Multilayer coextruded product biaxial stretching line

Abstract

The application relates to the field of plastic processing, in particular to a bidirectional stretching production line for a multilayer co-extrusion product, which comprises a base, a blowing device, a stretching assembly and a conveying assembly, blowing stations and stretching stations are arranged on the surface of the base at intervals, the blowing device comprises an extruder, a die head and a blowing assembly, the blowing assembly is connected to the surface of the base facing the blowing stations, the feeding end of the die head is connected to the discharging end of the extruder, the discharging end of the die head faces the feeding end of the blowing assembly, the stretching assembly is connected to the surface of the base, the conveying assembly comprises a conveying base, a moving plate and a mechanical hand, the conveying base is connected to the surface of the base, the moving plate is slidingly connected to the surface of the conveying base, and the mechanical hand is connected to the surface of the moving plate. In the application, the base, the blowing device, the stretching assembly and the conveying assembly are arranged, the transparency of a multilayer bottle body is improved through bidirectional stretching treatment of a bottle embryo, the mechanical strength of the multilayer bottle body is improved, the multilayer bottle body is not easy to break when falling during use, and the quality of the formed multilayer bottle body is improved.

Description

Technical Field

[0001] This application relates to the field of plastics processing, and in particular to a biaxial stretching production line for multilayer co-extrusion products. Background Technology

[0002] Multi-layer bottles are containers made of multiple layers of different materials through processes such as co-extrusion, injection molding, or blow molding. When manufacturing multi-layer bottles using blow molding, the rubber material in the extruder is processed into plastic tubes through the die head, and the plastic tubes are placed into the blow mold to form multi-layer bottles.

[0003] However, during the blow molding process of plastic round tubes in the blow molding mold, the plastic round tubes only undergo one lateral stretching, resulting in low transparency of the formed multi-layer bottle. The multi-layer bottle is prone to cracking when dropped during use, thus resulting in poor quality of the formed multi-layer bottle. Summary of the Invention

[0004] To improve the quality of multi-layer bottles, this application provides a biaxial stretching production line for multi-layer co-extrusion products.

[0005] This application provides a biaxial stretching production line for multi-layer co-extrusion products, which adopts the following technical solution: A biaxial stretching production line for multi-layer co-extrusion products includes a base, a blow molding device, a stretching assembly, and a transport assembly. The base surface is provided with blow molding stations and stretching stations spaced apart. The blow molding device includes an extruder, a die, and a blow molding assembly. The blow molding assembly is connected to the base surface facing the blow molding stations. The die's inlet end is connected to the extruder's outlet end, with the outlet end facing the blow molding assembly's inlet end. The extruded material passes through the die to form a cylindrical tube and enters the blow molding assembly. The blow molding assembly can blow mold the cylindrical tube to form a preform. The stretching assembly is connected to the base. Facing the stretching station, the stretching assembly is capable of vertically stretching and blow molding the preform. The transport assembly includes a transport seat, a moving plate, and a robot arm. The transport seat is connected to the base surface, the moving plate is slidably connected to the transport seat surface, and the robot arm is connected to the surface of the moving plate facing the feed end of the stretching assembly. When the moving plate approaches the blow molding station along the transport seat surface, the gripping end of the robot arm can grip the end of the preform formed in the blow molding assembly. When the moving plate approaches the stretching station along the transport seat surface, the gripping end of the robot arm clamps the preform and embeds it into the stretching assembly.

[0006] By adopting the above technical solution, during the production of multi-layer bottles, the rubber material in the extruder is formed into a round tube through the die and embedded in the blow molding assembly. The blow molding assembly blow molds the round tube to form a preform, realizing the lateral stretching process of the round tube. The moving plate moves along the transport seat to the blow molding station, and the robotic arm grips the end of the preform formed in the blow molding assembly. The moving plate moves along the transport seat to the stretching station, and the robotic arm grips the end of the preform and embeds it in the stretching assembly. The stretching assembly vertically stretches and blow molds the preform, realizing the vertical stretching process of the preform. By performing bidirectional stretching treatment on the preform, the transparency of the multi-layer bottle is improved, the mechanical strength of the multi-layer bottle is increased, and the multi-layer bottle is less likely to crack when dropped during use, thereby improving the quality of the formed multi-layer bottle.

