Three new calcium-zinc heat stabilizers for PVC wire and cable are said to perform better than previous lead substitutes and to be priced competitively with lead systems.

Three new calcium-zinc heat stabilizers for PVC wire and cable are said to perform better than previous lead substitutes and to be priced competitively with lead systems. Ferro Corp.'s Polymer Additives Div., Independence, Ohio, developed Therm-Chek 7208P for 105 C cable and automotive wire. It enables PVC compounds to meet most North American and European automotive insulation requirements. Compounds stabilized with 7208P reportedly exhibit significantly lower water absorption than those using conventional calcium-zincs. It also boasts excellent color hold and a broad processing window with processing characteristics similar to lead. Therm-Chek RC 556P is designed as a cost-effective replacement for lead stabilizers in general-purpose jacketing and insulation that do not require wet electrical properties. It reportedly provides good color hold and outstanding thermal stability at low use levels (typically 1.5 to 2.5 phr), plus exceptional color hold for color-critical applications when used at levels from 2.5 phr to 4.0 phr. According to Ferro, it also has been demonstrated to provide excellent performance in highly filled, flame-retardant jacketing where traditional g-p stabilizers often fall short. Besides providing good stability, it is said to interfere less with flame resistance than most g-p calcium-zincs. Therm-Chek RC 555P is said to be even more cost-effective than CaZn stabilizers currently used to replace lead in THWN and THHN wire and cable.

Ferro Corp
Polymer Additives Div
7061 E. Pleasant Valley Rd Independence, OH 44146
Phone (216) 641-8580 Fax (216) 439-7686