While PVOH has been around for some time, its applications areas have remained relatively limited. Yet the material offers advantages that today, are highly relevant for packaging applications.The materials experts at the Ljungby, Sweden-based packaging-focussed Emballator Innovation Center, the testing and development centre run collaboratively by the companies in the Emballator Group, decided it was time to take another look.
Polyvinyl alcohol (PVOH) is a polymer based on three elements – carbon, hydrogen, and oxygen. The PVOH material is considered safe and is widely used as a food additive. Once in contact with water it will dissolve completely. It is then easily converted into water and carbon dioxide by microbes.
“Many naturally occurring microorganisms have the ability to degrade PVOH, when it´s put in soil, sea or wastewater, without leaving any harmful residues, such as microplastics, but only carbon dioxide, water and biomass,” said Christian Olsson, Material Specialist at Emballator Innovation Center. Could this be an option for use in one of Emballator’s applications, he wondered.
At the Center, a container made from PVOH was injection moulded and filled with water. It was then placed in a refrigerator overnight, where it completely dissolved - an excellent result, according to Emballator Innovation Center.
“With a great barrier that extend shelf-life and the ability to dissolve in low temperatures, the main use is for dry products,” said Mats Jeppsson, Innovation Manager at Emballator Innovation Center. “This material can keep spices and dry goods fresh. Also, other applications with mainly dry content with a need for a more rigid packaging for a one-use dose it’s perfectly suitable.”
An added advantage is that PVOH is available in grades, ranging from those that are soluble in cold water to those that are soluble in hot water, making customisation according to each customer's specific requirement is possible.