High-toughness plastic bag processing technology

Abstract

The invention relates to the technical field of plastic product processing, and discloses a high-toughness plastic bag processing technology which comprises the following steps: firstly, primarily sorting recycled main raw materials, recording sources, grade classification and processing states, configuring a centralized feeding system and an intelligent proportioning program, and carrying out intelligent proportioning on the main raw materials; the mixed raw materials are injected into a five-layer co-extrusion die head or an annular die head structure, then an extrusion film body is controlled through a control system to conduct film blowing treatment on an extruded film to form film bubbles, then film blowing is conducted, the film bubbles are cooled through a 360-degree cooling air ring and an internal air core, the film obtained after film blowing is completed is pulled to a winding section through a winding system, and then the film is obtained. Before rolling, mechanical performance indexes are detected through an online monitoring instrument, and a finished film roll enters a bag making / slicing section according to order requirements. Through fine treatment and multi-layer co-extrusion process design of recycled plastics, high-proportion recycled materials are effectively applied to production of plastic bags, and the effect of remarkably improving the utilization rate of the recycled materials is achieved on the premise that the performance of finished products is not reduced.

Description

Technical Field

[0001] This invention relates to the field of plastic product processing technology, specifically a processing technology for high-toughness plastic bags. Background Technology

[0002] Plastic bags, as a widely used packaging material in daily life, are in increasing demand year by year. Traditional plastic bag manufacturing processes mainly include blow molding and casting, but these processes have limitations in terms of strength and toughness. With increasing environmental protection requirements and consumers' growing demand for durability, developing a high-toughness plastic bag processing technology has become an urgent need for the industry. Currently, the market mainly improves the toughness of plastic bags by increasing the plastic thickness or adding reinforcing agents, but these methods often lead to increased costs or decreased environmental performance.

[0003] In existing technologies, the main methods to improve the toughness of plastic bags are as follows: First, using high-density polyethylene (HDPE) material, which has high strength but poor flexibility; second, adding linear low-density polyethylene (LLDPE) to low-density polyethylene (LDPE) to improve toughness, but this method requires high production process standards; third, producing composite plastic bags through multi-layer co-extrusion technology, but this significantly increases equipment costs and process complexity; and fourth, adding toughening agents such as elastomers or nanomaterials to the plastic, but this may affect the transparency and recyclability of the material. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a high-toughness plastic bag processing technology that solves the problem that relying solely on traditional recycling methods results in limited performance improvements from recycled materials, easily leading to insufficient strength and toughness in the finished film, and even problems such as film brittleness and poor heat sealing.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a high-toughness plastic bag processing technology, comprising the following steps: First, the recycled main raw materials are initially sorted and their source, grade classification and processing status are recorded. Then, corresponding toughening agents and solvents are added for different grades of recycled materials to obtain the processed recycled materials. By configuring a centralized feeding system and intelligent proportioning program, the treated recycled materials, main raw materials, toughening agents and processing aids are fed into multiple extruder screws for mixing according to the process ratio; The mixed raw materials are injected into a five-layer co-extrusion die head or annular die head structure to form a five-layer layout of A / B / C / B / A. The die head structure adopts a spiral flow channel or a fan-shaped flow channel, and each screw is equipped with a zoned temperature control system. Then, through the control system, the extrusion body is controlled to blow the extruded film to form a film bubble, and an auxiliary detector is installed in the film bubble area to monitor the film bubble thickness distribution, tensile stability and offset trend in real time. Then, the blown film is cooled by a 360° cooling air ring and an internal air core. At the same time, after cooling, the static electricity elimination device removes the charge on the film surface. The air cooling speed is adjusted synchronously with the film thickness feedback. After the film is blown, it is pulled to the winding section by the winding system. Before winding, the mechanical performance indicators are tested by online monitoring instruments, and the data of each segment is electronically recorded, packaged and uploaded to the factory database. Finished film rolls are sent to the bag making / slicing section according to order requirements. During the packaging process, production information is marked on each roll of film or each bag using an online inkjet printing system. Finally, all data is uploaded to the factory database to form a complete quality traceability chain.

