Introduction

As the twenty-first century begins, the wired world finds itself in the midst of a number of significant business challenges and opportunities. The telecommunications industry in particular has been beset with a series of events that will certainly precipitate restructuring efforts. The good news is that although this rebuilding will cause short-term difficulties, the industry will then be poised for new possibilities. And, as the expanding global economy continues to bring more and more regions “on-line,” the demand for access to the wired world - through both power and telecommunications avenues - is likely to increase.

Mr John Yimoyines, Vice President, Dow Wire & Cable Compounds, The Dow Chemical Company

Innovative solutions for the future

Dow Wire & Cable Compounds is committed to creating value for its global customers by supplying material and compound solutions that are backed by solid research and development, product development, engineering and market validation expertise. The company is putting this expertise, plus that of The Dow Chemical Company, to work for customers in order to sustain business through difficult times and develop innovative solutions for the future. As a customer-focused provider of materials and solutions to the global wire and cable market, Dow Wire & Cable Compounds brings more than 50 years’ experience in product development, testing and optimisation to the industry. The company’s materials also meet customer requirements and global standards, including IEC, across the world. By evaluating market needs and trends from the earliest stages of concept and development through manufacturing and installation, Dow can better anticipate its customers’ current and coming needs.

The company primary focus is to provide innovative, market-leading products for a broad spectrum of power, telecommunications and flame retardant (FR) wire and cable applications. As the world’s leading producer of polyolefin-based wire and cable materials, Dow is able to deliver exceptional value, technology, performance and service to customers world-wide. Dow polyethylene compounds are used as insulation and jacketing materials, providing a unique combination of mechanical strength, flexibility, electrical properties, ageing stability and processability. Manufacturers across the industry are looking eagerly for ways to improve their total system economics while simultaneously improving performance. Following is an overview of several new and evolving products from Dow Wire & Cable Compounds that are designed to help cable manufacturers, and the industry as a whole, achieve simultaneous benefits in system economics and product advancements.

Improved XLPE insulation for underground power cable

Dow tree retardant crosslinked polyethylene (TR-XLPE) insulation material, HFDB-4202, provides significant manufacturing and performance advantages while maintaining the excellent dielectric properties expected from XLPE. With outstanding water tree retardant properties, this product has become the market standard for enhancing cable life, even in the most challenging environments. The total value system includes a simple cable design, which helps optimise manufacturing costs. Cable life is extended, which offers improved reliability and minimised cable failures, outage costs, and replacement costs when compared to XLPE and other TR-XLPE alternatives.

HFDB-4202, like its predecessor, HFDA-4202, is formulated to minimise water tree growth. By reducing water trees and maintaining Dow’s high-standard of cleanliness and smoothness in manufacturing and delivery systems, cables can be produced to minimise or avoid vented and bowtie trees. When coupled with the company’s specially engineered conductor and insulation shield materials, this helps enhance cable life.

In a recent US study, early generation TR-XLPE cables made from HFDA-4202 were literally dug-up at one of the earliest installation sites, a shopping mall that was developed in 1985. The cables were found to have essentially no loss in dielectric strength, no bowtie trees larger than 12 mils and no vented trees larger than 10 mils. The TR additive level was maintained uniformly across the insulation thickness and the cables boasted a stripping tension similar to that of fresh cable. The vintage 1985 power cables are expected to continue providing excellent field performance resulting in a long service life and, with the product advancements that have been made continually since that time, we continue to be pleased and optimistic about the performance of this product line.

Flexible insulation for medium voltage industrial power cables

HFDB-8202 is a new, unfilled TR-XLPE insulation compound with the flexibility of filled ethylene propylene rubber (EPR) and the electrical properties and long-life performance of TR-XLPE. With these product performance attributes and other properties, HFDB-8202 is an excellent alternative to filled EPR insulations. From a manufacturing standpoint, HFDB-8202 will run on existing equipment at full TR-XLPE line rates. This robust new product offers ease of installation (lightweight and flexible) with excellent electrical properties, low dissipation factor and lower density, and it meets all cable requirements.

