Preparation forming method and production line of low-viscosity high-elasticity regenerated PET (Polyethylene Terephthalate) slices

Abstract

The invention discloses a low-viscosity high-elasticity regenerated PET slice preparation forming method and a production line thereof, and relates to the technical field of regenerated PET slices. Comprising cleaning equipment, a crusher, an extruder, a cooling tank and a cutting machine, the cutting machine comprises a rack, a swing frame is arranged at one end of the rack, a drying mechanism is arranged above the swing frame, and a first rubber roller traction assembly, a second rubber roller traction assembly, a material conveying flat plate and a third rubber roller traction assembly are sequentially arranged above the rack; a feeding mechanism is arranged above the feeding flat plate, an upper cutter and a lower cutter are arranged on the side, away from the feeding flat plate, of the third rubber roller traction assembly, and a driven rubber roller is rotationally arranged in the rack. Strip-shaped rPET is stretched through the differential speed between the second rubber roller traction assembly and the third rubber roller traction assembly, elastic force detection is achieved, automatic material feeding can be conducted when materials are broken in cooperation with the material feeding mechanism, the front section and the rear section of the broken position are both collected in the waste box, and therefore the overall quality of rPET slices is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of recycled PET chips, in particular to a method for preparing and molding low-viscosity and high-elasticity recycled PET chips and a production line thereof. Background Art

[0002] Recycled PET is primarily produced through physical and chemical methods. The physical method, which melt-extrudes discarded PET bottle flakes into fibers or pellets, is a mature and low-cost method, but product performance may be limited. Chemical methods, through depolymerization, break down PET into monomers or oligomers, which are then repolymerized, enabling primary recycling and producing products with performance close to that of virgin PET. In recent years, the bio-enzymatic method has emerged as an emerging technology, utilizing enzymes to decompose PET under mild conditions. It offers advantages such as environmental friendliness and high efficiency, and is gradually moving towards commercialization.

[0003] In the production of recycled PET slices, specific slicing equipment is required, such as a PET slice production equipment and production process with patent publication number CN120134489A, which includes an integrated strip cold cutting component and a switching mesh cylinder. The integrated strip cold cutting component continuously extrude the polymer melt into strips. The PET slicing equipment of the present invention is provided with a switching mesh cylinder, which is arranged inside a horizontal cylinder. The inner wall of the switching mesh cylinder is provided with four screening zones, and the top of the horizontal cylinder is provided with a back-blowing component. During normal operation, only one screening zone of the switching mesh cylinder performs screening action. A positioning motor is provided on the rotating shaft of the switching mesh cylinder. When the mesh of one screening zone of the switching mesh cylinder is blocked, the positioning motor can drive the blocked screening zone of the switching mesh cylinder to move to the back-blowing component for self-cleaning without stopping the machine, avoiding production interruption caused by manual cleaning of the screen, greatly improving the continuity, automation level and production efficiency of the equipment, and the back-blowing component is used to quickly clean the screening zone. The production process of rPET (recycled PET) generally requires the use of cleaning equipment, crushers, extruders, cooling tanks and cutting machines. The materials are mixed at the feed end of the extruder and extruded in the extruder. However, the bottle flakes produced by the crusher are of different sizes, and it is difficult to ensure the uniformity of the material extruded by the extruder. In the above-mentioned slicing equipment and existing slicing equipment, the material extruded by the extruder is directly cooled and cut, and the material segments with insufficient local elasticity are not removed. When the PET slices have high elasticity requirements, the quality of the slices is reduced. Summary of the Invention

[0004] The object of the present invention is to provide a method for preparing and molding low-viscosity and high-elasticity recycled PET chips and a production line thereof, so as to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions: a production line for preparing and molding low-viscosity and high-elastic recycled PET chips, comprising a cleaning device, a crusher, an extruder, a cooling tank and a cutting machine, wherein the cutting machine comprises a frame, a swing frame is provided at one end of the frame, a drying mechanism is provided above the swing frame, a first rubber roller traction assembly, a second rubber roller traction assembly, a material feeding plate and a third rubber roller traction assembly are provided above the frame in sequence, a feeding mechanism is provided above the material feeding plate, and a material feeding mechanism is provided on the side of the third rubber roller traction assembly away from the material feeding plate. An upper cutter is slidingly arranged downward, and a cutter frame fixed to the frame is arranged below the upper cutter, a lower cutter is fixed on the cutter frame, a power connecting rod is hinged below the upper cutter, and an eccentric wheel is rotatably arranged in the frame, the lower end of the power connecting rod is sleeved on the outer side of the eccentric wheel, a cutting motor for driving the eccentric wheel to rotate is provided in the frame, a guide hopper is connected to the side of the cutter frame away from the third rubber roller traction assembly, a driven rubber roller is rotatably arranged inside the frame, and the driven rubber roller is located between the cutter frame and the third rubber roller traction assembly, and is in contact with the lower rubber roller of the third rubber roller traction assembly.