[0006] Preferably, the main raw materials include LDPE and LLDP, and the preliminary sorting is carried out by hot air or vacuum drying for deep drying treatment. The drying treatment controls the moisture content to below 0.1% to avoid subsequent extrusion of air bubbles and gelation problems. The toughening agent includes maleic anhydride-grafted polyethylene, and the compatibilizer includes MAH-grafted polyolefin. The preliminary sorting process also includes the following sub-steps: Metal impurity removal is used to remove metal impurities from recycled materials to prevent equipment damage. Color sorting is used to remove discolored impurities from recycled materials; Melt index testing is used to measure the melt flowability of recycled materials; The classification includes source classification, performance classification, color classification and pollution level classification. The toughening agent and solvent are used to compensate for performance loss and control the controllability and consistency of recycled materials. The source is recorded by means of QR code or RFID chip.

[0007] Preferably, the processing aids include slip agents, antioxidants, and stabilizers. The proportions are dynamically adjusted based on real-time detection data, and the proportion error is controlled within ±5% using a weighing and metering device, a spectral recognition device, and a control algorithm. The proportions of recycled materials in the ingredients are 40% to 60%, the proportions of main raw materials are 30% to 50%, the proportions of toughening agents are 5% to 15%, and the proportions of processing aids are less than 3%.

[0008] Preferably, in the five-layer layout, layer B is the main structural layer, which uses recycled materials as the main material to toughen and reinforce the structure and ensure load-bearing and impact performance. Layers A and C are the surface and heat-sealing layers, respectively, and are made of virgin HDPE / LLDPE to ensure heat-sealing performance and aesthetics. Based on the material interface compatibility, a solvent is added to the interface layer to enhance the bonding strength of the multilayer structure; In the five-layer layout, layer B is the structural load-bearing layer, accounting for 60% to 70% of the thickness, while the total thickness of layers A and C does not exceed 40%.

[0009] Preferably, the blown film process is set with a blow-up ratio of 2.5 to 3.0 and a traction ratio of 1.8 to 2.0, and uses laser detection, tension feedback and PID closed-loop control to stabilize the formation of the film bubble. The blown film process adopts a cooling air circulation method. The auxiliary detectors include an infrared / laser thickness detector, a micro wind speed detector and a tension sensor. The auxiliary detectors are installed. The control system adopts a PID closed-loop algorithm to automatically adjust the airflow of the air ring, the die head temperature and the traction speed according to the detection data.

[0010] Preferably, the cooling of the membrane bubble is used to control the uniformity of membrane thickness. The electrostatic elimination device uses an ion fan or electrostatic bar to remove the charge on the membrane surface to prevent dust adsorption and subsequent film winding wrinkling. The blown film area is equipped with an infrared or laser thickness detector, a wind speed detector and a tension sensor, and is connected to a PID closed-loop system. The air cooling wind speed is synchronized with the membrane thickness feedback to match the membrane cooling rate with the rheological rate.

[0011] Preferably, the performance indicators include longitudinal / transverse tensile strength, elongation at break, heat seal strength, and puncture resistance. The winding system is driven by constant tension dual rollers and equipped with an automatic correction system to ensure that the finished film roll is tightly and neatly arranged without wrinkles or air bubbles.

[0012] Preferably, the bag making / slicing section includes an automated process for heat sealing, edge cutting, and punching. The production information includes production batch, raw material ratio, recycled material grade, and inspection number. The quality traceability chain is used for subsequent quality review and process optimization.

[0013] This invention provides a processing technology for high-toughness plastic bags. It has the following beneficial effects: 1. This invention achieves the effective application of a high proportion of recycled materials in the production of plastic bags through the fine processing of recycled plastics and the design of a multi-layer co-extrusion process, resulting in a significant improvement in the utilization rate of recycled materials without reducing the performance of the finished product.

[0014] 2. By introducing laser thickness detection, wind speed control and PID closed-loop adjustment system into the blown film process, this invention achieves dynamic control of the film bubble and uniformity of film thickness, resulting in stability and excellent thickness consistency of the film under different production conditions.

[0015] 3. By employing high-precision classification and performance testing methods during the pretreatment of recycled materials, this invention achieves precise control over the source, performance, and contamination level of recycled materials, thereby ensuring the controllability and consistency of recycled materials and effectively guaranteeing the quality stability of the finished membrane.

