A method of reshaping plastic bottles and a reshaping die

Abstract

The application discloses a plastic bottle shaping method and a shaping mold, and belongs to the technical field of plastic packaging. The shaping method comprises the following steps: performing identification processing on a plastic bottle, and marking the position of an appearance defect; acquiring an infrared thermal image and processing the same to confirm and correct the appearance defect and the position thereof; based on the infrared thermal image identification result and the position confirmation result, adjusting the heating position of a local heating area on a shaping mold, so that the temperature of the local heating area reaches the melting point temperature of the material constituting the plastic bottle; closing the mold for shaping; and performing shaping quality determination on the plastic bottle. The shaping mold comprises a left mold, a right mold, a circular bottom mold and a pressure head. The left mold, the right mold and the circular bottom mold are respectively provided with a left runner, a right runner and a bottom mold runner. The plastic bottle shaping method and the shaping mold provided by the application can repair the appearance defects of part of the plastic bottles, and the plastic bottles after shaping and repairing can meet the use requirements and can be resold, so that a large amount of waste is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of plastic packaging, in particular to a plastic bottle shaping method and a shaping mold. BACKGROUND

[0002] Plastic bottles have the characteristics of not easy to break, low cost, high transparency, food-grade raw materials, etc., and are widely used as disposable plastic packaging containers for liquids or solids such as beverages, food, pickles, honey, dried fruits, edible oil, and agricultural and veterinary drugs.

[0003] At present, plastic bottles widely use polyester PET, polyethylene PE, polypropylene PP, etc. as raw materials, supplemented by corresponding processing aids, and are blow molded or extrusion blow molded after high-temperature melting. However, in actual production, due to fluctuations in raw materials, equipment, process parameters, etc., occasionally, plastic bottle finished products have appearance defects such as concave, leakage points, and bubbles. These plastic bottles with appearance defects cannot be directly sold, but all of them are discarded, which causes great waste. SUMMARY

[0004] The present application aims to provide a plastic bottle shaping method and a shaping mold, which can repair the appearance defects of some plastic bottles, and the plastic bottles after shaping and repairing can meet the use requirements and can be resold, thereby avoiding a large amount of waste.

[0005] The technical solution adopted by the present application is as follows:

[0006] A plastic bottle shaping method, the shaping method comprising:

[0007] Step S1, identifying and processing plastic bottles, retaining the plastic bottles that can be processed subsequently, and marking the positions of appearance defects on each plastic bottle; the appearance defects include leakage points, bubbles, and concave;

[0008] Step S2, rapidly injecting hot air into the plastic bottles retained in step S1 one by one until the pressure value in the plastic bottles reaches a sixth threshold value; simultaneously, acquiring infrared thermal images of the plastic bottles at multiple angles in the inflated state, and performing infrared identification processing on the infrared thermal images to confirm and correct the appearance defects and their positions on the plastic bottles;

[0009] Step S3, based on the infrared thermal image identification result and the position confirmation result in step S2, adjusting the heating position of the local heating area on the shaping mold, so that the temperature of the local heating area reaches the melting point temperature of the material constituting the plastic bottle;

[0010] Step S4, the heated plastic bottle in step S2 is put into the heated shaping mold in step S3, the appearance defect is roughly towards the local heating area, the mold is closed, the shaping mold stops heating after waiting for 5-30s, hot air is quickly injected into the plastic bottle until the pressure value in the plastic bottle reaches the seventh threshold value, continue to wait for 5-30s, open the mold and take out the plastic bottle;

[0011] Step S5, the plastic bottle shaped in step S4 is judged for shaping quality, and the shaping is completed.

[0012] Further, when the plastic bottle is identified in step S1, an artificial measurement method is adopted, which specifically includes:

[0013] The appearance defect on the plastic bottle is measured and calculated by artificial measurement tool, and then confirmed;

[0014] If the measurement result shows that the appearance defect on the plastic bottle exceeds the expected shaping requirement, it is discarded;

[0015] If the measurement result shows that the appearance defect on the plastic bottle is within the expected shaping requirement, it is retained for further processing, and the position of the appearance defect on each retained plastic bottle is marked.