[0006] Preferably, a mounting base is fixed on the inner side of the frame, and the mounting base is located between the upper cutter and the third rubber roller traction assembly. A screw is provided on the mounting base and a screw motor is installed. A fixing base is fixed to the side end of the screw motor, and a cylinder facing vertically downward is fixed on the fixing base. The lower end of the cylinder is connected to an extrusion head, and the upper end of the extrusion head is provided with a widening sleeve, and the lower end of the extrusion head is provided with a groove. The extrusion head is located directly above the driven rubber roller, and two cross plates are fixed on the inner side of the frame, and the two cross plates are symmetrically distributed directly above the driven rubber roller. The two cross plates are rotatably connected to a swing plate on the side close to each other, and a support spring is provided at the lower end of the swing plate. A cross bar is fixed in the frame, and the cross bar is located on the side of the third rubber roller traction assembly away from the mounting base, and a number of infrared sensors are installed below the cross bar.

[0007] Preferably, a fixed sleeve is fixed to the side end of the fixed seat, and a lifting rod is slidably provided on the inner side of the fixed sleeve, a protrusion is provided on the outer side of the lifting rod, and a spiral groove is provided on the side wall of the fixed sleeve, the protrusion is slidably provided in the spiral groove, and the spiral groove is deflected a quarter of a turn, the extrusion head is fixed to the lower end of the lifting rod, a through hole is provided inside the lifting rod, and the upper end of the lifting rod is connected to a telescopic tube, the upper end of the telescopic tube is sealed, and the upper end of the telescopic tube is fixed to the end of the cylinder, and a pressure spring is provided inside the telescopic tube.

[0008] Preferably, a material guide plate is fixed inside the frame, and the upper end of the material guide plate is located directly below the driven rubber roller. A placement plate is also fixed inside the frame, and a weighing module is provided on the placement plate. A waste box is provided above the weighing module, and the waste box is located directly below the lower end of the material guide plate. A cleaning wool strip is also fixed inside the frame, and the cleaning wool strip is located directly below the driven rubber roller and fits with the driven rubber roller.

[0009] Preferably, the feeding mechanism includes a vertical plate fixed on the feeding plate, and a main power rod is rotatably provided on the vertical plate, and a feeding motor for driving the main power rod is installed at the side end of the vertical plate, a plurality of long worm gears are rotatably provided between the cross bar and the vertical plate, and the end of the long worm gear is connected to the main power rod through a gear pair, a telescopic cutter head is installed at the lower end of the cross bar, a slide rail and a rubber strip for stabilizing the material are provided above the feeding plate, and a moving shell is slidably provided in the slide rail, a reset spring is provided on the outer side of the long worm gear, and the reset spring is connected to the moving shell The movable shell is provided with a rotating hole, in which a first rotating shaft is rotatably arranged, a first friction wheel and a worm wheel are fixed on the first rotating shaft, and the worm wheel is engaged with the long worm, a long slot is provided on the movable shell, and a second rotating shaft is rotatably arranged in the long slot, and the second rotating shaft can slide along the long slot, a second friction wheel and a limiting wheel are fixed on the second rotating shaft, the limiting wheel is located above the strip rPET and is against the strip rPET, and a tension spring is provided on the outside of the second rotating shaft, and the other end of the tension spring is hinged to the lower end corner of the movable shell.

[0010] Preferably, the drying mechanism includes a side frame fixed to the frame, two symmetrically distributed sliding rods are respectively provided on both sides of the side frame, and the swing frame is slidably arranged on the sliding rods, a swing motor is installed on the side frame to drive the swing frame to move left and right, and two symmetrically distributed tilting rods are hinged on the swing frame, a number of guide rubber rollers are provided between the two tilting rods, and a supporting leaf spring is provided between the tilting rod and the swing frame, a fourth rubber roller traction assembly is provided on the swing frame, a water guide plate is fixed on the frame, and the water guide plate is located below the guide rubber rollers and the fourth rubber roller traction assembly.

[0011] Preferably, a first positioning roller and a second positioning roller are provided in the frame, and a plurality of equally spaced wide grooves are provided on the first positioning roller, a plurality of equally spaced narrow grooves are provided on the second positioning roller, and a drying tube with sealed ends is provided on the frame, two air inlet pipes are connected to the two ends of the drying tube, and a plurality of equally spaced narrow slits are provided below the drying tube, and the narrow slits are aligned with the narrow grooves.

[0012] Preferably, a visual sensor is installed on the inner side of the frame, and the visual sensor faces between the first rubber roller traction assembly and the second rubber roller traction assembly.

[0013] Preferably, a baffle is provided at the upper end of the guide hopper, and the guide hopper is wide at the top and narrow at the bottom. A detachable cover is provided above the guide hopper, a handle is provided on the cover, and two symmetrically distributed side panels for supporting the cover are provided on both sides of the guide hopper.