[0016] 4. By establishing a complete quality traceability chain and production information recording system, this invention enables full-process data traceability from raw material procurement to finished product delivery, achieving rapid traceability and quality review capabilities, and providing a reliable basis for subsequent process optimization and quality management. Attached Figure Description

[0017] Figure 1 This is a perspective view of a high-toughness plastic bag processing technology according to the present invention. Detailed Implementation

[0018] The technical solution of the present invention will now be clearly and completely described 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.

[0019] Please see the appendix Figure 1 This invention provides a high-toughness plastic bag processing technology, including the following steps: First, the recycled main raw materials are initially sorted and their source, grade classification and processing status are recorded. Then, corresponding toughening agents and solvents are added for different grades of recycled materials to obtain the processed recycled materials. By configuring a centralized feeding system and intelligent proportioning program, the treated recycled materials, main raw materials, toughening agents and processing aids are fed into multiple extruder screws for mixing according to the process ratio; The mixed raw materials are injected into a five-layer co-extrusion die head or annular die head structure to form a five-layer layout of A / B / C / B / A. The die head structure adopts a spiral flow channel or a fan-shaped flow channel, and each screw is equipped with a zoned temperature control system. Then, through the control system, the extrusion body is controlled to blow the extruded film to form a film bubble, and an auxiliary detector is installed in the film bubble area to monitor the film bubble thickness distribution, tensile stability and offset trend in real time. Then, the blown film is cooled by a 360° cooling air ring and an internal air core. At the same time, after cooling, the static electricity elimination device removes the charge on the film surface. The air cooling speed is adjusted synchronously with the film thickness feedback. After the film is blown, it is pulled to the winding section by the winding system. Before winding, the mechanical performance indicators are tested by online monitoring instruments, and the data of each segment is electronically recorded, packaged and uploaded to the factory database. Finished film rolls are sent to the bag making / slicing section according to order requirements. During the packaging process, production information is marked on each roll of film or each bag using an online inkjet printing system. Finally, all data is uploaded to the factory database to form a complete quality traceability chain.

[0020] The main raw materials include LDPE and LLDP. Initial sorting is carried out by hot air or vacuum drying for deep drying. The drying process controls the moisture content to below 0.1% to avoid subsequent extrusion of air bubbles and gelation problems. The toughening agent includes maleic anhydride-grafted polyethylene, and the compatibilizer includes MAH-grafted polyolefin. The initial sorting process also includes the following sub-steps: Metal impurity removal is used to remove metal impurities from recycled materials to prevent equipment damage. Color sorting is used to remove discolored impurities from recycled materials; Melt index testing is used to measure the melt flowability of recycled materials; The grading system includes source classification, performance classification, color classification, and pollution level classification. Toughening agents and solvents are used to compensate for performance loss and control the controllability and consistency of recycled materials. The source is recorded using QR codes or RFID chips.

[0021] Specifically, the pretreatment of recycled materials begins with the initial sorting of polyolefin recycled plastics (such as LDPE and LLDP) to remove impurities. Then, hot air drying or vacuum drying technology is used to control the moisture content of the recycled materials to below 0.1% to prevent bubbles and gelation problems. Next, metal impurities are removed, color sorting and melt index testing are performed to ensure the quality of the recycled materials. The recycled materials are classified according to their source, properties, color, and contamination level to ensure consistency in subsequent processing. During the process, to compensate for the performance loss of the recycled materials, appropriate amounts of toughening agents (such as POE, EVA, or SEBS) and compatibilizers (such as MAH grafted polyolefins) are added. Toughening agents enhance the impact resistance and tensile strength of the recycled materials, while compatibilizers improve the compatibility between the recycled materials and the main raw materials, preventing delamination or separation and ensuring the uniformity of the multilayer film. During the batching process, real-time monitoring and dynamic adjustments are performed using weighing and metering units, spectral recognition devices, and AI algorithms to ensure that batching errors are controlled within ±1%. A real-time data feedback system guarantees the precise ratio of recycled materials to main raw materials, maximizing the use of recycled materials while ensuring consistent finished product quality, improving the efficiency of recycled material utilization, and guaranteeing the performance stability of the final membrane product. Pre-treatment and fine sorting of recycled materials ensure their quality, while the addition of toughening agents and solvents compensates for performance losses, resulting in membrane products with high toughness, excellent processing performance, and consistent quality.

