Method for preparing single-material VMPE recoverable hose through dynamic temperature control multi-layer co-extrusion

Abstract

The invention provides a method for preparing a single-material VMPE recoverable hose through dynamic temperature control multi-layer co-extrusion. The method comprises the steps that infrared temperature measurement modules are installed on all sections of an extruder respectively to construct a dynamic temperature control system; feeding the pretreated raw materials into a corresponding extruder, and adjusting a heating device and a cooling device of a charging barrel of the extruder in real time according to a preset extrusion temperature allowable range through a dynamic temperature control system to obtain a plasticized melt; carrying out bonding treatment on the plasticized melt by utilizing an ultrasonic vibration composite technology to obtain a multi-layer reinforced melt; detecting the thickness of the pipe wall of the multi-layer reinforced melt through a hyperspectral imager and judging whether the thickness of the pipe wall is qualified or not; if not, pipe wall thickness deviation data are fed back to a dynamic temperature control system and an extruder control system to conduct linkage adjustment on extrusion parameters; and if the multi-layer reinforced melt is qualified, cooling shaping and fixed-length cutting treatment are conducted on the multi-layer reinforced melt, the finished recoverable hose is obtained, and the hose forming precision and the recovery performance are effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of manufacturing recyclable plastic hoses, and particularly to a method for dynamically controlling temperature in multi-layer co-extrusion to prepare a single-material VMPE recyclable hose. Background Art

[0002] In the field of plastic hose production, single materials have become the focus of the industry due to their significant advantages. The single-material system shows strong adaptability in the recycling process, avoiding the separation problems caused by complex material compositions, greatly reducing the risk of secondary pollution during recycling, and having a low degree of attenuation of the recycled material properties, meeting the requirements of the development of circular economy; from the production perspective, single materials simplify the processing process, reduce the adaptation and debugging links between different materials, not only improve production efficiency but also reduce production costs. In addition, single materials perform stably during the forming process, effectively reducing product defects caused by material compatibility problems and ensuring the consistency of product quality.

[0003] The multi-layer co-extrusion technology can endow hoses with multiple characteristics such as barrier properties, flexibility, and chemical resistance by compounding different functional layers. The multi-layer fusion of single materials, while retaining these advantages, avoids the recycling problems brought by using multiple materials in traditional multi-layer co-extrusion. However, this combined technology still faces many challenges: the traditional temperature control system is difficult to achieve real-time and precise control of the extrusion temperature of each layer of material, resulting in mismatched melt viscosities, problems such as interlayer peeling and uneven thickness; in terms of interlayer bonding, relying on traditional hot pressing and compounding methods, improper temperature control will cause conditions such as material decomposition and poor plasticization, affecting the tightness of interlayer bonding and the molecular diffusion effect, making the hose prone to delamination and fragmentation during recycling; at the same time, the off-line detection efficiency during the preparation process is low, and process parameters cannot be corrected in time, resulting in a high rejection rate.

[0004] In addition, in fields with extremely high requirements for hygiene and safety such as medical drug packaging, with the improvement of people's living quality and hygiene awareness, the requirements for packaging materials are becoming increasingly strict. Traditional pharmaceutical packaging materials are difficult to meet the requirements. Although new hoses can meet the standards, they are expensive and have extremely high requirements for production processes. Existing aluminum-plastic sheet hoses and all-plastic hoses, due to their complex material compositions, are not single-material systems and cannot meet the recycling requirements. Therefore, there is an urgent need for a method for dynamically controlling temperature in multi-layer co-extrusion to prepare a single-material VMPE recyclable hose. Summary of the Invention

[0005] The present invention provides a method for dynamically controlling temperature in multi-layer co-extrusion to prepare a single-material VMPE recyclable hose, achieving the improvement of the forming accuracy and recycling performance of the single-material recyclable VMPE hose through a dynamic temperature control system, an ultrasonic vibration compounding technology, and an on-line defect detection system.

[0006] The present invention provides a method for dynamically controlling temperature in multi-layer co-extrusion to prepare a single-material VMPE recyclable hose, including:

[0007] Install infrared temperature measurement modules at each section of the extruder, and set the allowable range of extrusion temperature for each layer of the recyclable hose to construct a dynamic temperature control system;

[0008] Put the pretreated raw materials into the corresponding extruder, and through the dynamic temperature control system, adjust the heating device and cooling device of each section in real time according to the preset allowable range of extrusion temperature to obtain a plasticized melt;

[0009] Use ultrasonic vibration composite technology to bond the plasticized melt to obtain a multi-layer reinforced melt;

[0010] Detect the wall thickness of the multi-layer reinforced melt through a hyperspectral imager, and judge whether the wall thickness is qualified;

[0011] When the wall thickness is unqualified, feedback the wall thickness deviation data to the dynamic temperature control system and the extruder control system to jointly adjust the extrusion parameters;

[0012] When the wall thickness is qualified, cool and shape the multi-layer reinforced melt and perform fixed-length cutting to obtain a finished recyclable hose;

[0013] Among them, the outer layer of the recyclable hose is HDPE, the middle layer is VMPE, and the inner layer is HDPE.

[0014] Preferably, in a method for dynamically controlling temperature in multi-layer co-extrusion to prepare a single-material VMPE recyclable hose, it includes:

[0015] Install a 20 kHz ultrasonic generator at the composite die head, and its vibration direction is perpendicular to the extrusion direction of the recyclable hose.

