Apparatus and method for manufacturing a multilayer co-extruded film

Abstract

The application discloses a kind of manufacturing devices of multilayer co-extrusion film, comprising: blowing machine is used to extrude molten plastic material;Multilayer co-extrusion die is used to melt different materials and is co-extruded into multilayer structure;Sensing detection module is used to monitor film bubble diameter change and film bubble surface cooling state in real time;Control module is used to receive sensor signal, using PID control algorithm, output fan frequency, air valve opening degree instruction matrix;Wind power control module is used to adjust wind power according to fan frequency, air valve opening degree instruction matrix, and then control film bubble diameter;Film bubble forming module is used to form final film.The application also discloses a kind of using method of manufacturing devices of multilayer co-extrusion film.The application solves the problem that multilayer co-extrusion film is easily separated between film layers during manufacturing process, and film is broken or poorly bonded due to inaccurate film bubble diameter control.

Description

Technical Field

[0001] This invention belongs to the field of plastic film manufacturing technology, specifically a manufacturing apparatus and method for multilayer co-extruded film. Background Technology

[0002] Multilayer co-extruded films are widely used in various packaging fields due to their excellent weather resistance, temperature resistance, and chemical corrosion resistance. With the packaging industry's ever-increasing demands for material performance, the demand for multilayer co-extruded films is growing. However, existing technologies still face many challenges in the manufacturing process, such as film layer separation and unstable control of film bubble diameter. These problems directly affect the quality and application effect of the film.

[0003] Currently, the manufacturing of multilayer co-extruded films is mainly achieved through blown film extrusion using a blown film extrusion machine, where controlling the diameter of the film bubble is a crucial step. Conventional methods include adjusting the airflow of the blown film extruder to change the bubble diameter. However, excessive airflow can easily lead to film rupture, while insufficient airflow makes it difficult to achieve effective adhesion between the film layers. Furthermore, existing technologies also employ multilayer co-extrusion composite processes, forming multilayer structures through the co-extrusion of different materials; however, the adhesion strength between the layers is still limited by the precise control of process parameters.

[0004] The main drawback of existing technologies is that the membrane layers are prone to separation, and the control precision of the membrane bubble diameter is insufficient, leading to unstable membrane quality. The inaccuracy of wind power regulation further exacerbates the risk of membrane rupture or poor adhesion, affecting the overall performance and application reliability of multilayer co-extruded membranes.

[0005] Therefore, an apparatus for manufacturing a multilayer co-extruded film and a method for using it are provided. Summary of the Invention

[0006] To address the aforementioned problems in the prior art, this invention provides a manufacturing apparatus and method for multilayer co-extruded films, which solves the problems of easy separation between film layers and film rupture or poor adhesion caused by inaccurate control of film bubble diameter during the manufacturing process of multilayer co-extruded films.

[0007] The technical solution to achieve the above objectives is: An apparatus for manufacturing a multilayer co-extruded film according to one of the present invention includes: A blower is used to extrude molten plastic materials; Multi-layer co-extrusion die head is used to co-extrude melts of different materials into a multi-layer structure; The sensing and detection module is used to monitor the changes in membrane bubble diameter and the cooling status of the membrane bubble surface in real time. The control module is used to receive sensor signals, apply PID control algorithms, and output a command matrix for fan frequency and valve opening. The wind power control module is used to adjust the wind force according to the command matrix of the fan frequency and the opening of the air valve, thereby controlling the diameter of the membrane bubble; The membrane bubble forming module is used for the final membrane forming.

[0008] Preferably, the materials selected for the multilayer co-extrusion die include polyethylene, polypropylene and ethylene-vinyl acetate copolymer, with the thickness ratio of each layer being 5:3:2.

[0009] Preferably, the sensing and detection module includes: A diameter monitoring unit is used to non-contactly measure the diameter of a membrane bubble based on a laser diameter measuring instrument array. The temperature monitoring unit is used to monitor the cooling status of the membrane bubble surface based on the temperature distribution of the membrane bubble surface scanned across the entire swath by the infrared thermal imager.

[0010] Preferably, the control module includes: The signal processing unit is used to receive the real-time signal from the laser diameter measuring instrument, eliminate signal jitter caused by environmental vibration, and linearize the temperature sensor data to compensate for the cooling gradient differences at different heights of the membrane bubble. The multivariable PID control unit is used to obtain the diameter deviation and temperature change rate from the processed real-time signal, and to generate the instruction matrix of fan frequency and damper opening based on the diameter deviation, temperature change rate and historical trend data. The safety and diagnostic unit is used to monitor the operating status of the control module in real time, trigger audible and visual alarms and store error codes in case of hardware failure; An emergency protection unit is used to automatically cut off the power supply to the multi-layer co-extrusion die head and start emergency ventilation when the risk of membrane bubble rupture is detected.

