Rigid packaging: Chemical resistance
Chemical resistance is desired for jars which must contain aggressive fluids, powders or chips, such as for the transportation and storage of chemicals and agrochemicals. In this case the main matter is to prevent the corrosion of the packaging, and therefore to ensure safety for humans and the environment.
The highest chemical resistance is ensured by Kureha KF Polymer® PVDF (Poly-Vinylidene-Fluoride). KF Polymer is a fluoropolymer showing excellent resistance to degradation caused by chemical corrosion heat and weather. KF Polymer is also intrinsically flame retardant.
Kureha is one of the largest PVDF neat polymer producers since 1970 and it KF Polymer resin exerts high purity with very low level of extractables (Total Organic Carbons, metals and metal ions).
Easier to process and less expensive than other fluoropolymers, KF Polymer is used in injection moulding or extrusion.
Short and long chain polyamides are also often used for their good combination of chemical and thermal resistance. Specific PA6 and PA6.6 compounds for chemical resistance are available with Poliblend Polimid® portfolio. Specific tailor-made Ambramid® PA6 and PA6.6 can also be developed.
Long-chain polyamides are available with Arkema Rilsan® and Rilsamid®, and Nexis Fibers PA6.10 and 6.12.
Chemical resistant packaging may also often require gas-barrier properties, to avoid the potential permeation of corrosive, toxic or smelly vapours to the external environment. Good barrier to water vapour, oxygen and carbon dioxide – superior to those of polyolefins, and comparable to those of PET, PA6 and PA6.6. are achieved with Kureha KF Polymer® PVDF.
Very high gas-barrier properties in general require the use of Arkema Orevac® tie-layer plus Evasin® EVOH by multi-layer blow moulding or sheet extrusion / thermoforming in complex structures.