There are various bio-based materials available in the packaging market and continuously being innovated. Few of them are being criticized/banned by research institutes and government because of its negative impact on the environment and misleading the market. Whereas, many of them have written success stories, being commercialized and holding a significant share in the packaging industry.
The bio-based material should be originating from renewable resources completely and should have enough strength to get processed into packaging products. Various parameters like melt strength, tensile strength, elongation, processability, flexibility, thermal stability, biodegradability and composability decide the market acceptability and make any bio-based material to be commercially viable.
PLA (Polylactic acid)
It is one of the most successful and commercially viable bio-based and biodegradable polymers for the sustainable packaging industry so far. It was being marketed commercially since 2012 by Natureworks. Currently, there are commercial plants to manufacture PLA worldwide and being used in the sustainable packaging industry significantly. It can be seen in food packaging, carry bags, medical textile/product, 3D printing, etc. and requires an industrial composting facility for adequate end of life scenario. Industry and research institutes are claiming the technological development for PLA recycling, but not yet seen in the market. Commercial technology to convert sugar into PLA is also available as a turnkey solution by a few industry expert.
Figure 1 PLA products
Starch has been used in most of the sustainable packaging applications, as it is easily available in various renewable resources like corn, tapioca, potato, etc. and cost-effective. In addition, its better thermal processability and plasticization make it suitable for processing. It can also be blended with other polymers and/or biopolymers. The starch-based packaging product are mostly water-soluble, that limits the packaging applications where moisture is present. Mostly, it can be seen in extrusion/blown films like, carry bags and very few in other packaging applications.
Figure 2 Starch-based carry bag
Bio-PBS (Poly Butylene succinate)
It is a bio-based and biodegradable polymer and can be used in food packaging like, disposable tableware, paper cups and gas barrier packaging. It has high compatibility with fiber, one of the best examples is the PLA-PBS blend used to manufacture nonwoven fabric. Moreover, improved properties can be achieved by blending different biopolymers and building the desired compound. Only one company has successfully commercialised bio-PBS into the market so far and still developing various products of it.
Figure 3 Bio-PBS products
Bio-PET (Polyethylene Terephthalate)
Bio-PET has similar mechanical and chemical properties as petrochemical-based PET. Sourcing it from bio-based feedstock makes it more sustainable and lower carbon footprint due to renewable carbon content. Though, it needs to be recycled adequately for a sustainable end of life scenario. Currently, petrochemical based PET has wider use in food and beverage packaging, although being criticized heavily for creating plastic pollution.
Figure 4 Bio-PET bottle
PHA (Polyhydroxy alkenoates)
It is a natural bio-based and biodegradable polymer, produced from bacterial fermentation. It is used for biomedical applications and food packaging widely. Limitation on fermentation polymerization scale-up to large commercial scale has made it less popular in biopolymer packaging industries. Though the development on the technology to manufacture it commercially has been ongoing by research institutes and industries. There are some medium to small scale commercial plant of PHA and products are available in the market.
Figure 5 PHA products
At present, the biopolymer industry is on the developing stage and growing rapidly. Innovations on the commercial-scale technology have been coming briskly. End of life scenarios like adequate plastic waste segregation, collection and industrial composting facility are being developed. Environmental predicament forces government and large corporates to divert towards sustainable solutions, gives the motivation to invest in sustainable packaging solutions and biopolymers research & development. No one can deny that the future of the packaging industry will be in the hand of biopolymers only.