[0011] Preferably, the wind control module uses a variable frequency fan with a wind speed adjustment range of 0.5-5 m / s.

[0012] Preferably, in the membrane bubble forming module, ultrasonic energy is introduced to promote intermolecular bonding of the materials in each layer.

[0013] A method of using an apparatus for manufacturing a multilayer co-extruded film according to a second aspect of the present invention includes: Step S1: Set the temperature of the molten plastic material, the proportion of each layer of material, and the initial wind force parameters; Step S2: Install the multi-layer co-extrusion die head in place, start the blower and air control module, and preheat to the set temperature; Step S3: During the manufacturing process of the multilayer co-extruded film, the diameter of the film bubble is monitored in real time through a sensing and detection module; Step S4: The control module receives sensor signals, uses a PID control algorithm, and outputs a command matrix for the fan frequency and valve opening. Step S5: The wind power control module adjusts the wind force according to the instruction matrix of the fan frequency and the opening of the air valve, thereby controlling the diameter of the membrane bubble; Step S6: After the membrane bubble is formed, the membrane bubble forming module is cooled, shaped, and wound up.

[0014] Preferably, in step S1, the materials selected for each layer include polyethylene, polypropylene and ethylene-vinyl acetate copolymer, and the thickness ratio of each layer is 5:3:2.

[0015] Preferably, in step S3, the diameter of the membrane bubble is measured non-contactly using a laser diameter measuring array; and the cooling state of the membrane bubble surface is monitored by scanning the surface temperature distribution of the membrane bubble with an infrared thermal imager.

[0016] Preferably, in step S4, if a risk of membrane bubble rupture is detected, i.e., when the membrane bubble diameter is greater than a preset diameter, the power supply to the multi-layer co-extrusion die head is automatically cut off and emergency ventilation is initiated.

[0017] Compared with existing technologies, the beneficial effects of this invention are as follows: This invention uses a laser diameter gauge (accuracy ±0.03mm) + infrared thermal imager (±1℃) for real-time feedback, and a PID algorithm to dynamically adjust the fan frequency and the opening of the zoned air valves, improving the diameter control accuracy to ±0.5%, thus solving the problem of large fluctuations in film bubble diameter and uneven thickness in traditional blown film processes; This invention uses a multi-layer co-extrusion die head with temperature-air force coordinated control, reducing crystallinity differences and ensuring clear melt interfaces between each layer, thus solving the problem of easy peeling or mixing between co-extruded film layers; This invention uses a variable frequency fan, reducing energy consumption by 25%, solving the problem that traditional cooling systems account for up to 40% of energy consumption and have limited production speed. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a block diagram of a manufacturing apparatus for a multilayer co-extruded film according to the present invention; Figure 2 This is a detailed module diagram of the sensing and detection module in this invention; Figure 3 This is a detailed module diagram of the control module in this invention; Figure 4 This is a flowchart of the method of using a multilayer co-extruded film manufacturing apparatus according to the present invention. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] like Figure 1 As shown, a manufacturing apparatus for a multilayer co-extruded film includes: a blower 1, a multilayer co-extrusion die 2, a sensing and detection module 3, a control module 4, a wind power control module 5, and a film bubble forming module 6.

[0021] Blower 1 is used to extrude molten plastic material.

[0022] Multi-layer co-extrusion die 2 is used to co-extrude melts of different materials into a multi-layer structure.

[0023] In this embodiment, the materials selected include polyethylene, polypropylene and ethylene-vinyl acetate copolymer, with the thickness ratio of each layer being 5:3:2; wherein, the material ratio can be adjusted according to actual needs.

[0024] This invention employs a multi-layer co-extrusion die head with coordinated temperature and airflow control to reduce crystallinity differences, ensuring clear melt interfaces between each layer and solving the problem of easy peeling or mixing between co-extruded film layers.

[0025] The sensing module 3 is used to monitor the changes in membrane bubble diameter and the cooling status of the membrane bubble surface in real time.

[0026] like Figure 2 As shown, the sensing module 3 includes: a diameter monitoring unit 31 and a temperature monitoring unit 32. The diameter monitoring unit 31 is used to non-contactly measure the diameter of the membrane bubble based on the laser diameter measuring instrument array.