[0014] A method for preparing and molding low-viscosity and high-elasticity recycled PET chips, comprising: S1: The recycled PET is crushed into bottle flakes through cleaning equipment and crushers; S2: Use a liquid metering pump to inject polyethylene glycol into the extruder feed section; S3: The rPET material is extruded into strips through an extruder and cooled in a cooling tank; S4: The strip rPET is introduced into the swing frame of the cutting machine, dried by the drying mechanism, and sequentially passes through the second rubber roller traction assembly, the material feeding plate, and the third rubber roller traction assembly. The third rubber roller traction assembly and the second rubber roller traction assembly are used for differential traction elastic force testing; S5: The tested rPET strips are cut by the upper and lower cutters. The cut rPET slices move along the guide hopper and are discharged in a centralized manner for easy collection. S6: The rPET strips that fail the test will break and the broken parts will be pulled out downwards to remove the waste.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The strip rPET is stretched by the differential speed between the second rubber roller traction assembly and the third rubber roller traction assembly to realize the detection of elastic force. In addition, with the feeding mechanism, it can automatically feed the material when it breaks, and collect the front and rear sections of the broken part in the waste box for easy recycling, thereby improving the overall quality of the rPET slices. It is suitable for the manufacture of high-elasticity rPET slices.

[0016] Simultaneously, a chemical additive (polyethylene glycol) of a certain molecular weight is injected into the extruder feed section via a liquid metering pump. This additive reduces viscosity by diluting the PET, stabilizing the entire production process. Its excellent solubility, low toxicity, chemical stability, moderate viscosity, and hygroscopicity make it particularly suitable for applications requiring safety, stability, and environmental protection. The key benefit is that the resulting low-viscosity product exhibits a 30% increase in elongation at break, effectively acting as an elastic fiber within the bicomponent fiber, meeting application requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the overall axial side structure of the present invention; Figure 2 It is a side structural schematic diagram of the present invention; Figure 3 Schematic diagram of the structure of the upper cutter in the present invention; Figure 4 Schematic diagram of the structure of the swing plate and the driven rubber roller in the present invention; Figure 5 Schematic diagram of the structure of the screw motor in the present invention; Figure 6 Schematic diagram of the structure of the fixed sleeve in the present invention; Figure 7Schematic diagram of the cross-sectional structure of the lifting rod in the present invention; Figure 8 It is a structural diagram of the feeding mechanism in the present invention; Figure 9 It is a partial structural diagram of the feeding mechanism in the present invention; Figure 10 This is a schematic diagram of the disassembled structure of the mobile housing of the present invention; Figure 11 Schematic diagram of the structure of the drying mechanism of the present invention; Figure 12 It is a partial structural diagram of the drying mechanism in the present invention; Figure 13 Schematic diagram of the structure of the drying tube in the present invention; Figure 14 It is a structural schematic diagram of the guide hopper of the present invention.

[0018] In the figure: 1. frame; 2. swing frame; 3. first rubber roller traction assembly; 4. second rubber roller traction assembly; 5. feeding plate; 6. third rubber roller traction assembly; 7. upper cutter; 8. cutting motor; 9. power connecting rod; 10. eccentric wheel; 11. cutter frame; 12. lower cutter; 13. guide hopper; 14. driven rubber roller; 15. mounting base; 16. screw; 17. screw motor; 18. fixed base; 19. cylinder; 20. extrusion head; 21. cross plate; 22. swing plate; 23. support spring; 24. widening sleeve; 25. groove; 26. spiral notch; 27. lifting rod; 28. through hole; 29. ​​fixed sleeve; 30. protrusion; 31. telescopic tube; 32. pressure spring; 33. guide plate; 34. placement plate; 35. weighing module; 36. waste box; 37. cleaning top; 3 8. Horizontal bar; 39. Vertical plate; 40. Main power rod; 41. Gear pair; 42. Long worm; 43. Infrared sensor; 44. Telescopic cutter head; 45. Slide rail; 46. Rubber strip; 47. Moving housing; 48. Return spring; 49. Rotary hole; 50. First friction wheel; 51. Worm gear; 52. Long notch; 53. Limit wheel; 54. Second friction wheel; 55. Tension spring; 56. Side frame; 57. Slide bar; 58. Swing motor; 59. Tilt bar; 60. Guide rubber roller; 61. Support leaf spring; 62. Fourth rubber roller traction assembly; 63. First positioning roller; 64. Wide slot; 65. Second positioning roller; 66. Narrow slot; 67. Drying pipe; 68. Inlet pipe; 69. Narrow slit; 70. Water guide plate; 71. Visual sensor; 72. Baffle; 73. Cover plate; 74. Side panel; 75. Handle. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] like Figures 1-14 As shown, the present invention provides a technical solution: a low-viscosity and high-elasticity recycled PET chip preparation and molding production line, including a cleaning device, a crusher, an extruder, a cooling tank and a cutting machine, the cutting machine includes a frame 1, a swing frame 2 is provided at one end of the frame 1, a drying mechanism is provided above the swing frame 2, a first rubber roller traction assembly 3, a second rubber roller traction assembly 4, a material feeding plate 5 and a third rubber roller traction assembly 6 are sequentially provided above the frame 1, a material feeding mechanism is provided above the material feeding plate 5, an upper cutter 7 is provided on the side of the third rubber roller traction assembly 6 away from the material feeding plate 5, and the upper cutter 7 is provided on the side of the third rubber roller traction assembly 6 away from the material feeding plate 5. A cutting frame 11 fixed to the frame 1 is provided below the knife 7, and a lower cutting knife 12 is fixed on the cutting frame 11. A power connecting rod 9 is hinged below the upper cutting knife 7, and an eccentric wheel 10 is rotatably provided in the frame 1. The lower end of the power connecting rod 9 is sleeved on the outside of the eccentric wheel 10. A cutting motor 8 for driving the eccentric wheel 10 to rotate is provided in the frame 1. A guide hopper 13 is connected to the side of the cutting frame 11 away from the third rubber roller traction assembly 6. A driven rubber roller 14 is rotatably provided inside the frame 1, and the driven rubber roller 14 is located between the cutting frame 11 and the third rubber roller traction assembly 6, and is in contact with the lower rubber roller of the third rubber roller traction assembly 6.