[0022] Processing aids include slip agents, antioxidants, and stabilizers. The proportions are dynamically adjusted based on real-time detection data. Weighing and metering devices, spectral recognition devices, and control algorithms are used to control the proportion error within ±5%. The proportions of recycled materials in the ingredients are 40%–60%, main raw materials are 30%–50%, toughening agents are 5%–15%, and processing aids are less than 3%.

[0023] Specifically, the recycled plastics first undergo preliminary sorting to remove impurities, followed by hot air or vacuum drying to control the moisture content below 0.1% to prevent air bubbles and gel formation during extrusion. Subsequently, metal impurities are removed (to prevent equipment damage), color sorting is performed (to improve appearance consistency), and melt flow index testing is conducted (to assess melt flowability). The recycled materials are then classified according to their source, properties, color, and contamination level. Recycled material information is recorded via QR codes or RFID chips, enabling full-process traceability. In this formulation system, the main raw material is virgin LDPE / HDPE, supplemented with toughening agents (such as POE, EVA, or SEBS) to improve impact resistance. Simultaneously, a compatibilizer (such as maleic anhydride-grafted polyolefin) is added to enhance interfacial bonding and prevent delamination of the co-extruded layer. Processing aids, including slip agents, antioxidants, and heat stabilizers, are introduced to improve film surface lubrication, prevent oxidative degradation, and enhance thermal processing stability, respectively. The amount of all components added is dynamically adjusted using a weighing and metering device, a spectral identification device, and a control algorithm to ensure that the proportioning error is controlled within ±5%. The mixing ratio range is: recycled material 40%–60%, main raw material 30%–50%, toughening agent 5%–15%, and processing aids not exceeding 3%. This dynamic mixing system allows for adjustments to the proportions based on the real-time characteristics of the recycled material, improving process adaptability and the quality stability of the film product. Through strict recycled material treatment, scientific proportioning design, and real-time control, high toughness, high uniformity, and good processing stability of the film product are achieved under high recycled material conditions, making it suitable for the large-scale production of high-performance plastic bags.

[0024] In the five-layer layout, layer B is the main structural layer, which uses recycled materials as the main material for toughening and reinforcement to ensure load-bearing and impact performance; Layers A and C are the surface and heat-sealing layers, respectively, and are made of virgin HDPE / LLDPE to ensure heat-sealing performance and aesthetics. Based on the material interface compatibility, a solvent is added to the interface layer to enhance the bonding strength of the multilayer structure; In the five-layer layout, layer B is the structural load-bearing layer, accounting for 60% to 70% of the thickness, while the total thickness of layers A and C does not exceed 40%.

[0025] Specifically, recycled polyolefin plastics are first initially sorted, then dried using hot air or vacuum to control their moisture content to below 0.1% to avoid air bubbles and gelation during extrusion. After metal rejection, color sorting, and melt index testing, they are classified and managed according to source, performance, color, and pollution level. All batches of recycled materials are identified and traced using QR codes or RFID chips. To compensate for the performance loss of recycled materials, toughening agents (POE, EVA, SEBS) and compatibilizers (MAH grafted polyolefins) are added to improve their impact resistance and compatibility with multi-component materials. In co-extrusion formulation design, processing aids (such as slip agents, antioxidants, and stabilizers) are added to improve film surface treatability and thermal processing stability. All raw material proportions are adjusted in real time using weighing and metering devices, spectral recognition devices, and control algorithms, with control errors within ±5%. Recommended proportions for each component are: recycled materials 40%–60%, main raw materials 30%–50%, toughening agents 5%–15%, and processing aids not exceeding 3%.