[0016] Preferably, in a method for dynamically controlling temperature in multi-layer co-extrusion to prepare a single-material VMPE recyclable hose, install infrared temperature measurement modules at each section of the extruder, and set the allowable range of extrusion temperature for each layer of the recyclable hose to construct a dynamic temperature control system, including:

[0017] Associate the infrared temperature measurement modules installed at each section of the extruder with their corresponding cooling devices and heating devices respectively to obtain the control authority of the cooling devices and heating devices;

[0018] Based on the type of raw materials put into the extruder where the infrared temperature measurement module is installed, determine the allowable range of extrusion temperature corresponding to the detection position of each infrared temperature measurement module respectively, and set it.

[0019] Preferably, in a method for dynamically temperature-controlled multi-layer co-extrusion to prepare a single-material VMPE recyclable hose, through a dynamic temperature control system, the heating devices and cooling devices of each section are adjusted in real time according to the preset allowable range of extrusion temperature to obtain a plasticized melt, including:

[0020] Collect the real-time temperature of the raw materials in each section of the extruder through an infrared temperature measurement module, and judge whether the real-time temperature of the raw materials is within the corresponding preset allowable range of extrusion temperature;

[0021] When the real-time temperature of the raw materials is higher than the preset allowable range of extrusion temperature, start the cooling device to reduce the temperature and reduce the power of the heating device;

[0022] When the real-time temperature of the raw materials is lower than the preset allowable range of extrusion temperature, increase the power of the heating device.

[0023] Preferably, in a method for dynamically temperature-controlled multi-layer co-extrusion to prepare a single-material VMPE recyclable hose, feedback the wall thickness deviation data to the dynamic temperature control system and the extruder control system to jointly adjust the extrusion parameters, including:

[0024] After the extruder control system receives the wall thickness deviation data, based on the wall thickness deviation data, calculate the wall error degree corresponding to the current detection position. When the error degree is greater than the preset value, determine that the hose section corresponding to the current detection position is a defective section, mark the position of the defective section, and send the marking result to the fixed-length cutting device;

[0025] Otherwise, determine that the hose section corresponding to the current detection position is a qualified section.

[0026] Preferably, in a method for dynamically temperature-controlled multi-layer co-extrusion to prepare a single-material VMPE recyclable hose, after the extruder control system receives the wall thickness deviation data, it further includes:

[0027] Synchronously obtain the wall detection spectrum, determine the interlayer thickness, compare the interlayer thickness with its corresponding designed thickness, and obtain the interlayer thickness deviation;

[0028] Based on the interlayer thickness deviation and the unit standard material consumption of the recyclable hose, determine the actual material consumption error of each layer respectively;

[0029] Based on the actual material consumption error and the corresponding relationship between the screw speed and the material extrusion amount of the extruder, determine the first screw speed difference, and calculate the ratio between the screw speed difference and its corresponding original screw speed to obtain the screw speed error rate;

[0030] When the screw speed error rate is greater than or equal to the preset threshold, based on the first screw speed difference, correct the screw speed of the extruder;

[0031] Otherwise, obtain the initial output pipe wall thickness of the die bonding, compare the initial output pipe wall thickness with the detected pipe wall thickness to obtain the first traction thickness error, and obtain the traction-thickness error coefficient based on the actual distance between the die and the hyperspectral imager and the first traction thickness error;

[0032] Judge whether the traction-thickness error coefficient is within the preset coefficient range. If so, obtain the traction distance between the starting point of forming and cooling and the die, and obtain the second traction thickness error based on the traction distance and the traction-thickness error coefficient;

[0033] Based on the unit standard material consumption, the designed total thickness of the recyclable hose, and the second traction thickness error, calculate the first unit compensation material consumption, and combine the thickness proportion corresponding to each layer for compensation distribution to determine the second unit compensation material consumption corresponding to each layer of the recyclable hose;

[0034] Based on the actual material consumption error of each layer and the second unit compensation material consumption, obtain the compensation material consumption;

[0035] Based on the compensation material consumption and the corresponding relationship between the screw speed and the extrusion amount of the extruder, determine the second screw speed difference;

[0036] Based on the second screw speed difference, correct the screw speed of the extruder.

[0037] Preferably, in a method for dynamically temperature-controlled multi-layer co-extrusion to prepare a single-material VMPE recyclable hose, when the traction-thickness error coefficient is not within the preset coefficient range, it includes:

[0038] If the traction-thickness error is greater than the upper limit of the preset coefficient range, control the traction device to reduce the hose traction speed;

[0039] If the traction-thickness error is less than the lower limit of the preset coefficient range, control the traction device to increase the hose traction speed.

[0040] Preferably, in a method for dynamically temperature-controlled multi-layer co-extrusion to prepare a single-material VMPE recyclable hose, it includes:

[0041] When adjusting the traction speed of the traction device, adopt a multi-axis linkage control technology to synchronously control the traction devices corresponding to multiple extruders for producing the materials of each layer of the recyclable hose.

[0042] Preferably, in a method for dynamically temperature-controlled multi-layer co-extrusion to prepare a single-material VMPE recyclable hose, after the dynamic temperature control system receives the pipe wall thickness deviation data, it includes:

[0043] Compare the pipe wall thickness deviation data within a preset time period to judge the abnormal type of the pipe wall thickness of the recyclable hose;

[0044] When the overall wall thickness deviation is out of tolerance, keep the current temperature unchanged and wait for the extrusion machine control system to adjust the extrusion parameters;

[0045] When the wall thickness deviation is local over-thickness or local under-thickness, obtain the interlayer thickness, determine the layer with thickness deviation and its corresponding thickness difference, and based on the thickness difference, use the PID control algorithm to calculate and determine the temperature regulation amount corresponding to the layer with thickness deviation;

[0046] Based on the temperature regulation amount, control and adjust the heating device or cooling device corresponding to the layer with thickness deviation.