[0021] It should be noted that when in use, the strip rPET extruded by the extruder passes through the cooling water trough and is connected to the cutting machine, and thus passes through the drying mechanism, the first rubber roller traction assembly 3, the second rubber roller traction assembly 4, the feeding plate 5, the third rubber roller traction assembly 6 and the upper and lower cutters. When passing through the drying mechanism, the moisture attached to it through the cooling water trough is removed. When passing between the second rubber roller traction assembly 4 and the third rubber roller traction assembly 6, since the traction speed of the third rubber roller traction assembly 6 is greater than that of the second rubber roller traction assembly 4, a section of the strip rPET on the feeding plate 5 is stretched and an elasticity test is performed. The degree of elasticity test can be customized according to the traction speed difference. The strip rPET that passes the elasticity test passes between the upper cutter 7 and the lower cutter 12 under the push of the third rubber roller traction assembly 6. At this time, the cutting motor 8 drives the eccentric wheel 10 rotates, and then drives the upper cutter 7 to move up and down through the power connecting rod 9, and cooperates with the lower cutter 12 to realize the cutting function. The cut rPET slices move along the guide hopper 13 and are discharged in a centralized manner for easy collection. The strip rPET that fails the elasticity test will break, and the front section of the breaking position continues to move under the action of the third rubber roller traction assembly 6. After passing through the third rubber roller traction assembly 6, the end of its port falls downward and is clamped by the driven rubber roller 14 and the third rubber roller traction assembly 6, and the uncut part is pulled out downward to realize the removal of waste material, and the rear section after the break continues to enter the third rubber roller traction assembly 6 under the action of the feeding mechanism and continues to be sliced. The waste material at the broken position can be automatically removed, thereby improving the overall quality of the rPET slices, and does not require manual operation, thereby improving the production efficiency of the production line.

[0022] like Figure 4-Figure 6 As shown, a mounting base 15 is fixed on the inside of the frame 1, and the mounting base 15 is located between the upper cutter 7 and the third rubber roller traction assembly 6. A screw 16 is provided on the mounting base 15 and a screw motor 17 is installed. A fixing base 18 is fixed to the side end of the screw motor 17. A vertically downward cylinder 19 is fixed on the fixing base 18. The lower end of the cylinder 19 is connected to the extrusion head 20, and the upper end of the extrusion head 20 is provided with a widening sleeve 24, and the lower end of the extrusion head 20 is provided with a groove 25. 20 is located just above the driven rubber roller 14, two cross plates 21 are fixed on the inside of the frame 1, and the two cross plates 21 are symmetrically distributed just above the driven rubber roller 14, and the two cross plates 21 are rotatably connected to the swing plate 22 on the side close to each other, and a support spring 23 is provided at the lower end of the swing plate 22, a cross bar 38 is fixed in the frame 1, and the cross bar 38 is located on the side of the third rubber roller traction assembly 6 away from the mounting seat 15, and a number of infrared sensors 43 are installed below the cross bar 38.

[0023] It should be noted that during use, when the strip rPET breaks, a gap will be generated. When the infrared sensor 43 detects a gap directly below, the screw motor 17 will move to the position corresponding to the infrared sensor 43. Then, after a certain period of time (the gap completely passes through the third rubber roller traction assembly 6), the cylinder 19 drives the extrusion head 20 to descend, squeezing the front section of the break downward and passing through the two swing plates 22 (the swing plates 22 open downward), and then the cylinder 19 contracts, and the extrusion head 20 resets (the widening sleeve 24 can prevent the extrusion head 20 from being stuck by the swing plates 22 when it is reset). The broken part can be squeezed downward without relying on gravity, which is more stable and reliable. Moreover, the end material after the break is pushed by the third rubber roller traction assembly 6 and can move along the two swing plates 22 and the two cross plates 21. The end of the broken mouth will not fall downward due to gravity and be clamped by the driven rubber roller 14, making the device smoother to use.