[0007] Optionally, the blow molding assembly includes a blow molding base, a blow molding plate, a power cylinder, and two blow molding modules. The blow molding base is slidably connected to the surface of the base, and the sliding direction of the blow molding base is perpendicular to the sliding direction of the moving plate. The power cylinder is connected to the surface of the blow molding base, and the axis of the piston rod of the power cylinder is parallel to the sliding direction of the blow molding base, with the end of the piston rod facing the mold head. The blow molding plate is connected to the piston rod surface of the power cylinder. One of the blow molding modules is connected to the surface of the blow molding plate, and the other blow molding module is connected to the surface of the blow molding base facing the blow molding plate. When the piston rod of the power cylinder extends, the two blow molding modules close to form a cavity for blow molding, and the cavity opening faces the material outlet end of the mold head.

[0008] By adopting the above technical solution, during preform production, the piston rod of the power cylinder extends, and the two blow molding modules close to form a cavity for injection molding, with the cavity opening facing the die head discharge end. The extruded material in the extruder passes through the die head to form a round tube and enters the cavity. The round tube is blow molded in the cavity to form a preform. The moving plate moves along the surface of the transport seat to the blow molding station. The robot arm clamps the end of the preform blow-molded in the cavity, and the piston rod of the power cylinder retracts, driving one blow molding module away from the other blow molding module. At the same time, it pushes the blow molding seat, driving the blow molding module fixed on the blow molding seat away from the preform, realizing automatic demolding of the preform without the need for manual demolding by the operator, thereby improving the production efficiency of multi-layer bottles.

[0009] Optionally, the blow molding module includes a heating section and at least two cooling sections. The at least two cooling sections are connected one-to-one to the two ends of the heating section to form the blow molding module. The heating section is provided with a heating channel for hot water to flow through, and the cooling section is provided with a cooling channel for cold water to flow through. The heating section surrounds the bottle body of the preform, one of the cooling sections surrounds the bottle mouth of the preform, and the other cooling section surrounds the bottle bottom of the preform.

[0010] By adopting the above technical solution, two cooling sections are connected one-to-one to the two ends of the heating section to form a blow molding module. Cooling water cools the cooling section through the cooling channel, accelerating the cooling and forming of the bottle preform's mouth and bottom. At the same time, hot water heats the heating section through the heating channel, making the temperature of the bottle preform in the heating section meet the blow molding conditions. This facilitates the stretching component to vertically stretch and blow mold the bottle preform, eliminating the need for further heating of the bottle preform, reducing the processing steps for multi-layer bottles, shortening the processing cycle for multi-layer bottles, and thus reducing the processing cost of multi-layer bottles.

[0011] Optionally, a threaded groove is provided on the inner wall of the cavity near the cooling part of the die head, and the inner wall of the threaded groove can compress the outer peripheral surface of the bottle preform to form threads.

[0012] By adopting the above technical solution, when the two blow molding modules are closed to form a cavity, and the round tube is blow molded in the cavity, the inner wall of the threaded groove squeezes the outer circumferential surface of the bottle preform to form threads, so that the threading is completed at the same time as the round tube is blow molded to form the bottle preform, thereby further improving the processing efficiency of multi-layer bottles.

[0013] Optionally, the stretching assembly includes a stretching seat, a stretching plate, a lifting seat, a lifting plate, a stretching rod, and two stretching modules. The stretching seat is slidably connected to the surface of the base facing the stretching station, and the sliding direction of the stretching seat is parallel to the sliding direction of the blow molding seat. The stretching plate is slidably connected to the surface of the stretching seat, and the sliding direction of the stretching plate is parallel to the sliding direction of the stretching seat. One stretching module is connected to the surface of the stretching plate facing the moving plate, and the other stretching module is connected to the surface of the stretching seat facing the stretching plate. When the two stretching modules are closed, they form a cavity for blow molding, and the cavity opening faces the surface of the moving plate. The lifting seat is connected to the surface of the base, and the lifting plate is slidably connected to the surface of the lifting seat facing the cavity. One end of the stretching rod is connected to the surface of the stretching plate facing the cavity, and the other end of the stretching rod can be embedded in the inner cavity of the preform in the cavity and abut against the bottom of the preform.

[0014] By adopting the above technical solution, when the robot arm grips the end of the preform in the cavity, the moving plate moves along the surface of the transport seat to approach the stretching station. The preform gripped by the robot arm is located between two stretching modules. The stretching seat moves along the surface of the base to approach the preform. The inner cavity of the stretching module fixed on the stretching seat covers the surface of the preform. At the same time, the stretching plate is pushed along the stretching seat to approach the preform. The two stretching modules close to form a cavity. The lifting plate moves along the surface of the lifting seat to approach the cavity. The lifting plate drives the end of the stretching rod to embed into the inner cavity of the preform in the cavity and abut against the bottom of the preform. During the blow molding process of the preform in the cavity, the end face of the stretching rod abuts against the bottom of the preform and moves away from the mouth of the preform, realizing the vertical stretching of the preform. This completes the bidirectional stretching molding of the preform, improves the transparency of the multi-layer bottle, enhances the mechanical strength of the multi-layer bottle, and ensures that the multi-layer bottle is not easy to crack when dropped during use, thereby improving the quality of the molded multi-layer bottle.