[0047] Preferably, in a method for dynamically controlling temperature in multi-layer co-extrusion to prepare a single-material VMPE recyclable hose, the multi-layer reinforced melt is cooled and shaped and cut to a fixed length to obtain a finished recyclable hose, including:

[0048] Based on the defective section position mark, determine the starting position and ending position of the defective section;

[0049] Based on the starting position of the defective section and the previous cutting point position, obtain the defect interval;

[0050] When the defect interval is greater than the preset cutting length, determine that the defective section is within the current finished product, use the ending position of the defective section as the final cutting point of the current finished product, obtain a defective recyclable hose finished product, and make a defective mark;

[0051] When the defect interval is less than or equal to the preset cutting length, keep normal cutting.

[0052] Compared with the prior art, the present invention has at least the following beneficial effects:

[0053] The present invention realizes precise control of the extrusion temperature of each layer of raw materials of the hose by installing an infrared temperature measurement module at the key parts of the extruder and constructing a dynamic temperature control system, strictly controlling the temperature fluctuation within a very small range, so that the outer layer of HDPE, the middle VMPE layer, and the inner layer of HDPE are all in the optimal extrusion temperature range, effectively avoiding material thermal degradation and performance deterioration caused by too high temperature, and the problem of poor plasticization caused by too low temperature. Compared with the traditional temperature control method, the precise temperature control makes the extrusion process more stable and efficient, enables the PE material to maintain good physical and chemical properties during the processing, is conducive to improving the production speed and recycling quality of the recyclable hose. At the same time, the ultrasonic vibration composite technology is used to process the multi-layer melt. The 20 kHz ultrasonic wave causes high-frequency micro-amplitude oscillations in the melt, promoting the full diffusion and entanglement of the molecular chains between layers, forming a nano-level transition interface, so that the interlayer peel strength of the hose is greatly increased from 6-8 N / cm of the traditional process to 12 N / cm, and the increase range reaches 50%-100%, greatly enhancing the stability and reliability of the hose structure, effectively avoiding the problem of interlayer separation during use, significantly improving the product quality and service life. The extremely tight interlayer bonding enables the multi-layer PE material to maintain overall integrity, not only ensuring the performance of the hose during use, but also avoiding interlayer separation and fragmentation in the recycling link, laying a good foundation for subsequent recycling and utilization; through the hyperspectral imager, the wall thickness of the pipe is detected in real time with high precision (accuracy up to ±5 μm). When the wall thickness of the pipe is detected to be unqualified, the system immediately feeds back the deviation data to the dynamic temperature control system and the extruder control system, automatically adjusts the corresponding extrusion parameters (such as: extrusion temperature, screw speed, traction speed, etc.), forms a linkage between the hyperspectral imager, the dynamic temperature control system and the extruder control system, realizes the linkage adjustment of extrusion parameters such as temperature, screw speed and traction speed in the production process, completes the intelligent correction of the defects in the preparation of the hose. Compared with the traditional off-line sampling inspection method, the CV value of the wall thickness uniformity is reduced from 5-8% of the traditional process to ≤3%, effectively avoiding the strength difference and appearance defects caused by uneven wall thickness, greatly improving the production efficiency, reducing raw material waste, and reducing production costs. The present invention can flexibly adapt to the production requirements of a variety of recyclable plastic raw materials and hoses with different specifications and functions through adjustable temperature parameter settings, ultrasonic vibration parameter adjustments, and detection threshold settings.

[0054] Other features and advantages of the present invention will be described in the following specification, and in part will be obvious from the specification, or will be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained by the structure specifically pointed out in this application document.

[0055] The technical solution of the present invention will be further described in detail below through the drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The accompanying drawings are used to provide a further understanding of the present invention and form a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation to the present invention. In the accompanying drawings:

[0057] Figure 1 It is a flowchart of a method for dynamically controlling temperature and multi-layer co-extruding to prepare a single-material VMPE recyclable hose;

[0058] Figure 2 It is a flowchart for constructing a dynamic temperature control system;

[0059] Figure 3 It is a flowchart for fixed-length cutting treatment. Detailed implementation manners

[0060] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to explain and illustrate the present invention and are not used to limit the present invention.

[0061] Embodiment 1:

[0062] The present invention provides a method for dynamically controlling temperature and multi-layer co-extruding to prepare a single-material VMPE recyclable hose. As Figure 1 shown, it includes:

[0063] Install infrared temperature measurement modules at each section of the extruder, and set the allowable range of extrusion temperature for each layer of the recyclable hose to construct a dynamic temperature control system;

[0064] Put the pretreated raw materials into the corresponding extruder, and through the dynamic temperature control system, adjust the heating device and cooling device of each section in real time according to the preset allowable range of extrusion temperature to obtain a plasticized melt;

[0065] Use ultrasonic vibration composite technology to bond the plasticized melt to obtain a multi-layer reinforced melt;

[0066] Detect the wall thickness of the multi-layer reinforced melt through a hyperspectral imager, and judge whether the wall thickness is qualified;

[0067] When the wall thickness is unqualified, feed back the wall thickness deviation data to the dynamic temperature control system and the extruder control system to jointly adjust the extrusion parameters;

[0068] When the wall thickness is qualified, cool and shape the multi-layer reinforced melt and perform fixed-length cutting treatment to obtain a finished recyclable hose;

[0069] Among them, the outer layer of the recyclable hose is HDPE, the middle layer is VMPE, and the inner layer is HDPE;

[0070] Install a 20kHz ultrasonic generator at the composite die head, with its vibration direction perpendicular to the extrusion direction of the recyclable hose.

