Double-layer PET bottle blank hot melting self-cleaning forming equipment

Abstract

The invention discloses double-layer PET bottle blank hot melting self-cleaning forming equipment, and belongs to the packaging bottle forming technology. A melt sequentially passes through the filter screen and the porous ring piece from inside to outside, enters the collecting pipe through the heat preservation flow dividing pipe, then is rectified in the collecting pipe, enters the extrusion head and finally enters the forming die. The filter screen is arranged in the inner side of the porous ring piece, when the positions, corresponding to the filter screen and holes in the surface of the porous ring piece, of the heat preservation flow dividing pipe are switched (a worm and gear driving mode is adopted), blockages can be intercepted on the inner side of the filter screen, flow is guided to the tail through the separation body in the position switching process, and the blockages are concentrated on the tail in cooperation with melt scouring.

Description

Technical Field

[0001] The present invention belongs to packaging bottle molding technology, specifically a double-layer PET bottle preform hot-melt self-cleaning molding equipment, which can complete the self-cleaning operation during extrusion molding, and can be used to prepare double-layer PET packaging bottles. Background Art

[0002] Existing food packaging bottles and barrels are typically manufactured by directly adding PET raw material, drying it, heating it to melt it, and then injecting it into an injection system. A search revealed a double-layer preform injection molding mold proposed in CN101376259B. This mold, consisting of two sets of preform molds, can be assembled and used simultaneously with a single dual-color / dual-material injection molding machine. The mold completes the injection of both inner and outer layers within a single injection cycle. Using this mold, multiple double-layer preforms can be molded simultaneously, achieving high efficiency and high-quality finished products, facilitating the blow molding of high-performance finished bottles.

[0003] When this technology is actually implemented, since most packaging bottles are transparent, some impurities often appear in the raw materials, which in turn causes the finished packaging bottles to often have black spots or air holes, and packaging bottle quality problems in the subsequent blow molding process. Summary of the Invention

[0004] The first purpose of the present invention is to solve the problem of blockage during the molding of double-layer bottle blanks and the resulting blockage.

[0005] In order to solve the above technical problems, the inventors have come up with the technical solution of the present invention through practice and summary. The present invention adopts the following technical solution:

[0006] A double-layer PET bottle preform hot-melt self-cleaning molding device, comprising an inner layer injection molding assembly, an outer layer injection molding assembly, and a molding die;

[0007] Among them, the inner layer injection molding assembly and the outer layer injection molding assembly both include:

[0008] Hot melt box, one end of the hot melt box is connected to the raw material bin as an inlet, the other end is connected to the extrusion head through a filter, and a double-screw extrusion rod is provided inside;

[0009] An extrusion head, wherein an internal flow channel is provided inside the extrusion head;

[0010] A manifold, one end of which is connected to the internal flow channel of the extruder head;

[0011] The molding die includes a fixed die and a movable die. The fixed die is provided with an inner layer injection molding structure and an outer layer injection molding structure, and the movable die is provided with two molding cavities.

[0012] The inner layer injection molding structure includes an inner layer flow channel connected to the inner flow channel of one group of extrusion heads and an outer male die head that is socket-fitted to the inner side of the molding cavity;

[0013] The outer layer injection molding structure includes an inner layer flow channel connected to the inner flow channel of another group of extrusion heads and an outer convex die head secondly fitting with the end surface of the molding cavity;

[0014] The movable mold can move closer to or farther away from the fixed mold, and can also rotate at a set angle relative to the fixed mold.

[0015] In a more optimal solution, the filter includes an insulated diverter pipe and an insulated sleeve. There are two groups of symmetrically distributed insulated diverter pipes. The inlet of the manifold is connected to the outlet of the insulated diverter pipe. The inlet of the insulated diverter pipe is symmetrically distributed on the insulated sleeve. Mounting disks are installed at both ends of the insulated sleeve. The two mounting disks are mounting disk 1 installed at the output end of the hot melt box and independently fixed mounting disk 2. A porous ring is installed for rotation inside the insulated sleeve. The end of the porous ring close to the manifold extends to the outside of the mounting disk 2. A driving structure is installed on the outside of the mounting disk 2 for driving the porous ring to rotate to a set angle. A filter screen and a separator ring are installed inside the porous ring. The filter screen is located between the separator ring and the porous ring. A drain plug is installed inside the end of the porous ring away from the mounting disk 1.

