A method of manufacturing a wear-resistant polyethylene pipe

Abstract

The application discloses a kind of manufacturing methods of wear-resistant polyethylene pipe, it is suitable for PE100 / PE100-RC multilayer co-extrusion wear-resistant pipe and optional UHMWPE composite pipe.Method includes: raw material fingerprint acquisition and gate, precise metering and formula electronic locking;Melting plasticization-filtering pressure stabilization and monitoring ΔP and torque trend;Under the dynamic window of viscosity ratio, multilayer co-extrusion composite forming;On-line thickness / eccentricity and early warning quantity driven thickness predictive closed loop, combined with thickness self-adaptive distribution and collaborative correction under total wall thickness constraint;Multi-sensor fusion detection constructs thickness-eccentricity-roundness joint control domain;Vacuum sizing and cooling gradient model inhibit residual stress;Integrated peeling mark / stop mouth / weakness band improves welding consistency;And establish digital twin quality file and release score self-optimization rule.The method can front-end inhibit porosity, peeling and thickness drift, improve batch consistency, wear-resistant life and engineering reliability.

Description

Technical Field

[0001] This invention relates to the fields of polymer pipe manufacturing, online inspection, and closed-loop quality control, and particularly to a method for manufacturing wear-resistant polyethylene pipes for abrasive conditions. This method is applicable to the manufacturing of PE100 / PE100-RC multilayer co-extruded wear-resistant pipes, and can optionally be applied to the manufacturing of composite pipes with a UHMWPE wear-resistant layer. While maintaining wear resistance, it improves long-term pressure-bearing reliability, resistance to construction damage, and weld consistency and batch stability. Background Technology

[0002] Wear-resistant polyethylene pipes are widely used in scenarios such as slurry / tailings transportation, dredging and sand removal, wastewater containing particles, industrial circulating water, and trenchless laying. In actual service, they often encounter complex conditions including particle abrasion, point loads / scratches, long-term pressure, and on-site welding / traction friction. Therefore, the pipe material not only needs excellent wear resistance but also consistent and stable engineering performance in terms of long-term internal pressure, slow crack propagation, weld heat-affected zone toughness, and sensitivity to on-site construction damage.

[0003] Current manufacturing routes commonly include: single-layer polyethylene thickening or filler modification, multi-layer co-extruded outer sheath (such as PE100-RC sheath), and UHMWPE integral pipe or inner lining / composite solutions. However, in engineering applications and large-scale mass production, the following problems still exist: (1) UHMWPE has a narrow processing window, which makes it easy for insufficient powder fusion to cause pores, particle boundary defects and size fluctuations, thus affecting the consistency of strength and life. (2) The interfacial stability of the multilayer co-extrusion is insufficient, which can easily lead to insufficient interlayer bonding, interfacial ripples, and functional layer thickness drift and eccentricity, resulting in the thinnest point not meeting the standard or an increased risk of local failure. (3) There is a “tug-of-war” between wear resistance enhancement and welding / crack resistance index. For example, filler or hardening modification may reduce the toughness of the weld zone or the ability to resist slow crack propagation, resulting in welding consistency and life fluctuation. (4) The long-term performance verification cycle is long. If only type or long-term testing is relied upon, it is difficult to detect the drift in the mass production process and achieve process correction in time. (5) Scratches, point loads, traction friction and other “non-manufacturing defects” during transportation and construction can significantly amplify the probability of failure. The lack of structural design and release rules that are coordinated with the delivery procedures at the manufacturing end leads to insufficient risk control in advance.

[0004] Therefore, there is an urgent need for a manufacturing method that upgrades from "single process step" to "system solution + intelligent closed loop + process model and standard + full-process digital traceability" in order to achieve proactive prevention and consistency control in the manufacturing stage. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of the prior art as described in the background section, and to propose a method for manufacturing wear-resistant polyethylene pipes.

[0006] To achieve the above objectives, the wear-resistant polyethylene pipe manufacturing method provided by the present invention is based on a three-layer structure: an inner wear-resistant layer, a middle pressure-bearing structural layer, and an outer protective layer / sheath layer; optionally, the inner layer is a UHMWPE wear-resistant layer and forms a composite structure with the PE100-RC pressure-bearing layer.

[0007] This method introduces and defines data objects and control elements such as Material Fingerprint, Critical Quality Characteristic Vector (CTQVector), Joint Control Domain, Thickness Allocator, Correction Policy, Twin Record, and Release Score for pre-control and traceability loop in the manufacturing process.

