CX900 Hot Wedge Welder: Reliable & Efficient Geomembrane Welding

Advancing Geosynthetic Installation: The Role of Hot Wedge Welding Technology

In the rapidly evolving landscape of civil engineering, environmental protection, and resource management, the integrity of containment systems is paramount. Geosynthetic materials, particularly high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), and polypropylene (PP) geomembranes, form the backbone of these critical barriers, preventing contamination, ensuring water conservation, and stabilizing challenging terrains. The efficacy and longevity of these systems hinge not just on the quality of the materials themselves, but fundamentally on the strength and reliability of their seams. This is where advanced welding technologies, specifically hot wedge welding, play a decisive role. Hot wedge welding, a thermofusion process, utilizes a heated wedge to melt the surfaces of two overlapping geomembrane sheets, which are then fused together under controlled pressure and speed. This method is highly favored for its speed, efficiency, and the creation of consistently strong, hermetic seals that are crucial for applications ranging from landfill liners and heap leach pads to reservoir covers and canal lining. The industry's continuous drive for enhanced performance, reduced project timelines, and minimized environmental impact has spurred significant innovations in welding equipment. Current trends emphasize automated processes, integrated quality assurance mechanisms, and improved energy efficiency. As projects grow in scale and complexity, demanding flawless installations in diverse climatic conditions, the reliance on robust, intelligent, and user-friendly welding solutions becomes even more pronounced. The CX900 Hot Wedge Welder emerges as a direct response to these demands, embodying the pinnacle of precision engineering and operational reliability required by contemporary large-scale geosynthetic projects. Its design principles are rooted in delivering superior weld quality, operational intuitiveness, and exceptional durability, making it an indispensable tool for engineers and contractors tasked with ensuring the long-term performance and environmental safety of critical infrastructure. The inherent challenges of field welding, including varying ambient temperatures, wind conditions, and material properties, necessitate a machine that can maintain consistent heat, pressure, and speed across a broad spectrum of operational parameters, thereby mitigating human error and maximizing seam integrity. The industry's move towards digital integration for real-time monitoring and data logging further underscores the need for advanced welding equipment that can seamlessly integrate into modern project management workflows, providing verifiable proof of quality and compliance with stringent regulatory standards.

Precision Engineering: The Manufacturing Process of the CX900 Hot Wedge Welder

The robust performance and enduring reliability of the CX900 Hot Wedge Welder are direct results of a meticulously controlled manufacturing process, adhering to stringent engineering and quality assurance standards. From material selection to final assembly and testing, every stage is optimized to ensure the production of a high-precision, industrial-grade welding machine designed for demanding B2B applications. The core structural components of the CX900 Hot Wedge Welder are crafted from high-grade aluminum alloys, specifically chosen for their superior strength-to-weight ratio, excellent thermal conductivity, and resistance to corrosion, ensuring the unit remains durable yet portable. Precision casting is employed for critical frame elements, followed by advanced CNC (Computer Numerical Control) machining to achieve incredibly tight tolerances, typically within ±0.01 mm, for all mating surfaces and component interfaces. This level of precision is crucial for ensuring the smooth and consistent movement of the drive system and the accurate alignment of the hot wedge and pressure rollers, which are fundamental to achieving consistent weld quality. The heating elements, the heart of the hot wedge system, are manufactured using specialized high-temperature resistant alloys, often incoloy or nichrome, known for their rapid heat-up times, stable temperature maintenance, and exceptional longevity, even under continuous operation at temperatures exceeding 450°C. These elements undergo a specialized heat treatment process to enhance their thermal cycling resistance and prevent premature failure. The intelligent control system, including the PID (Proportional-Integral-Derivative) temperature controller and motor drive, integrates high-quality, industrial-grade microprocessors and sensors. These components are sourced from certified suppliers and undergo rigorous electrical testing, including EMI/RFI compatibility and voltage stability tests, to ensure reliable operation in diverse industrial environments. All electrical wiring and connections utilize high-strand count, flexible copper wire with robust insulation, designed to withstand vibration and temperature fluctuations. The drive wheels and pressure rollers, critical for material feeding and seam consolidation, are typically made from durable, heat-resistant silicone or specialized rubber compounds, chosen for their optimal friction properties and resistance to material sticking. These components are produced through high-pressure molding processes to ensure uniform density and surface finish. Throughout the entire manufacturing journey, the CX900 Hot Wedge Welder is subjected to a series of rigorous quality control checks. This includes material composition analysis via spectroscopy, dimensional verification using CMM (Coordinate Measuring Machine) systems, non-destructive testing (NDT) such as ultrasonic inspection for critical welds within the machine's frame, and comprehensive functional testing. Every unit undergoes a burn-in period, typically 8-12 hours, where it operates under simulated load conditions to detect any early-life failures and calibrate all operating parameters. Adherence to international standards like ISO 9001 for quality management systems and ANSI/UL standards for electrical safety is strictly enforced, ensuring that each CX900 Hot Wedge Welder not only meets but often exceeds industry benchmarks for safety, performance, and reliability. This meticulous approach to manufacturing directly translates into a product with an exceptional operational lifespan, typically exceeding 10,000 hours of continuous use with proper maintenance, significantly reducing the total cost of ownership for B2B enterprises. The inherent robustness and precision design enable its application across a broad range of industries, including petrochemical, where material integrity is critical for preventing spills; metallurgy, for durable lining of leaching ponds; and civil engineering, for reliable water management and environmental remediation projects, where its consistent performance ensures leak-free barriers.