[0016] Further, when the plastic bottle is identified in step S1, an image recognition method is adopted, which specifically includes:

[0017] Obtain the ordinary visible light image of the plastic bottle at multiple angles;

[0018] The ordinary visible light image is introduced into a visible light recognition model obtained by machine deep learning, and the visible light recognition model is used for judgment;

[0019] If the model judgment result shows that the appearance defect on the plastic bottle exceeds the expected shaping requirement, it is discarded;

[0020] If the model judgment result shows that the appearance defect on the plastic bottle is within the expected shaping requirement, it is retained for further processing, and the position of the appearance defect on each retained plastic bottle is automatically marked.

[0021] Further, the temperature of the hot air in step S2 is lower than the softening point temperature of the material constituting the plastic bottle.

[0022] Further, when the infrared thermal image is identified in step S2, an infrared recognition model based on machine deep learning is used for judgment.

[0023] Further, in the step S3, the temperature of the remaining regions of the shaping mold, except for the local heating region, is maintained at a temperature lower than the softening point temperature of the material of the plastic bottle.

[0024] Further, in the step S4, the temperature of the hot air is lower than the softening point temperature of the material of the plastic bottle.

[0025] Further, in the step S5, when the shaping quality of the plastic bottle shaped in the step S4 is determined, the appearance detection combined with the water tightness detection can be used, or the method used in the step S2 can be used.

[0026] Further, in the step S5, when the shaping quality is determined, if the shaping determination result is passed, the shaping of the plastic bottle is completed.

[0027] If the shaping determination result is failed, the plastic bottle is directly discarded or the steps S1 to S4 are re-implemented, and the number of repeated implementation is 1 to 3 times.

[0028] Based on the same inventive concept, the present application also provides a shaping mold for a plastic bottle, which can be used in the shaping method of the plastic bottle described above, and the shaping mold comprises:

[0029] a left mold having a left mold body, a left half cavity being formed from the parting surface of the left mold body; the left half cavity is adapted to the outer contour of the body of the plastic bottle; a plurality of independent left flow channels are distributed on the left mold body along the height direction of the left mold body; each of the left flow channels extends along the outer contour of the inner wall of the left half cavity in the circumferential direction, and the inlet and outlet of each of the left flow channels can be provided with an independent valve;

[0030] a right mold having a right mold body, a right half cavity being formed from the parting surface of the right mold body; the right half cavity is adapted to the outer contour of the body of the plastic bottle; a plurality of independent right flow channels are distributed on the right mold body along the height direction of the right mold body; each of the right flow channels extends along the outer contour of the inner wall of the right half cavity in the circumferential direction, and the inlet and outlet of each of the right flow channels can be provided with an independent valve;

[0031] a circular bottom mold having a bottom mold body, the diameter of the bottom mold body is substantially consistent with the diameter of the bottom of the plastic bottle, and the upper surface of the bottom mold body is adapted to the outer contour of the bottom of the plastic bottle; an S-shaped or spiral bottom mold flow channel is arranged on the bottom mold body; the inlet and outlet of the bottom mold flow channel are provided with a valve;

[0032] a press head having a press head body and an air inlet pipe; the press head body is provided with a circular positioning groove; the diameter of the circular positioning groove is substantially consistent with the outer diameter of the mouth of the plastic bottle; the air inlet pipe is in communication with the inner region of the circular positioning groove;

[0033] The parting surface of the left mold and the right mold is in contact when the shaping mold is closed, the left half cavity and the right half cavity form a surrounding structure, and the top and bottom of the surrounding structure are open, and the circular bottom mold is located at the lower part of the surrounding structure and closes the bottom of the surrounding structure; therefore, the hollow internal area of the combined structure of the left mold, the right mold and the circular bottom mold is the shaping cavity; when the shaping processing is needed to be performed by using the shaping mold, the bottle body and the bottle bottom of the preheated plastic bottle are located in the shaping cavity and are clamped by the left mold, the right mold and the circular bottom mold; the bottle mouth of the plastic bottle is located at the open top of the surrounding structure and extends to the outside; and the pressure head presses the bottle mouth of the plastic bottle and forms a structure seal.