[0026] The membrane adopts a five-layer co-extrusion structure A / B / C / B / A, where layer B is the main structural layer, mainly made of recycled material with added toughening agents, for load-bearing and impact resistance, and its thickness accounts for 60% to 70%. Layers A and C are the surface layer and heat-sealing layer, respectively, using a ratio of HDPE and LLDPE virgin materials to improve heat-sealing performance and surface aesthetics, and their total thickness does not exceed 40%. At the interfaces of each layer, appropriate amounts of compatibility solvents are added according to the compatibility between materials to enhance the bonding strength between the multilayer structure and prevent interlayer delamination or separation. Through raw material optimization, introduction of functional components, and multilayer structure design, the utilization rate of recycled materials and the overall performance of the membrane product are effectively improved, making it suitable for preparing high-performance, high-strength, and heat-sealing plastic bag products.

[0027] The screw extruder adopts a twin-screw design, the die head adopts an annular die head, the air ring cooling device adopts a multi-air outlet design, and the toughening agent is maleic anhydride grafted polyethylene (MAH-g-PE). After the raw material is melted in the screw extruder, it is extruded through the annular die to form a tubular film. Compressed air expands the film to the required thickness. The air ring cooling device quickly cools the film to stabilize its structure. The addition of toughening agent increases the degree of molecular chain entanglement, thereby enhancing the toughness of the film. In the blown film process, the blowing ratio is set to 2.5–3.0 and the traction ratio is set to 1.8–2.0. Laser detection, tension feedback, and PID closed-loop control are used to stabilize the film bubble formation. The blown film process adopts a cooling air circulation method. Auxiliary detectors include an infrared / laser thickness detector, a micro-wind speed detector, and a tension sensor. The control system adopts a PID closed-loop algorithm to automatically adjust the airflow of the air ring, the die head temperature, and the traction speed based on the detection data.

[0028] Specifically, during the blown film processing stage, to ensure stable bubble formation and uniform thickness of the finished product, the blow-up ratio is set to 2.5–3.0, and the draw ratio to 1.8–2.0. These parameters control film thickness and transparency variations while ensuring the film's orientation structure and strength. A cooling air circulation system is used to cool the bubble during the blown film process. The air ring has a 360° fully enclosed structure, and the cooling efficiency is improved through the linkage of internal and external airflows, preventing bubble instability or localized melt collapse. To achieve closed-loop control of the film bubble forming process, this process is equipped with multiple sets of auxiliary detectors, including infrared or laser thickness detectors, micro-wind speed detectors, and tension sensors, to monitor the film bubble thickness, the cooling effect of the air ring, and the tension status of the traction system in real time. The data collected by the detectors is fed back to the control system in real time through a closed-loop PID control algorithm, automatically adjusting the die head temperature, air ring airflow, and traction speed. This achieves dynamic stability of the film bubble size and thickness, preventing the risk of film bubble vibration, uneven thickness, or film breakage caused by environmental or raw material fluctuations. It plays a crucial role in multi-layer co-extrusion blown film, ensuring the coordination of the synchronous stretching, cooling, and curing processes of multiple film layers, improving the thickness uniformity, optical properties, and mechanical strength of the finished film, and providing a stable foundation for subsequent winding, bag making, and other processes.

[0029] Cooling the membrane bubble is used to control the uniformity of membrane thickness. The electrostatic elimination device uses an ion fan or electrostatic bar to remove the charge on the membrane surface to prevent dust adsorption and subsequent film winding wrinkling. The blown film area is equipped with an infrared or laser thickness detector, wind speed detector and tension sensor, which are connected to the PID closed-loop system. The air cooling wind speed is synchronized with the membrane thickness feedback to match the membrane cooling rate with the rheological rate.

[0030] Specifically, during the blown film processing, a cooling air circulation system is used to effectively cool the film bubble in order to achieve uniform control of film thickness and film formation stability. The cooling device uniformly cools the outer wall of the film bubble by adjusting the air volume of the air ring. The cooling rate is adjusted synchronously with the film thickness detection results and the extrusion flow rate to ensure that the cooling rate matches the rheological rate and avoid film bubble deformation and film thickness deviation. To improve membrane quality and reduce environmental interference, an electrostatic elimination device, including an ion fan or an electrostatic bar, is installed to eliminate the accumulation of static charge on the surface of the membrane bubble, prevent the membrane from adsorbing dust particles in the air, and reduce problems such as wrinkles and slippage on the membrane surface during subsequent winding or folding. The blown film area is equipped with infrared or laser thickness gauges, wind speed detectors, and tension sensors to monitor the thickness changes of the film bubble, cooling wind speed, and traction stability online. All detection data is transmitted to the central control system in real time, and the PID closed-loop control algorithm automatically adjusts the wind speed of the air ring, the die head temperature, and the traction speed to dynamically maintain the dimensional stability of the film bubble and the uniformity of interlayer thickness, effectively improving the forming quality and overall physical properties of multilayer films.