Unveiling the CX900 Hot Wedge Welder: Detailed Technical Specifications and Performance Benchmarks

Understanding the granular technical specifications of the CX900 Hot Wedge Welder is crucial for project managers and engineers to assess its compatibility with specific project requirements and to benchmark its performance against industry expectations. The design of the CX900 Hot Wedge Welder emphasizes precision, efficiency, and adaptability, ensuring optimal performance across a wide array of geosynthetic materials and environmental conditions. The machine typically operates on a standard input voltage of 220V AC (single phase) with a frequency of 50/60 Hz, drawing approximately 1800-2200 watts of power, which ensures sufficient energy for rapid heating and stable temperature maintenance even during continuous high-speed operation. Its welding speed is remarkably versatile, adjustable from 0.5 to 10.0 meters per minute (1.6 to 32.8 feet per minute), allowing operators to optimize for material thickness, ambient temperature, and project timelines. The welding temperature, controlled by a sophisticated closed-loop PID system, can be precisely set within a range of 0°C to 450°C (32°F to 842°F), with an accuracy of ±2°C, which is critical for preventing material degradation and ensuring consistent melt. This broad temperature range accommodates various geomembrane types, including HDPE, LLDPE, FPP, PVC, and other thermoplastic materials, typically ranging in thickness from 0.5 mm to 3.0 mm (20 to 120 mil). The hot wedge itself is precision-machined from high-conductivity alloy steel, often featuring a standard double-wedge design for creating two parallel weld beads with an un-welded air channel in between, facilitating non-destructive air pressure testing (AP Test) for quality assurance. The overlap width required for optimal welding is typically 100-150 mm (4-6 inches), ensuring ample material for a robust, wide seam. The pressure system is electro-mechanically controlled, providing adjustable pressure up to 1000 N (225 lbs) on the rollers, which is crucial for achieving proper fusion and consolidation of the molten material without extruding or thinning the geomembrane. The drive system, featuring robust gear motors and precision-ground rollers, ensures consistent traction and minimizes slippage, even on wet or textured geomembranes. The total weight of the CX900 Hot Wedge Welder is approximately 18-22 kg (40-48 lbs), making it portable enough for field deployment, yet sufficiently heavy to provide stability during operation. Its compact dimensions, typically around 450mm x 300mm x 250mm (17.7" x 11.8" x 9.8"), further enhance its maneuverability in confined spaces. Beyond these core parameters, the CX900 Hot Wedge Welder incorporates advanced features such as an intuitive digital display for real-time monitoring of temperature, speed, and pressure, and integrated data logging capabilities via a USB port, allowing for detailed record-keeping and verifiable quality control. The machine’s operational efficiency is further enhanced by its quick heat-up time, typically under 5 minutes, and its energy-saving design, which minimizes power consumption during standby. When evaluating performance, the resulting weld strength is paramount. Typically, the peel strength of seams produced by the CX900 Hot Wedge Welder exceeds 90% of the parent material's tensile strength, and shear strength often surpasses 100% of the parent material, indicating a stronger-than-material bond. This high degree of integrity is critical for applications demanding long-term environmental protection and containment, such as in landfill liners where leachate containment is essential, or in large-scale pond liners for mining operations where chemical resistance and impermeability are non-negotiable. The machine's consistent output drastically reduces the need for re-welding and repairs, leading to significant time and cost savings on major projects.

