Blow-and-suction forming process for soft-pack containers

Abstract

The application discloses a kind of soft package container blow suction forming process, comprising the following steps: after soft plastic material plasticizing, extrusion is formed tubular parison, and according to the target height and target wall thickness of soft package container control the plasticizing temperature, extrusion speed and sag length of tubular parison;The tubular parison is placed into forming die and closes mould, and the cavity of the forming die is divided into mouth along area, shoulder area, bottle body area, bottom area and support rib forming area, and the shoulder area, bottle body area, bottom area and support rib forming area are respectively communicated with independent negative pressure channel, and the application relates to the field of soft plastic package container forming technology.This kind of soft package container blow suction forming process, by dividing the forming cavity into mouth along area, shoulder area, bottle body area, bottom area and support rib forming area, and making each area correspond to independent negative pressure channel, different negative pressure time sequence and negative pressure intensity can be applied to different areas in the same forming cycle, and the mold reliability of complex curved surface area is improved.

Description

Technical Field

[0001] This invention relates to the field of flexible plastic packaging container molding, and more specifically, to a blow-suction molding process for flexible packaging containers. Background Technology

[0002] Flexible packaging containers are mostly made of polyethylene, polypropylene, or multi-layer co-extruded flexible plastic materials. Common molding methods include extrusion blow molding, thermoforming, and heat sealing. Publication number CN102490348A discloses a blow molding method and equipment, which uses a vacuum pump to extract air from the mold cavity, creating negative pressure between the outer surface of the preform and the cavity to assist in mold application. Publication number CN107775946A discloses a fully automated blow molding production line and process with human-machine interaction and intelligent closed-loop control, which monitors the preform wall thickness and adjusts process parameters to improve wall thickness distribution. Although the above solutions involve vacuum-assisted mold application or wall thickness feedback control, for thin-walled flexible packaging containers, it is still difficult to simultaneously address issues such as priority molding of support ribs, time-sharing mold application of complex areas at the shoulder and bottom, delayed mold application of the bottle body, and batch parameter correction within the same molding cycle. This easily leads to problems such as rim shrinkage, shoulder thinning, bottom wrinkling, incomplete support structure, and insufficient anti-collapse performance. Summary of the Invention

[0003] The purpose of this invention is to provide a blow-suction molding process for flexible packaging containers, which solves the problems of existing solutions, although they involve vacuum-assisted molding or wall thickness feedback control, still making it difficult to simultaneously take into account the priority molding of support ribs, time-sharing molding of complex areas such as the shoulder and bottom, delayed molding of the bottle body, and batch parameter correction within the same molding cycle for thin-walled flexible packaging containers. This easily leads to problems such as rim shrinkage, shoulder thinning, bottom wrinkling, incomplete support structure, and insufficient anti-collapse performance.

[0004] This invention achieves the above objectives through the following technical solution: a blow-dip molding process for flexible packaging containers, comprising the following steps: S1. Plasticize the soft plastic material and extrude it to form a tubular preform. Control the plasticizing temperature, extrusion speed and droop length of the tubular preform according to the target height and target wall thickness of the soft packaging container. S2. The tubular preform is placed into the molding mold and the mold is closed. The mold cavity of the molding mold is divided into a mouth rim area, a shoulder area, a bottle body area, a bottom area and a support rib forming area. The shoulder area, bottle body area, bottom area and support rib forming area are respectively connected to independent negative pressure channels. The support rib forming area is provided with one of the following: shallow rib groove, annular support groove and folding guide groove, or a groove structure formed by a combination of two or more of them. S3. Introduce the first stage pre-blown gas into the tubular preform to make the tubular preform form an initial expansion state that is not completely attached to the inner wall of the mold cavity; S4. In the initial expansion state, the independent negative pressure channels corresponding to the support rib forming area are opened first in the shoulder area, bottle body area and bottom area, so that the local material of the tubular preform enters the groove structure and forms the prototype of the support structure. S5. After the supporting structure prototype is formed, open the independent negative pressure channels corresponding to the shoulder area and the bottom area according to the set opening sequence, and increase the blowing pressure inside the tubular preform from the first stage pre-blowing pressure to the intermediate molding pressure, so that the shoulder area and the bottom area of ​​the tubular preform are attached to the inner wall of the corresponding mold cavity before the main body area of ​​the bottle. S6. After the target molding state is reached in the shoulder area and bottom area, the independent negative pressure channel corresponding to the bottle body area is opened, and the blowing pressure inside the tubular preform is increased from the intermediate molding pressure to the second stage molding pressure, so that the bottle body main body area of ​​the tubular preform fits the inner wall of the bottle body area mold cavity. S7. During S3 to S6, collect the local wall thickness, outer contour expansion and mold-attachment status of the tubular preform or molding intermediate, and adjust the blowing pressure rise rate, negative pressure adsorption intensity and negative pressure holding time of the corresponding area according to the collection results. S8. After the tubular preform is molded, maintain the internal pressure gas and cool the forming mold, while maintaining the negative pressure state of the mouth rim area, bottom area and support rib forming area, so that the mouth rim, main wall surface, bottom support structure and flexible support structure of the soft packaging container are simultaneously shaped. S9. After cooling is complete, release the negative pressure in the independent negative pressure channel and the internal pressure of the tubular preform, open the mold and take out the finished soft packaging container.