[0024] like Figure 6-Figure 7 As shown, a fixed sleeve 29 is fixed to the side end of the fixed seat 18, and a lifting rod 27 is slidably provided on the inner side of the fixed sleeve 29, a protrusion 30 is provided on the outer side of the lifting rod 27, and a spiral groove 26 is provided on the side wall of the fixed sleeve 29, the protrusion 30 is slidably provided in the spiral groove 26, and the spiral groove 26 is deflected a quarter of a turn, the extrusion head 20 is fixed to the lower end of the lifting rod 27, a through hole 28 is provided inside the lifting rod 27, and the upper end of the lifting rod 27 is connected to a telescopic tube 31, the upper end of the telescopic tube 31 is sealed, and the upper end of the telescopic tube 31 is fixed to the end of the cylinder 19, and a pressure spring 32 is provided inside the telescopic tube 31.

[0025] It should be noted that when the cylinder 19 squeezes downward, the lifting rod 27 descends synchronously, and during the descent process, it deflects as the protrusion 30 deflects in the spiral groove 26, and rotates the broken strip rPET a quarter of a turn through the groove 25 so that it is parallel to the driven rubber roller 14. This can prevent the thickness of the strip rPET from being too large after folding, causing rapid wear, thereby improving the service life of the driven rubber roller 14. Moreover, after being squeezed to the bottom, the pressure spring 32 will be compressed. At this time, the gas in the telescopic tube 31 will gush out from the through hole 28, impacting the strip rPET in the groove 25, preventing it from sticking or getting stuck in the groove 25.

[0026] like Figure 2 and Figure 4As shown, a material guide plate 33 is fixed inside the frame 1, and the upper end of the material guide plate 33 is located directly below the driven rubber roller 14. A placement plate 34 is also fixed inside the frame 1, and a weighing module 35 is provided on the placement plate 34. A waste box 36 is provided above the weighing module 35, and the waste box 36 is located directly below the lower end of the material guide plate 33. A cleaning wool strip 37 is also fixed inside the frame 1, and the cleaning wool strip 37 is located directly below the driven rubber roller 14 and is in contact with the driven rubber roller 14.

[0027] It should be noted that when the broken waste falls downward, it is first swept by the cleaning strips 37 and will not adhere to the driven rubber roller 14. Then the waste falls along the guide plate 33 into the waste box 36. The weighing module 35 below the waste box 36 can, on the one hand, judge the amount of waste in the waste box 36 for convenient and timely cleaning. On the other hand, it can detect the weight increase rate of the waste box 36. When the increase rate is too large, it cooperates with the communication equipment to promptly remind the operator to check the problem of excessive waste, so as to facilitate timely maintenance.

[0028] like Figure 4-Figure 6 As shown, the feeding mechanism includes a vertical plate 39 fixed on the feeding plate 5, and a main power rod 40 is rotatably provided on the vertical plate 39, and a feeding motor for driving the main power rod 40 is installed at the side end of the vertical plate 39, a plurality of long worm gears 42 are rotatably provided between the cross bar 38 and the vertical plate 39, and the ends of the long worm gears 42 are connected to the main power rod 40 through a gear pair 41, a telescopic cutter head 44 is installed at the lower end of the cross bar 38, a slide rail 45 and a rubber strip 46 for stabilizing the material are provided above the feeding plate 5, and a movable shell 47 is slidably provided in the slide rail 45, a reset spring 48 is provided on the outer side of the long worm gear 42, and the reset spring 48 is connected to the movable shell 47. The movable housing 47 is counteracted, and a rotating hole 49 is provided on the movable housing 47. A first rotating shaft is rotatably set in the rotating hole 49. A first friction wheel 50 and a worm wheel 51 are fixed on the first rotating shaft, and the worm wheel 51 is engaged with the long worm 42. A long slot 52 is provided on the movable housing 47, and a second rotating shaft is rotatably set in the long slot 52, and the second rotating shaft can slide along the long slot 52. A second friction wheel 54 and a limiting wheel 53 are fixed on the second rotating shaft. The limiting wheel 53 is located above the strip rPET and counteracts the strip rPET, and a tension spring 55 is provided on the outside of the second rotating shaft, and the other end of the tension spring 55 is hinged to the lower end corner of the movable housing 47.

[0029] It should be noted that when in use, when the strip rPET moves forward, under the action of the tension spring 55, the limiting wheel 53 is attached to the top of the strip rPET and rotates with the movement of the strip rPET. When the strip rPET breaks, the rear section of the strip rPET will shrink backward. At this time, the limiting wheel 53 moves obliquely downward along the long notch 52 under the action of the tension spring 55, pressing the strip rPET on the feeding plate 5 and clamping it. At this time, the first friction wheel 50 and the second friction wheel 54 are against each other. Since the limiting wheel 53 cannot rotate, the worm gear 51 cannot rotate, but the long worm 42 is in the active state. The force rod 40 continues to rotate under the action of the force rod 40, which will push the worm gear 51 forward, and then the movable shell 47 will move forward along the slide rail 45. At this time, the limiting wheel 53 will press the strip rPET on the feeding plate 5 and push it forward to achieve the effect of refilling. Moreover, when the infrared sensor 43 detects the refilling, after a certain delay, the telescopic blade 44 will cut the strip rPET downward, cut off a part of the back of the gap, and repeat the previous waste collection process, so that the front and back ends of the gap are recycled, further eliminating the secondary materials, and ensuring the product quality of the rPET slices.