Versatility in Practice: Application Scenarios Across Key Industries for the CX900 Hot Wedge Welder

The robust capabilities and precise performance of the CX900 Hot Wedge Welder make it an indispensable tool across a broad spectrum of heavy industries where geosynthetic materials are critical for containment, protection, and structural integrity. Its adaptability to varying geomembrane types and thicknesses ensures optimal results in challenging and diverse application scenarios. In the Petrochemical Industry, the CX900 Hot Wedge Welder is vital for constructing highly impermeable containment liners for crude oil storage, refined product tanks, and process water ponds. These applications demand zero-leakage performance to prevent soil and groundwater contamination. The welder’s ability to create consistent double-track welds with an integrated air channel for testing is paramount, allowing for non-destructive, verifiable leak detection that meets stringent environmental regulations (e.g., EPA standards for hazardous waste containment). Its robust design ensures reliable operation even in the harsh chemical environments often found on petrochemical sites, where geomembranes provide essential secondary containment barriers. For instance, in a large-scale oil refinery expansion project, the CX900 Hot Wedge Welder was instrumental in installing a 2.0 mm HDPE liner for a new series of stormwater retention ponds, handling over 100,000 square meters of material efficiently and ensuring complete environmental protection against accidental discharge. Similarly, in the Mining Industry, the CX900 Hot Wedge Welder is a cornerstone for constructing vast heap leach pads, tailings storage facilities, and evaporation ponds. These massive structures, often covering hundreds of acres, rely on robust geomembrane liners to prevent the seepage of acidic solutions and heavy metals into the environment. The welder’s high-speed capability (up to 10 m/min) is crucial for meeting aggressive construction schedules, while its precise temperature and pressure controls ensure high-strength seams that can withstand extreme chemical exposure and physical stresses from heavy machinery and material loads. A significant application case involved a gold mine in Nevada, where the CX900 Hot Wedge Welder was deployed to weld a 2.5 mm LLDPE liner for a 50-hectare heap leach pad, demonstrating exceptional seam integrity in a project valued at over $5 million, where liner failure could lead to catastrophic environmental damage and regulatory penalties. Within Water Supply and Drainage Infrastructure, the CX900 Hot Wedge Welder is indispensable for lining reservoirs, irrigation canals, wastewater treatment lagoons, and storm detention basins. The ability to create durable, waterproof barriers is critical for water conservation, preventing seepage losses, and ensuring the purity of water resources. Its capacity to handle varying material thicknesses allows for adaptation to different hydraulic pressures and subgrade conditions. In a large municipal water reservoir project in California, the CX900 Hot Wedge Welder was selected for welding 1.5 mm HDPE geomembranes, significantly reducing water loss from evaporation and seepage, thereby enhancing the region's water security. Its efficiency played a key role in completing the 250,000 square meter liner installation ahead of schedule. Furthermore, in Environmental Protection and Waste Management, specifically for landfill cell construction and closure projects, the CX900 Hot Wedge Welder is paramount. Landfill liners, composed of multiple layers of geosynthetics, must reliably contain leachate and prevent gas migration. The CX900 Hot Wedge Welder provides the precision and consistency required for these critical seals, which must maintain integrity for decades. Its versatility extends to geomembrane encapsulation for contaminated soil remediation projects, and the construction of gas collection systems within landfills. Beyond these primary sectors, the CX900 Hot Wedge Welder also finds applications in agriculture for pond liners and biogas digesters, in civil construction for tunnel waterproofing and road base stabilization, and in aquaculture for fish farm pond liners. The continuous innovation in materials science means the CX900 Hot Wedge Welder is designed to adapt to emerging geomembrane technologies, ensuring its relevance and efficacy in future industrial applications. The ability to produce strong, consistent welds across a wide range of thermoplastic materials, combined with its operational robustness, positions the CX900 Hot Wedge Welder as a cornerstone technology for critical infrastructure projects globally, contributing to enhanced safety, reduced environmental impact, and long-term asset integrity.

