The packaging industry is gradually shifting towards more sustainable packaging solutions, consisting mainly of bio-based and/or biodegradable materials. While this shift is necessary, it is critical to find a balance between environmental and economic aspects.
What are the major biodegradable plastic materials?
PLA, this aliphatic polyester is obtained from sugars such as corn starch, sugar beet or sugar cane. It is the oldest and best known biodegradable plastic and can be composted in industrial settings.
PHA, a polymer naturally produced by microorganisms, is 100% biodegradable and can be composted in homes and industries.PHA is formed primarily through injection molding.
PBAT, polybutylene terephthalate is a biodegradable polyester copolymer. Highly flexible, it is a very good candidate for replacing PE film packaging.
PBS/PBSA, is also a polyester. While it has long been made from petroleum-sourced materials, current PBS is typically 50 percent bio-based and mostly compostable.
PBSA, or polybutylene succinate adipate, is 35% bio-based, very flexible and biodegradable.
Other materials and innovations, other materials exist, including starch-based compounds, cellulose and biofibers.
Most biodegradable polymers on the market are certified as biodegradable in thin products, about 100 microns thick, with some manufacturers reaching one millimeter in standardized tests for home composting, but not certified. Fortunately, this biodegradation can be accelerated by adding additives, including enzymes and bacteria, or by blending the material with biodegradable polymers such as CareTips® resins.
Biodegradable polymers: more expensive than traditional plastics
According to Polyvia data, polyethylene prices for October 2023 are as follows.
LDPE: €1.55 to €1.65/kg
HDPE: €1.60 to €1.70/kg
LLDPE: €1.75 to €1.90/kg
Comparing these figures with the price of bioplastics, we can see that BioPE is at least twice as expensive as HDPE or LDPE, and the price difference between PHA and PBS reaches a factor of five.
What are the financial constraints for manufacturers of biodegradable polymers?
Raw material costs - As mentioned earlier, the high cost of bioplastics does not encourage industrialists to use these materials. These costs are partly due to the use of more expensive raw materials such as starch, vegetable oils and sucrose. However, this is expected to improve due to innovation.
Costs of adapting production equipment - The production of bioplastics requires different manufacturing processes than traditional plastics, especially those involving the biotechnology sector. Adaptation of current processes requires investment and therefore imposes additional costs on industrialists.
How can biodegradable alternatives be promoted and made more profitable?
Economies of scale - this is one of the main levers to reduce the cost of biodegradable materials: accelerating production to realize economies of scale and increase the availability of these new materials. Things are expected to move in the right direction: according to Bioplastics Europe, the annual production capacity of bioplastics (whether bio-based or biodegradable) will triple by 2027.
Innovation in production - Innovation also plays an important role in reducing production costs. Thus, the emergence of new, simpler and more environmentally friendly production processes will lead to the availability of cheaper materials. Example: In the “classic” PLA manufacturing process, the propylene glycol ester used is synthesized in a two-step process, which is very expensive and generates a lot of waste. Two Belgians, Michiel Dusselier and Bert Sels, have developed a single-step PLA manufacturing method using a synthetic zeolite catalyst. This innovative process is less energy intensive and more economical in terms of raw materials and can reduce the total production cost of PLA by up to 30%. For the first time in the world, PLA is synthesized in one step with carbon dioxide, crossing over to propylene glycol!
Regulatory developments - Current European regulations tend to favor recycling, which has slowed the emergence of biodegradable solutions. However, given the projected explosion in global plastic consumption, the growth of biodegradable polymers seems inevitable. Biodegradable polymer biowaste collection bags: application approved by ADEME. Several European countries have implemented the collection of biowaste, of which France has been part since January 1, 2024. In terms of collection, Italy is a leader in this field, opting for biodegradable plastic bags.
In France, ADEME also considers this solution to be relevant if it “contributes to increasing the amount of valuable biowaste and does not interrupt waste treatment channels”.
Conclude
The availability of biodegradable materials is increasing and new innovations will continue to emerge in the coming years. However, their adoption by industrialists will depend on their accessibility in terms of economic and production capacity.
Faced with the risk of scarcity or rising costs, professionals in the packaging industry also need to show resilience, especially by integrating the use of multiple materials into their processes.