[0008] This method includes: 1) Raw material fingerprint collection and gating: Establish material fingerprints for each layer of raw materials and bind them to batch number for traceability. After the material fingerprints are entered into the database, the recommended viscosity ratio window, die head temperature zone and cooling gradient parameters are output. For batches that exceed the limits, prohibit their use or downgrade their application, and establish a blacklist of material combinations for prohibited combinations management. 2) Multi-channel metering and electronic formula locking: The formula ratio, feeding sequence and batch number are electronically locked by using loss-in-weight metering or equivalent precision metering. Process parameter changes are authorized and recorded in TwinRecord. 3) Melting, plasticizing, filtering, and pressure stabilization: Zoned temperature-controlled plasticizing, collecting screw torque / current as an early indicator of viscosity fluctuation; monitoring the filter pressure difference ΔP and executing "feedforward fine-tuning → correction → line stop troubleshooting" according to rules; optional melt pump pressure stabilization and incorporating die pressure fluctuation into the control judgment; 4) Multi-layer co-extrusion composite forming: The integrated pipe wall is formed by splitting, merging and welding through a multi-layer co-extrusion die, and the viscosity ratio dynamic window is adaptively set according to the material fingerprint, and dynamically fine-tuned according to the die life status; 5) Predictive closed-loop control and adaptive thickness allocation for functional layer thickness: Collect data such as the thickness and eccentricity of each layer online, and establish a predictive model for predictive feedforward control by combining the precursors such as torque and die head pressure; dynamically optimize the thickness ratio between layers under the constraint of total wall thickness, prioritize ensuring that the thinnest point of the wear-resistant layer and / or protective layer meets the standard, and coordinate the adjustment according to the correction and coordination rules when multiple anomalies occur concurrently. 6) Multi-sensor fusion detection and joint control domain determination: The ultrasonic thickness measurement data is fused with the optional X-ray scanning / optical profile data to form a joint assessment of thickness-interface-defect; a three-dimensional joint control domain of thickness-eccentricity-roundness is constructed, and any index or combination thereof exceeding the limit will trigger correction and output a recommended action; 7) Vacuum sizing and cooling gradient control: Gradient cooling is adopted and linked to the traction speed. The model is adjusted in linkage based on the trend drift indicators such as ellipticity, weight per unit length or outer diameter springback, so as to suppress residual stress and reduce slow crack sensitivity. 8) Integrated and customized welding peeling structure and process: Markings and mechanical stops are set in the peeling area of ​​the pipe end, and a weakening ring can be optionally set; the port protection cap and the markings are linked to form a peeling guide, which reduces peeling error and improves welding consistency; 9) Digital twin traceability and release rule self-optimization: Establish a unique identifier for each meter / each pipe segment and form a TwinRecord, linking raw materials, online graphs, correction records, spot checks and subsequent verification; establish ReleaseScore and periodically self-optimize weights and thresholds based on historical verification data. Insufficient scores trigger encrypted spot checks, restricted uses, line stoppage for investigation or rollback to conservative process windows.

[0009] Optionally, when the inner layer is a UHMWPE wear-resistant layer, the outer surface of the UHMWPE is further surface activated and / or mechanically roughened, and the parameter window is quantified. The coating temperature difference and pressure gradient are limited to control thermal shock. A PE / UHMWPE gradient transition layer is set between UHMWPE and PE100-RC, and dovetail grooves or inverted conical holes are constructed on the UHMWPE surface to achieve mechanical interlocking. At the same time, the relevant processing parameters are recorded in TwinRecord and correlated with the peel strength sampling inspection to form a process-performance closed loop.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: Compared with the prior art, the present invention has at least the following beneficial effects: 1) Achieve proactive prevention in the manufacturing stage: By using material fingerprint gating and viscosity ratio dynamic window, reduce the risks of interface ripples, insufficient interlayer bonding, and thickness drift caused by raw material fluctuations; 2) Enhance the thinnest point protection capability of functional layers: Dynamically allocate layer thickness under the constraint of total wall thickness, prioritize ensuring that the thinnest point of wear-resistant functional layer and protective layer meets the standard, reduce material waste and improve consistency; 3) Upgrade from single-index control to joint control domain judgment: The thickness-eccentricity-roundness joint control domain is used to trigger correction, which reduces the probability of loss of control at the local thinnest point and improves process stability; 4) Shorten the quality drift detection cycle: Multi-sensor fusion detection and early warning of precursor trends enable process anomalies to be identified and corrected at an early stage, reducing scrap and rework; 5) Improve welding consistency and on-site operability: Through the integrated design of peeling marks and stop surfaces, reduce human peeling errors and improve the stability of welding quality; 6) Reduce construction damage sensitivity and delivery risks: The collaborative design and release strategy between the manufacturing end and delivery / construction can control risks such as scratches, point loads and traction friction in advance; 7) Form a traceable closed loop and self-optimizing rules: Establish a digital twin quality archive and release scoring system to achieve full-process traceability from raw materials to pipe sections, and continuously optimize the release threshold based on historical data to improve the accuracy of long-term performance prediction and engineering reliability. Detailed Implementation

[0011] The invention will be more readily understood by referring to the following detailed description of preferred embodiments and included examples. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In case of conflict, the definitions in this specification shall prevail.

[0012] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0013] This invention provides a method for manufacturing a wear-resistant polyethylene pipe. The method is based on a multi-layer composite structure, preferably a three-layer structure, including an inner wear-resistant layer, a middle pressure-bearing structural layer, and an outer protective layer / sheath layer.

[0014] The pressure-bearing structural layer is preferably made of PE100 or PE100-RC material, the protective layer / sheath layer is preferably made of PE100-RC or polyethylene formulation with scratch resistance / slow crack propagation resistance, and the wear-resistant layer is preferably made of wear-resistant modified polyethylene, PE100 wear-resistant formulation or UHMWPE; and under strong abrasive conditions, the wear-resistant layer can be set as UHMWPE wear-resistant layer and form a composite structure with PE100-RC pressure-bearing layer to ensure wear resistance life while taking into account long-term pressure-bearing reliability and welding consistency.