[0016] In a more preferred solution, the extrusion head is further equipped with a pressure sensor 1 for detecting the pressure on the blocking side of the filter screen and a pressure sensor 2 for detecting the pressure on the discharge side of the porous ring.

[0017] In a more optimal solution, the separating ring includes support rings at both ends and separators connected between the support rings. There are multiple groups of separators evenly distributed circumferentially. The multiple groups of separators are all arc-shaped structures and gradually deviate from the inlet direction along the direction of rotation of the porous ring member along the direction of melt conveying. The thickness of the separator is 0.5-1.5mm and the width is 1-5mm.

[0018] In a more preferred solution, a rectifying member is installed in the manifold, and arc-shaped structures are distributed on the rectifying member for axial flow guidance.

[0019] In a more preferred solution, the driving structure includes a deblocking motor and a worm mounted on the output end of the deblocking motor. The worm is rotatably mounted on the second mounting plate. A worm wheel is engaged on the outside of the worm, and the worm wheel is mounted on the outside of the porous ring.

[0020] In a more optimal solution, the blocking member includes a check ring and an active member. The check ring is installed on the inner side of the porous ring member and the inner ring gradually moves away from the mounting disk one. The active member is slidingly fitted inside the porous ring member. An outer edge body is provided on the outer side of the active member. The outer edge body is provided opposite to the mounting disk two. An axial guide rod is installed on the mounting disk two. The axial guide rod is inserted on the outer edge body. A constraint member is installed on the side of the axial guide rod away from the mounting disk two. A spring member is provided on the outer side of the axial guide rod between the constraint member and the check ring. An outer convex ring is provided on the side of the active member close to the mounting disk two. An outer extrusion member is installed on the outer side of the porous ring member. The circumferential positions of the outer extrusion member and the outer convex ring correspond and fit each other.

[0021] In a more optimal solution, the part of the active part that is inside the porous ring part is provided with a sealing head, the outer diameter of the sealing head is smaller than the outer diameter of the active part, the side of the sealing head facing away from the active part is a spherical body for sealing the check ring, the outer wall of the sealing head is provided with a reverse flow channel 1, the inlet of the reverse flow channel 1 is provided with a partition net, the middle part of the sealing head is provided with a reverse flow channel 2, both the reverse flow channel 1 and the reverse flow channel 2 are connected to the circulation pump, the circulation pump is installed inside the sealing head, and the outlet of the reverse flow channel 2 is provided with a one-way diaphragm.

[0022] In a more optimal solution, an outward convex structure is provided on the side of the outward convex ring opposite to the outward extrusion piece, and a slide groove is distributed on the outward convex structure. The outward convex structure compresses the spring part under the action of the outward extrusion piece to open the ring mouth of the check ring, and a moving body is installed in the slide groove.

[0023] In a more optimal solution, an annular groove is provided on the side of the active part facing away from the insulation sleeve, a sealing plate is installed at the notch of the annular groove, a travel switch is provided on the sealing plate, the travel switch is used to control the opening and closing action of the circulation pump, a moving ring is slidingly fitted in the annular groove, the moving body is fixed on the side of the moving ring facing away from the sealing plate, an opening and closing ring is provided on the side of the moving ring relative to the insulation sleeve, a diversion flow hole is provided on the side wall of the opening and closing ring, the opening and closing ring is used to open and close the reverse flow channel one, and a spring body is installed between the sealing plate and the moving ring.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. As the existing PET preform molding equipment is unable to perform the injection molding of the inner and outer double-layer structure, the movable mold is moved closer to or farther away from the fixed mold. After the inner layer structure is injection-molded, the movable mold is rotated 180° to complete the position swap of the two molding cavities, thereby completing the outer layer structure online. While the outer layer structure is being injection-molded, the other inner layer structure is also being injection-molded simultaneously, greatly improving production efficiency.

