Visico LE4421/LE4460/LE4437 is a scorch retardant, moisture-crosslinking polyethylene compound for low voltage insulation

LE4421/LE4460/LE4437 is a natural, moisture-induced crosslinking polyethylene compound that is designed for use as low voltage wire insulation and jacketing. The combination of a VISICO LE4421 base resin, along with the LE4460 brominated flame retardant masterbatch and the LE4437 catalyst, provides a highly scorch retardant compound with excellent thermal stability and good retardant flame properties. LE4421/LE4460/LE4437 contains a patented scorch retardant additive (SRA) that increases the processing window for a moisture crosslinking compound and minimizes the tendency for premature crosslinking in the extruder, head or die.

A finished compound that is composed of 75 parts of LE4421 mixed with 20 parts of LE4460 and 5 parts of LE4437 is recognized by Underwriters Laboratories as VISICO HORIZONTAL. VISICO HORIZONTAL is designed to reduce normal PE flame spread characteristics and achieve an HB-1 flame rating on 14 AWG wires and larger. LE4437 also provides, in addition to catalyst, a stabilization package containing suitable antioxidants, a metal passivator and a metal deactivator. Properly mixed, during the extrusion process, LE4421/LE4460/LE4437 exhibits excellent thermal stability to oxidation.

LE4421/LE4460/LE4437 is readily pigmented to a variety of colors using standard wire & cable color concentrates designed for thermoplastic or crosslinked polyethylene. UV weather resistance is obtained by the addition of a suitable carbon black or UV additive. Using Visico LE4432 in place of LE4437 combines a tin catalyst along with the proper carbon black to provide a black, UV resistant, moisture crosslinking cable insulation.