CN118456813A - Production line and production process for co-extrusion of hollow plastic plate by inorganic dust one-step method - Google Patents

Abstract

The application relates to an inorganic dust one-step method co-extrusion hollow plastic plate production line and a production process, and relates to the specific technical field, wherein the inorganic dust one-step method co-extrusion hollow plastic plate production line, a first extrusion device and a second extrusion device, the first extrusion device comprises a mixer, a feeder, a blanking assembly and a first extruder which are sequentially arranged, the blanking assembly comprises a blanking frame, at least two blanking screws and a blanking drive connected with the blanking screws, one end of the blanking frame is communicated with the feeding machine, at least two blanking screws are located in the blanking frame, one end of the blanking frame, which is far away from the feeding machine, is communicated with the first extruder, one end of the first extruder, which is far away from the feeding machine, is provided with a forming assembly, the forming assembly comprises a distributor, a die and a second extruder, the first extruder in the first extrusion equipment and the first extruder in the second extrusion equipment are communicated with the distributor, and the second extruder extrudes two molten raw materials. The application has the effect of being convenient for producing the flat and uniform-color double-layer hollow plastic plate.

Description

Production line and production process for co-extrusion of hollow plastic plate by inorganic dust one-step method

Technical Field

The application relates to the specific technical field, in particular to a production line and a production process for co-extruding hollow plastic plates by an inorganic dust one-step method.

Background

The plastic hollow board is a new environment-friendly packaging material, and can be applied to various industries such as electronics, packaging, machinery, light industry, postal service, food, medicine, pesticide, household appliances, advertisement, decoration, cultural goods, optomagnetic technology, bioengineering medicine and health.

The plastic hollow plate is made by extruding plastic particles, the raw materials are industrial solid waste, the energy is saved, the environment is protected, the solid waste is utilized, and the working procedures of melting plastic, extruding, mould shaping, cooling, cutting and the like are needed during the production and the processing. Thus, the plastic extruder is required to be matched with a plastic extruder to produce the plastic hollow plate, so that the plastic extruder on the market can only produce plastic hollow plates or plastic pipes with one color, and the single-color plastic hollow plates or plastic pipes can not meet the decoration requirements of people, so that plates or pipes with two colors on the surfaces are required to be obtained through different and complex welding or splicing processes, a great amount of labor time and cost and materials are wasted, and the surfaces after welding or splicing are not smooth and attractive.

Disclosure of Invention

In order to facilitate the production of flat and uniform-color double-layer hollow plastic plates, the application provides a production line and a production process for co-extruding inorganic dust by a one-step method.

In a first aspect, the application provides an inorganic dust one-step method co-extrusion hollow plastic plate production line, which adopts the following technical scheme:

The utility model provides an inorganic dust one-step method coextrusion cavity moulds board production line, first extrusion equipment and second extrusion equipment, first extrusion equipment is including blendor, feeding machine, unloading subassembly and the first extruder that sets gradually, blendor, feeding machine, unloading subassembly and first extruder all communicate in proper order, the blendor is used for sending into the feeding machine after mixing powder raw materials and granule raw materials, the unloading subassembly includes unloading frame and at least two unloading screw rods and the unloading drive of being connected with the unloading screw rods, unloading frame one end and feeding machine intercommunication, at least two unloading screw rods are located the unloading frame, and the unloading drive is used for driving at least two unloading screw rods and carries out the unloading, and the one end that the feeding machine was kept away from to the unloading frame communicates with first extruder, and first extruder is used for melting mixed raw materials and carries to shaping subassembly in, the one end that the feeding machine was kept away from to the first extruder is equipped with shaping subassembly, and shaping subassembly includes distributor, mould and second extruder, and second extrusion equipment is the same with first extrusion equipment structure, and the first extrusion equipment in first extruder and the second extruder in the first extrusion equipment and the first extruder in the first extruder and two extrusion equipment, two extrusion equipment and first extruder and two extrusion equipment are kept away from two extrusion equipment and are used for two extrusion equipment, and two extrusion equipment in the first extruder, and two extrusion equipment are connected to form the hollow raw materials.

