The influence of storage conditions and packaging on acetic acid generation in cellulose acetate fibers
The cellulose acetate polymer used in cigarette filters is made by acetylating wood pulp with acetic anhydride. One advantage of this modified natural polymer is that it readily degrades by multiple mechanisms. While the ultimate products are carbon dioxide and water, the interim products are acetic acid and cellulose from the deacetylation caused by microbes or chemical hydrolysis.
Recent experimental work has confirmed that Estron acetate tow has a shelf life of two years when stored in the original unopened package, in an enclosed area protected from moisture, high humidity, and extreme temperatures. The shelf life was confirmed by evaluating the odor threshold for acetic acid in cellulose acetate fibers and by measuring the rate of acetic acid generation. The acetic acid was measured in tow samples which were stored at 26 °C and 51 °C in both cardboard bales and new vacuum packaged bales. The results show a 10 fold increase in the amount of acetic acid generated at 51 °C as compared to 26 °C. No difference in the acetic acid generation rate was observed in regards to the packaging; thus, tow stored in both cardboard bales and vacuum-packaged bales has a two-year shelf life.