[0015] To ensure that the manufacturing process is implementable, reproducible, and verifiable, this invention introduces and defines data objects and control elements such as Material Fingerprint, Critical Quality Characteristic Vector (CTQVector), Joint Control Domain, Thickness Allocator, Correction Policy, Twin Record, and Release Score in the manufacturing process.

[0016] The material fingerprint describes the processability and service stability of each batch of raw materials, including at least melt flow index (MFR or equivalent viscosity index), density, moisture content, oxidation / thermal stability index (OIT or equivalent index), and rheological curve characteristics or equivalent rheological indicators, and is stored in conjunction with the batch number, supplier number, and drying conditions. The key quality characteristic vector includes at least total wall thickness, layer thickness, thinnest point thickness, eccentricity, roundness / ellipticity, outer diameter, mass per unit length, die pressure, melt temperature, filtration pressure difference, screw torque / current, traction speed, vacuum sizing vacuum degree, and cooling gradient-related parameters. The joint control domain uses total wall thickness, thinnest point thickness of functional layers, eccentricity, and roundness / ellipticity as core dimensions to construct single-index and combined-index out-of-bounds trigger conditions, used to identify risk situations such as "total wall thickness meets the standard but the thinnest point is insufficient." The thickness adaptive allocator prioritizes the thinnest point of the functional layer under the total wall thickness constraint, outputting the target thickness of each layer and the corresponding extrusion amount correction; the correction coordination rule is used to specify the priority, action boundary, maximum step size and minimum holding time when multiple anomalies occur concurrently, so as to avoid adjustment conflicts and system oscillations.

[0017] Digital twin quality files are used to establish unique identifiers for each meter or pipe segment and associate them with raw materials, online detection maps, control actions, alarms and sampling results to achieve traceability and auditability; release scoring is used to map rapid indicators such as material stability, process capability, interface / scratch resistance sampling to release grades, and supports self-optimization of weights and thresholds based on historical verification data.

[0018] Based on the aforementioned data objects and control elements, the manufacturing method of the present invention preferably includes the following process: First, material fingerprints are collected for the inner, middle, and outer layer raw materials, and online gating is implemented. After the material fingerprints are input into the database, viscosity ratio windows, die temperature zones, and cooling gradient parameters matching the batch of raw materials are output. For batches exceeding the limits, online use or downgrading is implemented, and a material combination blacklist is established to implement prohibited combinations for batches with historical associations of interface ripples, interlayer delamination, or gelation abnormalities. Subsequently, each layer of the extruder is fed separately using loss-in-weight metering or equivalent precision metering. The formulation ratio, feeding sequence, and batch number are electronically locked. Any changes to process parameters must be authorized, recorded, and written into the digital twin quality file.

[0019] Subsequently, during the melt plasticizing stage, zoned temperature control is used to stabilize plasticizing, and screw torque / current and die pressure are collected as precursors to viscosity fluctuations. Melt filtration is set up and the filtration pressure difference ΔP is monitored. When ΔP rises rapidly or the growth rate exceeds the limit, a graded strategy of "feedforward fine-tuning - correction processing - line stoppage investigation" is executed. Feedforward fine-tuning includes reducing shear strength and / or reducing extrusion speed in conjunction with temperature zone fine-tuning. Correction processing includes activating a pressure stabilizing device or melt pump to suppress die pressure fluctuations, and using the die pressure fluctuation amplitude as an additional judgment quantity of the joint control domain to identify and suppress interface ripple sources.

[0020] Subsequently, the flow is divided, merged, and welded through a multi-layer co-extrusion die to form an inseparable integrated tube wall structure. A dynamic window for the viscosity ratio entering the composite zone is adaptively set based on the material fingerprint, and can be dynamically fine-tuned according to the die life or wear cycle to maintain interface and layer thickness stability. Based on this, data such as total wall thickness, layer thickness, thinnest point thickness, and eccentricity are collected online. A predictive model for "extrusion parameter to thickness change" is established using precursors such as screw torque and die pressure to perform predictive feedforward adjustment. Simultaneously, under the constraint of total wall thickness, a thickness adaptive distributor dynamically optimizes the interlayer thickness ratio, using the thinnest point of the wear-resistant layer and / or the thinnest point of the protective layer as hard constraints and the eccentricity trend as a correction factor. In the event of multiple concurrent anomalies, the eccentricity is preferentially reduced according to the correction and coordination rule before layer thickness fine-tuning, avoiding material waste and residual stress accumulation caused by simply increasing thickness.

[0021] Furthermore, the detection end primarily uses ultrasonic thickness measurement and can optionally combine X-ray scanning and / or optical profile data for multi-source fusion, outputting a joint evaluation result of thickness, eccentricity, roundness / ellipticity, and defects. The results are input into the joint control domain for judgment. If any indicator or combination thereof exceeds the limit, the excess direction, risk level, and recommended set of corrective actions are output, and the action holding time and maximum step size constraints are executed. The recommended corrective actions include at least adjusting the layer extrusion amount, adjusting the traction speed, adjusting the vacuum degree of vacuum sizing, and / or adjusting the cooling intensity.