Better handling, good strippability performance with our HFDA-0792 compound, and low shrink characteristics are all immediately apparent in HFDB-8202. Dow is prepared to discuss customer sampling and qualification requirements to help realize the improved flexibility and cost advantages inherent with HFDB-8202.

New MV/HV power cable insulation system

To help customers manage the challenge of inventory management introduced by additive sweat-out concerns with XLPE insulations, Dow has developed HFDB-4201, a new insulation system for medium and high voltage power cables. HFDB-4201 has a dramatically reduced additive bloom level compared to conventional XLPE compounds. This, along with the superior scorch resistance of HFDB-4201, allows improved processability by increasing throughput and dimensional stability.

HFDB-4201 is a low-density, crosslinkable, unfilled polyethylene compound for applications that require a high degree of cleanliness. It also offers world-class low loss dielectric properties suitable for HV and EHV cable applications at very high stresses. With an extremely low level of contamination, HFDB-4201 is available in extra clean (EC) and super clean (SC) grades, and provides excellent surface finish and outstanding output rates over a broad range of conditions.

Fibre optic cable loose buffer tubes, core tubes and slotted cores

Novel products based on developmental INSPIRE (a trademark of The Dow Chemical Company) Performance Polymers featuring high-melt strength or a balance of high stiffness and toughness offer good potential to advance overall cost/performance improvements in key optic cable applications. For buffer tube use, high-stiffness/high-toughness materials are found to bring substantially improved crush resistance and cable grease compatibility versus medium impact polypropylenes currently in use, as well as a physical properties approaching or superior to those of polybutylene terephthalate (PBT). Enhanced compatibility with the less expensive buffer tube filling gels offers system cost advantages, and clearly superior physical properties, compared to conventional nucleated impact polypropylene (IMPP), which requires higher-viscosity and higher-priced gels.

For fibre optic core tube (centre tube) and slotted core applications, novel high-melt strength polymers offer good extrusion characteristics with minimal sag characteristics, while bringing the desirable high-modulus and corresponding crush resistance of conventional polypropylene materials. These materials have also demonstrated the necessary balance of other performance characteristics such as good surface smoothness, low post extrusion shrinkage contributing to excess fibre length and signal attenuation, and sufficient cold impact performance for outdoor installation and use in cold climates.

Slotted core fibre optic cable design

The focus of early development efforts for fibre optic telecommunications cables is to enhance technical performance, especially the improvement of optic signal attenuation performance by reducing the shrinkage behavior or excess fibre length, particularly in loose buffer tube constructions. This provides major cost and performance advantages by enhancing signal quality and increasing the spacing between optic signal amplifiers (also known as repeaters). Additionally, manufacturing cost savings initiatives are focused on maximising optimal mechanical protection and fibre yield to eliminate scrap and remove unnecessary components.

Jacketing compounds

Because competition and economics have required that cable makers pursue jacketing materials with enhanced performance and/or value-added functionality to further reduce the total cable system cost, Dow Wire & Cable Compounds has expanded its capabilities to design the chain architecture of polyethylene for enhanced jacketing performance. For decades, polyethylene compounds have been successfully extruded as jackets for wire and cable applications, and they continue to deliver cost-effective performance. The industry has long pondered the potential benefits of developing a polyethylene jacket to be included in the overall cable design, as an efficient material to extend the cable life and boost end-use performance. The ability to manufacture such compounds regionally around the globe adds to Dow ability to provide customers with the best balance of cost and performance.

By optimising the polyethylene chain architecture, the jacketing performance can be substantially improved relative to the typical linear structure-property relationships for conventional polyethylene technology

End-use performance of the jacket is determined by its ordered solid state morphology, as developed in the phase transformation from melt to solid states. This morphology is controlled by the chain architecture of the polyethylene. Recent advancements in catalyst and process provide flexibility to control the molecular structure of polyolefins and to break many of the rules and restrictions of conventional technologies to make polyethylene jacketing compounds more robust. Use of a dual reactor system provides flexibility to broaden molecular weight distribution and optimize the short chain distribution, which results in improved processability, shrinkage and slow crack resistance. Improved processability allows cable makers more latitude in the manufacturing process without impacting the material performance. Reduced shrinkage helps to maintain low signal attenuation in the cable manufacturing process, which is critical to the fibre optic application. Reduced slow crack growth rate provides more insurance that the jacketing will not crack during reel storage or during service, which is especially critical in thick-wall applications.