[0030] like Figure 11 As shown, the drying mechanism includes a side frame 56 fixed to the frame 1, two symmetrically distributed sliding rods 57 are respectively provided on both sides of the side frame 56, and the swing frame 2 is slidably set on the sliding rod 57, and a swing motor 58 is installed on the side frame 56 for driving the swing frame 2 to move left and right, and two symmetrically distributed tilting rods 59 are hinged on the swing frame 2, a number of guide rubber rollers 60 are provided between the two tilting rods 59, and a supporting leaf spring 61 is provided between the tilting rod 59 and the swing frame 2, a fourth rubber roller traction assembly 62 is provided on the swing frame 2, and a water guide plate 70 is fixed on the frame 1, and the water guide plate 70 is located below the guide rubber roller 60 and the fourth rubber roller traction assembly 62.

[0031] It should be noted that when in use, the fourth rubber roller traction assembly 62 pulls the strip rPET out of the cooling trough and passes through several guide rubber rollers 60 in sequence. During the movement of the strip rPET, the swing motor 58 drives the swing frame 2 to swing left and right, and the guide rubber roller 60 swings up and down under the support of the support leaf spring 61, achieving a multi-dimensional vibration effect, shaking off the water droplets attached to the material, achieving a preliminary drying effect, and the water droplets will be collected in the water guide plate 70 for convenient centralized processing.

[0032] like Figure 12 and Figure 13As shown, a first positioning roller 63 and a second positioning roller 65 are provided in the frame 1, and a plurality of equally spaced wide grooves 64 are provided on the first positioning roller 63, and a plurality of equally spaced narrow grooves 66 are provided on the second positioning roller 65. A drying pipe 67 with sealed ends is provided on the frame 1, and two air inlet pipes 68 are connected to the two ends of the drying pipe 67, and a plurality of equally spaced narrow slits 69 are provided below the drying pipe 67, and the narrow slits 69 are aligned with the narrow grooves 66.

[0033] It should be noted that during the vibration of the strip rPET, the wide groove 64 can provide a wider vibration space, and the narrow groove 66 can improve the position of the stable strip rPET during vibration, thereby improving the stability of the equipment. Moreover, when the strip rPET passes between the first positioning roller 63 and the second positioning roller 65, the drying pipe 67 can be connected to the air supply equipment to provide drying hot air, and blow it onto the strip rPET through the narrow gap 69 to achieve further drying effect.

[0034] like Figure 2 As shown, a visual sensor 71 is installed on the inner side of the frame 1 , and the visual sensor 71 faces between the first rubber roller traction assembly 3 and the second rubber roller traction assembly 4 .

[0035] It should be noted that, during use, the traction speed of the second rubber roller traction assembly 4 can be set to be slightly higher than the traction speed of the first rubber roller traction assembly 3. When the strip rPET breaks between the two, it means that the elasticity of the rPET is very poor. At this time, the visual sensor 71 cooperates with the communication equipment to notify the technicians to check in time whether there are serious problems such as errors in the formula of rPET, and shut down the machine for production.

[0036] like Figure 11 As shown, a baffle 72 is provided at the upper end of the guide hopper 13, and the guide hopper 13 is wide at the top and narrow at the bottom. A detachable cover 73 is provided above the guide hopper 13, and a handle 75 is provided on the cover 73. Two symmetrically distributed side panels 74 for supporting the cover 73 are respectively provided on both sides of the guide hopper 13.

[0037] It should be noted that, during use, the cut rPET slices move along the guide hopper 13 and are discharged in a centralized manner for easy collection. Moreover, when the inside of the guide hopper 13 is clogged, the cover plate 73 can be removed upwards for easy cleaning.

[0038] In this embodiment, the first rubber roller traction assembly 3, the second rubber roller traction assembly 4, the third rubber roller traction assembly 6, and the fourth rubber roller traction assembly 62 are all rubber roller structures, one of which is driven by a motor, and the other rubber roller can be displaced and clamp the material between the two. This structure is all existing technology and will not be repeated again.

[0039] A method for preparing and molding low-viscosity and high-elasticity recycled PET chips, comprising: S1: The recycled PET is crushed into bottle flakes through cleaning equipment and crushers; S2: Use a liquid metering pump to inject a chemical additive (polyethylene glycol) of a certain molecular weight into the extruder feed section; S3: The rPET material is extruded into strips through an extruder and cooled in a cooling tank; S4: The strip rPET is introduced into the swing frame 2 of the cutting machine, dried by the drying mechanism, and sequentially passes through the second rubber roller traction assembly 4, the material feeding plate 5, and the third rubber roller traction assembly 6. The third rubber roller traction assembly 6 and the second rubber roller traction assembly 4 are subjected to a differential traction elastic force test; S5: The tested rPET strips are cut by the upper cutter 7 and the lower cutter 12. The cut rPET slices move along the guide hopper 13 and are discharged in a centralized manner for easy collection. S6: The rPET strips that fail the test will break and the broken parts will be pulled out downwards to remove the waste.

