure 6 As shown, by placing the inner hopper 123 inside the outer hopper 112, the space occupied by the discharge mechanism 100 is reduced. After the suction hopper 111 draws the plastic pellets into the outer hopper 112, the plastic pellets flow out from the discharge end of the outer hopper 112, thereby discharging the plastic pellets. After the cyclone separator 121 introduces the plastic film scraps into the inner hopper 123, the plastic film scraps flow out from the discharge end of the inner hopper 123, thereby discharging the plastic film scraps. Because the discharge end of the inner hopper 123 passes through the discharge end of the outer hopper 112, the plastic film scraps never enter the outer hopper 112, thereby preventing the normal discharge of the plastic pellets and the plastic film scraps. Simultaneously, the inner hopper assembly 120 rotates the discharge screw 122 to push the scraps in the inner hopper 123 downward, achieving forced discharge and thereby improving the efficiency of scrap discharge.

[0032] Alternatively, as Figure 6As shown, the outer hopper assembly 110 further includes a forked hopper 113. The forked hopper 113 has a plurality of discharge ends. The discharge end of the suction hopper 111 is connected to the feed end of the forked hopper 113. The plurality of discharge ends of the forked hopper 113 are evenly arranged on the outer wall of the outer hopper 112 and are connected to the interior of the outer hopper 112. By arranging the forked hopper 113 between the suction hopper 111 and the outer hopper 112, the plastic particles sucked up by the suction hopper 111 can be delivered to the interior of the outer hopper 112 from multiple directions, so that the plastic particles are evenly distributed in the outer hopper 112, so as to avoid the plastic particles from being blocked on one side of the outer hopper 112 and reducing the discharge speed of the outer hopper assembly 110, thereby improving the efficiency of the discharge mechanism 100.

[0033] It is worth noting that the melting mechanism 200 also includes a push screw 240, which is rotatably disposed within the interior of the heating pipe 220. The push screw 240 is provided with a feed section 241, a compression section 242, and a metering section 243 in the axial direction. The feed section 241 has a first thread 2411 and a first spiral groove 2412. The compression section 242 has a second thread 2421 and a second spiral groove 2422, and the second thread 2421 is provided with a third spiral groove 2423. The metering section 243 has a third thread 2431 and a fourth spiral groove 2432. The first thread 2411, the second thread 2421, and the third thread 2431 have the same direction of rotation. The end of the first thread 2411 is connected to the beginning of the second thread 2421, and the end of the second thread 2421 is connected to the beginning of the third thread 2431. The end of the first spiral groove 2412 is connected to the beginning of the second spiral groove 2422, and the end of the third spiral groove 2423 is connected to the beginning of the fourth spiral groove 2432. The rod body of the compression section 242 has a taper, and the rod body diameter at the beginning of the compression section 242 is smaller than the rod body diameter at the end of the compression section 242. The groove width of the second spiral groove 2422 gradually changes to zero from the beginning of the compression section 242 to the end of the compression section 242. The groove depth of the second spiral groove 2422 gradually changes to zero from the beginning of the compression section 242 to the end of the compression section 242. Figure 7As shown, the feed section 241 of the push screw 240 uses its first thread 2411 to push material within the first spiral groove 2412, forcing the material just entering the heating pipe 220 forward to the compression section 242 for compression and melting. In the compression section 242, the solid material is contained within the second spiral groove 2422. Due to the tapered rod of the compression section 242, the groove depth and width of the second spiral groove 2422 gradually decrease to zero, achieving a narrowing of both width and depth. This gradually reduces the volume of the second spiral groove 2422 to zero, reducing the space between the second spiral groove 2422 and the inner wall of the heating pipe 220. This compresses the solid material within the second spiral groove 2422, improving its melting efficiency. The material melted in the second spiral groove 2422 is squeezed into the third spiral groove 2423, where it is then pushed forward to the metering section 243. In the metering section 243 , the third thread 2431 is used to quantitatively push the molten material that falls into the fourth spiral groove 2432 .

[0034] In some embodiments, a barrier portion 244 is further provided in the middle of the metering section 243. The barrier portion 244 is provided with a plurality of fourth threads 2441, a feed spiral groove 2442 and a discharge spiral groove 2443. The fourth threads 2441 have the same rotation direction as the first threads 2411. The depth of the feed spiral groove 2442 gradually changes to zero from the feed end to the discharge end, and the depth of the discharge spiral groove 2443 gradually changes to zero from the discharge end to the feed end. Figure 7 As shown, by setting a barrier portion 244 in the metering drive, the material enters the barrier portion 244 from the feed spiral groove 2442. After the incompletely melted solid material reaches the terminal of the feed spiral groove 2442, due to the extrusion of subsequent materials, the unmelted solid material passes over the fourth thread 2441 and enters the discharge spiral groove 2443, realizing secondary compression and melting of the solid material, and finally flows out from the discharge spiral groove 2443, performing secondary compression and melting of the incompletely melted material, thereby improving the melting efficiency of the melting mechanism 200.

[0035] Other structures and operations of the plastic extrusion device for a multi-layer co-extruded film according to an embodiment of the present invention are well known to those skilled in the art and will not be described in detail here.