[0022] Subsequently, vacuum sizing and gradient cooling were implemented. Gradient cooling included gentle shaping in the sizing section and enhanced cooling in the subsequent section. The cooling gradient was determined by the material fingerprint and linear velocity, and ellipticity, mass per unit length, and / or outer diameter springback tendency were used as drift indicators. When the drift tendency exceeded the limit, the cooling gradient and traction speed were adjusted in conjunction with the model to suppress residual stress and reduce slow crack sensitivity, thereby improving long-term internal pressure stability.

[0023] Meanwhile, visual markings and tactile stops (such as annular shallow grooves or ridges) are set in the peeling area of ​​the pipe end for guiding and positioning of the dedicated peeling tool. Weakening rings can be set at the marking positions or online laser etching can be used to form permanent markings. Port protection caps can be set so that their inner edges are locked at the markings. After disassembly, a peeling guide structure is formed to ensure consistent peeling depth and flat end face, thereby improving the consistency of butt joints and welding.

[0024] Finally, a unique identifier is assigned to each meter or pipe segment, and a digital twin quality file is established. The raw material batch number, material fingerprint, key quality characteristic vector time series, online detection spectrum, correction records, and sampling inspection results are linked and stored. A release score is established to map material stability indicators, process capability indicators, and sampling inspections such as interface peel strength and scratch resistance to release levels. When the score is insufficient, strategies such as encrypted sampling inspection, restricted use, line stoppage investigation, or regression to conservative process windows are triggered. The scoring weights and thresholds are periodically self-optimized and rewritten based on historical verification data and on-site feedback to achieve rule self-evolution and continuous improvement.

[0025] Optionally, when the wear-resistant layer is a UHMWPE wear-resistant layer, the method further includes an interface strengthening step: performing surface activation treatment and / or mechanical roughening treatment on the outer surface of UHMWPE, and setting the energy density, action time, atmosphere composition, and roughness Ra or peak-valley spacing as quantifiable windows; limiting the maximum temperature difference and contact pressure gradient of PE100-RC melt coating UHMWPE to control thermal shock; setting a gradient transition layer of PE / UHMWPE blend between UHMWPE and PE100-RC, and constructing regular micro dovetail grooves or inverted conical holes on the surface of UHMWPE as anchoring points, so that the coating melt flows in and solidifies to form a mechanical interlock; and associating the treatment parameters with the interface peel strength sampling inspection results and writing them into the digital twin quality file, thereby forming a process-performance closed loop and a traceable verification chain.

[0026] Through the above technical solutions, the present invention can establish a closed-loop association between material fingerprints, process precursors, online thinnest point quality control, correction actions, and sampling and release rules within a digital twin framework, making the manufacturing process reproducible, verifiable, and auditable. This enables early identification and correction of process drift in mass production, significantly improving batch consistency, welding consistency, and engineering reliability of wear-resistant polyethylene pipes.

[0027] Based on the above, the present invention provides the following specific embodiments: The production line for implementing the method of the present invention is configured as follows: In this embodiment, the manufacturing method of the present invention can be implemented on a multilayer co-extrusion pipe production line. This production line preferably includes: an inner layer extruder, an intermediate layer extruder, and an outer layer extruder; a multilayer co-extrusion composite die (with flow channels for splitting, merging, and welding); a melt filtration device (screen changer or equivalent filter); an optional melt pump pressure stabilizing device; a vacuum sizing box; a spray or water cooling section; a traction machine and a cutting machine; an online thickness measuring device (preferably ultrasonic thickness measuring, with optional X-ray scanning and / or optical profile measurement devices as supplements); an online outer diameter and ellipticity measuring device; and a data acquisition and control device (PLC and industrial computer or equivalent control system). Furthermore, the production line can also be equipped with inkjet / laser marking devices for unique identification coding, and testing equipment for interface peel strength, scratch / wear resistance, etc., for random inspection.

[0028] In this embodiment, the control system preferably establishes a material fingerprint database, a key quality characteristic vector recording module, a joint control domain judgment module, a thickness adaptive allocator module, a correction coordination rule module, a digital twin quality archive TwinRecord module, and a release score calculation module, which are used to record, judge, and correct the production process online.

[0029] Key data objects and judgment criteria (for ease of implementation and verification) are as follows: In this embodiment, to ensure the method is implementable and verifiable, the following approach is preferred: (1) The material fingerprint should record at least the following: melt flow index (MFR or equivalent viscosity index), density, moisture content, oxidation resistance / thermal stability index (OIT or equivalent index) and rheological indication, and be linked to the batch number, supplier number and drying conditions.

[0030] (2) The key quality characteristic vector CTQVector shall include at least the following: total wall thickness t_total, thickness of each layer t_in / t_mid / t_out, thickness of the thinnest point of the functional layer t_in,min, eccentricity e, ellipticity / roundness Ov, outer diameter D, mass per unit length m_L, die pressure P_die, filter pressure difference ΔP, screw torque / current I_s, traction speed v, vacuum degree Vac, and cooling gradient related parameters.