[0034] The beneficial effects of the present application are:

[0035] 1. The plastic bottle shaping method in the present application is used for shaping and repairing the plastic bottles with appearance defects (mainly including leakage points, depressions and bubbles), the heating position of the local heating area on the shaping mold is set according to the confirmation of the appearance defects, the temperature of the local heating area is heated to the melting point temperature of the material of the plastic bottle, the appearance defect area of the plastic bottle is attached to the local heating area of the shaping mold, the appearance defect area of the plastic bottle can be slightly softened and melted, and after re-injection of air, the local softening and melting state of the plastic bottle continues to be maintained under heat, and the local softening and melting of the plastic bottle is reblow shaped under pressure to repair the appearance defects of the plastic bottle, and the plastic bottle after shaping and repairing can meet the use requirements and can be resold, thereby avoiding a large amount of waste. In the long run, the plastic bottle shaping method in the present embodiment also has high economic value.

[0036] 2. The present application also provides a shaping mold for plastic bottles, which can correspondingly introduce a heating medium through independent left runner, right runner and bottom mold runner, so that the temperature of the local heating area of the shaping mold reaches the melting point temperature of the material of the plastic bottle, and the plastic bottles with appearance defects can be conveniently shaped to realize normal sales of the plastic bottles and avoid waste. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0038] Figure 1 For the flowchart of the plastic bottle shaping method in embodiment 1.

[0039] Figure 2 Figure 1 is a schematic diagram of the appearance defect in Example 1.

[0040] Figure 3 Figure 2 is a schematic diagram of the state of the shaping mold before the mold is closed in Example 2.

[0041] Figure 4 Figure 3 is a schematic diagram of the state of the shaping mold after the mold is closed in Example 2.

[0042] Figure 5 Figure 4 is a schematic diagram of the state of the shaping mold after the mold is opened in Example 2. Figure 4 Figure 5 is an A-A sectional view in Example 2.

[0043] Figure 6 Figure 6 is a B-B sectional view in Example 2. Figure 4 Figure 7 is a schematic diagram of the appearance defect in Example 3. DETAILED DESCRIPTION

[0044] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0045] The disclosure below provides many different embodiments or examples for implementing different structures of the present application. For the purpose of simplicity, the components and arrangements of the examples that are described below are shown in block diagram form. It will be readily apparent to those skilled in the art that the present application is not limited to the embodiments and examples described below and can be practiced with modifications and alterations limited only by the spirit and scope of the present application.

[0046] The embodiments of the present application will be described in detail below with reference to the accompanying drawings. Example 1

[0047] In order to avoid waste, in this embodiment, plastic bottles with appearance defects (mainly including pinholes, depressions, and bubbles) are subjected to shaping repair, so that the appearance defects of part of the plastic bottles are repaired, and the plastic bottles after shaping repair can meet the use requirements and can be resold.

[0048] Figure 1 shows the flow of the plastic bottle shaping method. As shown in Figure 2, the plastic bottle shaping method includes the following steps: Figure 1 Figure 1 Figure 1 shows the flow of the plastic bottle shaping method. As shown in Figure 2, the plastic bottle shaping method includes the following steps:

[0049] ​Step S1: Identify and process the plastic bottles to remove those that do not meet the shaping requirements. The remaining plastic bottles are retained for further processing, and the location of appearance defects on each retained plastic bottle is marked.

[0050] In this embodiment, plastic bottles that do not meet the shaping requirements typically exhibit the following characteristics:

[0051] (1) Obvious leaks, i.e., the diameter (or maximum size) at the leak point is ≥ the first threshold (e.g., 1 mm), as shown in the attached figure. Figure 2 As shown in a;

[0052] (2) Obvious bubbling or obvious dents, that is, when the bubbling or dent point is located on the body of the plastic bottle, the projected area of ​​the bubbling or dent point along the direction perpendicular to the height of the plastic bottle is ≤ the second threshold (e.g., 1cm). 2 Furthermore, the maximum distance between the bubbling point or dent and the body of the plastic bottle is ≤ the third threshold (e.g., 5mm), as shown in the attached document. Figure 2 As shown in b;

[0053] Alternatively, if the bulge or depression is located on the bottom of the plastic bottle, then along the direction parallel to the height of the plastic bottle, the projected area of ​​the bulge or depression is ≤ the fourth threshold (e.g., 1.5cm). 2 Furthermore, the maximum distance between the bubbling point or dent and the body of the plastic bottle is ≤ the fifth threshold (e.g., 7mm), as shown in the attached document. Figure 2 As shown in c. In this embodiment, the second threshold and the fourth threshold can also be the same, and the third threshold and the fifth threshold can also be the same.