[0071] In this embodiment, each layer of the extruder mainly includes: a feeding section, a compression section, a melting section, and a flow section.

[0072] In this embodiment, the extrusion temperature of the outer HDPE layer is 190 - 200 °C, the middle VMPE layer is 170 - 180 °C, and the inner HDPE layer is 180 - 190 °C. Among them, both the outer HDPE layer and the inner HDPE layer are hollow blow - molding grade HDPE layers. The VMPE layer includes a PE film and an aluminized layer formed on the surface of the PE film. The thickness of each layer of material can be flexibly set according to production requirements. At the same time, the shoulders and caps of the recyclable hose are also made of PE material (for example, low - melt - index HDPE material) to ensure that the overall material of the hose is single and convenient for recycling and reuse.

[0073] Among them, VMPE is the abbreviation of vacuum metallized PE film, which means vacuum aluminized polyethylene film; HDPE is the abbreviation of High Density Polyethylene, which means high - density polyethylene.

[0074] In this embodiment, the ultrasonic amplitude of the ultrasonic generator can be adjusted by the user according to actual production requirements, and the default value is 10 - 15 μm.

[0075] Beneficial effects of the above technical solution: By installing an infrared temperature measurement module at the key parts of the extruder and constructing a dynamic temperature control system, the present invention realizes precise control of the extrusion temperature of each layer of raw materials, strictly controls the temperature fluctuation within a very small range, so that the outer layer of HDPE, the middle layer of VMPE, and the inner layer of HDPE are all in the optimal extrusion temperature range, effectively avoiding material thermal degradation and performance deterioration caused by too high temperature, as well as poor plasticization caused by too low temperature. Compared with the traditional temperature control method, the precise temperature control makes the extrusion process more stable and efficient, enables the PE material to maintain good physical and chemical properties during the processing, is beneficial to improving the production speed and recycling quality of the recyclable hose. At the same time, the ultrasonic vibration composite technology is used to process the multi-layer melt. The 20 kHz ultrasonic wave induces high-frequency micro-amplitude oscillations in the melt, promotes the full diffusion and entanglement of the molecular chains between layers, forms a nano-scale transition interface, and increases the interlayer peel strength of the hose from 6-8 N / cm in the traditional process to 12 N / cm, with an increase range of 50%-100%, greatly enhancing the stability and reliability of the hose structure, effectively avoiding the problem of interlayer separation during use, significantly improving the product quality and service life. The extremely tight interlayer combination enables the multi-layer PE material to maintain overall integrity, not only ensuring the performance of the hose during use, but also avoiding interlayer separation and fragmentation in the recycling link, laying a good foundation for subsequent recycling. By using a hyperspectral imager to perform real-time detection of the wall thickness of the pipe with high precision (the precision reaches ±5 μm), when the wall thickness of the pipe is detected to be unqualified, the system immediately feeds back the deviation data to the dynamic temperature control system and the extruder control system, and automatically adjusts the corresponding extrusion parameters (such as: extrusion temperature, screw speed, traction speed, etc.), forming a linkage between the hyperspectral imager, the dynamic temperature control system and the extruder control system, realizing the linkage adjustment of extrusion parameters such as temperature, screw speed and traction speed in the production process, completing the intelligent correction of the defects in the preparation of the hose. Compared with the traditional off-line sampling inspection method, the CV value of the wall thickness uniformity is reduced from 5-8% in the traditional process to ≤3%, effectively avoiding strength differences and appearance defects caused by uneven wall thickness, greatly improving production efficiency, reducing waste of raw materials, and reducing production costs. The present invention can flexibly adapt to the production requirements of a variety of recyclable plastic raw materials and hoses with different specifications and functions through adjustable temperature parameter settings, ultrasonic vibration parameter adjustments and detection threshold settings.

[0076] Example 2:

[0077] On the basis of Example 1, infrared temperature measurement modules are installed in each section of the extruder, and the allowable range of extrusion temperature for each layer of the recyclable hose is set to construct a dynamic temperature control system, as Figure 2 shown, including:

[0078] Associate the infrared temperature measurement modules installed in each section of the extruder with their corresponding cooling devices and heating devices respectively, and obtain the control authority over the cooling devices and heating devices;

[0079] Based on the types of raw materials input into the extruder where the infrared temperature measurement modules are installed, determine the allowable range of extrusion temperature corresponding to the detection positions of each infrared temperature measurement module respectively, and make settings.

[0080] Advantages of the above technical solution: In the present invention, by installing infrared temperature measurement modules in each section of the extruder and associating them with the corresponding cooling and heating devices, the system is given direct control authority over the temperature regulation equipment, enabling real-time monitoring and rapid response adjustment of the temperatures at key parts of the extruder; and based on the types of raw materials input into different extruders, determine the allowable range of extrusion temperature corresponding to the detection positions of each infrared temperature measurement module respectively, making the dynamic temperature control system highly adaptable, ensuring that each material can be plasticized and extruded under the best temperature conditions, effectively avoiding problems such as material decomposition and performance deterioration caused by too high temperature, and poor plasticization caused by too low temperature, greatly improving the hose forming quality, reducing defects such as surface flow marks and bubbles on the product, and effectively increasing the product qualification rate. The present invention closely combines temperature detection with equipment control, and can achieve automatic temperature adjustment without frequent manual intervention. The operator only needs to preset the allowable temperature range corresponding to the raw material in the system, and the system can independently complete the temperature control of the entire production process, reducing manual operation errors, shortening the process adjustment time, and improving production efficiency.