Through adopting above-mentioned technical scheme, send into powder raw materials and granule raw materials respectively in the blendor of first extrusion equipment and second extrusion equipment, put into cavity lamellar powder in the first extrusion equipment, put into surface layer powder in the second extrusion equipment, powder raw materials and granule raw materials send into the feeding machine after the blendor mixes, the mixed raw materials passes through feeding machine and unloading screw rod and gets into in the first extruder and melts, the unloading screw rod mixes powder raw materials and granule raw materials once more when unloading, in the first extruder carries the distributor with melting raw materials, the distributor sends into the mould with the mixed raw materials after two kinds of melting and extrudes through the second extruder, form double-deck cavity plastic plate, be convenient for produce smooth, the even double-deck cavity plastic plate of double-deck bilayer of colour.

Optionally, the blanking assembly further comprises a blanking box, wherein the bottom of the blanking box is communicated with the first extruder, and the blanking box is communicated with one side, close to the feeding machine, of the blanking box.

Through adopting above-mentioned technical scheme, the unloading case communicates first extruder and unloading screw rod, reduces the possibility that the heat in the first extruder produced high temperature influence to the exit of unloading screw rod to reduce the powder raw materials and melt the possibility of being stained with on the unloading screw rod.

Optionally, be equipped with the guide subassembly in the unloading case, the guide subassembly includes control switch, stock guide and cooling piece, and control switch is located the unloading incasement and is located unloading frame below, and control switch is used for closing or opening the unloading passageway between unloading case and the first extruder regularly, and the stock guide is located the control switch below and is connected with the unloading case, and the cooling piece is connected with the stock guide, and the cooling piece is used for cooling down the stock guide.

Through adopting above-mentioned technical scheme, control switch makes mixed raw materials to fall into in the first extruder together after the certain weight down, and the possibility of control switch isolated first extruder and unloading screw rod when waiting for mixed raw materials to fall into, further reduces the temperature in the first extruder and influences unloading screw rod, reduces the temperature of first extruder simultaneously and gives off, and the stock guide that is equipped with the cooling member stops the steam on the one hand, and on the other hand also can reduce the possibility that mixed raw materials is stained with and attaches on the stock guide.

Optionally, the molding assembly further comprises a cooling component and a cutting component, wherein the cooling component is used for cooling and shaping the hollow plastic plate extruded by the second extruder, and the cutting component is used for cutting the hollow plastic plate.

By adopting the technical scheme, the extruded double-layer hollow plastic plate is convenient to shape and cut.

Optionally, all be equipped with the metering subassembly between first extruder and the distributor, the metering subassembly includes conveyer pipe and measuring pump, and the both ends of conveyer pipe communicate with first extruder and distributor respectively, and the measuring pump communicates with the conveyer pipe, and the measuring pump measures the molten raw materials that first extruder extruded.

Through adopting above-mentioned technical scheme, the metering pump can both carry out accurate measurement to the molten raw materials that gets into in the distributor in first extrusion equipment and the second extrusion equipment, improves the accurate quantity that molten raw materials got into in the mould to this evenness and the homogeneity degree of colour that improves the cavity and mould the board.

Optionally, one side of the discharging box is also provided with a recovery component, and the recovery component is used for crushing and recovering the cut leftover materials of the hollow plastic plate.

Through adopting above-mentioned technical scheme, retrieve the subassembly and retrieve the leftover bits of cavity plastic slab and recycle, energy-concerving and environment-protective.

Optionally, retrieve the subassembly and include breaker, conveying pipe, conveying piece and retrieve the fill, the unloading case one side is located to the breaker, and the breaker is used for the leftover bits with cavity plastic slab to become powdered, and the both ends of conveying pipe communicate with unloading case and breaker respectively, and conveying piece is located the conveying pipe, and conveying piece is used for carrying the powder raw materials after the breakage to the unloading incasement, retrieves the fill and locates breaker top and breaker intercommunication.

Through adopting above-mentioned technical scheme, when retrieving the leftover bits of cavity plastic slab, put into the breaker of first extrusion equipment with the leftover bits, in the breaker broken back is sent to the unloading incasement through the conveyer, falls into in the first extruder from the unloading case again and melts.

Optionally, a vibrator is arranged on the feeding machine.

By adopting the technical scheme, the vibrator reduces the powder raw material adhered in the feeder.

Optionally, a vacuum dehumidifier is arranged at one side of the first extruder.