[0031] Performance indicators include longitudinal / transverse tensile strength, elongation at break, heat seal strength, and puncture resistance. The winding system uses a constant tension dual-roll drive and is equipped with an automatic correction system to ensure that the finished film roll is tightly and neatly arranged without wrinkles or air bubbles.

[0032] Specifically, after film forming, the finished film needs to undergo online performance evaluation and precision winding. Performance indicators mainly include longitudinal and transverse tensile strength, elongation at break, heat seal strength, and puncture resistance. These indicators reflect the mechanical stability and sealing reliability of the film under different usage scenarios. Performance testing can be conducted using online sampling combined with laboratory tensile tests and heat seal peel tests to ensure the film meets the functional requirements for packaging use. After being output by the traction system, the finished film enters the winding system. The winding device adopts a constant tension dual-roller drive structure, which ensures consistent tension during the film winding process through tension control, preventing uneven film rolls, wrinkles, or edge shrinkage caused by tension fluctuations. An automatic correction system is also installed, which automatically adjusts the film roll arrangement through an edge tracking device and servo actuator to ensure neat film roll alignment, consistent edges, and no defects such as wrinkles or air bubbles. This system can adaptively adjust deviations as the film speed changes, effectively improving winding quality and ensuring smooth transitions to subsequent bag-making processes.

[0033] The bag making / slicing section includes automated heat sealing, edge cutting, and perforation processes. Production information includes production batch, raw material ratio, recycled material grade, and inspection number. The quality traceability chain is used for subsequent quality review and process optimization.

[0034] Specifically, after being wound up, the film roll enters the bag making or slicing section, where a series of post-processing procedures are completed by automated equipment, including heat sealing, edge trimming, and perforation. Heat sealing uses a constant-temperature hot-pressing method to achieve multi-point positioning and sealing, ensuring a firm seal on the bag. The edge trimming process uses high-speed blades for precise cutting, ensuring neat, burr-free bag edges. The perforation station is equipped with ventilation holes or hook holes depending on the product type, enhancing the functionality and applicability of the bag. In this process, the system automatically reads and prints or uses inkjet coding to identify various production information, including: production batch, raw material ratio, recycled material grade and test number, and can embed it into the product label through QR code or RFID, realizing full-process data binding from raw material source to factory packaging; This data system forms a complete quality traceability chain, enabling rapid traceability and analysis when product performance deviations, customer feedback, or batch sampling anomalies occur. It assists enterprises in conducting quality reviews, process adjustments, and formula optimization, thereby improving the transparency and quality control efficiency of the entire production process.

[0035] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A processing technology for high-toughness plastic bags, characterized in that, Includes the following steps: First, the recycled main raw materials are initially sorted and their source, grade classification and processing status are recorded. Then, corresponding toughening agents and solvents are added for different grades of recycled materials to obtain the processed recycled materials. By configuring a centralized feeding system and intelligent proportioning program, the treated recycled materials, main raw materials, toughening agents and processing aids are fed into multiple extruder screws for mixing according to the process ratio; The mixed raw materials are injected into a five-layer co-extrusion die head or annular die head structure to form a five-layer layout of A / B / C / B / A. The die head structure adopts a spiral flow channel or a fan-shaped flow channel, and each screw is equipped with a zoned temperature control system. Then, through the control system, the extrusion body is controlled to blow the extruded film to form a film bubble, and an auxiliary detector is installed in the film bubble area to monitor the film bubble thickness distribution, tensile stability and offset trend in real time. Then, the blown film is cooled by a 360° cooling air ring and an internal air core. At the same time, after cooling, the static electricity elimination device is set to remove the charge on the film surface. The air cooling speed is adjusted synchronously with the film thickness feedback. After the film is blown, it is pulled to the winding section by the winding system. Before winding, the mechanical performance indicators are tested by online monitoring instruments, and the data of each segment is electronically recorded, packaged and uploaded to the factory database. Finished film rolls are sent to the bag making / slicing section according to order requirements. During the packaging process, production information is marked on each roll of film or each bag using an online inkjet printing system. Finally, all data is uploaded to the factory database to form a complete quality traceability chain.