[0027] Temperature monitoring unit 32 is used to monitor the cooling status of the membrane bubble surface based on the temperature distribution of the membrane bubble surface scanned across the entire area by the infrared thermal imager.

[0028] Control module 4 is used to receive sensor signals, apply PID control algorithms, and output a command matrix for fan frequency and valve opening.

[0029] like Figure 3 As shown, the control module 4 includes: a signal processing unit 41, a multivariable PID control unit 42, a safety and diagnostic unit 43, and an emergency protection unit 44.

[0030] The signal processing unit 41 is used to receive the real-time signal from the laser diameter measuring instrument, eliminate signal jitter caused by environmental vibration, and linearize the temperature sensor data to compensate for the cooling gradient differences at different heights of the membrane bubble.

[0031] The multivariable PID control unit 42 is used to obtain the diameter deviation and temperature change rate from the processed real-time signal, and to generate the instruction matrix of fan frequency and valve opening based on the diameter deviation, temperature change rate and historical trend data.

[0032] The safety and diagnostic unit 43 is used to monitor the operating status of the control module 4 in real time, trigger audible and visual alarms and store error codes in case of hardware failure.

[0033] Emergency protection unit 44 is used to automatically cut off the power supply to the multi-layer co-extrusion die head and start emergency ventilation when the risk of membrane bubble rupture is detected.

[0034] This invention uses a laser diameter gauge and an infrared thermal imager for real-time feedback, and a PID algorithm to dynamically adjust the fan frequency and the opening of the zoned air valves, improving the diameter control accuracy to ±0.5%, thus solving the problem of large fluctuations in the film bubble diameter and uneven thickness in traditional blown film processes.

[0035] The wind power control module 5 is used to adjust the wind force according to the command matrix of the fan frequency and the opening of the air valve, thereby controlling the diameter of the membrane bubble.

[0036] In this embodiment, the wind control module 5 uses a variable frequency fan with a wind speed adjustment range of 0.5-5 m / s.

[0037] This invention uses a variable frequency fan, which reduces energy consumption by 25% and solves the problem that traditional cooling systems account for up to 40% of energy consumption and have limited production speed.

[0038] Membrane bubble forming module 6 is used for the final membrane forming.

[0039] In this embodiment, ultrasonic welding technology is introduced to enhance the adhesion strength between film layers. That is, ultrasonic energy is applied during the film bubble forming process to promote the molecular bonding of each layer of material, which significantly improves the interlayer adhesion strength of the multilayer co-extruded film and avoids the problem of film layer separation.

[0040] like Figure 4 As shown, a method of using an apparatus for manufacturing a multilayer co-extruded film includes: Step S1: Set the temperature of the molten plastic material, the proportion of each layer of material, and the initial wind force parameters.

[0041] In this embodiment, the materials selected for each layer include polyethylene, polypropylene and ethylene-vinyl acetate copolymer, and the thickness ratio of each layer is 5:3:2.

[0042] Step S2: Install the multi-layer co-extrusion die head 2 into place, start the blowing machine 1 and the air power control module 5, and preheat to the set temperature.

[0043] In step S3, during the manufacturing process of the multilayer co-extruded film, the diameter of the film bubble is monitored in real time through the sensing and detection module 3.

[0044] In this embodiment, the diameter of the membrane bubble is measured non-contactly using a laser diameter measuring array; the surface temperature distribution of the membrane bubble is monitored by scanning the entire surface of the membrane bubble with an infrared thermal imager; and by precisely controlling the membrane bubble diameter, the risk of membrane rupture and poor adhesion is reduced, thereby improving the quality stability of the membrane.

[0045] In step S4, the control module 4 receives the sensor signal, uses the PID control algorithm, and outputs a command matrix for the fan frequency and the valve opening.

[0046] In this embodiment, if a risk of membrane bubble rupture is detected, i.e., when the membrane bubble diameter is greater than a preset diameter, the power supply to the multi-layer co-extrusion die head is automatically cut off and emergency ventilation is initiated.

[0047] In step S5, the wind power control module 5 adjusts the wind force according to the instruction matrix of the fan frequency and the opening of the air valve, thereby controlling the diameter of the membrane bubble.

[0048] In step S6, after the membrane bubble is formed, the membrane bubble forming module 6 is cooled, shaped, and wound up.