[0015] Optionally, the stretching assembly further includes a top block connected to the surface of the base facing the stretching station. The top block is located between two stretching modules. The surface of each stretching module has a positioning cavity for the end of the top block to be embedded. When the two stretching modules are closed to form a chamber, the inner wall of the positioning cavity covers the outer peripheral surface of the top block to form a seal. The end face of the top block facing the chamber has a buffer surface that matches the bottom surface of the multi-layer bottle.

[0016] By adopting the above technical solution, when the robot arm holds the bottle preform between the two stretching modules, it pushes the stretching seat closer to the bottle preform. The inner cavity of the stretching module fixed on the stretching seat covers the surface of the bottle preform, and the inner wall of the positioning cavity abuts against the outer peripheral surface of the top block to form a positioning. At the same time, it pushes the stretching plate along the stretching seat closer to the bottle preform. The two stretching modules close to form a cavity, and the inner wall of the positioning cavity abuts against the outer peripheral surface of the top block to form a seal, thereby achieving precise positioning of the sliding distance of the stretching seat on the base surface.

[0017] Optionally, the end face of the tension rod facing the cavity is provided with a guide surface that matches the buffer surface. When the end of the tension rod is embedded in the inner cavity of the preform and abuts against the bottom of the preform, the guide surface abuts against the bottom of the preform and guides the bottom of the preform to approach the buffer surface. The buffer surface and the guide surface abut against both sides of the bottom of the preform and guide the preform to deform.

[0018] By adopting the above technical solution, when the end of the tension rod is embedded in the inner cavity of the preform and abuts against the bottom of the preform, the guide surface abuts against the bottom of the preform and guides the bottom of the preform to approach the buffer surface. The buffer surface and the guide surface abut against both sides of the bottom of the preform and guide the deformation of the bottom of the preform, preventing the end of the tension rod from penetrating the bottom of the preform, thereby improving the yield of multi-layer bottles.

[0019] Optionally, multiple chambers and cavities are provided, and multiple robotic arms are provided. The multiple robotic arms are divided into two groups, and the two groups of robotic arms are connected to the moving plate surface at intervals. The arrangement direction of multiple robotic arms in the same group is parallel to the moving direction of the moving plate. When multiple robotic arms in one group correspond one-to-one with the cavities, multiple robotic arms in the other group correspond one-to-one with the chambers.

[0020] By adopting the above technical solution, when the moving plate approaches the blow molding station along the transport seat, multiple robotic arms in one group correspond one-to-one with the cavity and clamp the end of the preform in the cavity, while multiple robotic arms in another group correspond one-to-one with the chamber and clamp the end of the multi-layer bottle in the cavity. When the moving plate approaches the stretching station along the transport seat, multiple robotic arms in one group clamp the preform and embed it between the two stretching modules, while multiple robotic arms in another group clamp the end of the multi-layer bottle and move away from the stretching station, thereby realizing the automatic unloading of multi-layer bottles on the stretching station and improving the degree of automation in the processing of multi-layer bottles.

[0021] Optionally, the stretching assembly further includes a stretching cylinder and a lifting cylinder. The stretching cylinder is connected to the surface of the stretching seat facing the stretching plate. The piston rod axis of the stretching cylinder and the sliding direction of the stretching seat are parallel to each other. The end face of the piston rod of the stretching cylinder is connected to the surface of the stretching plate. When the piston rod of the stretching cylinder extends, the stretching plate approaches the top block, and the top block is embedded in the positioning cavity. The lifting cylinder is connected to the surface of the lifting seat. The end of the piston rod of the lifting cylinder passes through the surface of the lifting seat and is connected to the surface of the lifting plate. When the piston rod of the lifting cylinder extends, the lifting plate approaches the lifting module, and the end of the stretching rod is embedded in the preform cavity located in the chamber and abuts against the bottom of the preform.

[0022] By adopting the above technical solution, when the piston rod of the stretching cylinder extends, it pushes the stretching plate along the stretching seat to approach the top block, and the two stretching modules close to form a cavity, and the inner wall of the positioning cavity abuts against the outer peripheral surface of the top block to form a seal; when the piston rod of the lifting cylinder extends, the lifting plate along the lifting seat approaches the stretching module, driving the end of the stretching rod to embed into the inner cavity of the preform located in the cavity and abut against the bottom wall of the preform, so as to achieve precise control of the sliding distance of the stretching plate and the lifting plate.