Unmatched Performance: Technical Advantages and Competitive Edge of the CX900 Hot Wedge Welder

In a competitive market populated by various hot wedge welders and alternative geomembrane joining technologies, the CX900 Hot Wedge Welder distinguishes itself through a suite of advanced technical advantages that directly translate into superior project outcomes, enhanced operational efficiency, and lower total cost of ownership for B2B clients. One of its foremost distinctions lies in its Advanced PID Temperature Control System. Unlike conventional welders that might experience temperature fluctuations, the CX900 utilizes a sophisticated Proportional-Integral-Derivative (PID) algorithm that continuously monitors and adjusts the wedge temperature with an exceptional accuracy of ±2°C. This closed-loop control ensures highly stable heat delivery, preventing overheating or underheating of the geomembrane, which is critical for achieving consistent melt viscosity and ultimately, a uniform, high-strength weld. This precision reduces material degradation and minimizes the risk of brittle seams, a common issue with less sophisticated temperature controls. For example, in field conditions where ambient temperatures can fluctuate rapidly, the CX900 maintains its set temperature, ensuring reliable fusion regardless of external factors. Furthermore, the CX900 Hot Wedge Welder incorporates an Integrated Data Logging System with Real-Time Monitoring. This feature is a game-changer for quality assurance and compliance. Through a user-friendly digital display, operators can monitor and record critical welding parameters—including temperature, speed, and applied pressure—in real-time. This data can then be downloaded via a USB port, providing an immutable record of the welding process for every linear meter of seam. This verifiable documentation is invaluable for regulatory compliance, client reporting, and troubleshooting, significantly enhancing the trustworthiness and transparency of the project. It allows engineers to prove adherence to ASTM D6392 standards for geosynthetic seam integrity, for instance. Traditional welders often lack this capability, relying on manual logs which are prone to error. The machine's Optimized Drive System and Pressure Control contribute significantly to its superior performance. Equipped with robust, high-torque gear motors and precision-machined pressure rollers, the CX900 ensures consistent welding speed and uniform pressure application across the geomembrane overlap. The adjustable pressure mechanism allows operators to fine-tune the clamping force to suit different material thicknesses and types, guaranteeing optimal material consolidation and eliminating air pockets within the weld. This meticulous control over pressure prevents material distortion or excessive thinning, which can compromise seam strength. Compared to machines with less refined pressure systems, the CX900 Hot Wedge Welder yields consistently strong welds that often surpass the parent material's tensile strength in peel and shear tests, a testament to its engineering superiority. Another key advantage is its Ergonomic Design and User-Friendly Interface. Despite its advanced capabilities, the CX900 Hot Wedge Welder is engineered for ease of use in challenging field conditions. Its balanced weight distribution, integrated handles, and intuitive digital interface minimize operator fatigue and reduce the learning curve. Quick setup and adjustment mechanisms reduce downtime between welds, contributing to significant productivity gains on large projects. Many competitor models are either too heavy, cumbersome, or have complex controls, leading to slower operation and increased training requirements. The Enhanced Durability and Longevity of the CX900 Hot Wedge Welder, owing to its high-grade material construction (aluminum alloys, stainless steel components) and rigorous manufacturing processes, ensures a longer operational lifespan and reduced maintenance costs. Its robust construction protects internal components from harsh environmental conditions, dust, and moisture, making it suitable for continuous outdoor use. This translates to a lower total cost of ownership over the machine's lifetime compared to less durable alternatives that may require frequent repairs or premature replacement. In essence, the CX900 Hot Wedge Welder is not merely a tool but a strategic asset, delivering measurable improvements in weld quality, project efficiency, and data integrity, setting a new benchmark for hot wedge welding technology in critical B2B applications.

Tailored Solutions and Comprehensive Support: Maximizing Your Investment in the CX900 Hot Wedge Welder