[0081] Example 3:

[0082] On the basis of Example 1, through the dynamic temperature control system, the heating device and the cooling device of the extruder barrel are adjusted in real time according to the preset allowable range of extrusion temperature, and a multi-layer melt is obtained, including:

[0083] Collect the real-time temperature of the raw materials in each section of the extruder through the infrared temperature measurement module, and judge whether the real-time temperature of the raw materials is within the corresponding preset allowable range of extrusion temperature;

[0084] When the real-time temperature of the raw materials is higher than the preset allowable range of extrusion temperature, start the cooling device to reduce the temperature;

[0085] When the real-time temperature of the raw materials is lower than the preset allowable range of extrusion temperature, increase the power of the heating device.

[0086] Advantages of the above technical solution: By using the infrared temperature measurement module to collect the temperature of the raw materials in each section of the extruder in real time and making accurate judgments and adjustments according to the preset allowable range of extrusion temperature, the present invention can strictly control the temperature fluctuation within the allowable range of extrusion temperature. Once the real-time temperature of the raw materials deviates from the preset range, the cooling or heating device will be immediately activated. When the temperature is higher than the upper limit of the allowable range, the cooling device quickly intervenes to cool down, avoiding production interruption caused by high temperature; when the temperature is lower than the lower limit, the heating device increases the power in time to prevent the extrusion speed from slowing down due to low temperature, so that the temperature abnormality in the production process can be corrected in a short time, greatly reducing the downtime adjustment time caused by temperature problems, making the production process of the recyclable hose more standardized and normalized, and facilitating the production management and quality control of enterprises.

[0087] Example 4:

[0088] On the basis of Example 1, the data of the wall thickness deviation is fed back to the dynamic temperature control system and the extruder control system to perform linkage adjustment on the extrusion parameters, including:

[0089] After the extruder control system receives the data of the wall thickness deviation, based on the data of the wall thickness deviation, calculate the wall error degree corresponding to the current detection position. When the error degree is greater than the preset value, determine that the hose section corresponding to the current detection position is a defective section, mark the position of the defective section, and send the marking result to the fixed-length cutting device;

[0090] Otherwise, determine that the hose section corresponding to the current detection position is a qualified section.

[0091] Advantages of the above technical solution: By calculating the wall error degree in real time and comparing it with the preset value, the system can accurately identify the defective sections with excessive thickness, avoiding the problems of missed inspection and lag in manual sampling inspection, marking the positions of the defective sections, and sending the marking results to the fixed-length cutting device to directly drive the fixed-length cutting device to remove the defective sections, ensuring the wall thickness uniformity of the final product, which is beneficial to meeting the strict requirements of high-end packaging for dimensional accuracy (such as the wall thickness error of medical hoses needs to be controlled within ±5μm).

[0092] Example 5:

[0093] On the basis of Example 4, after the extruder control system receives the data of the wall thickness deviation, it further includes:

[0094] Synchronously obtain the wall detection spectrum, determine the interlayer thickness, compare the interlayer thickness with its corresponding designed thickness, and obtain the interlayer thickness deviation;

[0095] Based on the interlayer thickness deviation and the unit standard material consumption of the recyclable hose, determine the actual material error of each layer respectively;

[0096] Based on the actual material usage error and the corresponding relationship between the screw speed and the material extrusion amount of the extruder, determine the first screw speed difference, calculate the ratio between the screw speed difference and its corresponding original screw speed, and obtain the screw speed error rate;

[0097] When the screw speed error rate is greater than or equal to the preset threshold, based on the first screw speed difference, correct the screw speed of the extruder;

[0098] Otherwise, obtain the initial output pipe wall thickness of the die bonding, compare the initial output pipe wall thickness with the detected pipe wall thickness to obtain the first traction thickness error, and based on the actual distance between the die and the hyperspectral imager and the first traction thickness error, obtain the traction-thickness error coefficient;

[0099] Judge whether the traction-thickness error coefficient is within the preset coefficient range. If so, obtain the traction distance between the starting point of forming and cooling and the die, and based on the traction distance and the traction-thickness error coefficient, obtain the second traction thickness error;

[0100] Based on the unit standard material usage amount, the designed total thickness of the recyclable hose, and the second traction thickness error, calculate the first unit compensated material usage amount, and combine the thickness proportion corresponding to each layer for compensation distribution to determine the second unit compensated material usage amount corresponding to each layer of the recyclable hose;

[0101] Based on the actual material usage error of each layer and the second unit compensated material usage amount, obtain the compensated material usage amount;

[0102] Based on the compensated material usage amount and the corresponding relationship between the screw speed and the material extrusion amount of the extruder, determine the second screw speed difference;

[0103] Based on the second screw speed difference, correct the screw speed of the extruder.

[0104] In this embodiment, the interlayer thickness refers to the actual thickness value corresponding to different materials. The designed thickness refers to the thickness value corresponding to each layer of the hose finished product set before production.

[0105] In this embodiment, the first screw speed difference refers to the actual material usage error calculated based on the interlayer thickness deviation, and through the corresponding relationship between the screw speed and the material extrusion amount, the converted screw speed adjustment amount.

[0106] In this embodiment, the screw speed error rate refers to the ratio of the first screw speed difference to the original screw speed.

[0107] In this embodiment, the preset threshold refers to the preset critical value of the screw speed error rate (usually 2%-5%).