[0005] Furthermore, the independent negative pressure channels include a shoulder negative pressure channel, a bottle body negative pressure channel, a bottom negative pressure channel, and a support rib negative pressure channel; The shoulder negative pressure channel, bottle body negative pressure channel, bottom negative pressure channel and support rib negative pressure channel are each connected to an independent control valve. The independent control valve is used to control the opening time, closing time, negative pressure gauge pressure and negative pressure holding time of the corresponding negative pressure channel.

[0006] Furthermore, the soft plastic material is selected from one of polyethylene, polypropylene, ethylene-vinyl acetate copolymer, thermoplastic elastomer, and multilayer co-extruded soft plastic material; The plasticizing temperature of the tubular preform is to The drooping length of the tubular preform is 1.02 to 1.25 times the height of the mold cavity.

[0007] Furthermore, in S3, the pre-blowing pressure in the first stage is... to The pre-blowing time is to ; The maximum outer contour dimension of the pre-blown tubular preform is 60% to 85% of the maximum inner contour dimension of the mold cavity in the bottle body area.

[0008] Furthermore, in S4, the opening time of the support rib negative pressure channel is earlier than that of the shoulder negative pressure channel, the bottle body negative pressure channel, and the bottom negative pressure channel; The negative pressure gauge reading of the negative pressure channel of the supporting rib is to The negative pressure holding time is to ; The prototype support structure includes one or more of the following: a prototype flexible support rib extending along the height direction of the flexible packaging container; a prototype bottom support ring located in the circumferential region at the bottom of the flexible packaging container; and a prototype folding guide located on the wall of the flexible packaging container.

[0009] Furthermore, in S5, the shoulder negative pressure channel and the bottom negative pressure channel are opened in a time-sharing manner; When the radius of curvature of the shoulder of the flexible packaging container is smaller than the radius of curvature of the bottle body, the shoulder negative pressure channel is opened first, and then the bottom negative pressure channel is opened. When the bottom of the flexible packaging container has a concave support structure, the bottom negative pressure channel is opened first, and then the shoulder negative pressure channel is opened. The intermediate forming pressure is to .

[0010] Furthermore, in S6, the negative pressure channel of the bottle body is opened after the target molding state is reached in the shoulder area and the bottom area; The molding pressure in the second stage is to The negative pressure gauge reading of the negative pressure channel in the bottle body is... to ; The target molding state is defined as follows: the mold cavity pressure change value reaches the target pressure change range; the negative pressure channel airflow change value reaches the target airflow change range; or the distance between the outer wall of the preform and the inner wall of the mold cavity is not greater than [value missing]. .