[0026] 2. The following improvements are made to the existing hot melt extrusion structure: the molten material passes through the filter screen, the porous ring, the insulation diverter pipe, and enters the manifold from the inside to the outside, and then enters the extrusion head after being rectified in the manifold, and finally enters the molding die. The filter screen is built into the inner side of the porous ring, and when the insulation diverter pipe is switched to the position of the holes on the surface of the filter screen and the porous ring (using a worm gear drive method), the blockage will be intercepted on the inner side of the filter screen, and during the position switching process, it will be diverted to the tail through the separator, and the molten material will be flushed and concentrated at the tail. If the separator is not added, it is easy to cause when switching the diversion channel to the corresponding filter screen position, because the flow direction of the molten material is always facing the filter screen where the diversion channel is located, the molten material rushing phenomenon will re-concentrate the blockage on the blocking side of the filter screen in the new position, and the blockage cannot be taken away from the blocking side. At the same time, since the corresponding positions of the filter and the porous ring need to be rotated to switch, if an external filter is installed, a small amount of the blockage intercepted on the blocking side will enter the rotating gap, which will aggravate the wear of the filter, easily cause damage to the filter, and even increase the impurity content in the melt; secondly, most of the blockage will accumulate on the surface of the filter at the new position to form a new blockage, and the new blockage will also accumulate at the new position, resulting in the problem of "treating the symptoms but not the root cause".

[0027] 3. The following improvements are also made to the extrusion structure. The blockage removal part is completed by using a check ring and an active part. The check ring can make the blockage move in one direction only when it is discharged. When the porous ring part is rotated, an external extrusion part is installed on the porous ring part. The external extrusion part causes the outer convex ring to rotate, and the active part of the outer convex structure on the outer convex ring moves outward, opening the end of the check ring. Then the external extrusion part will move out of the body to open the backflow channel 1. After the backflow channel 1 is opened, the circulation pump inside the active part can be opened at the same time, thereby forming a circulation of the molten material, and then the blockage enters the outside of the check ring and is isolated on the outside of the partition net to complete the blockage operation. When the sewage is discharged to a certain extent, the active part can be removed to clean the blockage and the partition net when clearing is required. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A top view of the overall structure of the device of the present invention;

[0029] Figure 2 Schematic diagram of the internal structure of the device of the present invention;

[0030] Figure 3 A diagram showing the positional relationship between the hot melt box and the extrusion head of the present invention;

[0031] Figure 4 for Figure 3 A partial enlarged view of point B in the middle;

[0032] Figure 5 Schematic diagram of the overall structure of the separator of the present invention;

[0033] Figure 6 It is a structural schematic diagram of the blockage removal member of the present invention;

[0034] Figure 7 It is a structural schematic diagram of the outer convex ring of the present invention;

[0035] Figure 8 for Figure 7 Top view of the outer convex ring under viewing angle;

[0036] Figure 9 for Figure 4 A cross-sectional view of the porous ring at the worm gear;

[0037] Figure 10 for Figure 1 Schematic diagram of the structure inside the forming mold.

[0038] In the picture:

[0039] 41. Hot melt box; 42. Extrusion head; 421. Pressure sensor 1; 422. Pressure sensor 2; 43. Manifold; 44. Rectifier; 45. Insulated manifold; 46. Insulation sleeve; 47. Mounting plate 1; 48. Mounting plate 2; 49. Porous ring; 410. Filter; 411. Double-screw extruder; 412. Worm; 413. Worm gear; 414. Blockage removal motor;

[0040] 50. Blocking member; 51. Check ring; 52. Active member; 521. Blocking head; 522. Reverse flow channel 1; 523. Separation net; 524. Circulation pump; 525. Reverse flow channel 2; 526. One-way diaphragm; 53. Outer edge body; 54. Axial guide rod; 55. Constraint; 56. External convex ring; 561. External convex structure; 562. Slide groove; 563. Moving body; 564. Ring groove; 565. Blocking plate; 566. Travel switch; 567. Open / close ring; 568. Flow hole; 569. Spring body; 5610. Moving ring; 57. External extrusion member; 58. Spring member;

[0041] 60. Separator ring; 61. Support ring; 62. Separator;

[0042] 70. Molding die; 71. Fixed die; 711. First outer convex die head; 712. Second outer convex die head; 72. Movable die; 721. Molding cavity. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0044] Example 1

[0045] like Figure 1 、 2 , 3, and 4, a double-layer PET bottle preform hot melt self-cleaning molding equipment, comprising:

[0046] A hot melt box 41, one end of which is connected to the raw material bin as an inlet and the other end is connected to the extrusion head 42 as an outlet, and a double-screw extrusion rod 411 is provided inside the hot melt box 41;

[0047] An extrusion head 42 is provided with an internal flow channel, and a rectifying member 44 is installed in the manifold 43;

[0048] A manifold 43 , one end of which is in communication with an internal flow channel of the extrusion head 42 ;

[0049] The filter includes an insulation diverter pipe 45 and an insulation sleeve 46. There are two groups of insulation diverter pipes 45 symmetrically distributed. The inlet of the manifold 43 is connected to the outlet of the insulation diverter pipe 45. The inlet of the insulation diverter pipe 45 is symmetrically distributed on the insulation sleeve 46. Mounting disks are installed at both ends of the insulation sleeve 46. The two mounting disks are mounting disk 1 47 mounted at the output end of the hot melt box 41 and an independently fixed mounting disk 2 48. A porous ring 49 is rotatably installed inside the insulation sleeve 46. The end of the porous ring 49 close to the manifold 43 extends to the outside of the mounting disk 2 48. A driving structure is installed on the outside of the mounting disk 2 48 for driving the porous ring 49 to rotate to a set angle. A filter screen 410 and a separator ring 60 are installed inside the porous ring 49. The filter screen 410 is located between the separator ring 60 and the porous ring 49. A blocking member 50 is installed at the end of the porous ring 49.

[0050] like Figure 1 and Figure 10 As shown, the hot melt box 41, the extrusion head 42, the manifold 43, and the filter are each provided in two groups;

[0051] The molding die 70 includes a fixed die 71 and a movable die 72. The fixed die 71 is provided with an inner layer injection molding structure and an outer layer injection molding structure, and the movable die 72 is provided with two molding cavities 721.

[0052] The inner layer injection molding structure includes an inner layer flow channel connected to the inner flow channel of one group of extrusion heads 42 and an outer male die head 711 that is socket-fitted into the inner side of the molding cavity 721;

[0053] The outer layer injection molding structure includes an outer layer flow channel connected to the inner flow channel of another set of extrusion heads 42 and an outer convex die head 712 that fits the end surface of the molding cavity 721;

[0054] The movable mold 72 can move closer to or farther away from the fixed mold 71 through a hydraulic cylinder independently set on the side of the movable mold 72 facing away from the fixed mold 71, and can also rotate to a set angle relative to the fixed mold 71. The movable mold 72 is set with its back to the fixed mold 71 and an independently installed stepper motor is used to drive the movable mold 72 to rotate 180° independently and automatically, thereby completing the position replacement of the two sets of molding cavities 721. The movable mold 72 includes a mold body and a fixed frame. The fixed frame is driven by a hydraulic cylinder, and the mold body is driven by a stepper motor fixed on the fixed frame to rotate relative to the fixed frame.

[0055] Two sets of hot melt systems are used, which are respectively connected to the internal flow channels of the inner layer injection molding structure and the outer layer injection molding structure of the fixed mold 71. The outer layer flow channel is filled with recycled PET melt, and the inner layer flow channel is filled with PET particle melt, ultimately achieving the production operation of bottle blanks with an outer layer thickness and inner layer thickness ratio of (1-3):1, and can also complete two-color injection molding operations.

[0056] During implementation, the raw material enters the hot melt box 41 for melting and is transported to the extrusion head 42 by the action of the double-screw extrusion rod 411. When entering the insulation sleeve 46, the molten material will pass through the separator ring 60, the filter screen 410, and the porous ring 49 into the insulation diverter pipe 45, enter the manifold 43, and after being rectified by the rectifying member 44, enter the internal flow channel of the extrusion head 42, and finally enter the internal flow channel in the forming mold 70, and finally enter the corresponding forming cavity 721. When a blockage occurs, the drive structure will drive the porous ring 49 to rotate the set angle, and use the separator ring 60 to cooperate with the flow direction of the molten material to transport the blocked impurities to the tail. It should be noted here that the separator ring 60 will not only fix the filter screen 410 but also transport the impurities accumulated on the surface of the filter screen 410 to the tail, so as to prevent the impurities from returning to the new position of the filter screen 410 under the action of the flow direction of the molten material during the angle adjustment process.