[0031] (3) The JointControlDomain takes (t_total, t_in, min, e, Ov) as the core dimension and sets two types of triggering conditions: "single index out of bounds" and "combined out of bounds". The combined out of bounds is used to identify situations such as "total wall thickness is qualified but eccentricity increases, resulting in insufficient thinnest point".

[0032] (4) The correction action is set with the maximum step size and minimum holding time, and follows the priority: the thinnest point of the functional layer takes priority over the total wall thickness, the eccentricity takes priority over the ellipticity, and the voltage stabilization takes priority over the thickening, so as to avoid adjustment conflicts and system oscillations.

[0033] Specifically: Example 1: Three-layer co-extruded wear-resistant polyethylene pipe (wear-resistant modified PE inner layer + pressure-bearing layer + outer sheath layer) (I) Structure and Raw Material Selection In this embodiment, the wear-resistant polyethylene pipe preferably has a three-layer structure: an inner wear-resistant layer, a middle pressure-bearing structural layer, and an outer protective layer / sheath layer. The pressure-bearing structural layer is preferably PE100 or PE100-RC, the outer protective layer is preferably PE100-RC, and the inner wear-resistant layer is preferably wear-resistant modified polyethylene or PE100 wear-resistant formulation (which can be a polyethylene system with added wear-resistant masterbatch).

[0034] (II) Raw material gating and process package generation In this embodiment, material fingerprints are collected for the three layers of raw materials and input into the material fingerprint database. The database outputs the viscosity ratio window, die temperature zone and cooling gradient parameters that match the batch of raw materials to form the recommended process package for the batch. Furthermore, when the fingerprint of any layer of raw material exceeds the allowable range, the preferred strategy is to "prohibit online / downgrade use / revert to conservative window"; at the same time, a blacklist of material combinations is established, and batch combinations that are historically strongly correlated with interface ripples, interlayer delamination or gel abnormalities are prohibited from being used, and are intercepted in the gating process before online.

[0035] (III) Metering and Formula Locking In this embodiment, each extruder preferably uses loss-in-weight metering for feeding, and the formula ratio, feeding sequence and batch number are electronically locked. Any change to the process parameters must be authorized and the values ​​before and after the change, the reason for the change, the operator and the timestamp must be recorded and written into TwinRecord for subsequent traceability and reproduction.

[0036] (iv) Graded treatment of plasticizing, filtration and pressure stabilization In this embodiment, zoned temperature control is used to stabilize plasticization, and screw torque / current I_s and die pressure P_die are collected as precursors to viscosity fluctuations; melt filtration is set up and the filtration pressure difference ΔP is monitored; When ΔP shows a rapid increase or an abnormal growth rate, it is preferable to follow a graded strategy of "feedforward fine-tuning → correction treatment → line stoppage investigation": feedforward fine-tuning includes reducing shear intensity (e.g., reducing rotation speed or extrusion rate) and coordinating with temperature zone fine-tuning; correction treatment includes activating the melt pump or equivalent pressure stabilizing device to suppress P_die fluctuations; if necessary, the line should be stopped to replace the screen and investigate the source of contamination or gel. Furthermore, the P_die fluctuation amplitude can be used as an additional decision value of the joint control domain to identify interface ripple risk and trigger the "voltage stabilization priority" correction strategy.

[0037] (v) Multi-layer co-extrusion composite molding and dynamic adjustment of viscosity ratio window In this embodiment, an inseparable integrated tube wall structure is formed by the splitting, merging, and welding of multiple co-extrusion dies. During the compounding process, the control system continuously calculates whether the viscosity ratio is within the dynamic window. When the torque trend or pressure trend indicates that the viscosity of a certain layer is drifting, feedforward compensation is preferably performed through the temperature zone of that layer, screw speed, and / or melt pump speed to bring the viscosity ratio back to the dynamic window, thereby reducing the risk of interface ripples, insufficient interlayer bonding, and layer thickness drift.

[0038] (vi) Predictive thickness closed loop and adaptive thickness allocation (thinnest point priority) In this embodiment, the online thickness measurement outputs t_total, t_in, t_mid, t_out and t_in,min, and calculates the eccentricity e. The control system preferably determines the drift direction based on the prediction model of "extrusion parameters - thickness change" and performs predictive feedforward adjustment.

[0039] When the prediction shows that t_in,min is close to the lower limit or the eccentricity is increasing, it is preferable to first execute the linkage action of "reducing eccentricity" (e.g., linkage adjustment of Vac and v, and can be combined with adjustment of local temperature of the die head or inner layer material distribution) to make the thinnest point rise again; under the constraint of total wall thickness, the thickness adaptive distributor outputs the target layer thickness (t_in*, t_mid*, t_out*) and the corresponding ΔQ correction amount, and executes it according to the correction coordination rule to make the thinnest point of the functional layer reach the target first, avoiding material waste and residual stress accumulation caused by simply increasing the thickness.

[0040] Furthermore, a maximum step size and hold time are set for each correction action, and the action execution and evaluation results are written into TwinRecord.