[0054] Specifically, in this embodiment, the method for removing plastic bottles that do not meet the shaping requirements can be either manual measurement or image recognition.

[0055] When using manual measurement, the appearance defects on the plastic bottles are measured and calculated using measuring tools such as magnifying glasses and rulers. If the measurement and calculation results show that the appearance defects on the plastic bottle exceed the expected shaping requirements, it is discarded; if the measurement and calculation results show that the appearance defects on the plastic bottle are within the expected shaping requirements, it is retained for further processing. At the same time, the location of the appearance defects on each retained plastic bottle is marked.

[0056] The specific marking rules are as follows:

[0057] If the appearance defect is located on the bottom of the plastic bottle, it is marked as "0".

[0058] If the appearance defect is located on the body of the plastic bottle, the height value is marked with the bottom surface of the bottle as the reference surface. For example, if the appearance defect is located on the body of the plastic bottle at a position 10cm from the bottom of the bottle, it is marked as "10".

[0059] When the image recognition method is used, the ordinary visible light images of the plastic bottles at multiple angles are first obtained, and then the ordinary visible light images are introduced into a visible light recognition model obtained by machine deep learning, and the visible light recognition model is used for determination. If the visible light recognition model determination result shows that the appearance defect of the plastic bottle exceeds the expected shaping requirement, it is discarded; if the visible light recognition model determination result shows that the appearance defect of the plastic bottle is within the expected shaping requirement, it is retained and waits for further processing. At the same time, the position of the appearance defect on each retained plastic bottle is marked.

[0060] Among them, the visible light recognition model is obtained in the following way: first, the original images of a plurality of plastic bottles with appearance defects are obtained, and then the original images are marked one by one by artificial. The contents of the marking include the appearance defect type (leakage, blister and depression), the appearance defect parameter (diameter, projection area, distance and position parameter, etc.) and the artificial recognition result (discard, process). The labeled data is collected and divided into training set and test set and sent into convolutional neural network, and finally the model with the highest recognition accuracy is retained as the visible light recognition model. The way to obtain the position parameter is referred to the marking rule in the foregoing artificial measurement method.

[0061] In this embodiment, the input of the artificial measurement method is low, and the efficiency of the image recognition method is high, and the two can be used or mixed according to the actual situation.

[0062] In this embodiment, in addition to the image recognition method based on machine deep learning, the image recognition method for identifying the appearance defect of the plastic bottle is also applicable.

[0063] Step S2, hot air is injected into the plastic bottles retained in step S1 one by one until the pressure value in the plastic bottle reaches the sixth threshold value (such as 0.15 MPa), and the temperature of the hot air generally needs to be lower than the softening point temperature of the material of the plastic bottle (such as the temperature of the hot air is 40~50℃, in order to avoid thermal deformation of the normal area of the plastic bottle during shaping); At the same time, the infrared thermal images of the plastic bottles at multiple angles in the inflated state are obtained synchronously, and the infrared recognition processing is performed on the infrared thermal images to confirm and correct the appearance defect and the position of the appearance defect on the plastic bottle.

[0064] Among them, the infrared recognition processing of the infrared thermal image can also be determined by an infrared recognition model obtained based on machine deep learning. The way to obtain the infrared recognition model determination can refer to the way to obtain the foregoing visible light recognition model. The determination process of the infrared recognition model can also refer to the determination process of the foregoing visible light recognition model.

[0065] In this embodiment, on the one hand, the plastic bottle is preheated by injecting hot air into the plastic bottle, thereby preparing for the subsequent process. On the other hand, by injecting hot air into the plastic bottle, the pressure inside the plastic bottle is slightly higher than the pressure outside the plastic bottle (i.e. the plastic bottle is in a slightly positive pressure state). If there is a leak in the plastic bottle (including the repairable leak identified in the previous step and the non-visible leak), it will be presented on the corresponding infrared thermal image (for example, the leak will present a clear "spray" pattern due to the leakage of hot air), which is equivalent to a secondary detection of the plastic bottle to further find invisible appearance defects (mainly small leaks). The marking rule of the new leak is the same as step S1. If the slight positive pressure inside the plastic bottle is maintained, some dents can be repaired. For example, the dent is caused by the collision between the plastic bottles or between the plastic bottle and the equipment during production, and the projection area and distance of the dent are small. The slight positive pressure can restore the dent, i.e. restore it to a smooth state. Finally, the infrared thermal images of the plastic bottle from multiple angles can further confirm or correct the positions of the dents or bubbles.