[0023] Optionally, the surface of the stretching seat facing the stretching plate is connected to a slide rail, and the surface of the stretching plate is provided with a slide track for the slide rail to slide.

[0024] By adopting the above technical solution, when the stretching cylinder pushes the stretching plate to slide on the surface of the stretching seat, the slide rail slides on the inner wall of the slide, making the stretching plate less prone to displacement, thereby improving the stability of the two stretching modules when closing the mold.

[0025] In summary, this application includes at least one of the following beneficial technical effects: The setup of the base, blow molding device, stretching assembly, and transport assembly improves the transparency of the multi-layer bottle by bidirectional stretching of the preform, enhances the mechanical strength of the multi-layer bottle, and ensures that the multi-layer bottle is not easily cracked when dropped during use, thereby improving the quality of the molded multi-layer bottle. The setup of the blow molding base, blow molding plate, power cylinder and blow molding module drives the blow molding module fixed on the blow molding base away from the preform, realizing automatic demolding of the preform without the need for manual demolding by the staff, thereby improving the production efficiency of multi-layer bottles. The inclusion of heating and cooling sections facilitates vertical stretching and blow molding of the preform by the stretching assembly, eliminating the need for further heating of the preform. This reduces the processing steps for multi-layer bottles, shortens the processing cycle, and thus lowers the processing cost of multi-layer bottles. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure in the embodiments of this application.

[0027] Figure 2 This is a schematic diagram of the overall structure of the blow molding device in the embodiments of this application.

[0028] Figure 3 This is a schematic diagram of the overall structure of the stretching component and the transport component in the embodiments of this application.

[0029] Figure 4 This is a partial cross-sectional view of an embodiment of this application, mainly showing the guide surface and the buffer surface.

[0030] Explanation of reference numerals in the attached drawings: 1. Base; 2. Blow molding device; 21. Extruder; 22. Die head; 23. Blow molding assembly; 231. Blow molding seat; 232. Blow molding plate; 233. Power cylinder; 234. Blow molding module; 2341. Heating section; 2342. Cooling section; 2343. Heating channel; 2344. Cooling channel; 2345. Threaded groove; 2346. Cavity; 3. Stretching assembly; 31. Stretching 32. Seat; 321. Stretching plate; 33. Slide rail; 34. Lifting seat; 35. Lifting plate; 36. Stretching rod; 37. Guide surface; 38. Top block; 39. Buffer surface; 30. Stretching cylinder; 31. Lifting cylinder; 32. Stretching module; 33. Positioning cavity; 34. Chamber; 5. Transport assembly; 6. Transport seat; 7. Moving plate; 8. Robotic arm; 9. Preform; 10. Round tube; 11. Slide rail. Detailed Implementation

[0031] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail.

[0032] This application discloses a biaxial stretching production line for multilayer co-extrusion products. (Refer to...) Figure 1The biaxial stretching production line for multi-layer co-extrusion products includes a base 1, a blow molding device 2, a stretching assembly 3, and a transport assembly 4. The base 1 has blow molding and stretching stations spaced apart at both ends along its length. The blow molding device 2 is installed on the surface of the base 1 facing the blow molding station and can laterally blow-mold the rubber compound to form a preform 5. The stretching assembly 3 is installed on the surface of the base 1 facing the stretching station and can vertically stretch and blow-mold the preform 5 to form a multi-layer bottle. The transport assembly 4 is installed on the surface of the base 1 and can clamp the preform 5 from the blow molding device 2 and embed it into the stretching assembly 3. Simultaneously, it clamps the multi-layer bottle on the stretching assembly 3 away from the stretching station, achieving automated blow molding of the multi-layer bottle. The biaxial stretching treatment of the preform 5 improves the transparency and mechanical strength of the multi-layer bottle, ensuring it is less prone to cracking when dropped during use, thus improving the quality of the formed multi-layer bottle.

[0033] Reference Figure 1 and Figure 2 The blow molding device 2 includes an extruder 21, a die 22, and a blow molding assembly 23. The blow molding assembly 23 is mounted on the surface of the base 1 facing the blow molding station. The feed end of the die 22 is fixed to the discharge end of the extruder 21 by bolts, and the discharge end of the die 22 faces the feed end of the blow molding assembly 23. The rubber material in the extruder 21 passes through the die 22 to form a round tube 6 and is embedded in the blow molding assembly 23. The blow molding assembly 23 performs transverse blow molding on the round tube 6 to form a preform 5. The blow molding assembly 23 includes blow molding... The assembly includes a base 231, a blow molding plate 232, a power cylinder 233, and two blow molding modules 234. The blow molding base 231 is slidably connected to the surface of the base 1. The sliding direction of the blow molding base 231 is parallel to the width direction of the base 1. The power cylinder 233 is fixed to the surface of the blow molding base 231 by bolts. The piston rod axis of the power cylinder 233 is parallel to the width direction of the base 1. The end of the piston rod of the power cylinder 233 faces the mold head 22 and is fixed to the surface of the blow molding plate 232 by bolts.