[0041] (vii) Multi-source fusion detection and joint control domain determination In this embodiment, ultrasonic thickness measurement is used as the main method, combined with online outer diameter / ellipticity measurement data to form a joint evaluation result of thickness-eccentricity-ellipticity. The result is input into the joint control domain judgment module. When a combined boundary violation occurs, the boundary violation direction, risk level and recommended set of correction actions are output, and the linkage adjustment of feeding, traction, vacuum or cooling is executed according to priority.

[0042] (viii) Vacuum sizing and gradient cooling In this embodiment, vacuum sizing and gradient cooling are employed, which includes gentle shaping in the sizing section and enhanced cooling in the subsequent section. The control system uses ellipticity Ov, mass per unit length m_L, and outer diameter springback trend as drift indicators; when the drift trend exceeds the limit, the cooling gradient and traction speed are adjusted in conjunction with the model to suppress residual stress and reduce slow crack sensitivity.

[0043] (ix) Improved consistency of peeling structure integration and welding In this embodiment, a visible marking and a tactile stop structure (annular shallow groove or ridge) are provided in the peeling area at the pipe end for peeling depth positioning and guidance of a dedicated peeling tool; optionally, a weakening ring is provided at the marking position or an online laser etching is used to form a permanent marking to form a controllable peeling boundary.

[0044] Furthermore, a port protection cap can be installed so that its inner edge is locked at the marking point. After disassembly, it can be used as a peeling guide structure to improve the consistency of peeling depth and the flatness of the end face, thereby improving the consistency of welding.

[0045] (x) Traceability, random inspection and release In this embodiment, each meter or each pipe segment is assigned a unique identifier. TwinRecord is associated with raw material batches, material fingerprints, CTQVector time series, alarm codes, corrective actions, and sampling inspection results. The ReleaseScore maps material stability, process capability indicators, and interface / scratch resistance / wear resistance sampling inspections to release levels. When the score is insufficient, it triggers encrypted sampling inspections, usage restrictions, line shutdown for investigation, or rollback to a conservative window. The score weights and thresholds can be periodically rewritten and optimized based on historical verification and on-site feedback.

[0046] Example 2: UHMWPE wear-resistant composite pipe (UHMWPE inner layer + PE100-RC pressure-bearing layer + outer sheath layer), including interface reinforcement In this embodiment, the inner wear-resistant layer is UHMWPE, the middle pressure-bearing structural layer is PE100-RC, and the outer protective layer is PE100-RC. Because the interface between UHMWPE and the PE system is more sensitive to thermal shock, this embodiment adds the following interface strengthening steps based on Embodiment 1.

[0047] First, the outer surface of UHMWPE undergoes surface activation and / or mechanical roughening treatment, and energy density, reaction time, atmosphere composition, and roughness Ra or peak-to-valley spacing are set as quantifiable windows. UHMWPE material outside these windows is preferably re-treated or disabled. Second, the maximum temperature difference and contact pressure gradient when PE100-RC melt coats UHMWPE are limited to control thermal shock. Third, a gradient transition layer of PE / UHMWPE blend is set between UHMWPE and PE100-RC to mitigate abrupt changes in interfacial properties.

[0048] Furthermore, regular micro-dovetail grooves or inverted conical holes are constructed on the UHMWPE surface as anchor points, allowing the PE100-RC melt to flow in and solidify during coating, forming a mechanical interlock to improve interfacial peel strength and impact delamination resistance. Finally, the interface pretreatment parameters, transition layer parameters, anchor point density, and interface peel strength sampling results are written into TwinRecord. When a decrease in peel strength or an abnormal peeling mode occurs, the pretreatment window is tightened, the anchor point density is increased, or the transition layer ratio is adjusted, and the parameters revert to conservative coating temperature / pressure gradient parameters, thus forming a process-performance closed loop and a traceable verification chain.

[0049] In this embodiment, to ensure that the quality is verifiable and release is feasible, the sampling inspection preferably includes at least: interface bonding ability sampling inspection (applicable to multilayer composite pipes, preferably interface peel strength and peel morphology judgment), scratch / wear resistance sampling inspection (equivalent test of standardized wear or scratch evaluation method can be used), size and appearance sampling inspection (including outer diameter, total wall thickness, ellipticity and surface defects), and sampling inspection related to material stability (such as OIT or equivalent thermal stability index).

[0050] The sampling frequency is preferably set according to the strategy of "first article confirmation - intensive sampling inspection for material / screen change / major parameter changes - periodic sampling inspection for stable production". When the release score is lower than the threshold or a high-risk out-of-bounds event occurs in the joint control domain, intensive sampling inspection is preferably triggered. The judgment rule preferably adopts a combination of "rapid indicators + sampling indicators": rapid indicators are used for early identification of process drift, and sampling indicators are used for confirmation of key performance. The disposal strategy preferably adopts a tiered output: when the sampling inspection is qualified and the score meets the standard, it is released directly; when the sampling inspection is qualified but the score is low, its use is restricted or intensive sampling inspection is carried out for release; when the sampling inspection is unqualified or there are abnormal interface peeling patterns, persistent thinnest point risks, etc., it is preferably judged to stop the line for investigation and fall back to the conservative process window. If necessary, screen change, prohibited ingredients or raw material downgrading are performed, and the disposal reason code and corrective action are written into TwinRecord for subsequent playback and threshold optimization.