[0066] Step S3: Based on the identification result and position confirmation result of the infrared thermal image in step S2, adjust the position of the local heating area on the shaping mold so that the temperature of the local heating area reaches the melting point temperature of the material of the plastic bottle, and the temperature of the remaining area is maintained at about the softening point temperature of the material of the plastic bottle (for example, maintained at 40-50°C to avoid thermal deformation of the normal area of the plastic bottle during shaping). The shaping mold has a shaping cavity that is roughly consistent with the shape of the qualified plastic bottle.

[0067] For example, the plastic bottle is made of PE blow molding, and the appearance defect is located on the bottle body of the plastic bottle at a position 10 cm away from the bottom. The temperature of the area between 9-11 cm from the left mold to the circular bottom mold of the shaping mold is adjusted to about 125°C, and the temperature of the remaining area of the left mold and the right mold is maintained at about 40-50°C.

[0068] Step S4: Put the plastic bottle heated in step S2 into the shaping mold heated in step S3, with the appearance defect roughly facing the local heating area of the shaping mold, close the mold, wait for 5-30 seconds, then stop heating the shaping mold, quickly inject hot air into the plastic bottle until the pressure value inside the plastic bottle reaches the seventh threshold value (for example, 0.2 MPa), the temperature of the hot air is 40-50°C, continue to wait for 5-30 seconds, open the mold and take out the plastic bottle.

[0069] In this embodiment, after the plastic bottle is placed in the forming mold, the defective area of ​​the plastic bottle comes into contact with the locally heated area of ​​the forming mold, and the defective area on the plastic bottle may slightly soften and melt. After air is reinjected, the locally softened and melted state of the plastic bottle under heat continues, and at the same time, under pressure, the softened and melted part of the plastic bottle is re-blow molded and shaped.

[0070] Step S5: The plastic bottle shaped in step S4 is subjected to a shaping quality assessment. If the shaping assessment result is satisfactory, the shaping of the plastic bottle is complete. If the shaping assessment result is unsatisfactory, the bottle is discarded directly or steps S1 to S4 are repeated 1 to 3 times. For example, if the appearance inspection and water tightness inspection still fail after repeating steps S1 to S4 twice, the shaping process will not continue.

[0071] In this embodiment, the method for determining the shaping quality can combine visual inspection with water tightness testing. Visual inspection can be performed by visual observation. Water tightness testing can be conducted using a water-filling test.

[0072] Alternatively, the shaping quality determination method in this embodiment can also be performed in the manner described in step S2.

[0073] The plastic bottle shaping method described in this embodiment is used to reshape and repair plastic bottles with appearance defects (mainly including leaks, dents, and bubbles). This allows some of the appearance defects to be repaired, and the repaired plastic bottles can meet usage requirements and be resold, avoiding significant waste. In the long run, the plastic bottle shaping method described in this embodiment also has high economic value. Example 2

[0074] This embodiment provides a plastic bottle shaping mold, the structure of which is shown in the attached figure. Figure 3 and attached Figure 4 As shown in the diagram. The shaping mold includes a left mold 1, a right mold 2, a circular bottom mold 3, and a pressure head 4. (See attached diagram) Figure 3 Appendix Figure 4 and attached Figure 6 As shown, the left mold 1 includes a left mold body 11. A left half-cavity 12 is formed from the parting surface of the left mold body 11. This left half-cavity 12 is adapted to the outer contour of the plastic bottle. Along the height direction of the left mold body 11, several independent left flow channels 13 are distributed on the left mold body 11. Each left flow channel 13 extends circumferentially along the outer contour of the inner wall of the left half-cavity 12, and its inlet and outlet can be equipped with independent valves. Thus, when it is necessary to heat a local area of ​​the left mold 1, a heating medium (such as heat transfer oil) is introduced into the corresponding left flow channel 13.