[0049] This invention achieves precise control of the membrane bubble diameter and high-strength adhesion between membrane layers by optimizing the design of the multi-layer co-extrusion die head 2 and the wind power control module 5.

[0050] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An apparatus for manufacturing a multilayer co-extruded film, characterized in that, include: A blower is used to extrude molten plastic materials; Multi-layer co-extrusion die head is used to co-extrude melts of different materials into a multi-layer structure; The sensing and detection module is used to monitor the changes in membrane bubble diameter and the cooling status of the membrane bubble surface in real time. The control module is used to receive sensor signals, apply PID control algorithms, and output a command matrix for fan frequency and valve opening. The wind power control module is used to adjust the wind force according to the command matrix of the fan frequency and the opening of the air valve, thereby controlling the diameter of the membrane bubble; The membrane bubble forming module is used for the final membrane forming.

2. The apparatus for manufacturing a multilayer co-extruded film according to claim 1, characterized in that, In the multi-layer co-extrusion die, the materials selected include polyethylene, polypropylene and ethylene-vinyl acetate copolymer, and the thickness ratio of each layer is 5:3:

2.

3. The apparatus for manufacturing a multilayer co-extruded film according to claim 1, characterized in that, The sensing and detection module includes: A diameter monitoring unit is used to non-contactly measure the diameter of a membrane bubble based on a laser diameter measuring instrument array. The temperature monitoring unit is used to monitor the cooling status of the membrane bubble surface based on the temperature distribution of the membrane bubble surface scanned across the entire swath by the infrared thermal imager.

4. The apparatus for manufacturing a multilayer co-extruded film according to claim 3, characterized in that, The control module includes: The signal processing unit is used to receive the real-time signal from the laser diameter measuring instrument, eliminate signal jitter caused by environmental vibration, and linearize the temperature sensor data to compensate for the cooling gradient differences at different heights of the membrane bubble. The multivariable PID control unit is used to obtain the diameter deviation and temperature change rate from the processed real-time signal, and to generate the instruction matrix of fan frequency and damper opening based on the diameter deviation, temperature change rate and historical trend data. The safety and diagnostic unit is used to monitor the operating status of the control module in real time, trigger audible and visual alarms and store error codes in case of hardware failure; An emergency protection unit is used to automatically cut off the power supply to the multi-layer co-extrusion die head and start emergency ventilation when the risk of membrane bubble rupture is detected.

5. The apparatus for manufacturing a multilayer co-extruded film according to claim 1, characterized in that, The wind control module uses a variable frequency fan, and the wind speed adjustment range is 0.5-5 m / s.

6. The apparatus for manufacturing a multilayer co-extruded film according to claim 1, characterized in that, In the membrane bubble forming module, ultrasonic energy is introduced to promote intermolecular bonding of the materials in each layer.

7. A method of using an apparatus for manufacturing a multilayer co-extruded film, characterized in that, include: Step S1: Set the temperature of the molten plastic material, the proportion of each layer of material, and the initial wind force parameters; Step S2: Install the multi-layer co-extrusion die head in place, start the blower and air control module, and preheat to the set temperature; Step S3: During the manufacturing process of the multilayer co-extruded film, the diameter of the film bubble is monitored in real time through a sensing and detection module; Step S4: The control module receives sensor signals, uses a PID control algorithm, and outputs a command matrix for the fan frequency and valve opening. Step S5: The wind power control module adjusts the wind force according to the instruction matrix of the fan frequency and the opening of the air valve, thereby controlling the diameter of the membrane bubble; Step S6: After the membrane bubble is formed, the membrane bubble forming module is cooled, shaped, and wound up.

8. The method of using the apparatus for manufacturing a multilayer co-extruded film according to claim 7, characterized in that, In step S1, the materials selected for each layer include polyethylene, polypropylene and ethylene-vinyl acetate copolymer, and the thickness ratio of each layer is 5:3:

2.

9. The method of using the apparatus for manufacturing a multilayer co-extruded film according to claim 7, characterized in that, In step S3, the diameter of the membrane bubble is measured non-contactly using a laser diameter measuring instrument array; and the cooling state of the membrane bubble surface is monitored by scanning the temperature distribution on the membrane bubble surface with an infrared thermal imager across the entire area.

10. The method of using the apparatus for manufacturing a multilayer co-extruded film according to claim 7, characterized in that, In step S4, if a risk of membrane bubble rupture is detected, i.e., when the membrane bubble diameter is greater than the preset diameter, the power supply to the multi-layer co-extrusion die head is automatically cut off and emergency ventilation is started.

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