I have compiled the main causes and solutions to problems you may encounter in the production and practical application of ultra-high molecular weight polyethylene (UHMWPE) pipes, for your quick reference. The following table summarizes the most common categories of issues:

Problem Type
Specific Problems
Main Causes
Solutions

Production Appearance Issues
Dimension/Shape Issues
Misalignment of die and mandrel, uneven temperature or cooling, excessive traction force, or equipment misalignment
Adjust die concentricity, optimize temperature and cooling system, calibrate production line and adjust traction force

Pipe Wall Issues
Uneven die gap, mismatch between extrusion and traction speed, mold deformation
Adjust die gap, ensure speed matching, repair or replace mold

Surface Quality Issues
Inappropriate die temperature, damp raw materials, excessively high extrusion speed
Adjust die temperature, preheat and dry raw materials, reduce extrusion speed

Production Intrinsic Defects
Extrusion Whitening/Impurities
Raw material contamination or degradation, poor plasticization or localized overheating, unclean equipment
Switch raw material batches and conduct material analysis, optimize process parameters, thoroughly clean equipment

Practical Application Failures
Pipeline Burst Due to Pressure
Non-compliant installation, stress concentration, or connection process issues with steel-reinforced composite pipes
Strictly follow construction specifications, Focus on verifying the compound pipe connection process (focus on inspecting composite pipe connection processes)

Collapsed Liner Pipe
Large difference in expansion coefficients between liner material and steel pipe, temperature difference or negative pressure difference inside and outside
Select matching material combinations, optimize operating conditions to avoid drastic temperature changes

Pipe Cracking/Leakage
Insufficient chemical resistance or hydrolysis resistance of the material (especially in high-temperature and high-humidity environments)
Select appropriate pipes based on the conveyed medium, choose hydrolysis-resistant materials and maintain system dryness

🔍 How to Systematically Prevent and Solve Problems
To avoid the aforementioned issues, control can be exercised from the following three core stages:

– Source Control: Ensure High-Quality Raw Materials and Precise Formulations
Raw materials are the core determinant of pipe performance. The first step is to select high-quality resins with stable molecular weight and no pollution. Additionally, formulations should be designed or selected based on the final application (such as pressure resistance, wear resistance, and chemical corrosion resistance), ensuring that all additives (e.g., antioxidants, lubricants) are evenly dispersed.

– Key Control: Optimize Mold Design and Production Processes
Molds are the most critical factor affecting quality. A well-designed mold can ensure stable production, dense pipes, and minimal raw material degradation. Extrusion processes (especially temperature control) are equally crucial; for raw materials with a molecular weight of approximately 2.5 million, the plasticizing temperature is typically around 240°C, which needs to be finely adjusted based on actual conditions.

– Application Adaptation: Scientific Selection and Standardized Construction Based on Operating Conditions
Many problems in applications arise from \”using the wrong product in the wrong place.\” When selecting products, it is essential to clearly define the conveyed medium (whether it has chemical corrosivity, contains water) and operating conditions (temperature, pressure range, risk of negative pressure). Meanwhile, standardized installation and construction are the final link to ensure the long-term safe operation of the pipeline; any installation stress may become a hidden danger.

💡 Problem Troubleshooting Approach
When encountering specific problems, you can follow these steps for troubleshooting, especially suitable for handling complex production defects:

1. Simplify Variables: First, try testing with a different batch of raw materials. This can quickly determine if the problem originates from a specific batch of materials.
2. Optimize Processes: While keeping other conditions fixed, systematically fine-tune key process parameters such as temperature, screw speed, and traction speed, and observe changes in the problem.
3. Check Equipment: Thoroughly clean the extruder and mold, check and replace filters, and confirm that all heating and cooling units are working properly.
4. In-depth Analysis: If the above steps fail to resolve the issue, it is recommended to conduct laboratory analysis on problematic samples (e.g., sections with white spots) (such as thermogravimetric analysis, infrared spectroscopy, and microscopic observation) to determine the micro-components and structure of the defect, thereby accurately locating the root cause.

If you can share the specific problems you are encountering (e.g., particular defects in production or types of failures in applications), I can provide more targeted analysis for you.