[0057] Example 2

[0058] In the hot melt forming equipment, in order to fix and support the filter 410 while also solving the problem that the filter 410 cannot be completely blocked by the outside-in filtering method, the inventors have also made the following improvements:

[0059] like Figure 4 、 5As shown, the separator ring 60 includes support rings 61 at both ends and separators 62 connected between the support rings 61. There are multiple groups of separators 62 evenly distributed circumferentially. The separator ring 60 is cylindrical as a whole. The multiple groups of separators 62 are all arc-shaped structures and gradually deviate from the inlet direction along the rotation direction of the porous ring 49 along the melt conveying direction. By optimizing the size parameters of the separator 62, the negative impact on the flow and pressure is reduced. Secondly, it can also effectively intercept the blockage and prevent it from moving to the filter screen 410 near the new position. The thickness of the separator 62 is 0.5-1.5mm and the width is 1-5mm. The side wall of the separator 62 here can be provided with a flow hole with a mesh size smaller than the mesh size of the filter screen 410.

[0060] During normal molding, impurities are intercepted by the filter 410 and concentrated on the surface of the filter 410 or stuck in the mesh. When a blockage problem occurs, the driving structure drives the porous ring 49 to rotate to a set angle, and the inlet of the insulation sleeve 46 corresponds to the position of the new filter 410. During the rotation, the separator 62 not only prevents the blockage from moving to the new position of the filter 410, but also cooperates with the flow direction of the molten material to guide the blockage to the check ring 51, thereby solving the problem of the blockage being stuck on the filter 410 at the new position.

[0061] Example 3

[0062] In the hot melt forming equipment, in order to automatically adjust the position of the heat-insulating shunt pipe 45 relative to the porous ring 49 and the filter 410, the inventors have also made the following improvements:

[0063] like Figure 4 、 9 As shown, the drive structure includes a blockage removal motor 414 and a worm 412 mounted at the output end of the blockage removal motor 414. The worm 412 is rotatably mounted on the second mounting plate 48. A worm gear 413 engages the outer side of the worm 412, and the worm gear 413 is mounted on the outer side of the porous ring 49. The blockage removal motor 414 drives the worm 412 to rotate, which in turn drives the worm gear 413 to rotate, thereby rotating the porous ring 49 to a set angle, so that the filter screen 410, which is not blocked, is aligned with the inlet of the thermal insulation diversion pipe 45, thereby solving the problem of blockage. It should be noted that the use of a worm gear drive method also utilizes its self-locking effect.

[0064] Example 4

[0065] In the hot melt forming equipment, in order to automatically identify the blockage phenomenon, the inventors have also made the following improvements:

[0066] like Figure 3As shown, the extruder head 42 is also equipped with a pressure sensor 421 for detecting the pressure on the blocking side of the filter 410 and a pressure sensor 422 for detecting the pressure on the discharge side of the porous ring 49. The pressure difference between the pressure values ​​detected by the pressure sensor 421 and the pressure sensor 422 is used to determine whether the pressure difference exceeds the set safety range. If so, the system will control the unblocking motor 414 to automatically start to complete the angle adjustment of the filter 410. The filter 410 in the new position is used in conjunction with the insulation diversion pipe 45, and then the pressure difference will return to the set safety range.

[0067] Example 5

[0068] In the hot melt forming equipment, in order to achieve automatic blockage removal and concentrate blockage in the area between the check ring 51 and the active member 52, and to prevent the insulation diversion pipe 45 from being re-blocked at the new filter screen 410 position due to the directional flow of the molten material after the heat preservation diversion pipe 45 corresponds to the new filter screen 410 position, the inventors have also made the following improvements:

[0069] like Figure 4 、 5 As shown in , 6, 7, and 8, the blocking member 50 includes a check ring 51 and an active member 52. The check ring 51 is installed on the inner side of the porous ring member 49 and the inner ring gradually moves away from the mounting plate 1 47. The thickness of the side of the support ring 61 close to the separator 62 gradually decreases. The active member 52 is slidably mounted inside the porous ring member 49 (the two are sealed by multiple sealing rings). An outer edge body 53 is provided on the outer side of the active member 52. The outer edge body 53 is arranged opposite to the mounting plate 2 48. An axial guide rod 54 is installed on the second disk 48, and the axial guide rod 54 is inserted on the outer edge body 53. A restraining part 55 is installed on the side of the axial guide rod 54 away from the mounting disk 2 48. A spring part 58 is sleeved on the outer side of the axial guide rod 54 between the restraining part 55 and the active part 52. An outer convex ring 56 is provided on the side of the active part 52 relative to the mounting disk 2 48, and an outer extrusion part 57 is installed on the outer side of the porous ring part 49. The outer extrusion part 57 and the outer convex ring 56 correspond in position and are adapted to each other.

[0070] The part of the active part 52 inside the porous ring part 49 is provided with a blocking head 521, the outer diameter of the blocking head 521 is smaller than the outer diameter of the active part 52, the side of the blocking head 521 facing away from the active part 52 is a spherical body for blocking the check ring 51, the outer wall of the blocking head 521 is evenly distributed with a reverse flow channel 1 522, the inlet of the reverse flow channel 1 522 is provided with a partition net 523, the middle part of the blocking head 521 is provided with a reverse flow channel 2 525, the reverse flow channel 1 522 and the reverse flow channel 2 525 are both connected to the circulation pump 524, the circulation pump 524 is installed inside the blocking head 521, the outlet of the reverse flow channel 2 525 is provided with a one-way diaphragm 526, the one-way diaphragm 526 is used to drain the molten material through the reverse flow channel 2 525 only into the insulation sleeve 46 for processing, and the reverse flow is blocked and cannot pass through.

[0071] In specific implementation, when the filter screen 410 is clogged, the de-blocking motor 414 rotates to rotate the porous ring 49 to a set angle, and the outer extrusion member 57 acts on the outer convex ring 56 to open the check ring 51 of the sealing head 521, and the circulation pump 524 is started to return a part of the molten material to the inner side of the filter screen 410 through the reverse flow channel 1 522 and the reverse flow channel 2 525. The slag is discharged by using the directional flow of the molten material, and the impurities in the discharged slag molten material are intercepted by the separation net 523 in the space between the check ring 51 and the sealing head 521.

[0072] Example 6

[0073] In the hot melt forming equipment, Figure 6 、 7 As shown in Figures 8 and 9, an outer protrusion ring 56 is provided with an outer protrusion structure 561 on the side opposite to the outer extrusion member 57. A chute 562 is distributed on the outer protrusion structure 561. Under the action of the outer extrusion member 57, the outer protrusion structure 561 compresses the spring member 58 to open the ring opening of the check ring 51. A moving body 563 is installed in the chute 562. Both the outer extrusion member 57 and the moving body 563 are made of wear-resistant materials.

[0074] like Figure 6 As shown, at least one sealing ring is provided between the outer wall of the active part 52 and the inner wall of the porous ring part 49, an annular groove 564 is provided on the side of the active part 52 facing away from the thermal insulation sleeve 46, a sealing plate 565 is installed at the notch of the annular groove 564, a travel switch 566 is provided on the sealing plate 565, and the travel switch 566 is used to control the opening and closing action of the circulation pump 524, a moving ring 5610 is slidably fitted in the annular groove 564, the moving body 563 is fixed on the side of the moving ring 5610 facing away from the sealing plate 565, an opening and closing ring 567 is provided on the side of the moving ring 5610 relative to the thermal insulation sleeve 46, a diversion flow hole 568 is provided on the side wall of the opening and closing ring 567, and the opening and closing ring 567 is used to open and close the reverse flow channel 1 522, a spring body 569 is installed between the sealing plate 565 and the moving ring 5610, the reverse flow channel 1 522 is radially distributed, and the reverse flow channel 2 525 is axially distributed.