[0040] It should be noted that existing technologies hydrolyze rPET at high temperatures in an extruder reactor by adding water or oxygen, resulting in varying degrees of molecular fragmentation within the rPET to produce low-viscosity rPET. This approach can damage the inherent properties of PET and make the entire production process extremely unstable, with significant viscosity fluctuations. This approach fails to meet market demand for stable viscosity and elasticity for low-viscosity rPET. In contrast, this embodiment uses a liquid metering pump to inject a chemical additive (polyethylene glycol) of a certain molecular weight (PEG600, a 1.5% diluent, is used in this embodiment) into the extruder feed section. This additive reduces viscosity by diluting the PET, stabilizing the entire production process. Furthermore, its excellent solubility, low toxicity, chemical stability, moderate viscosity, and hygroscopicity make it highly suitable for applications requiring safety, stability, and environmental friendliness. A key point is that the resulting low-viscosity product exhibits a 30% increase in elongation at break, making it an excellent elastic fiber in bicomponent fibers, meeting application requirements.

[0041] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is limited by the accompanying embodiments and their equivalents.

Claims

1. A production line for preparing and molding low-viscosity, high-elasticity recycled PET chips, comprising a cleaning device, a crusher, an extruder, a cooling tank, and a cutting machine, characterized in that: The cutting machine comprises a frame (1), a swing frame (2) is provided at one end of the frame (1), a drying mechanism is provided above the swing frame (2), a first rubber roller traction assembly (3), a second rubber roller traction assembly (4), a material feeding plate (5) and a third rubber roller traction assembly (6) are sequentially provided above the frame (1), a material feeding mechanism is provided above the material feeding plate (5), an upper cutter (7) is provided on a side of the third rubber roller traction assembly (6) away from the material feeding plate (5) and is slidably arranged with the frame (1), and a cutter frame (11) fixed to the frame (1) is provided below the upper cutter (7), and a lower cutter frame (11) is fixed on the cutter frame (11). A cutter (12) is provided, a power connecting rod (9) is hingedly connected to the lower portion of the upper cutter (7), and an eccentric wheel (10) is rotatably provided in the frame (1), the lower end of the power connecting rod (9) is sleeved on the outer side of the eccentric wheel (10), a cutting motor (8) is provided in the frame (1) for driving the eccentric wheel (10) to rotate, a guide hopper (13) is connected to the side of the cutter frame (11) away from the third rubber roller traction assembly (6), a driven rubber roller (14) is rotatably provided in the frame (1), and the driven rubber roller (14) is located between the cutter frame (11) and the third rubber roller traction assembly (6), and is in contact with the rubber roller below the third rubber roller traction assembly (6).

2. The low-viscosity, high-elasticity recycled PET chip production line according to claim 1, characterized in that: A mounting seat (15) is fixed on the inner side of the frame (1), and the mounting seat (15) is located between the upper cutter (7) and the third rubber roller traction assembly (6). A screw (16) is provided on the mounting seat (15) and a screw motor (17) is installed. A fixing seat (18) is fixed to the side end of the screw motor (17), and a cylinder (19) facing vertically downward is fixed on the fixing seat (18). The lower end of the cylinder (19) is connected to an extrusion head (20), and a widening sleeve (24) is provided on the upper end of the extrusion head (20). A groove (25) is provided on the lower end of the extrusion head (20). The head (20) is located just above the driven rubber roller (14), two transverse plates (21) are fixed inside the frame (1), and the two transverse plates (21) are symmetrically distributed just above the driven rubber roller (14), and the two transverse plates (21) are rotatably connected to the swing plate (22) on the side close to each other, and the lower end of the swing plate (22) is provided with a support spring (23), a transverse bar (38) is fixed inside the frame (1), and the transverse bar (38) is located on the side of the third rubber roller traction assembly (6) away from the mounting seat (15), and a plurality of infrared sensors (43) are installed below the transverse bar (38).

3. The low-viscosity, high-elasticity recycled PET chip production line according to claim 2, characterized in that: A fixed sleeve (29) is fixed to the side end of the fixed seat (18), and a lifting rod (27) is slidably provided on the inner side of the fixed sleeve (29), a protrusion (30) is provided on the outer side of the lifting rod (27), and a spiral groove (26) is provided on the side wall of the fixed sleeve (29), the protrusion (30) is slidably provided in the spiral groove (26), and the spiral groove (26) is deflected by a quarter of a turn, the extrusion head (20) is fixed to the lower end of the lifting rod (27), a through hole (28) is provided inside the lifting rod (27), and the upper end of the lifting rod (27) is connected to a telescopic tube (31), the upper end of the telescopic tube (31) is sealed, and the upper end of the telescopic tube (31) is fixed to the end of the cylinder (19), and a pressure spring (32) is provided inside the telescopic tube (31).

4. The low-viscosity, high-elasticity recycled PET chip production line according to claim 1, characterized in that: A guide plate (33) is fixed inside the frame (1), and the upper end of the guide plate (33) is located directly below the driven rubber roller (14). A placement plate (34) is also fixed inside the frame (1), and a weighing module (35) is provided on the placement plate (34). A waste box (36) is provided above the weighing module (35), and the waste box (36) is located directly below the lower end of the guide plate (33). A cleaning strip (37) is also fixed inside the frame (1), and the cleaning strip (37) is located directly below the driven rubber roller (14) and is in contact with the driven rubber roller (14).

