Modified High-Density Polyethylene (HDPE) Coil Tube — Product Technical Specification
Manufactured by Wenzhou Jixing Metal Materials Co., Ltd.
1. Product Overview
The Modified High-Density Polyethylene (HDPE) Coil Tube is an advanced polymer-based tubing product engineered through proprietary molecular modification techniques applied to virgin HDPE resin. This product represents a significant advancement over conventional HDPE tubing, offering enhanced mechanical strength, superior thermal stability, improved chemical resistance, and extended service life under demanding operating conditions. The coil tube is supplied in continuous spiral-coiled form, facilitating ease of handling, storage, and on-site installation without the need for jointing or welding, thereby minimizing labor costs and installation time.
Wenzhou Jixing Metal Materials Co., Ltd. leverages state-of-the-art polymer compounding and extrusion technologies to deliver a coil tube product that meets international quality benchmarks while maintaining competitive cost efficiency. The product is designed for a broad spectrum of civil engineering, agricultural irrigation, industrial fluid conveyance, and underground utility applications.
2. Material & Properties
2.1 Base Material
The base resin is virgin-grade High-Density Polyethylene (HDPE) conforming to ASTM D1248 specifications, characterized by a density range of 0.941–0.965 g/cm³ and a melting point of approximately 130–138°C. The polymer matrix is further modified through the incorporation of specialized additives to achieve targeted performance enhancements.
2.2 Modification Technology
The proprietary modification process involves the following key enhancements:
- Crosslinking Agents: Silicon-based or organic peroxide crosslinking systems are introduced to improve thermal resistance and environmental stress crack resistance (ESCR), elevating the material's long-term hydrostatic pressure rating.
- UV Stabilizers: Hindered Amine Light Stabilizers (HALS) and carbon black (2–3 wt%) are incorporated to provide long-term ultraviolet radiation protection, ensuring durability in above-ground and buried applications.
- Antioxidants: Phosphite-based primary and secondary antioxidants are blended to retard oxidative degradation during processing and service life, maintaining mechanical integrity over decades of operation.
- Nucleating Agents: Beta-nucleating agents are employed to control crystallinity and spherulite morphology, resulting in improved impact strength, reduced shrinkage, and enhanced dimensional stability.
- Reinforcing Fillers: Selective incorporation of mineral fillers (e.g., calcium carbonate, talc) or glass fiber is available upon request to increase stiffness, reduce thermal expansion, and lower material costs.
2.3 Key Performance Properties
- Tensile Strength: ≥ 25 MPa (ASTM D638)
- Elongation at Break: ≥ 350% (ASTM D638)
- Hydrostatic Design Stress (HDS) at 20°C/50 years: ≥ 10.0 MPa (PE100 grade)
- Environmental Stress Crack Resistance (ESCR): ≥ 1000 hours at 23°C, ASTM D1693 Method A
- Notch Impact Strength: ≥ 200 J/m (ASTM D256, Izod, at -40°C)
- Thermal Coefficient of Linear Expansion: 8.0–10.0 × 10⁻⁵ /°C
- Operating Temperature Range: -40°C to +60°C (sustained)
- Chemical Resistance: Excellent resistance to acids, alkalis, salts, and most organic solvents
- Electrical Insulation: Volume resistivity ≥ 1 × 10¹⁴ Ω·cm
3. Specifications
| Parameter | Specification |
|---|---|
| Product Name | Modified HDPE Coil Tube |
| Material Grade | PE80 / PE100 / PE100-RC (Modified) |
| Outer Diameter (OD) | 16 mm – 160 mm (custom sizes available) |
| Wall Thickness | 1.5 mm – 8.0 mm (SNR 4, 8, 10, 12, 16, 20, 25, 40) |
| Coil Diameter | 3.0 m – 12.0 m (standard); custom coil diameters available |
| Coil Length per Roll | 50 m – 500 m (standard); up to 1000 m upon request |
| Pressure Rating | PN 6 – PN 16 (0.6 – 1.6 MPa at 20°C) |
| Color | Black with blue stripes (default); custom colors available |
| Carbon Black Content | 2.0% – 3.0% (per ISO 4427 / ISO 4437) |
| Coiling Temperature | 40°C – 60°C (controlled cooling) |
| Storage Temperature | -20°C to +60°C |
| Applicable Standards | ISO 4427, ISO 4437, ASTM D1248, ASTM F711, ASTM F714, EN 12201, GB/T 13663 |
| Test Standards | ASTM D2241 (hydrostatic), ASTM D1525 (flame), ASTM D1693 (ESCR), ISO 1167 (long-term hydrostatic strength) |
4. Manufacturing Process
4.1 Raw Material Preparation
Virgin HDPE resin pellets are received, inspected, and blended with the proprietary additive package in a high-efficiency twin-screw compounding extruder. The compounding process ensures homogeneous dispersion of crosslinking agents, stabilizers, nucleating agents, and reinforcing fillers within the polymer matrix. The resulting modified compound is pelletized and stored under controlled temperature and humidity conditions to prevent premature crosslinking or degradation.
4.2 Extrusion
The modified HDPE compound is fed into a single-screw or twin-screw extruder equipped with a precision die head. The extrusion temperature is maintained between 180°C and 220°C to ensure adequate melt flow without thermal degradation. The extruder is fitted with a gear pump to ensure uniform melt delivery and consistent wall thickness. Real-time melt temperature monitoring and pressure sensors provide closed-loop process control.