By adopting the technical scheme, the vacuum dehumidifier reduces the moisture generated in the first extruder, and reduces the influence of the moisture on the molten raw material.

On the other hand, the application also provides a production method suitable for the production line of the hollow plastic plate co-extruded by the inorganic dust one-step method.

The production process of the inorganic dust one-step co-extrusion hollow plastic plate comprises the following steps:

Respectively placing the powder raw material and the particle raw material in a mixer of the first extrusion equipment and a mixer of the second extrusion equipment according to the proportion;

the ratio of the powder raw material to the particle raw material is 1:0.7-0.3;

The first extrusion equipment is filled with hollow slab powder, and the second extrusion equipment is filled with surface layer powder;

After the molten raw materials in the first extrusion equipment and the molten raw materials in the second extrusion equipment pass through a die and a second extruder, forming a double-layer hollow plastic plate with one smooth surface layer;

And cutting and stacking the formed double-layer vacuum plastic plate by an operator.

Through adopting above-mentioned technical scheme, through adjusting the duty ratio of powder raw materials and granule raw materials to put into corresponding extrusion equipment respectively with the powder, first extrusion equipment extrudes the cavity sheet layer, and the second extrusion equipment extrudes the surface layer, and first extrusion equipment and second extrusion equipment mutually support, extrude the melting raw materials simultaneously, make two kinds of melting raw materials form the double-deck cavity plastic board that has one side to be smooth surface layer in the second extruder, be convenient for produce the double-deck cavity plastic board.

In summary, the present application includes at least one of the following beneficial technical effects:

1. Through setting up first extrusion equipment and second extrusion equipment, hollow sheet layer is extruded to first extrusion equipment, and the surface layer is extruded to second extrusion equipment, and two kinds of molten raw materials form double-deck cavity in the second extruder and mould the board to be convenient for produce double-colored double-deck cavity and mould the board.

2. Through setting up unloading subassembly and metering component, unloading subassembly carries out again mix to the mixed raw materials after mixing and carries, improves the mixed degree of consistency that mixed raw materials got into in the first extruder to improve the degree of consistency of the colour of melting raw materials, metering component control gets into the quantity of two kinds of melting raw materials in the distributor, improves the roughness of double-deck cavity plastic slab, is convenient for produce smooth, the even double-deck cavity plastic slab of colour.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a production line of a co-extrusion hollow plastic plate with inorganic dust in one step according to an embodiment of the application.

FIG. 2 is a schematic diagram of a structure of another view of a production line for co-extruding hollow plastic panels with inorganic dust in one step according to an embodiment of the present application.

FIG. 3 is a schematic diagram of a partial structure of a material guiding assembly of an inorganic dust one-step co-extrusion hollow plastic plate production line according to an embodiment of the application.

FIG. 4 is a schematic view of a partial structure of a material guiding assembly of a one-step co-extrusion hollow plastic panel production line with inorganic dust according to another embodiment of the present application.

Reference numerals illustrate: 1. a first extrusion device; 11. a mixer; 12. a feeding machine; 13. a vibrator; 14. a blanking assembly; 141. a blanking frame; 142. a blanking screw; 143. discharging boxes; 15. a first extruder; 16. a vacuum dehumidifier; 2. a molding assembly; 21. a dispenser; 22. a mold; 23. a second extruder; 24. a cooling member; 25. a cutting member; 3. a metering assembly; 31. a delivery tube; 32. a metering pump; 4. a material guiding component; 41. a control switch; 42. a material guide plate; 43. a cooling member; 5. a recovery assembly; 51. a crusher; 52. a feed pipe; 53. a conveying member; 54. and (5) recovering the hopper.

Detailed Description

The application is described in further detail below with reference to fig. 1-4.

The embodiment of the application discloses a production line for co-extruding hollow plastic plates by using an inorganic dust one-step method.