Recognizing that B2B projects often come with unique challenges and specific requirements, MMTechWeld offers more than just a standard product; we provide comprehensive solutions centered around the CX900 Hot Wedge Welder, encompassing customization, dedicated support, and robust trustworthiness. Our approach ensures that clients not only acquire a state-of-the-art welding machine but also gain a reliable partner committed to their project's success and long-term operational efficiency. While the standard CX900 Hot Wedge Welder is designed to meet a broad range of applications, we understand that certain projects may benefit from specific modifications. For instance, for applications requiring welding of exceptionally thick geomembranes (e.g., beyond 3.0 mm) or specialized composite materials, we can explore options for higher wattage heating elements or custom-designed pressure roller configurations to ensure optimal material fusion and seam integrity. Similarly, for operations in extreme cold environments, specialized cold-weather kits including insulated components and heating blankets for the machine can be provided to maintain peak performance. For clients with specific data integration needs, we can discuss custom software protocols for the data logging system, allowing for seamless integration with existing project management or QA/QC software platforms. These customization discussions typically begin with a detailed technical consultation, where our expert engineers work closely with your project team to understand the nuances of your application, material specifications, and environmental conditions. This collaborative approach ensures that any proposed customization is technically feasible, cost-effective, and directly addresses your project's unique demands, maximizing the utility and value of your investment in the CX900 Hot Wedge Welder. Beyond customization, MMTechWeld provides an unparalleled level of customer support, a critical component of any B2B relationship. Our comprehensive support ecosystem includes initial operator training programs, available both on-site and through virtual platforms, ensuring your team is fully proficient in operating, maintaining, and troubleshooting the CX900 Hot Wedge Welder. These training sessions cover advanced welding techniques, parameter optimization, routine maintenance, and best practices for quality assurance, including proper peel and shear testing procedures. We maintain a readily available inventory of genuine spare parts, ensuring minimal downtime in the event of component wear or unforeseen issues. Our global network of certified service technicians is capable of providing rapid on-site support and maintenance services, preventing costly project delays. For complex technical queries, our dedicated customer support hotline and online portal offer expert assistance, often resolving issues remotely. The trustworthiness aspect of our service is underpinned by our transparent delivery process. Upon order confirmation, clients receive a detailed delivery schedule, including estimated transit times and tracking information. We employ robust packaging solutions to ensure the CX900 Hot Wedge Welder arrives at your site in pristine condition, ready for immediate deployment. Furthermore, every CX900 Hot Wedge Welder comes with a comprehensive warranty, typically covering manufacturing defects for a period of 12 to 24 months, underscoring our confidence in the product's quality and reliability. This warranty is backed by our commitment to swift and efficient service for any covered issues. Our long-standing history in the industry, coupled with countless successful project partnerships globally, serves as a testament to our authoritativeness and reliability. We are not just selling a machine; we are offering a complete solution backed by expertise, experience, and an unwavering commitment to trust, ensuring your projects are executed flawlessly and sustainably.

Frequently Asked Questions (FAQ) about the CX900 Hot Wedge Welder

To further enhance transparency and address common queries, this FAQ section provides concise answers regarding the CX900 Hot Wedge Welder, covering aspects from operational best practices to maintenance and material compatibility, ensuring prospective and existing clients have all necessary information at their fingertips for effective project planning and execution.

Q1: What types of geosynthetic materials can the CX900 Hot Wedge Welder effectively weld?

A1: The CX900 Hot Wedge Welder is specifically engineered for a wide range of thermoplastic geomembranes, including but not limited to High-Density Polyethylene (HDPE), Linear Low-Density Polyethylene (LLDPE), Flexible Polypropylene (FPP), Polyvinyl Chloride (PVC), and other specialized thermoplastic lining materials. Its broad temperature control range (0°C to 450°C) and adjustable pressure settings allow for precise adaptation to the unique melting characteristics and thickness requirements of each material, typically from 0.5 mm to 3.0 mm (20 to 120 mil). For optimal results with PVC, it's recommended to utilize specialized PVC welding accessories (e.g., non-stick wedge coatings or specific roller types) and to adjust parameters according to material data sheets, as PVC generally requires lower temperatures and different pressure profiles compared to polyolefins like HDPE. Always consult the material manufacturer's recommendations for welding parameters to ensure maximum seam integrity and material preservation.

Q2: What is the typical delivery timeframe for a CX900 Hot Wedge Welder after an order is placed?

A2: The standard delivery timeframe for a CX900 Hot Wedge Welder typically ranges from 2 to 4 weeks, depending on current stock levels, order volume, and destination. For urgent project requirements, expedited shipping options may be available at an additional cost. We pride ourselves on transparent communication throughout the order fulfillment process. Upon confirmation of your order, a dedicated account manager will provide you with a detailed estimated delivery schedule, including tracking information, allowing you to monitor your shipment's progress in real-time. International orders may require additional time for customs clearance and freight logistics; however, our logistics team is experienced in managing global shipments to ensure efficient and timely delivery to your project site. We recommend placing orders well in advance of critical project phases to ensure timely receipt of equipment and prevent any potential delays.