[0108] In this embodiment, the initial output pipe wall thickness refers to the total thickness of the multi-layer melt when initially extruded from the die head; the detected pipe wall thickness refers to the total pipe wall thickness measured by the hyperspectral imager at the downstream detection position (usually 3 - 5 meters away from the die head).

[0109] In this embodiment, the traction-thickness error coefficient is a dimensionless coefficient characterizing the degree of deviation of the thickness change from the theoretical value during the traction process, and is obtained by the ratio of the first traction thickness error to the actual distance.

[0110] In this embodiment, the preset coefficient range refers to the reasonable range of the traction-thickness error coefficient (usually ±0.05).

[0111] In this embodiment, the second traction thickness error refers to the overall pipe wall thickness error caused by the elongation during traction before the multi-layer reinforced melt enters the cooling process, considering the traction-thickness error coefficient.

[0112] In this embodiment, the unit standard material consumption refers to the theoretical designed material consumption of each layer when producing a qualified hose per unit length (usually 1 meter).

[0113] In this embodiment, the designed total thickness refers to the thickness of the hose finished product set before production, that is, the sum of the designed thicknesses of each layer.

[0114] In this embodiment, the first unit compensation material consumption refers to the total additional material consumption required per unit length of the hose calculated based on the traction-thickness error coefficient, and the calculation formula is:

[0115]

[0116] where M represents the first unit compensation material consumption; n represents the number of hose layers; N i represents the unit standard material consumption of the i-th layer; Δh2 represents the value of the second traction thickness error; h0 represents the designed total thickness.

[0117] In this embodiment, the second unit compensation material consumption refers to the additional material consumption required for each layer after distributing the first unit compensation material consumption according to the thickness ratio of each layer, and the calculation formula is:

[0118]

[0119] where m i represents the second unit compensation material consumption corresponding to the i-th layer material; h i represents the designed total thickness of the i-th layer material.

[0120] In this embodiment, the compensation material consumption refers to the final material consumption that needs to be adjusted for each layer after considering the actual material consumption error and the thickness change during the traction process, and is the sum of the actual material consumption error corresponding to each layer and the second unit compensation.

[0121] In this embodiment, the second screw rotation speed difference refers to the final screw rotation speed adjustment amount calculated according to the compensation material consumption and the relationship between the screw rotation speed and the extrusion amount.

[0122] Advantages of the above technical solution: By obtaining the wall thickness detection spectrum to determine the interlayer thickness and comparing it with the designed thickness, the present invention can achieve high-precision monitoring of the hose interlayer structure, which is beneficial to controlling the interlayer thickness deviation within a very small range, effectively avoiding the problem of hose performance degradation caused by uneven interlayer thickness. Subsequently, based on the interlayer thickness deviation, the actual material consumption error is calculated, and in combination with the relationship between the screw rotation speed and the extrusion amount, the screw rotation speed difference is determined, which can accurately correct the screw rotation speed in real time. When the screw rotation speed error rate is greater than the preset threshold, the screw rotation speed is directly adjusted; when the error rate is small, the screw rotation speed is corrected through compensation calculation (such as calculating the compensation material consumption based on the traction-thickness error coefficient), so that the extrusion amount of each layer of material highly matches the designed material consumption, effectively avoiding the situation of material waste or insufficient material consumption, and effectively improving the raw material utilization rate. The present invention realizes the dynamic adjustment of the screw rotation speed according to various factors such as the change of the interlayer thickness and the thickness error during the traction process in the production process, realizes the autonomous correction of the process parameters during the hose production process, ensures the dimensional accuracy of the hose at different production stages, and effectively reduces the generation of waste products caused by problems such as unqualified thickness and material consumption deviation.

[0123] Example 6:

[0124] On the basis of Example 5, when the traction-thickness error coefficient is not within the preset coefficient range, it includes:

[0125] If the traction-thickness error is greater than the upper limit of the preset coefficient range, the traction device is controlled to reduce the hose traction speed;

[0126] If the traction-thickness error is less than the lower limit of the preset coefficient range, the traction device is controlled to increase the hose traction speed;

[0127] When adjusting the traction speed of the traction device, the multi-axis linkage control technology is adopted to synchronously control the traction devices corresponding to multiple extruders for producing each layer of material of the recyclable hose.

[0128] Advantages of the above technical solution: When the traction-thickness error coefficient of the present invention exceeds the preset range, the system immediately adjusts the traction speed to quickly return the wall thickness to the design value. When the error coefficient is greater than the upper limit (indicating that the wall is too thick), reducing the traction speed can increase the residence time of the melt at the die outlet, promote interlayer diffusion and thickness uniformity. Conversely, increasing the traction speed can stretch the melt to thin the wall. The autonomous correction of the traction speed during the production process is realized, and the multi-axis linkage control technology is adopted to synchronously control the traction equipment corresponding to multiple extruders for each layer of material of the recyclable hose, ensuring that each layer of material maintains the same linear speed and tension during traction, avoiding problems such as interlayer misalignment and stretching deformation caused by speed differences, thereby ensuring the structural stability and dimensional consistency of the multi-layer coextruded hose during the forming process, and effectively reducing the CV value of the product thickness and the defective and waste rates of the product.