[0075] The right mold 2 and the left mold 1 have similar structures. (See attached image.) Figure 3and attached Figure 4 As shown in the attached

[0076] As shown in the attached Figure 3 , the attached Figure 4 and the attached Figure 5 As shown in the attached

[0077] As shown in the attached Figure 3 and the attached Figure 4 As shown in the attached

[0078] When the shaping mold is closed, the parting surface of the left mold 1 and the right mold 2 are in contact. The left half cavity 12 and the right half cavity 22 form a surrounding structure, and the top and bottom of the surrounding structure are open. The circular bottom mold 3 is located at the lower part of the surrounding structure and closes the bottom of the surrounding structure. Thus, the hollow interior region of the combined structure of the left mold 1, the right mold 2 and the circular bottom mold 3 is the shaping cavity.

[0079] When the plastic bottle needs to be reshaped, the bottle body and the bottle bottom of the preheated plastic bottle are located in the reshaping cavity and clamped by the left mold 1, the right mold 2 and the circular bottom mold 3. The bottle mouth of the plastic bottle is located at the open top of the enclosing structure and extends to the outside. The pressure head 4 presses the bottle mouth of the plastic bottle and forms a structure (i.e. the bottle mouth is inserted into the circular positioning groove). After the plastic bottle is placed in the reshaping mold, the appearance defect area of the plastic bottle is in contact with the local heating area of the reshaping mold (for example, the PE bottle, the concave part of the plastic bottle at the left upper part of the bottle body 10 cm away from the bottom is in contact with the inner wall of the left half cavity 12 of the left mold 9-11 cm away from the circular bottom mold, which is heated to 125℃), and the appearance defect area of the plastic bottle can be slightly softened and melted. The mold is closed, and after waiting for 5-30s, the reshaping mold stops heating, hot air is quickly injected into the plastic bottle until the pressure value in the plastic bottle reaches the seventh threshold value (for example, 0.2MPa), the temperature of the hot air is 40-50℃, and the mold is opened to take out the plastic bottle after continuing to wait for 5-30s.

[0080] The reshaping mold in the embodiment can correspondingly introduce the heating medium through the independent left flow channel, right flow channel and bottom mold flow channel, so that the temperature of the local heating area of the reshaping mold reaches the melting point temperature of the material of the plastic bottle, and the plastic bottle with appearance defects can be conveniently reshaped to realize normal sales of the plastic bottle and avoid waste.

Claims

1. A method of reshaping a plastic bottle, characterized by, The plastic bottle shaping method comprises the following steps: Step S1, identifying the plastic bottles, retaining the plastic bottles that can be processed subsequently, and marking the positions of the appearance defects on each plastic bottle; the appearance defects include leakage points, bubbles, and depressions; Step S2, rapidly injecting hot air into the plastic bottles retained in step S1 one by one until the pressure value in the plastic bottles reaches a sixth threshold value; simultaneously, acquiring infrared thermal images of the plastic bottles at multiple angles in the inflated state, and performing infrared identification processing on the infrared thermal images to confirm and correct the appearance defects and their positions on the plastic bottles; Step S3, based on the infrared thermal image identification result and position confirmation result in step S2, adjusting the heating position of the local heating area on the shaping mold so that the temperature of the local heating area reaches the melting point temperature of the material constituting the plastic bottle; Step S4, placing the plastic bottles heated in step S2 into the shaping mold heated in step S3, with the appearance defects facing the local heating area, closing the mold, waiting for 5-30 seconds, and then stopping heating of the shaping mold, rapidly injecting hot air into the plastic bottles until the pressure value in the plastic bottles reaches a seventh threshold value, continuing to wait for 5-30 seconds, opening the mold, and taking out the plastic bottles; Step S5, determining the shaping quality of the plastic bottles shaped in step S4, and completing shaping.

2. The plastic bottle shaping method according to claim 1, wherein When identifying the plastic bottles in step S1, the artificial measurement method is adopted, which specifically comprises the following steps: Artificially measuring and calculating the appearance defects on the plastic bottles by means of measuring tools to confirm the appearance defects; If the measurement and calculation result shows that the appearance defects on the plastic bottles exceed the expected shaping requirement, the plastic bottles are discarded; If the measurement and calculation result shows that the appearance defects on the plastic bottles are within the expected shaping requirement, the plastic bottles are retained for further processing, and the positions of the appearance defects on each retained plastic bottle are marked.

