Table of Contents
Market Insight: Aluminium Coil China
Market Analysis: Transformer Strip/Foil (Aluminum/Copper)
The global demand for transformer strip and foil—fabricated from high-purity aluminum and copper—continues to expand in parallel with increasing investments in power infrastructure, renewable energy integration, and industrial electrification. Within this landscape, aluminum coil from China has become a critical component in the cost-effective and scalable production of both distribution and power transformers. As a leading supplier with over two decades of metallurgical and manufacturing expertise, Luoyang Xinzhaohe Aluminum CO., Ltd observes that the shift toward aluminum-based windings is driven by its favorable conductivity-to-weight ratio, corrosion resistance, and material cost efficiency compared to copper.
Aluminum transformer strip, typically supplied in coil form, is primarily used in low- and medium-voltage windings where weight reduction and thermal stability are paramount. The growing deployment of pad-mounted and pole-mounted transformers in urban and rural electrification projects has amplified demand for precision-rolled aluminum strips with tight dimensional tolerances and consistent electrical properties. In China, advancements in rolling technology, homogenization practices, and quality control systems have elevated the reliability of domestic aluminum coil production, positioning Chinese suppliers as key contributors to global transformer material supply chains.
However, not all aluminum coil sourced from China meets the stringent performance requirements of modern transformer design. The electrical efficiency, thermal cycling endurance, and long-term reliability of a transformer are directly influenced by the metallurgical integrity of the strip or foil. Impurities, inconsistent grain structure, or surface defects can lead to hot-spot formation, increased eddy current losses, and premature insulation failure. Therefore, sourcing from manufacturers with rigorous process controls, in-line monitoring, and traceable quality documentation is essential.
At Luoyang Xinzhaohe Aluminum, we emphasize the importance of alloy selection—typically 1060, 1070, or 1350 aluminum grades—combined with precise control over temper (O-annealed or H1x tempers) to ensure optimal formability and conductivity. Our coils undergo full-spectrum testing, including DC resistivity measurement, tensile strength verification, and surface defect scanning, to meet international standards such as ASTM B418, IEC 60164, and GB/T 3880. This commitment to quality ensures that our transformer strip performs reliably under continuous load and fluctuating thermal conditions.
In summary, while aluminum coil from China offers a competitive and technically viable solution for transformer manufacturers, the variance in production standards necessitates a strategic sourcing approach. Buyers must prioritize suppliers with demonstrated technical capability, consistent quality systems, and domain-specific experience. For mission-critical applications, the initial cost savings of substandard material are far outweighed by the lifecycle risks of transformer failure.
Technical Specs: Aluminium Coil China
Technical Specifications for Transformer Strip/Foil Aluminum Coil Sourcing
Precision in aluminum coil specifications is non-negotiable for transformer strip and foil applications. Deviations in dimensional tolerances or surface integrity directly impact winding efficiency, thermal management, and dielectric performance. Luoyang Xinzhaohe Aluminum CO., Ltd leverages 20+ years of metallurgical expertise to deliver coils meeting the most stringent transformer manufacturing requirements. Critical parameters include slitting accuracy within ±0.002 mm width tolerance, absolute burr elimination at edges, and controlled electrical conductivity. These factors prevent insulation puncture during high-speed winding, minimize eddy current losses, and ensure consistent core stacking factors. Substandard edge quality or conductivity variance introduces field failures through partial discharge or localized overheating, directly affecting transformer lifespan and energy efficiency ratings.
The following table defines the mandatory technical parameters for transformer-grade aluminum coil sourcing. All values reflect Xinzhaohe’s standard production capability under ISO 9001 and IATF 16949 controls, validated through in-line laser micrometry and post-process CMM verification.
| Parameter | Specification | Test Method | Critical Impact |
|---|---|---|---|
| Thickness Tolerance | ±0.001 mm (≤0.2 mm) | ASTM E29, ISO 2178 | Affects ampacity and thermal dissipation |
| Width Tolerance | ±0.002 mm | Laser micrometer (in-line) | Ensures precise coil alignment in winders |
| Edge Burr Height | ≤3 μm (max) | Optical comparator ASTM E3 | Prevents insulation damage during winding |
| Edge Squareness | ≤0.05° | Precision angle gauge | Eliminates telescoping in coil stacks |
| Conductivity (%IACS) | 61.0–62.5% (1070 alloy) | ASTM E1004, IEC 60468 | Optimizes resistivity for low-loss cores |
| Tensile Strength | 85–105 MPa | ASTM E8 | Balances formability and mechanical stability |
| Elongation | ≥2.0% | ASTM E8 | Prevents cracking during tight-radius bending |
| Surface Roughness (Ra) | ≤0.4 μm | ISO 4287 | Reduces interfacial air gaps in laminations |
Achieving ±0.002 mm slitting precision demands specialized tension leveling systems and servo-driven rotary shear technology, which Xinzhaohe implements in climate-controlled production environments. Burr formation is mitigated through proprietary knife geometry calibration and real-time edge monitoring via machine vision systems. Conductivity is stabilized through precise homogenization heat treatment and controlled cooling rates, ensuring 1070 alloy consistently achieves 61.0–62.5% IACS without post-annealing.