[0036] Throughout this specification, reference to terms such as "embodiment" or "example" indicates that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0037] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A plastic extrusion device for multi-layer co-extruded film, characterized by: It includes a material discharge mechanism, a melting mechanism, a co-extrusion compound distributor, a co-extrusion die head, a frame platform and a gantry frame; The melting mechanism has a base; The gantry body is provided with a linear movable boom that slides back and forth; The base is slidably arranged on the frame platform, and the sliding direction of the base is parallel to the length direction of the melting mechanism; The gantry body is arranged in front of the frame platform, the co-extrusion die head is fixedly connected to the linear movable boom, and the co-extrusion compound distributor is installed on the co-extrusion die head; The discharge end of the blanking mechanism is connected to the feed end of the melting mechanism to form a raw material melting unit, and the output ends of the melting mechanisms in the multiple raw material melting units are respectively connected to the feed end of the co-extrusion composite distributor through metal hoses, and the discharge end of the co-extrusion composite distributor is connected to the feed end of the co-extrusion die head; when the melting mechanism is in a thermal expansion process, the metal hose can bend to reduce the distance between the co-extrusion composite distributor and the melting mechanism; when the melting mechanism is in a cold contraction process, the metal hose can open to increase the distance between the co-extrusion composite distributor and the melting mechanism; The linear movable boom comprises a slide, an adjustment frame and a hanging plate; The slide is linearly slidably arranged on the gantry frame body; the adjustment frame is connected to the bottom pin of the slide in a left-right sliding manner; the hanging plate is slidably arranged at the bottom of the adjustment frame in an up-and-down manner; The hanging plates in the two linear movable hanging arms are fixedly connected to the two ends of the co-extrusion die head respectively; when the co-extrusion die head expands and contracts with heat, the two ends of the co-extrusion die head extend and retract respectively.

2. The plastic extrusion device for a multi-layer co-extruded film according to claim 1, characterized in that: The adjusting frame is provided with an adjusting hole and an adjusting nut, and the adjusting nut is located in the adjusting hole; An adjusting stud is provided on the top of the hanging plate, and the top end of the adjusting stud passes through the bottom of the adjusting frame into the adjusting hole and is threadably matched with the adjusting nut.

3. The plastic extrusion device for a multi-layer co-extruded film according to claim 1, characterized in that: The metal hose is provided with a heating element and a heat-insulating cover. The heating element is arranged around the outer periphery of the metal hose, and a plurality of heat-insulating covers are arranged in sections around the outer periphery of the heating element.

4. The plastic extrusion device for a multi-layer co-extruded film according to claim 1, characterized in that: The base is provided with rollers, the frame platform is provided with guide rails, the guide rails extend along the length direction of the melting mechanism, and the rollers are slidably matched with the guide rails.

5. The plastic extrusion device for a multi-layer co-extruded film according to claim 1, characterized in that: The melting mechanism includes a heating pipe, the heating pipe is provided with a feed port, the outer periphery of the heating pipe is provided with a water-cooled hopper seat, and the unloading mechanism is installed on the water-cooled hopper seat; The water-cooled hopper seat has a feed opening, a mounting cavity and a cold water chamber; The feed opening is connected to the interior of the installation cavity; The installation cavity is sleeved on the outer circumference of the heating pipe, and the feed opening is connected to the feed opening; The cold water chamber is arranged around the periphery of the installation cavity; The discharge end of the discharge mechanism is connected to the discharge port.

6. The plastic extrusion device for a multi-layer co-extruded film according to claim 5, characterized in that: The feeding mechanism includes an outer hopper assembly for feeding plastic particles and an inner hopper assembly for feeding plastic film scraps; The outer hopper assembly includes a suction hopper and an outer hopper; The inner hopper assembly includes a cyclone separator, a feeding screw and an inner hopper; The inner hopper is arranged inside the outer hopper; The suction hopper is used to suck the plastic particles into the interior of the outer hopper; The cyclone separator is used to introduce the cast film scrap into the interior of the inner hopper; The unloading screw is rotatably arranged inside the inner hopper; The discharge end of the outer hopper is connected to the installation cavity through the discharge port, and the discharge end of the inner hopper passes through the discharge end of the outer hopper and is connected to the installation cavity.

7. The plastic extrusion device for a multi-layer co-extruded film according to claim 6, characterized in that: The outer hopper assembly also includes a forked hopper; The forked hopper has a plurality of discharge ends; The discharge end of the suction hopper is connected to the feed end of the forked hopper; The plurality of discharge ends of the forked hopper are evenly arranged on the outer wall of the outer hopper and communicated with the interior of the outer hopper.

8. The plastic extrusion device for a multi-layer co-extruded film according to claim 5, characterized in that: The melting mechanism further includes a pushing screw, which is rotatably arranged inside the heating pipe and has a feeding section, a compression section and a metering section in sequence along the axial direction; The feeding section has a first thread and a first spiral groove; the compression section has a second thread and a second spiral groove, and the second thread is provided with a third spiral groove; the metering section has a third thread and a fourth spiral groove; The first thread, the second thread, and the third thread have the same rotation direction, the end of the first thread is connected to the beginning of the second thread, and the end of the second thread is connected to the beginning of the third thread; the end of the first spiral groove is connected to the beginning of the second spiral groove, and the end of the third spiral groove is connected to the beginning of the fourth spiral groove; The rod body of the compression section has a taper, the rod body diameter at the starting end of the compression section is smaller than the rod body diameter at the end of the compression section, the groove width of the second spiral groove gradually changes to zero from the starting end of the compression section to the end of the compression section, and the groove depth of the second spiral groove gradually changes to zero from the starting end of the compression section to the end of the compression section.

9. The plastic extrusion device for a multi-layer co-extruded film according to claim 8, characterized in that: A barrier portion is also provided in the middle of the metering section, and the barrier portion is provided with multiple fourth threads, feed spiral grooves and discharge spiral grooves. The fourth threads have the same rotation direction as the first threads. The groove depth of the feed spiral groove gradually changes to zero from the feed end to the discharge end, and the groove depth of the discharge spiral groove gradually changes to zero from the discharge end to the feed end.

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