[0011] Furthermore, in S7, the local wall thickness is acquired by an online wall thickness detection component, the outer contour expansion is acquired by a contour detection component, and the mold-fitting state is determined by one of the following: mold cavity pressure change value, negative pressure channel airflow change value, and distance between the outer wall of the blank and the inner wall of the mold cavity. When the local wall thickness in the shoulder or bottom area is lower than the target wall thickness limit, reduce the absolute value of the negative pressure gauge in the corresponding area and reduce the rate of increase of the blowing pressure. When the bottle body area has not reached the target molding state, increase the absolute value of the negative pressure gauge of the negative pressure channel of the bottle body or extend the negative pressure holding time of the negative pressure channel of the bottle body. When the forming depth of the support rib forming area is lower than the target groove depth ratio, the negative pressure holding time of the support rib negative pressure channel is extended.

[0012] Furthermore, in S8, the pressure of the internal pressure-holding gas is lower than the second-stage molding pressure and higher than the first-stage pre-blowing pressure; The pressure holding time of the internal pressure-holding gas is to The cooling temperature of the molding die is to ; During the pressure holding and cooling process, the rim area maintains a limiting negative pressure, the bottom area maintains a shaping negative pressure, and the support rib forming area maintains a rib groove negative pressure. The pressure gauge readings for the limiting negative pressure, shaping negative pressure, and rib groove negative pressure are all... to .

[0013] Further, after S9, a batch parameter correction step is performed, the batch parameter correction step including: Record the first-stage pre-blowing pressure, intermediate forming pressure, second-stage forming pressure, negative pressure gauge pressure of each independent negative pressure channel, negative pressure holding time of each independent negative pressure channel, pressure holding time, local wall thickness and mold adhesion status during the forming process of the current batch of flexible packaging containers; The local wall thickness is compared with the target wall thickness range, and the molding state is compared with the target molding range; When 3 to 20 consecutive flexible packaging containers have a local wall thickness lower than the target lower limit in the same area, reduce the absolute value of the negative pressure gauge of the corresponding negative pressure channel in the next batch, and reduce the rate of increase of the blowing pressure. When 3 to 20 consecutive flexible packaging containers show a molding status below the target molding range in the same area, the absolute value of the negative pressure gauge of the corresponding negative pressure channel in the next batch should be increased, or the opening time of the corresponding negative pressure channel in the next batch should be advanced.

[0014] The beneficial effects of this invention are as follows: 1. This invention divides the molding cavity into a rim area, a shoulder area, a bottle body area, a bottom area, and a support rib molding area, and makes each area correspond to an independent negative pressure channel. Different negative pressure sequences and negative pressure intensities can be applied to different areas within the same molding cycle, thereby improving the molding reliability of complex curved areas.

[0015] 2. In this invention, after low-pressure pre-blowing, the independent negative pressure channel corresponding to the forming area of ​​the support rib is first opened, so that the local material of the tubular preform enters the groove structure to form the prototype of the support structure, and then the shoulder area, bottom area and bottle body area are molded. This is beneficial to improve the forming integrity of the flexible support rib, bottom support ring and folding guide.

[0016] 3. This invention opens the shoulder negative pressure channel and the bottom negative pressure channel in a timed manner, and opens the bottle body negative pressure channel only after the target molding state is reached in the shoulder area and the bottom area. This can reduce the restraint on the flow of shoulder material and bottom material caused by premature molding in the main body area of ​​the bottle, and reduce the thinning of the shoulder and the wrinkling of the bottom.

[0017] 4. During the molding process, the present invention collects local wall thickness, outer contour expansion and molding status, and adjusts the blowing pressure rise rate, negative pressure gauge absolute value and negative pressure holding time according to the collected results. This can compensate for thin-walled areas and areas with insufficient molding, and improve the wall thickness uniformity and shape consistency of flexible packaging containers.

[0018] 5. This invention records molding parameters and test results during continuous production, and corrects the negative pressure gauge pressure, air blowing pressure rise rate, or negative pressure opening time of the next batch based on the deviation of the same area of ​​continuous products, which can improve the stability of batch production of flexible packaging containers. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a flow chart of the blow-suction forming process for flexible packaging containers according to the present invention; Figure 2 This is a schematic diagram of the molding die partitions and independent negative pressure channels of the present invention; Figure 3 This is a schematic diagram of the wall thickness feedback compensation and batch parameter correction control of the present invention.