3. The plastic bottle shaping method according to claim 1, wherein When identifying the plastic bottles in step S1, the image recognition method is adopted, which specifically comprises the following steps: Acquiring ordinary visible light images of the plastic bottles at multiple angles; Importing the ordinary visible light images into a visible light recognition model obtained through machine deep learning, and determining by the visible light recognition model; If the model determination result shows that the appearance defects on the plastic bottles exceed the expected shaping requirement, the plastic bottles are discarded; If the model determination result shows that the appearance defects on the plastic bottles are within the expected shaping requirement, the plastic bottles are retained for further processing, and the positions of the appearance defects on each retained plastic bottle are automatically marked.

4. The plastic bottle shaping method according to claim 1, wherein The temperature of the hot air in step S2 is lower than the softening point temperature of the material constituting the plastic bottle.

5. The plastic bottle shaping method according to claim 1, wherein When performing infrared identification processing on the infrared thermal images in step S2, an infrared identification model obtained based on machine deep learning is adopted for determination.

6. The plastic bottle shaping method according to claim 1, wherein In step S3, the temperature of the regions on the shaping mold other than the local heating area is maintained below the softening point temperature of the material constituting the plastic bottle.

7. The plastic bottle shaping method according to claim 1, wherein The temperature of the hot air in the step S4 is lower than the softening point temperature of the material of the plastic bottle.

8. The plastic bottle shaping method according to claim 1, wherein In the step S5, the shaping quality of the plastic bottle shaped in the step S4 is determined, which can be determined by appearance detection combined with water tightness detection, or by the method in the step S2.

9. The plastic bottle shaping method according to claim 1, wherein If the shaping determination result is passed, the shaping of the plastic bottle is completed. If the shaping determination result is failed, the plastic bottle is directly discarded or the steps S1-S4 are re-implemented, and the number of repeated implementation is 1-3 times.

10. A plastic bottle shaping mold which is used for the plastic bottle shaping method described in any one of claims 1 to 9, characterized by, The shaping mold comprises: a left mold having a left mold body, a left half cavity being formed from a parting surface of the left mold body, the left half cavity being adapted to the outer contour of the body of the plastic bottle, a plurality of independent left flow channels being distributed on the left mold body along the height direction of the left mold body, each of the left flow channels extending along the outer contour of the inner wall of the left half cavity in the circumferential direction, and an independent valve being provided at the inlet and outlet of each of the left flow channels; a right mold having a right mold body, a right half cavity being formed from a parting surface of the right mold body, the right half cavity being adapted to the outer contour of the body of the plastic bottle, a plurality of independent right flow channels being distributed on the right mold body along the height direction of the right mold body, each of the right flow channels extending along the outer contour of the inner wall of the right half cavity in the circumferential direction, and an independent valve being provided at the inlet and outlet of each of the right flow channels; a circular bottom mold having a bottom mold body, the diameter of the bottom mold body being consistent with the diameter of the bottom of the plastic bottle, the upper surface of the bottom mold body being adapted to the outer contour of the bottom of the plastic bottle, and an S-shaped or spiral bottom mold flow channel being provided on the bottom mold body, the inlet and outlet of the bottom mold flow channel being provided with a valve; a pressure head having a pressure head body and an air inlet pipe, the pressure head body being provided with a circular positioning groove, the diameter of the circular positioning groove being consistent with the outer diameter of the mouth of the plastic bottle, and the air inlet pipe being in communication with the inner region of the circular positioning groove. When the shaping mold is closed, the parting surfaces of the left mold and the right mold are in contact, the left half cavity and the right half cavity form a closed structure, the top and bottom of the closed structure are open, the circular bottom mold is located at the lower part of the closed structure and closes the bottom of the closed structure, and thus the hollow inner region of the combination of the left mold, the right mold and the circular bottom mold is the shaping cavity. When the shaping mold is used for shaping, the body and the bottom of the preheated plastic bottle are located in the shaping cavity and are clamped by the left mold, the right mold and the circular bottom mold, the mouth of the plastic bottle is located at the open top of the closed structure and extends to the outside, and the pressure head presses the mouth of the plastic bottle and forms a structural seal.

Images