[0075] When the unblocking motor 414 drives the porous ring 49 to rotate, the outer extrusion member 57 will act on the convex structure 561 to squeeze the active member 52 outward to compress the spring member 58, and then the sealing head 521 will open the ring mouth of the check ring 51 by 1-5mm. It should be noted that when the ring mouth is opened, the pressure effect inside the thermal insulation sleeve 46 can be ignored. After the ring mouth is opened, the outer extrusion member 57 will continue to rotate in the forward direction relative to the convex structure 561, which is conducive to the impurities being as close to the position of the check ring 51 as possible, thereby squeezing the movable body 563 exposed on the outside of the slide groove 562. The movable body 563 is compressed by the spring body 569 under the action of the outer extrusion member 57, thereby opening the bypass flow hole 568 on the opening and closing ring 567 to open the reverse flow channel 1 522, and the reverse flow When channel 1 522 is opened, the movable ring 5610 will act on the travel switch 566 to control the opening of the circulation pump 524, thereby completing the directional flow of the molten material, and cooperating with the separator 62 to drain the blockage and concentrate it in the area between the check ring 51 and the sealing head 521. When the inlet of the insulation diversion pipe 45 corresponds to the new position of the filter 410, the outer extrusion part 57, the outer protrusion structure 561, and the movable body 563 will be instantly separated at the same time, the travel switch 566 will automatically reset, and the circulation pump 524 will automatically close. It should be noted that the circulation flow of the circulation pump 524 is less than the flow through the filter 410, which is almost one tenth. Under the action of the spring part 58, the active part 52 automatically blocks the sealing head 521 at the ring mouth of the check ring 51. When the external extrusion piece 57 squeezes the exposed moving body 563 inward until the end face is flush with the convex structure 561, the limit switch 566 controls the circulation pump 524 to turn on, and at the same time the diversion hole 568 will open the reverse flow channel 1 522. It should be noted that this application adopts an insulation method between the output end of the hot melt box 41 and the output end of the extrusion head 42, and the best choice is constant temperature treatment.

Claims

1. A double-layer PET bottle preform hot melt self-cleaning molding equipment, characterized in that: It includes an inner layer injection molding assembly, an outer layer injection molding assembly, and a molding die (70); Among them, the inner layer injection molding assembly and the outer layer injection molding assembly both include: A hot melt box (41), one end of the hot melt box (41) is connected to the raw material bin as an inlet, and the other end is connected to the extrusion head (42) through a filter, and a double-screw extrusion rod (411) is provided inside the hot melt box (41); An extrusion head (42), wherein an internal flow channel is provided inside the extrusion head (42); A manifold (43), one end of which is in communication with an internal flow passage of the extrusion head (42); The molding die (70) includes a fixed die (71) and a movable die (72); the fixed die (71) is provided with an inner layer injection molding structure and an outer layer injection molding structure; and the movable die (72) is provided with two molding cavities (721); The inner layer injection molding structure includes an inner layer flow channel connected to the inner flow channel of one group of extrusion heads (42) and an outer convex die head (711) that is socket-fitted inside the molding cavity (721); The outer layer injection molding structure includes an inner layer flow channel connected to the inner flow channel of another group of extrusion heads (42) and a second outer convex die head (712) that is fitted with the end surface of the molding cavity (721); The movable mold can move closer to or farther away from the fixed mold (71), and can also rotate at a set angle relative to the fixed mold (71).

2. The device according to claim 1, characterized in that The filter comprises a heat-insulating shunt pipe (45) and a heat-insulating sleeve (46). The heat-insulating shunt pipe (45) is symmetrically distributed in two groups. The inlet of the confluence pipe (43) is connected to the outlet of the heat-insulating shunt pipe (45). The inlet of the heat-insulating shunt pipe (45) is symmetrically distributed on the heat-insulating sleeve (46). The two ends of the heat-insulating sleeve (46) are respectively equipped with mounting plates. The two mounting plates are respectively a mounting plate 1 (47) mounted on the output end of the hot melt box (41) and an independently fixed mounting plate 2 (48). The internal rotating mounting plate of the heat-insulating sleeve (46) is A porous ring member (49) is provided, and one end of the porous ring member (49) close to the manifold (43) extends to the outside of the second mounting plate (48). A driving structure is installed on the outside of the second mounting plate (48) for driving the porous ring member (49) to rotate a set angle. A filter screen (410) and a separation ring (60) are installed inside the porous ring member (49). The filter screen (410) is located between the separation ring (60) and the porous ring member (49). A blocking member (50) is installed inside the end of the porous ring member (49) away from the first mounting plate (47).