[0020] Explanation of reference numerals in the attached drawings: 1. Molding mold; 2. Tubular preform; 3. Air blowing channel; 4. Rim area; 5. Shoulder area; 6. Bottle body area; 7. Bottom area; 8. Support rib forming area; 9. Shoulder negative pressure channel; 10. Bottle body negative pressure channel; 11. Bottom negative pressure channel; 12. Support rib negative pressure channel; 21. Online wall thickness detection component; 22. Contour detection component; 23. Mold application status detection component; 24. Controller; 25. Air blowing pressure adjustment module; 26. Shoulder negative pressure control valve; 27. Bottle body negative pressure control valve; 28. Bottom negative pressure control valve; 29. ​​Support rib negative pressure control valve; 30. Pressure holding and cooling module; 31. Molding mold; 32. Batch parameter correction module. Detailed Implementation

[0021] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0022] I. Overall Process like Figures 1 to 3 As shown, this embodiment provides a blow-dip molding process for flexible packaging containers, used to prepare flexible packaging containers with a rim, shoulder, bottle body, bottom support structure, and flexible support structure. This process utilizes the synergistic effect of internal blowing pressure and external zoned negative pressure to ensure that the tubular preform is molded in the order of support rib forming area, shoulder area, bottom area, and bottle body area. Furthermore, it improves continuous production stability through wall thickness feedback compensation and batch parameter correction.

[0023] II. Plasticization of Soft Plastic Materials and Preparation of Tubular Preforms The soft plastic material is fed into an extrusion plasticizing unit for heating and plasticizing, and then extruded through an extruder head to form a tubular preform. The soft plastic material is selected from polyethylene, polypropylene, ethylene-vinyl acetate copolymer, thermoplastic elastomer, and multilayer co-extruded soft plastic material.

[0024] The plasticizing temperature of the tubular preform is controlled as follows: to The specific value is determined based on the melt index, softening temperature, and target wall thickness of the soft plastic material. The sag length of the tubular preform is determined by the following formula: , in, The droop length of the tubular preform. This refers to the height of the mold cavity.

[0025] III. Molding mold zoning and independent negative pressure channel settings The tubular preform is placed into the molding die and the die is closed. The mold cavity of the molding die is divided into the rim area, shoulder area, bottle body area, bottom area, and support rib forming area. The shoulder area is connected to the shoulder negative pressure channel, the bottle body area is connected to the bottle body negative pressure channel, the bottom area is connected to the bottom negative pressure channel, and the support rib forming area is connected to the support rib negative pressure channel.

[0026] The shoulder negative pressure channel, bottle body negative pressure channel, bottom negative pressure channel, and support rib negative pressure channel are each connected to an independent control valve. The independent control valve is used to control the opening time, closing time, negative pressure gauge pressure, and negative pressure holding time of the corresponding negative pressure channel. A groove structure is set in the support rib forming area. The groove structure is one of the following: shallow rib groove, annular support groove, and folded guide groove, or a combination of two or more of them.

[0027] IV. First Stage Low-Pressure Pre-blowing After mold closing, the first-stage pre-blown gas is introduced into the tubular preform, causing it to form an initial expanded state where it is not completely in contact with the inner wall of the mold cavity. The first-stage pre-blown pressure is... to The pre-blowing time is to .

[0028] The maximum outer contour dimension of the pre-blown tubular preform is controlled by the following formula: in, This refers to the maximum outer contour dimension of the pre-blown tubular preform. This is the maximum inner contour dimension of the mold cavity in the bottle body area.

[0029] V. Negative pressure traction is prioritized in the forming zone of the supporting ribs. When the tubular preform is in its initial expansion state, the negative pressure channels for the support ribs are activated first in the shoulder area, body area, and bottom area. The gauge pressure of the negative pressure channels for the support ribs is [value missing]. to The negative pressure holding time is to .

[0030] Under the negative pressure generated by the negative pressure channel of the support rib, some material of the tubular billet enters the groove structure and forms a preliminary support structure. The preliminary support structure includes one of the following: a preliminary flexible support rib, a preliminary bottom support ring, and a preliminary folded guide section, or a structure formed by a combination of two or more of them.