[0129] Example 7:

[0130] Based on Example 1, after the dynamic temperature control system receives the wall thickness deviation data, it includes:

[0131] Compare the wall thickness deviation data within the preset time period to determine the abnormal type of the wall thickness of the recyclable hose;

[0132] When the wall thickness abnormality is overall over-tolerance, keep the current temperature unchanged and wait for the extruder control system to adjust the extrusion parameters;

[0133] When the wall thickness abnormality is local over-thickness or local under-thickness, obtain the interlayer thickness, determine the thickness abnormal layer and its corresponding thickness difference, and based on the thickness difference, use the PID control algorithm to calculate and determine the temperature regulation amount corresponding to the thickness abnormal layer;

[0134] Based on the temperature regulation amount, control and adjust the heating equipment or cooling equipment corresponding to the thickness abnormal layer.

[0135] Advantages of the above technical solution: By analyzing the characteristics of thickness deviation data (such as fluctuation frequency and amplitude distribution) within a preset time period, the system can automatically distinguish between overall out-of-tolerance and local anomalies. For example, when the thickness deviation of all detection points exceeds ±5% within 5 consecutive seconds, it is determined as overall out-of-tolerance; if only the thickness deviation in a certain area exceeds the threshold, it is identified as a local anomaly, providing a basis for adopting more targeted control strategies, effectively avoiding excessive correction of extrusion parameters, and improving the accuracy of thickness anomaly response. For local over-thickness or under-thickness problems, the system calculates the temperature control amount of the abnormal layer through the PID control algorithm. For example, when local over-thickness of the inner layer is detected, the system reduces the temperature of the corresponding area by 5 - 8 °C, increasing the melt viscosity and flow resistance, thereby reducing the material accumulation in this area; conversely, when local under-thickness occurs, the temperature is increased to enhance fluidity, effectively solving the problem of reducing local deviation of the hose, improving the thickness uniformity of the hose, and the introduction of the PID control algorithm achieves dynamic balance of temperature control. By setting reasonable proportional, integral, and differential parameters (such as K p = 0.8, K i = 0.2, K d = 0.1), the system can effectively suppress temperature overshoot and oscillation while quickly responding to thickness changes, ensuring process stability.

[0136] Example 8:

[0137] On the basis of Example 1, the multi-layer reinforced melt is subjected to cooling and shaping and fixed-length cutting treatment to obtain a finished recyclable hose, as Figure 3 shown, including:

[0138] Based on the position mark of the defective section, determine the starting position and ending position of the defective section;

[0139] Based on the starting position of the defective section and the position of the previous cutting point, obtain the defect interval;

[0140] When the defect interval is greater than the preset cutting length, it is determined that the defective section is within the current finished product. The ending position of the defective section is used as the final cutting point of the current finished product to obtain a defective recyclable hose finished product and mark the defect;

[0141] When the defect interval is less than or equal to the preset cutting length, normal cutting is maintained.

[0142] In this embodiment, normal cutting means determining the cutting point according to the preset cutting length (for example: 100 meters, 500 meters, etc.) and performing cutting at the cutting point to obtain a qualified finished product.

[0143] Advantages of the above technical solution: By accurately identifying the start and end positions of the defective section and combining the judgment of the defect interval and the preset cutting length, the present invention only cuts off the part containing the defective product. For example, when there is a defective section with local wall thickness deviation in the hose, if the defect interval is greater than the preset cutting length, the system takes the end point of the defective section as the cutting point and retains the qualified part before this section. Compared with the traditional whole-section cutting or unified specification cutting, it effectively improves the material utilization rate, avoids material waste, and minimizes the impact of the defective section on the finished product to the greatest extent, and can effectively reduce the defective rate of the finished product.

[0144] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these changes and modifications.

Claims

1. A method for dynamically controlling temperature during multi-layer co-extrusion to prepare a single-material VMPE recyclable hose, characterized in that, Including: Install infrared temperature measurement modules at each section of the extruder, and set the allowable range of extrusion temperature for each layer of the recyclable hose to construct a dynamic temperature control system; Put the pretreated raw materials into the corresponding extruder, and through the dynamic temperature control system, adjust the heating device and cooling device of each section in real time according to the preset allowable range of extrusion temperature to obtain a plasticized melt; Use ultrasonic vibration composite technology to bond the plasticized melt to obtain a multi-layer reinforced melt; Detect the wall thickness of the multi-layer reinforced melt through a hyperspectral imager, and judge whether the wall thickness is qualified; When the wall thickness is unqualified, feedback the wall thickness deviation data to the dynamic temperature control system and the extruder control system to jointly adjust the extrusion parameters; When the wall thickness is qualified, cool and shape the multi-layer reinforced melt and perform fixed-length cutting to obtain a finished recyclable hose; Among them, the outer layer of the recyclable hose is HDPE, the middle layer is VMPE, and the inner layer is HDPE.

2. A method for dynamically controlling temperature during multi-layer co-extrusion to prepare a single-material VMPE recyclable hose according to claim 1, characterized in that, Including: Install a 20kHz ultrasonic generator at the composite die head, and its vibration direction is perpendicular to the extrusion direction of the recyclable hose.

3. The method for dynamically temperature-controlled multi-layer co-extrusion to prepare a single-material VMPE recyclable hose according to claim 1, characterized in that Install infrared temperature measurement modules at each section of the extruder, and set the allowable range of extrusion temperature for each layer of the recyclable hose to construct a dynamic temperature control system, including: Associate the infrared temperature measurement modules installed at each section of the extruder with their corresponding cooling devices and heating devices respectively to obtain the control authority of the cooling devices and heating devices; Based on the type of raw materials put into the extruder where the infrared temperature measurement module is installed, determine the allowable range of extrusion temperature corresponding to the detection position of each infrared temperature measurement module respectively, and set it.

