Abstract
Linear Low Density Polyethylene (LLDPE) is manufactured by copolymerizing ethylene wih an alpha-olefin The most common and commercially important comonomers are butene-1, hexene-1, 4-methylpentene-1, and octene-1. This paper focuses on the use of octene-1. Ultra Low Density Polyethylene (ULDPE), a select case of LLDPE, has a density of ≤ 0.915 g/cc. Due to superior impact strength, optical properties, and heat sealing characteristics, ULDPE resins are beneficial to the packaging industry, particularly in food contact applications. Compliance with federal government Food and Drug Administration (FDA) regulations by ULDPE (and LLDPE, in general) must be met for such food contact. One test (n-hexane extraction) is used as an FDA approved method to assure that the control of produc tion is maintaining the previously demonstrated suitable level of extractability from a polymer by food. It is desirable for resin producers to control resin design such that maximum product performance results and regulatory guidelines are both met.
Control of the short chain branching distribution (SCBD) has been found to significantly affect product performance, especially for ULDPE. In addition to enhancing performance, the bonus of decreased n-hexane extractables has resulted from narrowing the SCBD.
Get full access to this article
View all access options for this article.