[0031] The forming depth ratio of the supporting structure is calculated using the following formula: in, To support the proportion of the structural forming depth, To support the actual forming depth of the structure, Design depth for the groove structure.

[0032] VI. Negative pressure adsorption when separating the shoulder area and the bottom After the supporting structure is initially formed, the shoulder negative pressure channel and the bottom negative pressure channel are opened in the predetermined sequence, and the blowing pressure inside the tubular preform is increased from the first-stage pre-blowing pressure to the intermediate forming pressure. The intermediate forming pressure is... to .

[0033] When the radius of curvature of the shoulder of the flexible packaging container is smaller than the radius of curvature of the bottle body, the shoulder negative pressure channel is opened first, followed by the bottom negative pressure channel; when the bottom of the flexible packaging container has a concave support structure, the bottom negative pressure channel is opened first, followed by the shoulder negative pressure channel.

[0034] 7. Delayed overall molding of the bottle body area After the target molding state is achieved in the shoulder and bottom areas, the negative pressure channel of the bottle body is opened, and the blowing pressure inside the tubular preform is increased from the intermediate molding pressure to the second-stage molding pressure. The second-stage molding pressure is... to The negative pressure gauge of the negative pressure channel on the bottle body is to .

[0035] The target mold-fitting state is determined by the change in mold cavity pressure, the change in airflow in the negative pressure channel, or the distance between the outer wall of the preform and the inner wall of the mold cavity; when the distance between the outer wall of the preform and the inner wall of the mold cavity is not greater than When the target molding state is reached, it can be determined that the corresponding area has reached the target molding state.

[0036] 8. Joint feedback compensation for wall thickness, contour, and molding status During the first stage of low-pressure pre-blowing, priority negative pressure traction in the support rib forming area, timed negative pressure adsorption in the shoulder area and bottom area, and delayed overall molding in the bottle body area, the local wall thickness, outer contour expansion, and molding status of the tubular preform or forming intermediate were collected.

[0037] Local wall thickness is collected by an online wall thickness detection component, outer contour expansion is collected by a contour detection component, and mold attachment status is determined by one of the following: mold cavity pressure change value, negative pressure channel airflow change value, and distance between the outer wall of the blank and the inner wall of the mold cavity.

[0038] When the local wall thickness of the shoulder or bottom area is lower than the target lower wall thickness limit, reduce the absolute value of the negative pressure gauge in the corresponding area and reduce the rate of increase of the blowing pressure; when the bottle body area has not reached the target molding state, increase the absolute value of the negative pressure gauge in the bottle body negative pressure channel or extend the negative pressure holding time of the bottle body negative pressure channel; when the molding depth of the support rib forming area is lower than the target groove depth ratio, extend the negative pressure holding time of the support rib negative pressure channel.

[0039] 9. Pressure holding, cooling, and shaping After the tubular preform is attached to the mold, the internal pressure gas is maintained and the forming mold is cooled. The pressure of the internal pressure gas... First stage pre-blowing pressure Second stage molding pressure Satisfy the following formula: The pressure holding time of the internal pressure-holding gas is to The cooling temperature of the molding die is to During the pressure holding and cooling process, the rim area maintains a limiting negative pressure, the bottom area maintains a shaping negative pressure, and the support rib forming area maintains a rib groove negative pressure; the gauge pressures for the limiting negative pressure, shaping negative pressure, and rib groove negative pressure are all... to .

[0040] 10. Pressure relief and demolding, and batch parameter correction After cooling, the negative pressure in the shoulder negative pressure channel, bottle body negative pressure channel, bottom negative pressure channel, and support rib negative pressure channel is released, and the internal pressure of the tubular preform is released. Then the molding die is opened and the finished flexible packaging container is removed.

[0041] After the finished flexible packaging containers are removed, record the first-stage pre-blowing pressure, intermediate forming pressure, second-stage forming pressure, negative pressure gauge pressure of each independent negative pressure channel, negative pressure holding time of each independent negative pressure channel, pressure holding time, local wall thickness, and mold application status during the forming process of the current batch of flexible packaging containers.

