This photo shows a woman handling dishes made from bamboo and waste from the food industry. Photo credit: Ruby Wallau / Northeastern University
Scientists have designed a set of “green” crockery made of sugar cane and bamboo that does not compromise comfort or functionality and could serve as a possible alternative to plastic cups and other disposable plastic containers. Unlike traditional plastics or biodegradable polymers, which can take up to 450 years to break down or require high temperatures to break down, this non-toxic, environmentally friendly material only takes 60 days to break down and is clean enough to keep your morning coffee folder to go . This plastic alternative will be presented in the magazine on November 12, 2020 matter.
This photo shows a mug made from biodegradable materials. Photo credit: Liu et al
“To be honest, when I first came to the US in 2007, I was shocked by the one-off plastic containers available in the supermarket,” says Northeastern University writer Hongli (Julie) Zhu. “It makes our lives easier, but in the meantime it becomes waste that cannot decompose in the environment.” Later, at seminars and parties, she saw many more plastic bowls, plates and utensils thrown in the trash can and thought: “Can we use a more sustainable material?”
To find an alternative to plastic-based food containers, Zhu and her colleagues turned to bamboo and one of the food industry’s largest waste products: bagasse, also known as sugarcane pulp. The team wrapped long and thin bamboo fibers with short and thick bagasse fibers to form a tight network and formed containers from the two materials that were mechanically stable and biodegradable. Not only are the new green dishes strong enough to hold liquids like plastic and cleaner than biodegradable fabrics made from recycled materials that may not be completely discolored, but they also begin to decompose in the soil after 30-45 days and lose its completely Form after 60 days.
“Making food containers is a challenge. It takes more than being biodegradable, ”said Zhu. “On the one hand, we need a material that is safe for food. On the other hand, the container must have good mechanical wet strength and be very clean since the container is used for holding hot coffee and hot lunch. ”
This picture shows the decomposition of the biodegradable dishes over 60 days. Photo credit: Liu et al
The researchers added alkyl ketene dimer (AKD), an environmentally friendly chemical widely used in the food industry, to increase the oil and water resistance of the molded dishes and ensure the product is robust when wet. With the addition of this ingredient, the new crockery outperformed commercially available biodegradable food containers such as other bagasse-based crockery and egg cartons in terms of mechanical strength, fat resistance and non-toxicity.
The dishes developed by the researchers have another advantage: a significantly lower CO2 footprint. The manufacturing process of the new product emits 97% less CO2 than commercially available plastic containers and 65% less CO2 than paper products and biodegradable plastic. The next step for the team is to make the manufacturing process more energy efficient and cut costs even further to compete with plastic. Although the cost of cups made from the new material ($ 2,333 / ton) is twice that of biodegradable plastic ($ 4,750 / ton), traditional plastic cups are still slightly cheaper ($ 2,177 / ton).
“It is difficult to ban people from using disposable containers because it is cheap and convenient,” says Zhu. “But I think one of the good solutions is to use more sustainable materials and use biodegradable materials to make these containers for single use.”
Reference: November 12, 2020, matter.
DOI: 10.1016 / j.matt.2020.10.004
