The Truth About PLA-nts, Corn Plastic, and Biobased Plastic
According to the Environment Agency of the UK, single-use plastic bags have the smallest carbon footprint when comparing to paper bags and reusable cotton bags. Sadly, plastics have still gathered criticism because they are made from fossil fuels, finite resources, and polluting the environment when disposed of inappropriately. Bio-based plastics are sometimes considered to be carbon neutral because their renewable sources (feedstock) capture carbon dioxide from the atmosphere.
Biobased polymers such as polylactic acid (PLA), a compostable polymer (a subset of biodegradable polymers), are typically made from feedstocks originated from corn starch, tapioca roots, or sugar cane. Under controlled conditions, the process of fermentation can produce several distinct types of PLA with varying properties. Thus the resin should be chosen wisely depending on the application.
Imagine you were handed a hot cup of coffee. Suddenly, the cup starts to distort and melt in your hand. PLA has low melting crystalline characteristics, which limit the service temperature. Therefore, in applications such as hot beverage cups, the finished article may distort. Nucleating agents can be added to increase the crystallization speed and degree of crystallinity. This improves heat resistance, resulting in a higher heat-deflection temperature. Colortech provides PLA nucleator products.
Like the much more widely used polyethylene (PE) and polypropylene (PP) resins, PLA can be compounded, pelletized, extruded, thermoformed, injection-molded, and blown into films. Using existing equipment, many manufacturers can process PLA as raw material. PLA may sometimes be substituted for PS, PET, and PP applications with the same additives traditionally used. PLA is accepted as GRAS by the FDA when used in food packaging. Today, PLA is utilized in single-use packaging like; bottles, straws, cups, and animal waste bags. The medical field also uses PLA in medical devices and sutures.
Ask Colortech about additives you need for your FDA or non-FDA applications. We offer slip agents, SLAB, UV’s, AO’s, antiblocks, and more. From lemon scents for trash bags to an array of colors for straws, Colortech has compatible fragrance and color packages for PLA products.
PLA-nts coming up short: The challenges
Consumer pressure has led to the push for more sustainable alternatives to "regular" plastic. Due to the demand, PLA has been in a worldwide shortage, impacting prices.
Considering renewable feedstock comes from plants grown in fertile regions of the planet, climate change is also a potential threat to sourcing PLA.
It is a public misconception that PLA can be thrown into curbside recycling bins. MRF's do not have the capabilities to recycle #7 plastics leading to PLA contaminating current recycling streams. PLA plastics should be sent to a composting facility where the conditions are controlled. High temperatures (>140F) and adequate moisture levels are needed to break it down into its natural elements. A home compost pile does not provide the stable conditions required to break down PLA plastics efficiently. When PLA is sent to a traditional landfill, there is speculation that it may last as long as a PET bottle, depending on the conditions.
Contact our Sales to learn more about our custom additive packages that suit your PLA applications.
Rachael Matthews, Ph.D.
Technical Services Representative