[0042] When 3 to 20 consecutive flexible packaging containers have a local wall thickness lower than the target lower limit in the same area, the absolute value of the negative pressure gauge of the corresponding negative pressure channel in the next batch will be reduced, and the rate of increase of the blowing pressure will be reduced. When 3 to 20 consecutive flexible packaging containers have a molding state lower than the target molding range in the same area, the absolute value of the negative pressure gauge of the corresponding negative pressure channel in the next batch will be increased, or the opening time of the corresponding negative pressure channel in the next batch will be advanced.

[0043] Example 1: Blow molding of ordinary thin-walled flexible plastic bottles In this embodiment, polyethylene is selected as the soft plastic material, and the plasticizing temperature of the tubular preform is [temperature missing]. The tubular preform's drooping length is 1.10 times the mold cavity height. The first-stage pre-blowing pressure is... The pre-blowing time is The maximum outer contour dimension of the pre-blown tubular preform is 75% of the maximum inner contour dimension of the mold cavity in the bottle body area.

[0044] The negative pressure channel of the support rib is opened first, and the negative pressure gauge pressure is... The negative pressure holding time is This allows some material from the tubular preform to enter shallow rib grooves set along the height direction. Subsequently, the shoulder negative pressure channel and the bottom negative pressure channel are opened, with the intermediate forming pressure being... After the shoulder and bottom areas reach the target molding state, open the negative pressure channel of the bottle body and increase the blowing pressure to [value missing]. The negative pressure gauge of the negative pressure channel on the bottle body is .

[0045] After the molding is completed, the internal pressure holding gas pressure is: The pressure holding time is The mold cooling temperature is The rim area, bottom area, and supporting rib forming area remain unchanged. Negative pressure. After demolding, a thin-walled soft plastic bottle with flexible support ribs is obtained.

[0046] Example 2: Blow-suction molding of a self-standing flexible packaging container with a concave bottom In this embodiment, the soft plastic material selected is a multi-layer co-extruded soft plastic material, and the plasticizing temperature of the tubular preform is [temperature missing]. The tubular preform's drooping length is 1.18 times the mold cavity height. The first-stage pre-blowing pressure is... The pre-blowing time is .

[0047] An annular support groove and a folded guide groove are provided within the forming area of ​​the support rib. The negative pressure gauge pressure of the negative pressure channel of the support rib is... The negative pressure holding time is This allows the initial shapes of the bottom support ring and the folding guide section to be formed first. Because the bottom of the flexible packaging container has a concave support structure, during the time-sharing negative pressure adsorption process, the bottom negative pressure channel is opened first, followed by the shoulder negative pressure channel, with the intermediate forming pressure being... .

[0048] When the distance between the outer wall of the preform and the inner wall of the bottom mold cavity is not greater than When the bottom area reaches the target molding state, it is determined that the bottom area has reached the target molding state; when the pressure change value of the corresponding mold cavity in the shoulder area reaches the target pressure change range, it is determined that the shoulder area has reached the target molding state. Then, the negative pressure channel of the bottle body is opened, and the blowing pressure is increased to [value missing]. This completes the application of the mold to the main body of the bottle.

[0049] Example 3: Continuous Production Molding Based on Batch Parameter Correction In this embodiment, during continuous production, the first-stage pre-blowing pressure, intermediate forming pressure, second-stage forming pressure, negative pressure gauge pressure of each independent negative pressure channel, negative pressure holding time, pressure holding time, local wall thickness, and mold-attachment status are recorded for each flexible packaging container.

[0050] When 10 consecutive flexible packaging containers exhibit localized wall thicknesses below the target lower limit in the shoulder area, the negative pressure gauge of the shoulder negative pressure channel in the next batch will be adjusted from... Adjusted to And reduce the rate of increase of blowing pressure by 10% to 25%.

[0051] If 10 consecutive flexible packaging containers have a molding condition below the target molding range in the bottle area, the opening time of the negative pressure channel in the next batch will be brought forward. to Alternatively, the absolute value of the negative pressure gauge in the negative pressure channel of the bottle can be increased. to The above corrections reduce the wall thickness deviation in the shoulder area of ​​the next batch of flexible packaging containers and stabilize the molding state in the bottle body area.