Referring to fig. 1 and 2, an inorganic dust one-step method co-extrusion hollow plastic plate production line, a first extrusion device 1 and a second extrusion device, wherein the first extrusion device 1 comprises a mixer 11, a feeder 12, a blanking assembly 14 and a first extruder 15 which are sequentially arranged, the mixer 11, the feeder 12, the blanking assembly 14 and the first extruder 15 are sequentially communicated, the mixer 11 is a high-speed mixer 11, the mixer 11 is used for mixing powder raw materials and particle raw materials and then sending the mixed powder raw materials into the feeder 12, a vibrator 13 is arranged on the feeder 12, and the vibrator 13 is a high-frequency vibrator; the blanking assembly 14 comprises a blanking frame 141, at least two blanking screws 142 and a blanking drive connected with the blanking screws 142, in this embodiment, the two blanking screws 142 are arranged side by side, one end of the blanking frame 141 is welded and communicated with the feeder 12, the two blanking screws 142 are located in the blanking frame 141, the blanking drive is of a gear transmission structure and is used for driving the at least two blanking screws 142 to perform blanking, the blanking drive is not shown in the drawing, the blanking assembly 14 further comprises a blanking box 143, the bottom of the blanking box 143 is welded and communicated with the first extruder 15, and one side, close to the feeder 12, of the blanking frame 141 and the blanking box 143 is welded and communicated.

Referring to fig. 1 and 2, the first extruder 15 is a plastic extruder, the first extruder 15 is used for melting and mixing raw materials and conveying the raw materials into the molding assembly 2, and a vacuum dehumidifier 16 is arranged at one side of the first extruder 15. The first extruder 15 is kept away from the one end of feed machine 12 and is equipped with shaping subassembly 2, shaping subassembly 2 includes distributor 21, mould 22 and second extruder 23, the second extrusion equipment is the same with first extrusion equipment 1 structure, second extrusion equipment is not shown in the figure, first extruder 15 in the first extrusion equipment 1 and first extruder 15 in the second extrusion equipment all communicate with distributor 21, mould 22 is the cuboid form box that can hold the cavity of different melting raw materials respectively, distributor 21 is used for sending the melting raw materials in two first extruders 15 into the cavity that mould 22 corresponds, second extruder 23 and mould 22 keep away from the one end intercommunication of first extruder 15, second extruder 23 is the plastics extruder too, second extruder 23 extrudes two kinds of melting raw materials, form double-deck cavity plastic slab.

Referring to fig. 1 and 2, a metering assembly 3 is disposed between the first extruder 15 and the distributor 21, the metering assembly 3 includes a conveying pipe 31 and a metering pump 32, two ends of the conveying pipe 31 are respectively communicated with the first extruder 15 and the distributor 21, two ends of the conveying pipe 31 are respectively fixedly connected with the first extruder 15 and the distributor 21 through flanges, the metering pump 32 is communicated with the conveying pipe 31 through flanges, and the metering pump 32 meters molten raw materials extruded by the first extruder 15.

Referring to fig. 3 and 4, a material guiding assembly 4 is arranged in a material discharging box 143, the material guiding assembly 4 comprises a control switch 41, material guiding plates 42 and cooling pieces 43, the control switch 41 is located in the material discharging box 143 and located below a material discharging frame 141, the control switch 41 is a gate valve, the control switch 41 is used for closing or opening a material discharging channel between the material discharging box 143 and the first extruder 15 at regular time, the material guiding plates 42 are arranged below the control switch 41 and connected with the material discharging box 143, in the embodiment, the material guiding plates 42 are provided with two, the two material guiding plates 42 are symmetrically arranged, the material guiding plates 42 are inclined downwards near the center of the material discharging box 143, the cooling pieces 43 are connected with the material guiding plates 42, the cooling pieces 43 are used for cooling the material guiding plates 42, the cooling pieces 43 are water-cooling radiators, and moisture absorbing layers are adhered to the peripheral sides of the material guiding plates 42 and are drying plates.

Further, referring to fig. 3 and 4, the molding assembly 2 further includes a cooling component 24 and a cutting component 25, the cooling component 24 is used for cooling and shaping the hollow plastic plate extruded by the second extruder 23, the cooling component 24 is a box body provided with an air cooling machine, the cutting component 25 is used for cutting the hollow plastic plate, and the cutting component 25 includes a cutting knife driven by an air cylinder to lift and a chain plate type conveying belt located below the cutting knife.