4.3 Sizing and Cooling
The extruded tube passes through a vacuum sizing die that sets the precise outer diameter and wall thickness to within ±0.1 mm tolerance. The tube is then conveyed through a multi-stage water bath cooling system. The cooling water temperature is progressively reduced from 25°C to 15°C across the cooling zones to control crystallization rate and minimize residual stresses. An inline diameter measurement system (laser gauge) provides continuous dimensional verification.
4.4 Coiling
The cooled tube is fed into an automated coiling machine that winds the tube into a controlled spiral coil. The coiling tension is precisely regulated to prevent ovality, flattening, or kinking. The coiling temperature is maintained at 40°C–60°C to ensure the tube retains sufficient flexibility for coiling without introducing permanent deformation. The coil is then wrapped with protective packaging and labeled with product identification information.
4.5 Quality Control
Every production batch undergoes rigorous quality assurance testing, including:
- Visual inspection for surface defects, color consistency, and stripe alignment
- Dimensional verification (OD, wall thickness, coil diameter) using calibrated gauges
- Melt Flow Rate (MFR) testing per ASTM D1238
- Density determination per ASTM D1505
- Tensile testing per ASTM D638
- Hydrostatic pressure testing per ASTM D2241 (short-term and long-term)
- Carbon black content analysis per ISO 3060
- Flame resistance testing per ASTM D1525
- Environmental stress crack resistance testing per ASTM D1693
5. Applications
The Modified HDPE Coil Tube is engineered for versatility across multiple industrial and civil engineering sectors:
5.1 Agricultural Irrigation
Ideal for drip irrigation, sprinkler systems, and center-pivot irrigation networks. The coil format allows rapid deployment over large field areas without excavation, reducing installation time by up to 70% compared to conventional pipe-in-groove methods.
5.2 Municipal Water Supply and Drainage
Used for potable water distribution, sewer laterals, and stormwater drainage systems. The material's compliance with NSF/ANSI 61 and EN 17301 standards ensures suitability for drinking water applications. The coil format eliminates the need for joints, reducing leak points to zero.
5.3 Gas Distribution
Available in gas-grade specifications (PE100-RC) for low- and medium-pressure natural gas distribution networks. The enhanced ESCR and long-term hydrostatic strength ensure safe and reliable gas conveyance over a 50-year design life.
5.4 Industrial Fluid Conveyance
Suitable for conveying chemical slurries, wastewater, and process fluids in manufacturing facilities. The chemical resistance of modified HDPE eliminates corrosion concerns associated with metallic piping, reducing maintenance costs and extending service intervals.
5.5 Underground Utility Conduits
Employed as protective conduits for electrical cables, telecommunications fibers, and data lines. The coil format enables rapid installation through directional drilling or open-trench methods, with minimal site disturbance.
5.6 Mining and Dewatering
Used for dewatering pipelines, tailings transport, and slurry conveying in mining operations. The abrasion-resistant modification extends service life in high-wear environments.
6. Quality Certifications and Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management system and holds the following certifications:
- ISO 9001:2015 — Quality Management System certification ensuring consistent product quality and continuous improvement
- ISO 14001:2015 — Environmental Management System certification demonstrating commitment to environmental sustainability
- ISO 45001:2018 — Occupational Health and Safety Management System certification
- CE Marking — Conformity with European Construction Products Regulation (CPR) for construction applications
- NSF/ANSI 61 — Drinking water system components certification (where applicable)
- WRAS Approval — Water Regulations Advisory Scheme approval for potable water applications (where applicable)
- GB/T 13663 — Chinese national standard compliance for PE pipes for water supply
- RoHS Compliance — Restriction of Hazardous Substances directive compliance
7. Unique Selling Points
- Joint-Free Installation: The continuous coil format eliminates the need for butt fusion, electrofusion, or mechanical joints, reducing installation time by up to 70% and eliminating potential leak points entirely.
- Proprietary Molecular Modification: Advanced crosslinking and nucleation technologies deliver superior mechanical properties, thermal stability, and long-term hydrostatic pressure resistance compared to standard HDPE tubing.
- Exceptional Chemical and Corrosion Resistance: Immune to electrochemical corrosion, rust, and most chemical attacks, ensuring a design service life of 50+ years without degradation.
- Lightweight and Flexible: Significantly lighter than equivalent steel or PVC pipes, reducing transportation and handling costs. The inherent flexibility allows installation in confined spaces and over uneven terrain without excavation.
- UV and Weather Resistance: Multi-layer UV stabilization system (carbon black + HALS) provides decades of outdoor exposure resistance without embrittlement or property loss.
- Cost-Effective Lifecycle: Although the unit cost per meter may be higher than conventional pipe, the elimination of jointing materials, reduced labor costs, zero maintenance requirements, and extended service life result in a significantly lower total cost of ownership (TCO).
- Customizable Specifications: Flexible manufacturing capability allows customization of diameter, wall thickness, coil size, pressure rating, color, and additive formulation to meet specific project requirements.
- Sustainable and Recyclable: 100% recyclable material with no halogenated compounds, supporting green building certifications (LEED, BREEAM) and circular economy initiatives.
8. Packaging, Storage, and Handling
Each coil is wrapped in a protective plastic film and secured with steel strapping bands. The coil is labeled with product identification, batch number, manufacturing date, and handling instructions. Coils should be stored in a cool, dry location away from direct sunlight and heat sources. Storage temperature should not exceed 60°C. Coils should be stored on flat, level surfaces and stacked no more than two layers high to prevent deformation. During transportation, coils must be secured to prevent shifting or rolling.
Note: For project-specific requirements, custom formulations, or technical consultation, please contact Wenzhou Jixing Metal Materials Co., Ltd. engineering team. All specifications are subject to verification against applicable standards and may be modified based on project-specific design criteria.