Accession Number : AD0656416

Title :   NEW DEVELOPMENTS IN HI-FAX COVERINGS FOR WIRE AND CABLE,

Corporate Author : HERCULES POWDER CO WILMINGTON DEL

Personal Author(s) : Acton,W. P. ; Bracken,W. O.

Report Date : DEC 1957

Pagination or Media Count : 5

Abstract : The article discusses two types of Hi-fax to the wire and cable industry. The 1600 type is recommended for use in all applications not requiring the ultimate in stress-crack resistance. This type has moderate stress-crack resistance, somewhat better than the stress-crack resistance of 1-2 melt index low molecular weight polyethylene which has found wide acceptance in this market. The heat-shock resistance of 1600 Hi-fax at normal operating temperatures is at least comparable to the heat-shock resistance of 1-2 melt index low density polyethylene. Extended exposure to high temperatures is not recommended for either low density polyethylene or Hi-fax because of the susceptibility to oxidation. However, even at 90C., the heat-shock resistance of 1600 type Hi-fax is very good. Applications such as cable sheaths, where the ultimate in stress-crack resistance is required, require use of 1800 type Hi-fax. Although this is a higher molecular weight resin than the 1600 type, it has similar physical and electrical properties, but has a substantially higher level of stress-crack and heat-shock resistance. The higher molecular weight resin will withstand more than 1,000 hours' exposure without failure in the Bell Laboratories stress-cracking test. Therefore, in stress-crack resistance, it is equivalent to the low melt index, low density polyethylene now used for sheaths.

Descriptors :   (*PLASTIC COATINGS, *POLYETHYLENE PLASTICS), ELECTRIC WIRE, ELECTRIC CABLES, SHOCK RESISTANCE, STRESSES, FRACTURE(MECHANICS), PERFORMANCE(ENGINEERING)

Subject Categories : Electrical and Electronic Equipment
      Coatings, Colorants and Finishes

Distribution Statement : APPROVED FOR PUBLIC RELEASE