Dow Wire & Cable Compounds is optimistic that emerging advancements in polyethylene manufacturing technologies, including catalysis and reaction processes with state-of-the-art compounding, will continue to demonstrate that polyethylene is the most cost-effective means to achieve the primary performance requirements in jacketing applications.

Insulation for telecommunications copper and LAN segments

Based on customer need for enhanced expansion capabilities and high-line speeds in foamed, solid, or foam/skin insulation, Dow is investigating ways to replace HDPE or conventional polypropylene with solid and chemically foamed cellular insulation products utilising developmental INSPIRE Performance Polymers and other high-melt strength polyolefin systems. These would offer customers a next generation replacement for solid and chemical insulations with innovative materials solutions.

Dow Wire & Cable Compounds early research and development studies have analysed traditional chemically foamable compounds to investigate potential improvements to both the resin and the blowing agent systems for better expansion at high line speeds. Many customers are challenged by rheological requirements for products that offer improved performance in manufacturing and application. These new insulations offer better design in the electrical and physical properties of the foam or solid layer, offering higher throughput, better economics, and potentially, light-weighting or down-gauging of the insulation system.

Automotive low-tension Primary cable insulation applications

Dow has introduced a new automotive wire compound, UNIGARD™ RE HFDD-1441 NT, designed to meet SAE J-1127 and J-1128 performance standards for battery cable and primary cable application. HFDD-1441 provides competitive advantages in density, processability, adhesion force, and heat aging performance.

UNIGARD™RE HFDD-1441 NT for automotive low-tension Primary cable insulation applications

As auto makers raise performance standards for under-the-hood cables, these key advantages will enable cable manufacturers to provide a consistent, cost-effective, lighter weight, high performance cable. HFDD-1441 is also designed to meet the specifications for appliance wire. Key performance characteristics include lower density formulations for raw material volume savings; high-temperature, pinch and abrasion resistance; stripability; and processing and curing characteristics.

Market trends

Looking at the market today, Dow sees several trends influencing the business. The consolidation of cable manufacturers, utilities and suppliers means that the market is shrinking in terms of customer numbers. It is definitely becoming more competitive on a global basis, as partnerships between compound suppliers and equipment suppliers become more common. And, of course, the company all knows that there is a strong drive for lower total system costs. While there are no quick, easy answers to these market forces, we are working diligently to continue to deliver solutions and support.

The Dow business model focuses on customer needs and market needs. The company develops materials to address specific challenges and opportunities. For example, Dow is utilising the combined capability of polymer technologies and resources available to the company, and encouraging its customers to share in the value of that knowledge and experience by relying on Dow global development, technology and research capabilities to help address industry needs that are immediate as well as longer-term.

Market experience

Some of Dow Wire & Cable Compounds newer products and technologies have been mentioned here. Overall, Dow is the world’s leading producer of polyolefin-based wire and cable materials, coated metals, and the technology, performance and service support for power cable and telecommunications products. More recently, the company has added a specific emphasis on flame retardant (FR) products, as customers and the industry require materials that support this important fire safety feature.

For the power cable market, Dow provides products and services for:

• Medium and high-voltage semiconductive power cable shields;
• Medium and high-voltage power cable insulation compounds;
• Low voltage power cable compounds (black and colorable);
• Jacketing compounds (black and colorable).

For the telecommunications market, the company provides:

• Solid insulation compounds;
• Expandable insulation compounds; CATV insulation compounds;
• Compounds for fiber optic cable tubes and cores;
• Ocean cable compounds;
• Jacketing compounds (black and colorable);
• Purge compound.

And for the FR market, Dow provides a growing list of products that currently includes:

• Low-halogen FR crosslinkable and thermoplastic (black and colorable);
• Non-halogen FR crosslinkable and thermoplastic (black and colorable).