3. The device according to claim 1, characterized in that The extrusion head (42) is also provided with a first pressure sensor (421) for detecting the pressure on the blocking side of the filter screen (410) and a second pressure sensor (422) for detecting the pressure on the discharge side of the porous ring (49).

4. The device according to claim 1, characterized in that The separator ring (60) includes support rings (61) at both ends and separators (62) connected between the support rings (61). The separators (62) are evenly distributed in multiple groups in the circumferential direction. The multiple groups of separators (62) are all arc-shaped structures and gradually deviate from the inlet direction along the direction of rotation of the porous ring member (49) along the direction of molten material conveying. The thickness of the separators (62) is 0.5-1.5 mm and the width is 1-5 mm.

5. The device according to claim 1, characterized in that A rectifying member (44) is installed in the manifold (43), and arc-shaped structures are distributed on the rectifying member (44) for axial flow guidance.

6. The device according to claim 1, characterized in that The driving structure comprises a blockage removal motor (414) and a worm (412) mounted at the output end of the blockage removal motor (414). The worm (412) is rotatably mounted on the second mounting plate (48). A worm wheel (413) is meshed on the outer side of the worm (412). The worm wheel (413) is mounted on the outer side of the porous ring (49).

7. The device according to claim 1, characterized in that The blocking member (50) includes a check ring (51) and an active member (52). The check ring (51) is installed on the inner side of the porous ring member (49) and the inner ring gradually moves away from the mounting plate 1 (47). The active member (52) is installed in a sliding fit inside the porous ring member (49). An outer edge body (53) is provided on the outer side of the active member (52). The outer edge body (53) is arranged opposite to the mounting plate 2 (48). An axial guide rod (54) is installed on the mounting plate 2 (48). The axial guide rod (54) is inserted through the inner edge body (53). Inserted on the outer edge body (53), a restraining member (55) is installed on the side of the axial guide rod (54) away from the second mounting plate (48), a spring member (58) is sleeved on the outer side of the axial guide rod (54) between the restraining member (55) and the check ring (51), an outer convex ring (56) is provided on the side of the active member (52) close to the second mounting plate (48), and an outer extrusion member (57) is installed on the outer side of the porous ring member (49), and the circumferential positions of the outer extrusion member (57) and the outer convex ring (56) correspond to each other and are adapted to each other.

8. The device according to claim 7, characterized in that The active member (52) is provided with a plugging head (521) at the portion inside the porous ring member (49). The outer diameter of the plugging head (521) is smaller than the outer diameter of the active member (52). The side of the plugging head (521) facing away from the active member (52) is a spherical body for plugging the check ring (51). The outer wall of the plugging head (521) is provided with a reverse flow channel 1 (522). The inlet of the reverse flow channel 1 (522) is provided with a partition net (523). The middle part of the plugging head (521) is provided with a reverse flow channel 2 (525). Both the reverse flow channel 1 (522) and the reverse flow channel 2 (525) are connected to a circulation pump (524). The circulation pump (524) is installed inside the plugging head (521). The outlet of the reverse flow channel 2 (525) is provided with a one-way diaphragm (526).

9. The device according to claim 7, characterized in that An outer convex structure (561) is provided on one side of the outer convex ring (56) opposite to the outer extrusion member (57), and a slide groove (562) is distributed on the outer convex structure (561). Under the action of the outer extrusion member (57), the outer convex structure (561) compresses the spring member (58) to open the ring opening of the check ring (51), and a moving body (563) is installed in the slide groove (562).

10. The device according to claim 8, characterized in that The active member (52) is provided with an annular groove (564) on the side facing away from the heat-insulating sleeve (46), a blocking plate (565) is installed at the notch of the annular groove (564), a travel switch (566) is provided on the blocking plate (565), and the travel switch (566) is used to control the opening and closing action of the circulation pump (524), a moving ring (5610) is slidably fitted in the annular groove (564), a moving body (563) is fixed on the side of the moving ring (5610) facing away from the blocking plate (565), an opening and closing ring (567) is provided on the side of the moving ring (5610) facing the heat-insulating sleeve (46), a diversion flow hole (568) is provided on the side wall of the opening and closing ring (567), and the opening and closing ring (567) is used to open and close the reverse flow channel 1 (522), and a spring body (569) is installed between the blocking plate (565) and the moving ring (5610).

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