[0034] Reference Figure 1 and Figure 2The blow molding module 234 includes a heating section 2341 and two cooling sections 2342. The two cooling sections 2342 are fixed to the two ends of the heating section 2341 respectively to form the blow molding module 234. The heating section 2341 is provided with a heating channel 2343. The mold temperature controller supplies hot water to the heating channel 2343. The cooling section is provided with a cooling channel 2344. The mold temperature controller supplies cold water to the cooling channel 2344. One blow molding module 234 is fixed to the surface of the blow molding plate 232 facing the mold head 22, and the other blow molding module 234 is fixed to the surface of the blow molding base 231 facing the blow molding plate 232. When the piston rod of the power cylinder 233 extends, the two blow molding modules 234 close to form a cavity 2346 for blow molding of the round tube 6. The cavity 2346 opening faces the discharge end of the mold head 22 and allows the round tube 6 on the mold head 22 to be embedded.

[0035] Reference Figure 1 and Figure 2 The number of cavities 2346 can be one, two or more. In this embodiment, there are two cavities 2346. The arrangement direction of the two cavities 2346 is parallel to the length direction of the base 1. The cooling part 2342 near the mold head 22 is provided with a threaded groove 2345 facing the inner wall of the cavity 2346. The inner wall of the threaded groove 2345 can squeeze the outer peripheral surface of the bottle mouth of the bottle preform 5 in the cavity 2346 to form threads.

[0036] Reference Figure 1 and Figure 2 When the round tube 6 on the die head 22 is embedded in the cavity 2346, the round tube 6 is blow-molded in the cavity 2346 to form a preform 5. The heating part 2341 surrounds the body of the preform 5 in the cavity 2346, and one cooling part 2342 surrounds the mouth of the preform 5 and the other cooling part 2342 surrounds the bottom of the preform 5. The mold temperature controller pushes cold water through the cooling channel 2344 to cool the cooling part 2342, accelerating the cooling and molding of the mouth and bottom of the preform 5. At the same time, the mold temperature controller pushes hot water through the heating channel 2343 to heat the heating part 2341, so that the temperature of the body of the preform 5 in the heating part 2341 meets the blow molding conditions, thus facilitating the stretching component 3 to perform vertical stretch blow molding of the preform 5 without further heating of the preform 5, reducing the processing steps of multi-layer bottles, shortening the processing cycle of multi-layer bottles, and thus reducing the processing cost of multi-layer bottles.

[0037] Reference Figure 1 and Figure 3The stretching assembly 3 includes a stretching seat 31, a stretching plate 32, a lifting seat 33, a lifting plate 34, a stretching rod 35, a top block 36, a stretching cylinder 37, a lifting cylinder 38, and two stretching modules 39. The stretching seat 31 is slidably connected to the surface of the base 1 facing the stretching station. The sliding direction of the stretching seat 31 is parallel to the width direction of the base 1. The stretching cylinder 37 is fixed to the surface of the stretching seat 31 facing the stretching plate 32 by bolts. The piston rod axis of the stretching cylinder 37 is parallel to the width direction of the base 1. The end of the piston rod of the stretching cylinder 37 is fixed to the surface of the stretching plate 32 by bolts. The stretching cylinder 37 drives the stretching plate 32 to slide on the surface of the stretching seat 31. A slide rail 7 is fixed to the surface of the stretching seat 31 facing the stretching plate 32 by bolts. A slide rail 321 for the slide rail 7 to slide is opened on the surface of the stretching plate 32.

[0038] Reference Figure 1 and Figure 3 When the stretching cylinder 37 drives the stretching plate 32 to slide, it drives the slide rail 7 to slide on the inner wall of the slide rail 321, making it less likely for the stretching plate 32 to deviate when sliding on the surface of the stretching seat 31, thereby improving the stability of the stretching plate 32 sliding.