Synergies of technology and service

Dow Wire & Cable Compounds approach to supporting and growing its business, and the businesses of its customers, is to continually improve DOw technologies and service, and the company is making great strides globally in both areas. Dow has an enormous technology base focused on continually growing its product portfolio, which is complimented by an extensive network of customer-focused service and communications programs. It is important that technology drives development of new processes and materials. And likewise, it is important that customers gain timely, convenient access to important and accurate information via many sources.

Power timeline

On the technology side of the equation, the company offers an extensive range of services at its fully-integrated Global Wire and Cable Technology Center (GTC) and its Materials Processing Skill Center (MPSC), both located at the company’s Weston Canal Centre in Somerset, New Jersey, USA. Global satellite facilities, including one in Horgen, Switzerland, support these world-class facilities, enabling Dow to better serve customers world-wide. The GTC is a leading research and development facility dedicated to wire and cable product development. A large group of Dow scientists, engineers and support staff work at the facility, which features state-of-the-art equipment, scale-up facilities and pilot plants. Dow leading-edge laboratories include the capabilities for fundamental electrical and flame retardant testing, materials characterisation, advanced scanning electron microscopy, Fourier Transfer Infrared, thermal analysis, and liquid chromatography, as well as state-of-the-art compounding equipment. The laboratory and pilot plant wire and extrusion lines allow the company to quickly develop and scale up new products.

At the MPSC, the focus is on compounding and materials processing technology and development for all polyolefins and elastomers businesses. Facilities include the Processing Development Centre at Weston Canal, which handles compounding, pelletizing and additive incorporation, as well as compounding facilities at Freeport, Texas, and Schkopau, Germany. Together, this team is well-versed in materials science, failure mechanisms, rheology and similar disciplines. Working closely with customers to address manufacturing and development issues helps Dow learn about what customers need and provides them with immediate world-class support. The company’s technical service and development group is another example of the synergistic relationship between its technology and its customer service, as they are positioned to work with customers to troubleshoot problems and assist in developing new technologies. Within this group is the customer technical service centre, supported by advanced information technologies and telecommunications capabilities, which allow customers to call from anywhere in the world to get quick, expert information.

Telco timeline

Throughout Dow, the company’s commitment to the “Six Sigma” discipline benefits global customers. This business excellence initiative provides a data-driven discipline that focuses on product and service excellence. Dow has gained reliability, timeliness and innovation improvements and have raised our quality and efficiency as well. This helps lower costs, speed cycle times and improve customer satisfaction. The company has also a dedicated group that focuses on end-use marketing, with a charter to understand key drivers and needs from the ultimate users’ perspective. This helps in streamlining product development and improvements, while adding value to the manufacturers and cable users. Additionally, dedicated customer service resources include a team of sales, telesales, tele-tech and field tech service representatives. Dow’s staff is also experienced in order management, inquiry response and financial service.

Conclusion

Economic forces and market challenges are impacting all wire and cable businesses. For material/compound suppliers, the biggest challenge is to create innovative solutions that offer advanced functionality while contributing to overall system economics. Dow Wire & Cable Compounds introduces several key products that accomplish those goals. The company realises, however, that new products alone cannot solve industry problems. Relationships, perhaps more than products, will be the key to adding sustainable value and growth opportunities for all of the company’s businesses. Dow builds these relationships by staying close to its customers and giving them access to the best and brightest minds, advanced engineering and design expertise, the most current validation data and superior materials solutions.

Acknowledgements

1. Geoffre D. Brown, K.P. (Peter) Pang, and Scott H. Wasserman, “Design of New Easy Processing High Modulus Compounds for Fiber Optic Cable Use,” Proceedings of the 51st IWCS/Focus Meeting, Orlando, Florida, 2002.

2. Day-Chyuan Lee, “Structure-Property Relationships of Higher Performance Wire & Cable Jacketing Compounds,” Proceedings of the 51st IWCS/Focus Meeting, Orlando, Florida, 2002.

3. Evaluation of 1985 Field Aged 35kV TR-XLPE and EPR Cables presented by Southern Company, Dow and The National Electric Energy Testing Research and Applications, Fall ICC, St. Petersburg, FL, Oct. 2002