[0052] The above embodiments provide a detailed description of the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A blow-suction forming process for flexible packaging containers, characterized in that, Includes the following steps: S1. Plasticize the soft plastic material and extrude it to form a tubular preform. Control the plasticizing temperature, extrusion speed and droop length of the tubular preform according to the target height and target wall thickness of the soft packaging container. S2. The tubular preform is placed into the molding mold and the mold is closed. The mold cavity of the molding mold is divided into a mouth rim area, a shoulder area, a bottle body area, a bottom area and a support rib forming area. The shoulder area, bottle body area, bottom area and support rib forming area are respectively connected to independent negative pressure channels. The support rib forming area is provided with one of the following: shallow rib groove, annular support groove and folding guide groove, or a groove structure formed by a combination of two or more of them. S3. Introduce the first stage pre-blown gas into the tubular preform to make the tubular preform form an initial expansion state that is not completely attached to the inner wall of the mold cavity; S4. In the initial expansion state, the independent negative pressure channels corresponding to the support rib forming area are opened first in the shoulder area, bottle body area and bottom area, so that the local material of the tubular preform enters the groove structure and forms the prototype of the support structure. S5. After the supporting structure prototype is formed, open the independent negative pressure channels corresponding to the shoulder area and the bottom area according to the set opening sequence, and increase the blowing pressure inside the tubular preform from the first stage pre-blowing pressure to the intermediate molding pressure, so that the shoulder area and the bottom area of ​​the tubular preform are attached to the inner wall of the corresponding mold cavity before the main body area of ​​the bottle. S6. After the target molding state is reached in the shoulder area and bottom area, the independent negative pressure channel corresponding to the bottle body area is opened, and the blowing pressure inside the tubular preform is increased from the intermediate molding pressure to the second stage molding pressure, so that the bottle body main body area of ​​the tubular preform fits the inner wall of the bottle body area mold cavity. S7. During S3 to S6, collect the local wall thickness, outer contour expansion and mold-attachment status of the tubular preform or molding intermediate, and adjust the blowing pressure rise rate, negative pressure adsorption intensity and negative pressure holding time of the corresponding area according to the collection results. S8. After the tubular preform is molded, maintain the internal pressure gas and cool the forming mold, while maintaining the negative pressure state of the mouth rim area, bottom area and support rib forming area, so that the mouth rim, main wall surface, bottom support structure and flexible support structure of the soft packaging container are simultaneously shaped. S9. After cooling is complete, release the negative pressure in the independent negative pressure channel and the internal pressure of the tubular preform, open the mold and take out the finished soft packaging container.

2. The flexible packaging container blow-suction forming process according to claim 1, characterized in that: The independent negative pressure channels include a shoulder negative pressure channel, a bottle body negative pressure channel, a bottom negative pressure channel, and a support rib negative pressure channel; The shoulder negative pressure channel, bottle body negative pressure channel, bottom negative pressure channel and support rib negative pressure channel are each connected to an independent control valve. The independent control valve is used to control the opening time, closing time, negative pressure gauge pressure and negative pressure holding time of the corresponding negative pressure channel.

3. The blow-suction forming process for flexible packaging containers according to claim 2, characterized in that: The flexible plastic material is selected from one of polyethylene, polypropylene, ethylene-vinyl acetate copolymer, thermoplastic elastomer, and multilayer co-extruded flexible plastic material; The plasticizing temperature of the tubular preform is to The drooping length of the tubular preform is 1.02 to 1.25 times the height of the mold cavity.

4. The blow-suction forming process for flexible packaging containers according to claim 1, characterized in that: In S3, the first-stage pre-blowing pressure is to The pre-blowing time is to ; The maximum outer contour dimension of the pre-blown tubular preform is 60% to 85% of the maximum inner contour dimension of the mold cavity in the bottle body area.