[0039] Reference Figure 1 and Figure 3 One of the stretching modules 39 is fixed to the surface of the stretching plate 32 away from the stretching cylinder 37, and the other stretching module 39 is fixed to the surface of the stretching seat 31 facing the stretching plate 32. When the piston rod of the stretching cylinder 37 extends, the two stretching modules 39 close to form a cavity 392 for blow molding of the preform 5 into a multi-layer bottle. The number of cavities 392 can be one, two or more. In this embodiment, the number of cavities 392 is two, and the arrangement direction of the two cavities 392 is parallel to the length direction of the base 1.

[0040] Reference Figure 3 and Figure 4 The number of top blocks 36 can be one, two or more. In this embodiment, there are two top blocks 36. The two top blocks 36 are fixed at intervals on the surface of the base 1 facing the stretching station. The top blocks 36 correspond one-to-one with the chambers 392. The end faces of the two stretching modules 39 facing each other have positioning cavities 391 for the ends of the top blocks 36 to be embedded. When the two stretching modules 39 are closed to form the chamber 392, the inner wall of the positioning cavity 391 covers the outer peripheral surface of the top block 36 to form a seal. The end face of the top block 36 facing the chamber 392 is provided with a buffer surface 361. The buffer surface 361 matches the bottom surface of the multi-layer bottle and can abut against the bottom of the multi-layer bottle to form support.

[0041] Reference Figure 3 and Figure 4The lifting seat 33 is fixed to the surface of the base 1 by bolts, and the lifting cylinder 38 is fixed to the top surface of the lifting seat 33 by bolts. The piston rod axis of the lifting cylinder 38 is parallel to the height direction of the base 1. The end of the piston rod of the lifting cylinder 38 passes through the surface of the lifting seat 33 and is fixed to the surface of the lifting plate 34. The lifting cylinder 38 drives the lifting plate 34 to slide on the surface of the lifting seat 33. The lifting plate 34 faces away from the plate surface of the lifting cylinder 38 and towards the chamber 392.

[0042] Reference Figure 3 and Figure 4 The number of tension rods 35 can be one, two, or more. In this embodiment, there are two tension rods 35. One end of each tension rod 35 is fixed at a distance from the surface of the tension plate 32 facing the chamber 392. Each tension rod 35 corresponds to a chamber 392. The end of each tension rod 35 can be embedded into the inner cavity of the preform 5 located in the chamber 392 and abut against the bottom of the preform 5. The end face of the tension rod 35 facing the chamber 392 is provided with a guide surface 351 that matches the buffer surface 361. When the end of the tension rod 35 is embedded into the inner cavity of the preform 5 and abuts against the bottom of the preform 5, the guide surface 351 abuts against the bottom of the preform 5 and guides the bottom of the preform 5 to approach the buffer surface 361. The guide surface 351 and the buffer surface 361 abut against both sides of the bottom of the preform 5 and guide the bottom of the preform 5 to deform, preventing the end of the tension rod 35 from penetrating the bottom of the preform 5, thereby improving the yield of multi-layer bottles.

[0043] Reference Figure 1 and Figure 3 The transport component 4 includes a transport seat 41, a movable plate 42, and a robot arm 43. The transport seat 41 is fixed to the surface of the base 1, and the movable plate 42 is slidably connected to the surface of the transport seat 41. The sliding direction of the movable plate 42 is parallel to the length direction of the base 1. The number of robot arms 43 can be one, two, or more. In this embodiment, the number of robot arms 43 is more than one. The multiple robot arms 43 are divided into two groups, and the two groups of robot arms 43 are fixed at intervals on the surface of the movable plate 42. The arrangement direction of the multiple robot arms 43 in the same group is parallel to the length direction of the base 1. When the multiple robot arms 43 in one group correspond one-to-one with the cavity 2346 and clamp the end of the bottle preform 5 in the cavity 2346, the multiple robot arms 43 in the other group correspond one-to-one with the chamber 392 and clamp the end of the multi-layer bottle body in the chamber 392.