4. A method for dynamically controlling temperature during multi-layer co-extrusion to prepare a single-material VMPE recyclable hose according to claim 1, characterized in that, Through the dynamic temperature control system, adjust the heating device and cooling device of each section in real time according to the preset allowable range of extrusion temperature to obtain a plasticized melt, including: Collect the real-time temperature of the raw materials at each section of the extruder through the infrared temperature measurement module, and judge whether the real-time temperature of the raw materials is within the corresponding preset allowable range of extrusion temperature; When the real-time temperature of the raw materials is higher than the preset allowable range of extrusion temperature, start the cooling device to reduce the temperature and reduce the power of the heating device; When the real-time temperature of the raw materials is lower than the preset allowable range of extrusion temperature, increase the power of the heating device.

5. A method for dynamically controlling temperature during multi-layer co-extrusion to prepare a single-material recyclable VMPE hose according to claim 1, characterized in that, Feedback the wall thickness deviation data to the dynamic temperature control system and the extruder control system to jointly adjust the extrusion parameters, including: After the extruder control system receives the wall thickness deviation data, based on the wall thickness deviation data, calculate the wall error degree corresponding to the current detection position. When the error degree is greater than the preset value, determine that the hose section corresponding to the current detection position is a defective section, mark the position of the defective section, and send the marking result to the fixed-length cutting equipment; Otherwise, determine that the hose section corresponding to the current detection position is a qualified section.

6. A method for preparing a single-material VMPE recyclable hose by dynamic temperature control multi-layer co-extrusion according to claim 5, characterized in that, After the extruder control system receives the wall thickness deviation data, it also includes: Synchronously obtain the wall detection spectrum, determine the interlayer thickness, compare the interlayer thickness with its corresponding designed thickness to obtain the interlayer thickness deviation; Based on the interlayer thickness deviation and the unit standard material consumption of the recyclable hose, determine the actual material error of each layer respectively; Based on the actual material usage error and the corresponding relationship between the screw speed and the material extrusion volume of the extruder, determine the first screw speed difference, calculate the ratio between the screw speed difference and its corresponding original screw speed, and obtain the screw speed error rate; When the screw speed error rate is greater than or equal to the preset threshold, based on the first screw speed difference, correct the screw speed of the extruder; Otherwise, obtain the initial output pipe wall thickness of the die bonding, compare the initial output pipe wall thickness with the detected pipe wall thickness to obtain the first traction thickness error, and based on the actual distance between the die and the hyperspectral imager and the first traction thickness error, obtain the traction-thickness error coefficient; Judge whether the traction-thickness error coefficient is within the preset coefficient range. If so, obtain the traction distance between the starting point of forming and cooling and the die, and based on the traction distance and the traction-thickness error coefficient, obtain the second traction thickness error; Based on the unit standard material usage amount, the designed total thickness of the recyclable hose, and the second traction thickness error, calculate the first unit compensation material usage amount, and combine the thickness proportion corresponding to each layer for compensation distribution to determine the second unit compensation material usage amount corresponding to each layer of the recyclable hose; Based on the actual material usage error of each layer and the second unit compensation material usage amount, obtain the compensation material usage amount; Based on the compensation material usage amount and the corresponding relationship between the screw speed and the material extrusion volume of the extruder, determine the second screw speed difference; Based on the second screw speed difference, correct the screw speed of the extruder.

7. A method for dynamically controlling temperature and preparing a single-material VMPE recyclable hose by multi-layer co-extrusion according to claim 6, characterized in that, When the traction-thickness error coefficient is not within the preset coefficient range, it includes: If the traction-thickness error is greater than the upper limit of the preset coefficient range, control the traction device to reduce the hose traction speed; If the traction-thickness error is less than the lower limit of the preset coefficient range, control the traction device to increase the hose traction speed.

8. A method for preparing a single-material VMPE recyclable hose by dynamic temperature control multi-layer co-extrusion according to claim 7, characterized in that, It includes: When adjusting the traction speed of the traction device, adopt the multi-axis linkage control technology to synchronously control the traction devices corresponding to multiple extruders for producing each layer of materials of the recyclable hose.

9. A method for dynamically controlling temperature during multi-layer co-extrusion to prepare a single-material VMPE recyclable hose according to claim 1, characterized in that, After the dynamic temperature control system receives the pipe wall thickness deviation data, it includes: Compare the pipe wall thickness deviation data within the preset time period to judge the abnormal type of the pipe wall thickness of the recyclable hose; When the pipe wall thickness abnormality is overall over-tolerance, keep the current temperature unchanged and wait for the extrusion parameter adjustment of the extruder control system; When the pipe wall thickness abnormality is local over-thickness or local under-thickness, obtain the interlayer thickness, determine the thickness abnormal layer and its corresponding thickness difference, and based on the thickness difference, use the PID control algorithm to calculate and determine the temperature regulation amount corresponding to the thickness abnormal layer; Based on the temperature regulation amount, control and adjust the heating device or cooling device corresponding to the thickness abnormal layer.

10. The method for dynamically controlling temperature and preparing a single-material VMPE recyclable hose by multi-layer co-extrusion according to claim 1, characterized in that, For the multi-layer reinforced melt, perform cooling and shaping and fixed-length cutting treatments to obtain the finished recyclable hose, including: Based on the defective section position mark, determine the starting position and the ending position of the defective section; Based on the starting position of the defective section and the position of the previous cutting point, obtain the defect interval; When the defect interval is greater than the preset cutting length, determine that the defective section is within the current finished product, use the ending position of the defective section as the final cutting point of the current finished product, obtain the defective recyclable hose finished product, and perform defective marking; When the defect interval is less than or equal to the preset cutting length, normal cutting is maintained.

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