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2020/11/20
Ultrasonics Expand Packaging Potential for Sustainable, Bio-Based Plastic Materials (part 1 of 2)
Ultrasonics Expand Packaging Potential for Sustainable, Bio-Based Plastic Materials
Source from: https://www.flexpackmag.com/articles/90734-ultrasonics-expand-packaging-potential-for-sustainable-bio-based-plastic-materials
Even as the COVID-19 pandemic has caused a short-term upswing in demand for single-use plastic packaging, the longer-term trend is toward sustainability. And so, with an eye toward the future, more and more manufacturers are striving to increase the use of bio-based plastic materials as a sustainable solution for many product packaging applications.
Consumer-conscious manufacturers know that the use of biodegradable or industrially compostable bio-based plastics is one way to reduce the solid-waste burden of packaging for everything from straws and drink containers, to single-use snack food and beverage packages, to the bubble wraps and films that protect e-commerce items being shipped to homes. More than 250 of these manufacturers, representing 20% of all plastic packaging produced worldwide, have made a global commitment to eliminate plastic waste and pollution at its source, pledging that 100% of their plastic packaging must be reusable, recyclable or compostable by 2025. Signatories to this pledge include a who’s who of major global corporations: Mars, Nestle, Walmart, SJ Johnson, Unilever, Colgate-Palmolive, Apple, Coca-Cola, Johnson & Johnson, PepsiCo and many more.
Central to the success of plastic packaging sustainability efforts is the continued development of biodegradable or compostable bio-based materials like polylactic acid (PLA), polybutyrate (PBAT) and polyhydroxyalkanoate (PHA) as replacements for conventional plastic materials such as polypropylene (PP) or polyethylene. And, whether these materials are utilized in the form of pouches, bags or other containers, these next-generation sustainable packages will have to perform to high standards, combining all of the integrity, safety, attractiveness and convenience of current conventional packages.
But adapting current packaging designs and traditional package-sealing equipment to bond newer bio-based plastic materials with commercial-grade quality and reliability poses challenges. First, bio-based plastics are more difficult to seal because they contain a lower amount of thermoplastic polymer. Instead of conventional polymer, they generally incorporate 20% or more biologically based materials — starch, soymeal, sugarcane bagasse, coconut shell extract or other plant-based material — to aid in biodegradability or compostability.
Second, the heat-sealing equipment used to fabricate many current-generation packages does not lend itself to the sensitive process control. Typical heat-sealing equipment provides only simple controls such as time, temperature and pressure, so it can be difficult to manage changes in material type or thickness. For this reason, more machine builders are offering, and more manufacturers and packagers are considering, a different option for fabricating and sealing packages: ultrasonic welding technology.