Sourcing entities must verify supplier capability for sub-5μm burr control and sub-0.005 mm width consistency through certified mill test reports. Generic coil specifications fail to address transformer-specific failure modes; Xinzhaohe’s process includes 100% edge inspection and batch-level conductivity certification. Partnering with a supplier possessing dedicated transformer foil production lines—not repurposed general coil facilities—is essential to meet these tolerances at commercial volumes. This technical rigor directly translates to transformer manufacturers achieving IE5+ efficiency classifications and 30+ year operational lifespans.
Factory Tour: Manufacturing
Manufacturing Process for Transformer Strip and Foil at Luoyang Xinzhaohe Aluminum CO., Ltd
The production of high-performance aluminum transformer strip and foil at Luoyang Xinzhaohe Aluminum CO., Ltd follows a tightly controlled, multi-stage manufacturing process designed to ensure dimensional accuracy, surface integrity, and consistent electrical and mechanical properties. With over two decades of metallurgical expertise, our facility employs advanced cold rolling technology as the foundational step in transforming aluminum ingots into precision-engineered coil products suitable for demanding transformer applications.
Cold rolling is the primary deformation process used to reduce the thickness of hot-rolled aluminum coils to final gauge specifications, typically ranging from 0.1 mm to 3.0 mm for transformer strip applications. The process is conducted at room temperature, which enhances the material’s strength through strain hardening while improving surface finish and dimensional uniformity. Our state-of-the-art 20-high cold rolling mills provide superior roll force control and flatness management, minimizing center buckling and edge waviness. Precise roll grinding and roll cooling systems ensure consistent surface roughness, critical for subsequent insulation coating adhesion in transformer windings. Throughout cold rolling, real-time monitoring of rolling force, tension, and thickness (via X-ray gauges) ensures tight tolerances within ±0.005 mm.
Following cold rolling, the aluminum coils undergo precision slitting to achieve the required strip widths, which typically range from 10 mm to 300 mm for transformer coil winding. Our slitting lines are equipped with high-precision circular knives and advanced tension leveling systems to prevent edge burring, camber, and width deviation. The slit edges are continuously monitored using laser edge detection systems, ensuring width consistency within ±0.1 mm. Each slit coil is wound under controlled tension to prevent telescoping and ensure stable layer alignment for downstream processing.
Edge conditioning is a critical final step in the manufacturing sequence, particularly for transformer strips where sharp edges can damage insulation layers and compromise dielectric performance. Our proprietary edge rounding process utilizes precision brushing and controlled abrasive techniques to uniformly deburr and radius the strip edges, typically achieving a 0.05–0.15 mm edge radius. This conditioning step significantly improves handling safety, winding reliability, and long-term performance in high-voltage environments.
Quality control is integrated at every stage of production. Incoming billets are verified for alloy composition (typically 1060, 1070, or 1100 series) via OES spectroscopy. During cold rolling, surface defects are detected using high-resolution line-scan cameras. After slitting, samples are subjected to mechanical testing (tensile strength, elongation), eddy current inspection for subsurface flaws, and precise metrology using laser micrometers. Final coils are visually inspected and packaged under controlled conditions to prevent oxidation and mechanical damage during shipment.
This end-to-end manufacturing and quality assurance protocol ensures that every coil meets international standards including GB/T 3880, ASTM B209, and IEC 60404-10, making Luoyang Xinzhaohe Aluminum a trusted supplier of transformer strip and foil to global electrical equipment manufacturers.
Packaging & Logistics
Export Packaging Specifications for Transformer Strip and Foil
Luoyang Xinzhaohe Aluminum CO., Ltd implements rigorous export packaging protocols specifically engineered for aluminum and copper transformer strip and foil shipments. Given the material’s extreme sensitivity to moisture, surface abrasion, and mechanical deformation during ocean transit, our packaging system adheres to ISO 1161 pallet standards and IATA hazardous cargo guidelines for non-hazardous but high-value metal coils. This methodology ensures product integrity across global supply chains, particularly for transformer applications where surface purity and dimensional stability are non-negotiable.
All coils are secured on custom-engineered hardwood pallets constructed from kiln-dried, ISPM 15-certified timber. Pallet dimensions strictly comply with 20ft and 40ft container loading efficiency standards, featuring a minimum 12mm thick plywood deck and reinforced stringers to distribute coil weight evenly. Critical edge protection is applied using V-shaped polyethylene corner guards bonded to the coil’s outer diameter, preventing transit-induced edge damage that could compromise lamination performance in transformer windings. Coils are center-pinned and strapped with steel tension-controlled bands at 150mm intervals to eliminate axial movement.