[0051] Modifications (without departing from the spirit of the invention) Without departing from the concept of this invention, the online thickness measurement device can be ultrasonic thickness measurement, X-ray scanning, or a combination of both; the voltage stabilizing device can be a melt pump or an equivalent voltage stabilizing mechanism; the peeling and weakening ring can be achieved by pre-setting a thin layer, microstructure, or laser etching in the die head; the weight of the release score (ReleaseScore) can be adjusted according to the application scenario, and periodic rewriting and optimization with historical verification data are allowed.

[0052] The examples described herein are merely illustrative, intended to explain some features of the methods described herein. The appended claims are intended to claim the broadest possible scope, and the embodiments presented herein are merely illustrative of selected implementations based on combinations of all possible embodiments. Therefore, the applicant intends that the appended claims are not limited by the selection of examples illustrating the features of the invention. Some numerical ranges used in the claims also include sub-ranges within them, and variations within these ranges should be interpreted, where possible, as covered by the appended claims.

Claims

1. A method for manufacturing a wear-resistant polyethylene pipe, characterized in that, Includes the following steps: S1. Raw Material Fingerprint Acquisition and Gating: Material fingerprints are established for the raw materials of the pressure-bearing structural layer, wear-resistant layer, and protective layer / sheath layer, and batch number traceability is bound to them. The material fingerprint includes at least melt flow rate, density, moisture content, oxidation resistance index, and rheological curve characteristics or equivalent rheological indicators. The material fingerprint is input into the material fingerprint database, and the viscosity ratio window, die temperature band, and cooling gradient parameters matching the batch of raw materials are output. Batches exceeding the limits are prohibited from use or downgraded for application. S2. Multi-channel metering feeding and electronic formula locking: The inner extruder, middle extruder and outer extruder are fed by loss-in-weight metering or equivalent precision metering. The formula ratio, feeding sequence and batch number are electronically locked. The authorization of process parameter changes and change records are written into the digital twin quality file TwinRecord. S3, Melting, Plasticizing, Filtration and Pressure Stabilization: Each layer of extruder is temperature-controlled in its zone for plasticizing, and screw torque or current is collected as a precursor to viscosity fluctuations; melt filtration is set and the filtration pressure difference ΔP is monitored. When ΔP rises rapidly or shows a continuous upward trend, an early warning is triggered and feedforward fine-tuning, correction and line stop troubleshooting are performed according to preset rules. It can also optionally suppress die head pressure fluctuations through a melt pressure stabilizing device; S4. Multi-layer co-extrusion composite molding: Multi-layer co-extrusion die head is used to complete the splitting, merging and welding to form an inseparable integrated tube wall structure; the viscosity ratio dynamic window entering the composite zone is adaptively set according to the material fingerprint, and dynamic fine adjustment is allowed according to the die life state or wear cycle; S5. Predictive Closed-Loop and Adaptive Thickness Allocation for Functional Layers: The total wall thickness, thickness of each layer, and eccentricity data are acquired online. A predictive model of "extrusion parameters → thickness change" is established by combining precursors such as screw torque and die pressure, and predictive feedforward control is executed. Under the constraint of total wall thickness, the thickness adaptive allocator ThicknessAllocator is run to dynamically optimize the thickness ratio of each layer according to the thinnest point thickness and eccentricity trend, so as to ensure that the thinnest point of the wear-resistant layer and / or protective layer meets the threshold. S6. Multi-sensor fusion detection and joint control domain determination: Multi-source data fusion is used for thickness detection to construct a joint control domain with thickness, eccentricity and roundness as the core dimensions. If any index or combination of them exceeds the limit, correction is triggered and the direction of the exceedance and the recommended correction action are output. The recommended correction action includes at least adjusting the layer feeding, adjusting the traction speed, adjusting the vacuum degree of vacuum sizing and / or adjusting the cooling intensity. S7. Vacuum sizing and cooling gradient control: Vacuum sizing and gradient cooling are adopted. The cooling gradient is adjusted in conjunction with the traction speed. Ellipticity, weight per unit length and / or outer diameter springback trend are used as drift indicators. The linkage adjustment is made according to the model to suppress residual stress and reduce slow crack sensitivity. S8. Integration and process specialization of welding peeling structure: Marking and mechanical stop structure for peeling positioning and guidance are formed in the peeling area of ​​the pipe end, and an easily peelable weakened ring can be formed at the marking position to reduce peeling error and improve welding consistency. S9. Establishment of TwinRecord digital twin quality archive: Assign a unique identifier to each pipe section or each meter, and link it with raw material batch number, material fingerprint, real-time value of critical quality characteristic vector CTQVector, online detection spectrum, correction record and sampling results to form a traceable digital twin quality archive; S10. Release Score and Rule Self-Optimization: Establish a set of rapid release indicators and map them to the release score ReleaseScore. The rapid release indicators include at least batch antioxidant indicators or equivalent indicators, melt flow indicators, gel risk indicators, online thickness / eccentricity process capability indicators, interface peeling inspection and / or scratch resistance inspection. The indicator weights and release thresholds of the release score are periodically self-optimized based on historical validation data. When the release score is lower than the threshold, strategies such as encrypted inspection, restriction of use, line stoppage for investigation, or regression to a conservative process window are triggered. The wear-resistant polyethylene pipe has a three-layer structure: an inner wear-resistant layer, a middle pressure-bearing structural layer, and an outer protective / sheathing layer. Optionally, the inner layer is a UHMWPE wear-resistant layer, and the middle layer is a PE100-RC pressure-bearing layer, which together form a composite structure with the UHMWPE wear-resistant layer.