Q3: What kind of warranty and after-sales support does MMTechWeld offer for the CX900 Hot Wedge Welder?

A3: MMTechWeld stands behind the quality and reliability of the CX900 Hot Wedge Welder with a comprehensive warranty package. Typically, the machine is covered by a 12 to 24-month warranty against manufacturing defects from the date of purchase, contingent on proper operation and maintenance as outlined in the user manual. This commitment underscores our confidence in the durability and performance of our equipment. Beyond the warranty period, we offer extensive after-sales support, including access to genuine spare parts, technical assistance via phone and email, and a network of certified service centers for maintenance and repair. We also provide comprehensive training programs for operators and maintenance personnel to ensure optimal use and longevity of the machine. Our goal is to provide continuous support throughout the entire lifecycle of your CX900 Hot Wedge Welder, ensuring maximum operational uptime and safeguarding your investment.

Q4: How does the CX900 Hot Wedge Welder ensure weld quality and allow for testing?

A4: The CX900 Hot Wedge Welder is designed with several features to ensure superior weld quality and facilitate non-destructive testing, crucial for critical containment applications. Primarily, it utilizes a double hot wedge system, which creates two parallel weld seams with a continuous un-welded air channel (approximately 10-15 mm wide) in between. This air channel is instrumental for conducting non-destructive air pressure tests (AP Test) using a needle gauge and pressure pump. By pressurizing this channel to a specified pressure (e.g., 20-30 psi for HDPE geomembranes) and monitoring for pressure drops, operators can quickly verify the integrity and airtightness of both weld beads along the entire seam length. Furthermore, the integrated data logging system records critical welding parameters (temperature, speed, pressure) in real-time, providing verifiable documentation that adheres to stringent quality assurance protocols (e.g., ASTM D6392). This data serves as an objective record of welding conditions, ensuring compliance and traceability for auditing purposes. For destructive testing, samples can be easily cut from the end of welded panels for peel and shear strength tests in a laboratory or on-site, demonstrating that the weld strength meets or exceeds project specifications and industry standards.

Q5: Is specialized training required to operate the CX900 Hot Wedge Welder?

A5: While the CX900 Hot Wedge Welder is designed with an intuitive interface for ease of use, specialized training is highly recommended, if not mandatory, especially for critical infrastructure projects. Proper training ensures operators can fully leverage the machine’s advanced features, accurately set welding parameters for different materials and environmental conditions, perform routine maintenance, and conduct essential quality control procedures, such as non-destructive and destructive seam testing. MMTechWeld offers comprehensive training programs tailored to various skill levels, ranging from basic operation to advanced troubleshooting and maintenance. These programs cover theoretical aspects of geomembrane welding, practical hands-on experience with the CX900 Hot Wedge Welder, and adherence to industry best practices and safety protocols. Investing in professional training minimizes human error, optimizes welding efficiency, and significantly contributes to overall project quality and safety. We can arrange on-site training or provide detailed instructional materials and virtual support to ensure your team is fully proficient.

References and Further Reading

• Koerner, R. M. (2012). Designing with Geosynthetics (6th ed.). Xlibris Corporation. This seminal work provides extensive details on geosynthetic materials, their applications, and quality assurance for welding.
  https://www.geosyntheticstextbook.com/

• International Geosynthetics Society (IGS). The official body for geosynthetics professionals, offering publications and forums on best practices, including welding techniques and equipment.
  https://www.geosynthetics-society.org/

• ASTM International. Standard Guide for Test Methods for Geomembrane Seams (ASTM D6392/D6392M). Critical for understanding seam integrity and testing protocols relevant to the CX900.
  https://www.astm.org/d6392_d6392m.htm

• Lapeyre, R., & Touze-Foltz, N. (2016). Hot Wedge Welding of Polyethylene Geomembranes: A Review of Recent Research. Geosynthetics International, 23(4), 263-278. This academic article delves into the science behind hot wedge welding.
  https://www.icevirtuallibrary.com/doi/abs/10.1680/jgein.16.00010 (Subscription or access required)