In the first initiative of its kind in the wire and cable industry, Teknor Apex Company has advised customers that it will supply only non-lead stabilized (NLS) PVC compounds after July 31 of this year, it was announced today by the company's Vinyl Division.  In the case of NLS compounds that have already been fully developed and established as compliant with requisite codes and standards, the company will cease producing lead-stabilized versions effective immediately.

 Also included in the changeover are pre-colored compounds, for which the Vinyl Division's sister business Teknor Color Company has developed color concentrates that comply with the European Union's Reduction of Hazardous Substances (RoHS) regulations, including restrictions against use of lead.

Underscoring the significance of this initiative is the pioneering role of Teknor Apex in developing PVC as a workhorse compound for insulation and jacketing, as well as the sheer number of such compounds—over 3,000—now offered by the company, according to Mike Patel, industry manager.

"For decades after Teknor Apex began manufacturing PVC wire and cable compounds in the 1940s, lead-containing additives were the most effective means of making PVC thermally stable while maintaining its outstanding electrical properties," Patel said. "All that has now changed. New non-lead stabilizers plus advanced compounding technology has enabled us to manufacture NLS compounds whose performance and cost are comparable to lead-stabilized materials."

Customers that have not already initiated a changeover to NLS compounds are urged to do so as soon as possible, noted Patel. Teknor Apex representatives will contact these companies to provide NLS-compound recommendations and other advice.

"After years of work with additive suppliers and customers seeking to eliminate lead, Teknor Apex has developed its capability for formulating fully comparable NLS alternatives to the point where we anticipate no problem in converting any remaining lead-stabilized product into its NLS equivalent and supplying it by July 31 of this year," said Patel.

Until recently, tribasic lead sulfate and other lead-based stabilizers were the most efficient and cost-effective additives available for rendering the PVC polymer in vinyl resistant to thermal degradation. Polymer degradation causes deterioration of the mechanical properties of PVC and compromises its electrical properties.

The key to replacing lead stabilizers was the development by additive companies, starting in the 1990s, of new stabilizers that are more efficient than previous formulations.

"New stabilizers alone were no magic solution to the problem of eliminating lead," said Patel. "The challenge for compounders like Teknor Apex was to develop formulations in which the new stabilizers function in concert with all the other ingredients that make up so complex a compound as PVC for wire and cable."

Unlike many other commonly used polymers, PVC has no commercial value unless it is compounded with plasticizers, lubricants, heat stabilizers, colorants, and other additives. A change in one of these components may affect the functioning of the others, which in turn can affect processing, mechanical, and electrical properties, or the cost of the compound.