2. The method for manufacturing a wear-resistant polyethylene pipe according to claim 1, characterized in that: In step S1, a blacklist of material combinations is established, and batch combinations that have historically exhibited interface ripples, interlayer delamination, or gel abnormalities are subject to disabling management. The disabling rules are then written into the material fingerprint database for pre-launch gating.

3. The method for manufacturing a wear-resistant polyethylene pipe according to claim 1, characterized in that: In step S3, when the filter pressure difference ΔP triggers an early warning, the following steps are executed in sequence: "feedforward fine adjustment → correction → line stop and screen replacement / troubleshooting". The feedforward fine adjustment includes at least reducing the shear strength and / or reducing the extrusion speed, and the correction includes at least adjusting the temperature zone setting of the corresponding layer and / or the screw speed setting.

4. The method for manufacturing a wear-resistant polyethylene pipe according to claim 1, characterized in that: In step S3, a melt pump is set to stabilize the pressure, and the amplitude of the die head pressure fluctuation is used as an additional decision value of the JointControlDomain to identify and suppress interface ripple sources.

5. The method for manufacturing a wear-resistant polyethylene pipe according to claim 1, characterized in that: The viscosity ratio dynamic window described in step S4 is adaptively adjusted according to the mold life state; when the torque trend or pressure trend shows viscosity drift, the system performs feedforward adjustment of the corresponding layer speed, temperature zone and / or melt pump speed to make the viscosity ratio return to the dynamic window.

6. The method for manufacturing a wear-resistant polyethylene pipe according to claim 1, characterized in that: In step S5, the thickness adaptive allocator optimizes the thickness ratio of each layer under the constraint of constant total wall thickness, prioritizing the thinnest point of the wear-resistant layer and the thinnest point of the protective layer, and uses the eccentricity trend as a correction amount. When multiple layers are abnormal at the same time, the coordinated correction is performed according to the correction policy, which prioritizes the functional layer over the structural layer and the inner layer over the outer layer. The traction speed and vacuum sizing are also adjusted in a coordinated manner to avoid adjustment conflicts.

7. The method for manufacturing a wear-resistant polyethylene pipe according to claim 1, characterized in that: The multi-source data fusion in step S6 is mainly based on ultrasonic thickness measurement, and can optionally be combined with X-ray scanning and / or optical profilometry data to form a joint evaluation result of thickness, interface and defects; the joint evaluation result is used to output the out-of-bounds direction and the recommended set of correction actions.

8. The method for manufacturing a wear-resistant polyethylene pipe according to claim 1, characterized in that: The gradient cooling described in step S7 includes gentle shaping in the sizing section and enhanced cooling in the subsequent section; the cooling water temperature gradient and spray intensity are determined by the material fingerprint and linear velocity; when the ellipticity, weight per unit length, or outer diameter springback shows a trend of drift, the cooling gradient and traction speed are adjusted in conjunction with the model to reduce residual stress and slow crack sensitivity.

9. The method for manufacturing a wear-resistant polyethylene pipe according to claim 1, characterized in that: In step S8, the marking line and mechanical stop structure are tactilely positioned by an annular shallow groove and / or ridge, and serve as a guide for a dedicated peeling tool; and a port protection cap is provided, the inner edge of which is engaged at the marking line. After removing the port protection cap, a peeling guide is formed to ensure consistent peeling depth and flat end face; the weakening ring is formed by online laser etching to create a permanent marking line and / or by pre-setting a weakening thin layer or a micro-foaming layer at the marking line position in the co-extrusion die.

10. A method for manufacturing a wear-resistant polyethylene pipe according to claim 1, characterized in that: When the wear-resistant layer is a UHMWPE wear-resistant layer, the process further includes an interface strengthening step: surface activation treatment and / or mechanical roughening treatment of the outer surface of UHMWPE, and setting energy density, action time, atmosphere composition, and roughness Ra or peak-valley spacing as quantifiable windows, and establishing a corresponding relationship with the interface peel strength sampling inspection and writing it into the process specification; limiting the maximum temperature difference and contact pressure gradient of PE100-RC melt coating UHMWPE to control thermal shock; setting a gradient transition layer of PE / UHMWPE blend between UHMWPE and PE100-RC, and constructing regular micro dovetail grooves or inverted conical holes on the surface of UHMWPE as anchoring points, so that the coating melt flows in and solidifies to form a mechanical interlock; recording the energy density, time, roughness Ra and anchoring point density in TwinRecord and correlating them with the peel strength sampling inspection to form a process-performance closed loop.