2. The high-toughness plastic bag processing technology according to claim 1, characterized in that: The main raw materials include LDPE and LLDP. The initial sorting is carried out by hot air or vacuum drying for deep drying. The drying process controls the moisture content to below 0.1% to avoid subsequent extrusion of air bubbles and gelation problems. The toughening agent includes maleic anhydride-grafted polyethylene, and the compatibilizer includes MAH-grafted polyolefin. The preliminary sorting process also includes the following sub-steps: Metal impurity removal is used to remove metal impurities from recycled materials to prevent equipment damage. Color sorting is used to remove discolored impurities from recycled materials; Melt index testing is used to measure the melt flowability of recycled materials; The classification includes source classification, performance classification, color classification and pollution level classification. The toughening agent and solvent are used to compensate for performance loss and control the controllability and consistency of recycled materials. The source is recorded by means of QR code or RFID chip.

3. The high-toughness plastic bag processing technology according to claim 1, characterized in that: The processing aids include slip agents, antioxidants, and stabilizers. The proportions are dynamically adjusted based on real-time detection data, using a weighing and metering device, a spectral recognition device, and a control algorithm to control the proportion error within ±5%. The proportions of recycled materials in the ingredients are 40%–60%, the proportions of main raw materials are 30%–50%, the proportions of toughening agents are 5%–15%, and the proportions of processing aids are less than 3%.

4. The high-toughness plastic bag processing technology according to claim 1, characterized in that: In the five-layer layout, layer B is the main structural layer, which uses recycled materials as the main material to toughen and reinforce the structure and ensure load-bearing and impact performance. Layers A and C are the surface and heat-sealing layers, respectively, and are made of virgin HDPE / LLDPE to ensure heat-sealing performance and aesthetics. Based on the material interface compatibility, a solvent is added to the interface layer to enhance the bonding strength of the multilayer structure; In the five-layer layout, layer B is the structural load-bearing layer, accounting for 60% to 70% of the thickness, while the total thickness of layers A and C does not exceed 40%.

5. The high-toughness plastic bag processing technology according to claim 1, characterized in that: The blown film process is set with a blow-up ratio of 2.5 to 3.0 and a traction ratio of 1.8 to 2.

0. Laser detection, tension feedback, and PID closed-loop control are used to stabilize film bubble formation. The blown film process adopts a cooling air circulation method. The auxiliary detectors include an infrared / laser thickness detector, a micro-wind speed detector, and a tension sensor. The auxiliary detectors are installed. The control system adopts a PID closed-loop algorithm to automatically adjust the airflow of the air ring, the die head temperature, and the traction speed based on the detection data.

6. The high-toughness plastic bag processing technology according to claim 1, characterized in that: The cooling of the membrane bubble is used to control the uniformity of membrane thickness. The electrostatic elimination device uses an ion fan or electrostatic bar to remove the charge on the membrane surface to prevent dust adsorption and subsequent film winding wrinkling. The blown film area is equipped with an infrared or laser thickness detector, a wind speed detector and a tension sensor, and is connected to a PID closed-loop system. The air cooling wind speed is synchronized with the membrane thickness feedback to match the membrane cooling rate with the rheological rate.

7. The high-toughness plastic bag processing technology according to claim 1, characterized in that: The performance indicators include longitudinal / transverse tensile strength, elongation at break, heat seal strength, and puncture resistance. The winding system is driven by constant tension dual rollers and equipped with an automatic correction system to ensure that the finished film rolls are tightly and neatly arranged without wrinkles or air bubbles.

8. The high-toughness plastic bag processing technology according to claim 1, characterized in that: The bag making / slicing section includes automated heat sealing, edge cutting, and punching processes. The production information includes production batch, raw material ratio, recycled material grade, and inspection number. The quality traceability chain is used for subsequent quality review and process optimization.

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