[0044] Reference Figure 1 and Figure 3When the moving plate 42 approaches the blow molding station along the transport seat 41, one group of multiple robotic arms 43 corresponds one-to-one with the cavity 2346 and clamps the end of the preform 5 inside the cavity 2346, while another group of multiple robotic arms 43 corresponds one-to-one with the chamber 392 and clamps the end of the multi-layer bottle inside the cavity 2346. When the moving plate 42 approaches the stretching station along the transport seat 41, one group of multiple robotic arms 43 clamps the preform 5 and embeds it between the two stretching modules 39, while the other group of multiple robotic arms 43 clamps the end of the multi-layer bottle and moves away from the stretching station, realizing automatic unloading of multi-layer bottles at the stretching station, thereby improving the degree of automation in the processing of multi-layer bottles. The implementation principle of a biaxial stretching production line for multi-layer co-extrusion products in this application embodiment is as follows: When producing multi-layer bottles, the rubber material in the extruder 21 forms a round tube 6 through the die head 22 and is embedded in the blow molding assembly 23. The blow molding assembly 23 blow molds the round tube 6 to form a preform 5, realizing the lateral stretching processing of the round tube 6. The moving plate 42 moves along the transport seat 41 to the blow molding station, and the gripper 43 clamps the end of the preform 5 formed in the blow molding assembly 23. The moving plate 42 moves along the transport seat 41 to the stretching station, and the gripper 43 clamps the end of the preform 5 and embeds it in the stretching assembly 3. The stretching assembly 3 performs vertical stretching blow molding on the preform 5, realizing the vertical stretching processing of the preform 5. By biaxially stretching the preform 5, the transparency of the multi-layer bottle is improved, the mechanical strength of the multi-layer bottle is improved, and the multi-layer bottle is less likely to crack when dropped during use, thereby improving the quality of the formed multi-layer bottle.

[0045] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A biaxial stretching production line for multi-layer co-extrusion products, characterized in that: The assembly includes a base (1), a blow molding device (2), a stretching assembly (3), and a transport assembly (4). The base (1) has blow molding stations and stretching stations spaced apart on its surface. The blow molding device (2) includes an extruder (21), a die (22), and a blow molding assembly (23). The blow molding assembly (23) is connected to the surface of the base (1) facing the blow molding station. The feed end of the die (22) is connected to the discharge end of the extruder (21), and the discharge end of the die (22) faces the feed end of the blow molding assembly (23). The rubber material in the extruder (21) passes through the die (22) to form a round tube (6) and enters the blow molding assembly (23). The blow molding assembly (23) can blow mold the round tube (6) to form a preform (5). The stretching assembly (3) is connected to the surface of the base (1) facing the stretching station. The stretching assembly (3) is capable of vertically stretching and blow molding the preform (5). The transport assembly (4) includes a transport seat (41), a moving plate (42), and a robot (43). The transport seat (41) is connected to the surface of the base (1). The moving plate (42) is slidably connected to the surface of the transport seat (41). The robot (43) is connected to the surface of the moving plate (42) facing the feeding end of the stretching assembly (3). When the moving plate (42) moves along the surface of the transport seat (41) towards the blow molding station, the gripping end of the robot (43) can grip the end of the preform (5) formed in the blow molding assembly (23). When the moving plate (42) moves along the surface of the transport seat (41) towards the stretching station, the gripping end of the robot (43) grips the preform (5) and embeds it into the stretching assembly (3).

2. The biaxial stretching production line for multi-layer co-extrusion products according to claim 1, characterized in that: The blow molding assembly (23) includes a blow molding base (231), a blow molding plate (232), a power cylinder (233), and two blow molding modules (234). The blow molding base (231) is slidably connected to the surface of the base (1). The sliding direction of the blow molding base (231) and the sliding direction of the moving plate (42) are perpendicular to each other. The power cylinder (233) is connected to the surface of the blow molding base (231). The piston rod axis of the power cylinder (233) is parallel to the sliding direction of the blow molding base (231), and the piston of the power cylinder (233) is parallel to the sliding direction of the blow molding base (231). The rod end faces the mold head (22), the blow molding plate (232) is connected to the piston rod surface of the power cylinder (233), one of the blow molding modules (234) is connected to the plate surface of the blow molding plate (232), and the other blow molding module (234) is connected to the surface of the blow molding seat (231) facing the blow molding plate (232). When the piston rod of the power cylinder (233) extends, the two blow molding modules (234) close to form a cavity (2346) for blow molding, and the cavity (2346) opening faces the discharge end of the mold head (22).

3. The biaxial stretching production line for multi-layer co-extrusion products according to claim 2, characterized in that: The blow molding module (234) includes a heating section (2341) and at least two cooling sections (2342). The at least two cooling sections (2342) are connected one-to-one to the two ends of the heating section (2341) to form the blow molding module (234). The heating section (2341) is provided with a heating channel (2343) for hot water to flow through, and the cooling section (2342) is provided with a cooling channel (2344) for cold water to flow through. The heating section (2341) surrounds the bottle body of the preform (5), one of the cooling sections (2342) surrounds the bottle mouth of the preform (5), and the other cooling section (2342) surrounds the bottle bottom of the preform (5).

4. The biaxial stretching production line for multi-layer co-extrusion products according to claim 3, characterized in that: The cooling section (2342) near the mold head (22) has a threaded groove (2345) on the inner wall facing the cavity (2346). The inner wall of the threaded groove (2345) can squeeze the outer peripheral surface of the bottle mouth of the preform (5) to form threads.