Specifically, referring to fig. 3 and 4, a recovery assembly 5 is further disposed at one side of the blanking box 143, and the recovery assembly 5 is used for crushing and recovering the leftover materials of the cut hollow plastic plate. The recycling assembly 5 comprises a crusher 51, a feeding pipe 52, a conveying piece 53 and a recycling hopper 54, wherein the crusher 51 is arranged on one side of a blanking box 143, the crusher 51 is used for crushing leftover materials of a hollow plastic plate into powder, two ends of the feeding pipe 52 are respectively communicated with the blanking box 143 and the crusher 51 in a welding mode, the conveying piece 53 is positioned in the feeding pipe 52, the conveying piece 53 is a screw conveyor, the conveying piece 53 is used for conveying crushed powder raw materials into the blanking box 143, and the recycling hopper 54 is welded above the crusher 51 and communicated with the crusher 51.

The implementation principle of the production line for co-extruding the hollow plastic plates by the inorganic dust one-step method in the embodiment of the application is as follows: through setting up first extrusion equipment 1 and second extrusion equipment, realize the one-step method and extrude altogether, add corresponding powder raw materials and granule raw materials in the extrusion equipment that corresponds, carry cavity lamellar fusion powder and superficial layer fusion powder respectively in distributor 21, and carry out the measurement to required fusion powder through metering pump 32, when the extrusion fusion powder of second extruder 23 produces double-deck cavity and mould the board, the planarization of cavity mould the board, and when the transportation of powder raw materials and granule raw materials, keep apart through control switch 41 and the cooling of heat conduction board, reduce the powder raw materials that the powder raw materials is stained with and is adhered to on the heat conduction board or the powder raw materials that leads to on unloading screw 142 lacks, thereby lead to the uneven problem production of double-deck cavity plastics colour, thereby be convenient for produce smooth, the even double-deck cavity of colour and mould the board.

In addition, the application also discloses a production method of the production process of the inorganic dust one-step co-extrusion hollow plastic plate, which comprises the following steps:

Placing the powder raw material and the particle raw material in a mixer 11 of the first extrusion device 1 and a mixer 11 of the second extrusion device respectively according to the proportion;

The ratio of the powder raw material to the particle raw material is 1:0.7-0.3, and in the embodiment, 1:0.5;

the first extrusion equipment 1 is filled with hollow slab powder, and the second extrusion equipment is filled with surface layer powder;

After the molten raw material in the first extrusion device 1 and the molten raw material in the second extrusion device pass through the die 22 and the second extruder 23, a double-layer hollow plastic plate with one smooth surface layer is formed;

And cutting and stacking the formed double-layer vacuum plastic plate by an operator.

Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this application belongs. The terms "first," "second," "third," and the like in the description and in the claims, are not used for any order, quantity, or importance, but are used for distinguishing between different elements. The terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one. The word "comprising" or "comprises", and the like, is intended to mean that elements or items that are present in front of "comprising" or "comprising" are included in the word "comprising" or "comprising", and equivalents thereof, without excluding other elements or items. "upper", "lower", "left", "right", etc. are used merely to denote relative positional relationships, which may also change accordingly when the absolute position of the object to be described changes.

The foregoing are all optional embodiments of the present application, and are not intended to limit the scope of the present application in this way, therefore: all equivalent changes in structure, shape and principle of the application should be covered in the scope of protection of the application.

Claims (10)

1. Inorganic dust one-step method is crowded cavity and is moulded board production line altogether, its characterized in that: the first extrusion device (1) and the second extrusion device, the first extrusion device (1) comprises a mixer (11), a feeder (12), a blanking component (14) and a first extruder (15) which are sequentially arranged, the mixer (11), the feeder (12), the blanking component (14) and the first extruder (15) are all sequentially communicated, the mixer (11) is used for mixing powder raw materials and particle raw materials and then feeding the mixed raw materials into the feeder (12), the blanking component (14) comprises a blanking frame (141) and at least two blanking screws (142) and a blanking drive connected with the blanking screws (142), one end of the blanking frame (141) is communicated with the feeder (12), the at least two blanking screws (142) are positioned in the blanking frame (141), one end of the blanking frame (141) far away from the feeder (12) is communicated with the first extruder (15), the first extruder (15) is used for melting and conveying the mixed raw materials into the first extruder (2) and further away from the first extruder (22), one end of the blanking frame (142) is provided with the first extruder (2) and one end of the blanking component (22) is far away from the first extruder (2), the first extruder (2) is provided with a molding device (23), the first extruders (15) in the first extrusion equipment (1) and the first extruders (15) in the second extrusion equipment are both communicated with the distributor (21), the distributor (21) is used for feeding molten raw materials in the two first extruders (15) into the die (22), the second extruder (23) is communicated with one end, far away from the first extruders (15), of the die (22), and the second extruder (23) extrudes the two molten raw materials to form a double-layer hollow plastic plate.