5. The blow-suction forming process for flexible packaging containers according to claim 4, characterized in that: In S4, the opening time of the support rib negative pressure channel is earlier than that of the shoulder negative pressure channel, the bottle body negative pressure channel and the bottom negative pressure channel; The negative pressure gauge reading of the negative pressure channel of the supporting rib is to The negative pressure holding time is to ; The prototype support structure includes one or more of the following: a prototype flexible support rib extending along the height direction of the flexible packaging container; a prototype bottom support ring located in the circumferential region at the bottom of the flexible packaging container; and a prototype folding guide located on the wall of the flexible packaging container.

6. The blow-suction forming process for flexible packaging containers according to claim 5, characterized in that: In S5, the shoulder negative pressure channel and the bottom negative pressure channel are opened in a time-sharing manner; When the radius of curvature of the shoulder of the flexible packaging container is smaller than the radius of curvature of the bottle body, the shoulder negative pressure channel is opened first, and then the bottom negative pressure channel is opened. When the bottom of the flexible packaging container has a concave support structure, the bottom negative pressure channel is opened first, and then the shoulder negative pressure channel is opened. The intermediate forming pressure is to .

7. The blow-suction forming process for flexible packaging containers according to claim 6, characterized in that: In S6, the negative pressure channel of the bottle body is opened after the target molding state is reached in the shoulder area and the bottom area; The molding pressure in the second stage is to The negative pressure gauge reading of the negative pressure channel in the bottle body is... to ; The target molding state is defined as follows: the mold cavity pressure change value reaches the target pressure change range; the negative pressure channel airflow change value reaches the target airflow change range; or the distance between the outer wall of the preform and the inner wall of the mold cavity is not greater than [value missing]. .

8. The blow-suction forming process for flexible packaging containers according to claim 7, characterized in that: In S7, the local wall thickness is acquired by an online wall thickness detection component, the outer contour expansion is acquired by a contour detection component, and the mold-fitting state is determined by one of the following: mold cavity pressure change value, negative pressure channel airflow change value, and distance between the outer wall of the blank and the inner wall of the mold cavity. When the local wall thickness in the shoulder or bottom area is lower than the target wall thickness limit, reduce the absolute value of the negative pressure gauge in the corresponding area and reduce the rate of increase of the blowing pressure. When the bottle body area has not reached the target molding state, increase the absolute value of the negative pressure gauge of the negative pressure channel of the bottle body or extend the negative pressure holding time of the negative pressure channel of the bottle body. When the forming depth of the support rib forming area is lower than the target groove depth ratio, the negative pressure holding time of the support rib negative pressure channel is extended.

9. The blow-suction forming process for flexible packaging containers according to claim 8, characterized in that: In S8, the pressure of the internal pressure-holding gas is lower than the second-stage molding pressure and higher than the first-stage pre-blowing pressure; The pressure holding time of the internal pressure-holding gas is to The cooling temperature of the molding die is to ; During the pressure holding and cooling process, the rim area maintains a limiting negative pressure, the bottom area maintains a shaping negative pressure, and the support rib forming area maintains a rib groove negative pressure. The pressure gauge readings for the limiting negative pressure, shaping negative pressure, and rib groove negative pressure are all... to .

10. The blow-suction forming process for flexible packaging containers according to claim 9, characterized in that, After S9, a batch parameter correction step is performed, which includes: Record the first-stage pre-blowing pressure, intermediate forming pressure, second-stage forming pressure, negative pressure gauge pressure of each independent negative pressure channel, negative pressure holding time of each independent negative pressure channel, pressure holding time, local wall thickness and mold adhesion status during the forming process of the current batch of flexible packaging containers; The local wall thickness is compared with the target wall thickness range, and the molding state is compared with the target molding range; When 3 to 20 consecutive flexible packaging containers have a local wall thickness lower than the target lower limit in the same area, reduce the absolute value of the negative pressure gauge of the corresponding negative pressure channel in the next batch, and reduce the rate of increase of the blowing pressure. When 3 to 20 consecutive flexible packaging containers show a molding status below the target molding range in the same area, the absolute value of the negative pressure gauge of the corresponding negative pressure channel in the next batch should be increased, or the opening time of the corresponding negative pressure channel in the next batch should be advanced.

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