5. The biaxial stretching production line for multi-layer co-extrusion products according to claim 2, characterized in that: The stretching assembly (3) includes a stretching seat (31), a stretching plate (32), a lifting seat (33), a lifting plate (34), a stretching rod (35), and two stretching modules (39). The stretching seat (31) is slidably connected to the surface of the base (1) facing the stretching station. The sliding direction of the stretching seat (31) is parallel to the sliding direction of the blow molding seat (231). The stretching plate (32) is slidably connected to the surface of the stretching seat (31). The sliding direction of the stretching plate (32) is parallel to the sliding direction of the stretching seat (31). One of the stretching modules (39) is connected to the surface of the stretching plate (32) facing the moving plate (42), and the other... The stretching module (39) is connected to the stretching seat (31) facing the stretching plate (32). When the two stretching modules (39) are closed, they form a cavity (392) for blow molding. The cavity (392) opening faces the moving plate (42). The lifting seat (33) is connected to the surface of the base (1). The lifting plate (34) is slidably connected to the surface of the lifting seat (33) facing the cavity (392). One end of the stretching rod (35) is connected to the surface of the stretching plate (32) facing the cavity (392). The other end of the stretching rod (35) can be embedded in the cavity of the preform (5) in the cavity (392) and abut against the bottom of the preform (5).

6. The biaxial stretching production line for multi-layer co-extrusion products according to claim 5, characterized in that: The stretching assembly (3) also includes a top block (36), which is connected to the surface of the base (1) facing the stretching station. The top block (36) is located between two stretching modules (39). The surface of the stretching module (39) is provided with a positioning cavity (391) for the end of the top block (36) to be embedded. When the two stretching modules (39) are closed to form a cavity (392), the inner wall of the positioning cavity (391) covers the outer peripheral surface of the top block (36) to form a seal. The end face of the top block (36) facing the cavity (392) is provided with a buffer surface (361), which matches the bottom surface of the multi-layer bottle.

7. The biaxial stretching production line for multi-layer co-extrusion products according to claim 6, characterized in that: The end face of the tension rod (35) facing the cavity (392) is provided with a guide surface (351) that matches the buffer surface (361). When the end of the tension rod (35) is embedded in the inner cavity of the preform (5) and abuts against the bottom of the preform (5), the guide surface (351) abuts against the bottom of the preform (5) and guides the bottom of the preform (5) to approach the buffer surface (361). The buffer surface (361) and the guide surface (351) abut against both sides of the bottom of the preform (5) and guide the bottom of the preform (5) to deform.

8. The biaxial stretching production line for multi-layer co-extrusion products according to claim 5, characterized in that: The chamber (392) and the cavity (2346) are each provided with multiple robotic arms (43). The multiple robotic arms (43) are divided into two groups. The two groups of robotic arms (43) are connected to the surface of the moving plate (42) at intervals. The arrangement direction of the multiple robotic arms (43) in the same group is parallel to the movement direction of the moving plate (42). When the multiple robotic arms (43) in one group correspond one-to-one with the cavity (2346), the multiple robotic arms (43) in the other group correspond one-to-one with the chamber (392).

9. The biaxial stretching production line for multi-layer co-extrusion products according to claim 6, characterized in that: The stretching assembly (3) further includes a stretching cylinder (37) and a lifting cylinder (38). The stretching cylinder (37) is connected to the surface of the stretching seat (31) facing the stretching plate (32). The piston rod axis of the stretching cylinder (37) and the sliding direction of the stretching seat (31) are parallel to each other. The end face of the piston rod of the stretching cylinder (37) is connected to the surface of the stretching plate (32). When the piston rod of the stretching cylinder (37) extends, the stretching plate (32) approaches the top block (36). The top block (36) is embedded in the positioning cavity (391); the lifting cylinder (38) is connected to the surface of the lifting seat (33), the piston rod end of the lifting cylinder (38) passes through the surface of the lifting seat (33) and is connected to the surface of the lifting plate (34). When the piston rod of the lifting cylinder (38) extends, the lifting plate (34) approaches the lifting module, and the end of the tension rod (35) is embedded in the inner cavity of the preform (5) located in the chamber (392) and abuts against the bottom of the preform (5).

10. The biaxial stretching production line for multi-layer co-extrusion products according to claim 5, characterized in that: The surface of the stretching seat (31) facing the stretching plate (32) is connected to a slide rail (7), and the surface of the stretching plate (32) is provided with a slide rail (321) for the slide rail (7) to slide.

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