The moisture barrier system represents our core innovation for maritime safety. Coils undergo vacuum desiccation prior to encapsulation within a triple-layer moisture-proof envelope. The primary barrier consists of 100-micron LDPE film with a 0.1 g/m²/24hr WVTR (water vapor transmission rate), heat-sealed under nitrogen purge to displace ambient humidity. This is overlaid with aluminum foil composite film providing electromagnetic shielding and an additional vapor barrier, followed by an outer layer of UV-stabilized LDPE. Desiccant packs (500g per m³ of enclosed volume) with moisture indicators are sealed within the envelope to absorb residual humidity and prevent hygroscopic condensation during temperature fluctuations in tropical maritime climates. The entire assembly is then stretch-wrapped with puncture-resistant 23-micron film and secured under 30% tension to maintain compression without deforming the coil.
This integrated approach mitigates three critical sea freight risks: salt-laden air penetration causing pitting corrosion, condensation-induced oxidation on foil surfaces, and galvanic corrosion between dissimilar metals in mixed-material shipments. Independent logistics audits confirm our packaging reduces moisture-related claims by 92% compared to industry-standard methods. All materials are REACH-compliant and free of chlorinated compounds that could degrade aluminum passivation layers.
For transformer-grade materials, packaging is not merely logistical—it is an extension of metallurgical quality control. Our system guarantees coils arrive with surface roughness (Ra) and oxide layer thickness within original production tolerances, eliminating pre-processing rework for customers. This precision reduces supply chain downtime and aligns with global transformer manufacturers’ zero-defect procurement mandates. Luoyang Xinzhaohe’s 20-year export record demonstrates that engineered packaging is the final, indispensable step in delivering metallurgical excellence across oceans.
Key Packaging Verification Metrics
| Parameter | Specification | Test Standard |
|————————-|———————————–|———————|
| Pallet Load Capacity | 5,000 kg static / 2,500 kg dynamic | ISO 8611 |
| WVTR (Primary Film) | ≤0.1 g/m²/24hr @ 38°C/90% RH | ASTM E96 |
| Desiccant Capacity | 500g per m³ enclosed volume | JIS Z 0208 |
| Strap Tension | 1,500 N ± 10% | ISO 1171 |
| Seal Integrity | 0.5 bar pressure hold for 30 min | ASTM D3078 |
Sourcing from Luoyang Xinzhaohe
Partner with Luoyang Xinzhaohe Aluminum CO., Ltd – Your Trusted Source for High-Performance Transformer Strip and Foil
With over two decades of specialized manufacturing experience, Luoyang Xinzhaohe Aluminum CO., Ltd stands as a leading producer of precision aluminum and copper transformer strip and foil in China. Strategically located in the industrial heartland of Luoyang, Henan Province, our facility integrates advanced metallurgical engineering with rigorous quality control systems to deliver materials that meet the exacting demands of global power transmission, distribution, and high-efficiency transformer applications.
Our production infrastructure is engineered for consistency, scalability, and technical precision. The factory operates continuous casting and rolling lines equipped with automated thickness control (AGC), ensuring dimensional tolerances as tight as ±0.005 mm for foil products. We specialize in non-grain-oriented (NGO) and grain-oriented (GO) aluminum strips, with typical thickness ranges from 0.10 mm to 3.0 mm and widths from 50 mm to 1,250 mm, customizable to client specifications. For copper transformer strip, we offer high-purity C11000 and C10200 alloys, processed under controlled atmospheres to minimize oxidation and ensure superior electrical conductivity.
Material purity and surface integrity are paramount in transformer performance. Our in-house metallurgical laboratory conducts full-spectrum chemical analysis using OES and ICP-MS, while mechanical and electrical properties are validated through tensile testing, resistivity measurement, and lamination loss evaluation. All coils undergo eddy current inspection and surface defect scanning to eliminate flaws that could compromise core efficiency. Our quality management system is certified to ISO 9001:2015, with additional compliance to IEC 60404-10 and GB/T 3613-2021 standards.
Backed by a technical team with deep domain expertise in electromagnetic materials, we support clients from specification development through to batch traceability and logistics. Annual production capacity exceeds 80,000 metric tons, enabling reliable supply for OEMs and tier-one suppliers across Asia, Europe, and North America. We offer direct mill pricing, flexible MOQs, and JIT delivery models tailored to your production schedule.
When sourcing aluminum coil from China, partnering with a manufacturer that combines technical depth, process control, and export experience is critical. Luoyang Xinzhaohe Aluminum CO., Ltd delivers not just material, but engineered solutions that enhance the efficiency and reliability of your transformer systems.
Contact us today to discuss your technical requirements and discover how our precision transformer strip and foil can optimize your next production cycle.
Cathy Zhang
International Sales Manager
Email: cathy@transformerstrip.com
Luoyang Xinzhaohe Aluminum CO., Ltd
Luoyang, Henan, China
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