2. The inorganic dust one-step method co-extrusion hollow plastic plate production line according to claim 1, wherein: the blanking assembly (14) further comprises a blanking box (143), the bottom of the blanking box (143) is communicated with the first extruder (15), and the blanking frame (141) is communicated with one side, close to the feeding machine (12), of the blanking box (143).

3. The inorganic dust one-step method co-extrusion hollow plastic plate production line according to claim 2, wherein: be equipped with guide subassembly (4) in unloading case (143), guide subassembly (4) are including control switch (41), stock guide (42) and cooling piece (43), control switch (41) are located unloading case (143) and are located unloading frame (141) below, control switch (41) are used for closing or opening the unloading passageway between unloading case (143) and first extruder (15) regularly, stock guide (42) are located control switch (41) below and are connected with unloading case (143), cooling piece (43) are connected with stock guide (42), cooling piece (43) are used for cooling down stock guide (42).

4. The inorganic dust one-step method co-extrusion hollow plastic plate production line according to claim 1, wherein: the molding assembly (2) further comprises a cooling component (24) and a cutting component (25), the cooling component (24) is used for cooling and shaping the hollow plastic plate extruded by the second extruder (23), and the cutting component (25) is used for cutting the hollow plastic plate.

5. The inorganic dust one-step method co-extrusion hollow plastic plate production line according to claim 1, wherein: the metering device is characterized in that metering components (3) are arranged between the first extruder (15) and the distributor (21), each metering component (3) comprises a conveying pipe (31) and a metering pump (32), two ends of each conveying pipe (31) are respectively communicated with the first extruder (15) and the distributor (21), each metering pump (32) is communicated with the conveying pipe (31), and the metering pumps (32) meter molten raw materials extruded by the first extruder (15).

6. The inorganic dust one-step method co-extrusion hollow plastic plate production line according to claim 2, wherein: one side of the discharging box (143) is also provided with a recovery component (5), and the recovery component (5) is used for crushing and recovering the cut leftover materials of the hollow plastic plate.

7. The inorganic dust one-step method co-extrusion hollow plastic plate production line according to claim 6, wherein: retrieve subassembly (5) including breaker (51), conveying pipe (52), conveying piece (53) and retrieve fill (54), in unloading case (143) one side is located to breaker (51), breaker (51) are used for the leftover bits broken into powder with cavity plastic slab, the both ends of conveying pipe (52) are respectively with unloading case (143) and breaker (51) intercommunication, conveying piece (53) are located conveying pipe (52), conveying piece (53) are used for carrying the powder raw materials after the breakage to unloading incasement (143), retrieve fill (54) and locate breaker (51) top and breaker (51) intercommunication.

8. The inorganic dust one-step method co-extrusion hollow plastic plate production line according to claim 1, wherein: and a vibrator (13) is arranged on the feeding machine (12).

9. The inorganic dust one-step method co-extrusion hollow plastic plate production line according to claim 1, wherein: one side of the first extruder (15) is provided with a vacuum dehumidifier (16).

10. A process for producing a co-extrusion hollow plastic plate by using inorganic dust in one step, which is used for the production line of the co-extrusion hollow plastic plate by using the inorganic dust in one step as claimed in any one of claims 1 to 9, and is characterized in that the production method is as follows:

respectively placing the powder raw material and the particle raw material in a mixer (11) of the first extrusion equipment (1) and a mixer (11) of the second extrusion equipment according to the proportion;

the ratio of the powder raw material to the particle raw material is 1:0.7-0.3;

the first extrusion equipment (1) is filled with hollow slab powder, and the second extrusion equipment is filled with surface layer powder;

after the molten raw material in the first extrusion equipment (1) and the molten raw material in the second extrusion equipment pass through a die (22) and a second extruder (23), forming a double-layer hollow plastic plate with one smooth surface layer;

And cutting and stacking the formed double-layer vacuum plastic plate by an operator.