5. The low-viscosity, high-elasticity recycled PET chip production line according to claim 1, characterized in that: The feeding mechanism includes a vertical plate (39) fixed on the feeding plate (5), and a main driving rod (40) is rotatably provided on the vertical plate (39), and a feeding motor for driving the main driving rod (40) is installed at the side end of the vertical plate (39), a plurality of long worms (42) are rotatably provided between the cross bar (38) and the vertical plate (39), and the ends of the long worms (42) are connected to the main driving rod (40) through a gear pair (41), a telescopic cutter head (44) is installed at the lower end of the cross bar (38), a slide rail (45) and a rubber strip (46) for stabilizing the material are provided above the feeding plate (5), and a movable housing (47) is slidably provided in the slide rail (45), a return spring (48) is provided on the outer side of the long worm (42), and the return spring (48) is connected to the main driving rod (40) through a gear pair (41). ) is against the movable housing (47), a rotating hole (49) is provided on the movable housing (47), a first rotating shaft is rotatably provided in the rotating hole (49), a first friction wheel (50) and a worm wheel (51) are fixed on the first rotating shaft, and the worm wheel (51) is engaged with the long worm (42), a long slot (52) is provided on the movable housing (47), and a second rotating shaft is rotatably provided in the long slot (52), and the second rotating shaft can slide along the long slot (52), a second friction wheel (54) and a limiting wheel (53) are fixed on the second rotating shaft, the limiting wheel (53) is located above the strip rPET and is against the strip rPET, and a tension spring (55) is provided on the outside of the second rotating shaft, and the other end of the tension spring (55) is hinged to the lower end corner of the movable housing (47).

6. The low-viscosity, high-elasticity recycled PET chip production line according to claim 1, characterized in that: The drying mechanism comprises a side frame (56) fixed on the frame (1), two symmetrically distributed sliding rods (57) are respectively provided on both sides of the side frame (56), and the swing frame (2) is slidably provided on the sliding rods (57), a swing motor (58) is installed on the side frame (56) for driving the swing frame (2) to move left and right, and two symmetrically distributed tilting rods (59) are hinged on the swing frame (2), a plurality of guide rubber rollers (60) are provided between the two tilting rods (59), and a supporting leaf spring (61) is provided between the tilting rod (59) and the swing frame (2), a fourth rubber roller traction assembly (62) is provided on the swing frame (2), and a water guide plate (70) is fixed on the frame (1), and the water guide plate (70) is located below the guide rubber rollers (60) and the fourth rubber roller traction assembly (62).

7. The low-viscosity, high-elasticity recycled PET chip production line according to claim 6, characterized in that: A first positioning roller (63) and a second positioning roller (65) are provided in the frame (1), and a plurality of equally spaced wide grooves (64) are provided on the first positioning roller (63), and a plurality of equally spaced narrow grooves (66) are provided on the second positioning roller (65). A drying pipe (67) with sealed ends is provided on the frame (1), two air inlet pipes (68) are connected to the two ends of the drying pipe (67), and a plurality of equally spaced narrow slits (69) are provided below the drying pipe (67), and the narrow slits (69) are aligned with the narrow grooves (66).

8. The low-viscosity, high-elasticity recycled PET chip production line according to claim 1, characterized in that: A visual sensor (71) is installed on the inner side of the frame (1), and the visual sensor (71) faces between the first rubber roller traction assembly (3) and the second rubber roller traction assembly (4).

9. The low-viscosity, high-elasticity recycled PET chip production line according to claim 1, characterized in that: A baffle (72) is provided at the upper end of the guide hopper (13), and the guide hopper (13) is wide at the top and narrow at the bottom. A detachable cover (73) is provided above the guide hopper (13), and a handle (75) is provided on the cover (73). Two symmetrically distributed side plates (74) for supporting the cover (73) are respectively provided on both sides of the guide hopper (13).

10. A method for preparing and molding low-viscosity, high-elasticity recycled PET chips, using the production line for preparing and molding low-viscosity, high-elasticity recycled PET chips according to any one of claims 1 to 9, characterized in that: include: S1: The recycled PET is crushed into bottle flakes through cleaning equipment and crushers; S2: Use a liquid metering pump to inject polyethylene glycol into the extruder feed section; S3: The rPET material is extruded into strips through an extruder and cooled in a cooling tank; S4: The strip rPET is introduced into the swing frame (2) of the cutting machine, dried by the drying mechanism, and sequentially passes through the second rubber roller traction assembly (4), the material feeding plate (5), and the third rubber roller traction assembly (6), and a differential traction elastic force test is performed with the third rubber roller traction assembly (6) and the second rubber roller traction assembly (4); S5: The tested strip rPET is cut by the upper cutter (7) and the lower cutter (12). The cut rPET slices move along the guide hopper (13) and are discharged in a centralized manner for easy collection. S6: The rPET strips that fail the test will break and the broken parts will be pulled out downwards to remove the waste.

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