Kynar® PVDF protection of outdoor plastic components

Citation

(1999), "Kynar® PVDF protection of outdoor plastic components", Anti-Corrosion Methods and Materials, Vol. 46 No. 4. https://doi.org/10.1108/acmm.1999.12846dad.015

Kynar® PVDF protection of outdoor plastic components

Kynar® PVDF protection of outdoor plastic components

Keywords: Elf Atochem, Films, Corrosion prevention

Polyvinylidene fluoride (PVDF) produced by Elf Atochem and marketed under the trade name Kynar is said to be a high performance material with outstanding weathering resistance.

Kynar claims to withstand the combined action of light, heat and moisture, and is said to be insensitive to thermal shock and the frost-thaw cycle. Its chemical stability is also said to make it insensitive to corrosion, pollution, solvents and decay caused by some chemical agents. In addition, it does not yellow, keeps its initial gloss, and withstands scratches and abrasion. Other benefits claimed include minimum maintenance as its fluorinated nature makes it stain- and dust-repellent.

These stability and surface properties are thought to be even more appealing as they are long-lasting, based on ongoing experimentation over the last 30 years involving the very first projects which used Kynar, in the USA.

Kynar's UV-stability and abrasion-resistance are said to be fully utilised to protect other, more sensitive, plastics such as ABS, PVC and other thermoplastics. Applied as a film, either by coextrusion or by lamination, Kynar is an ideal coating for plastic components used in outdoor applications. These were its first applications in the construction sector, for the manufacture of external wall panels and cladding panels, as well as in the automotive sector, for the manufacture of mirror shells, finishers, bumpers (lower part) and fascias in bodywork colours.

The technology used to manufacture Kynar/ABS and Kynar/PVC compounds for use in external wall panels made from thermoformed sheets is multimaterial coextrusion using an Elf Atochem patented process, with an intermediate thermoplastic binder, Adheflon, which bonds both polymers very tightly. Under these processing conditions, the adhesion produced is so strong that attempts at measuring it result in destroying the compound altogether. This adhesion remains intact after both natural and accelerated ageing as well as in extreme conditions.

The process used for bodywork components normally consists of moulding the Kynar protective film over the component, or using a pressure-sensitive adhesive film.

For details contact: Elf Atochem Ltd. Tel: +44 (0) 1635 870000; Fax: +44 (0) 1635 871254.