We know that single-use plastics are detrimental for our planet and science has been focused to create viable alternatives. Research and many studies have been undergone to produce reusable options and improve the recycling process. Many cities and counties have banned plastic bags at supermarkets, shops, and other consumer establishments, trading them in for the popular paper bag. Even though paper bags are a better alternative to plastic, they need to be used multiple times over in order to fulfill its lifespan and counteract its waste potential, but they are low in durability especially when wet. Recently, a credible study conducted by researchers at Penn State recorded a new process which makes paper bags stronger and more durable, leading to another potential alternative to plastic.
"By switching to stronger, reusable paper shopping bags, we could eliminate much of that waste. The implications of a technology like the one we demonstrated in this research -- if it can be perfected -- including using the worn-out bags as a substrate for biofuel production, would be huge," stated Tripathi.
Lead researcher, Jaya Tripathi, believes that the lifespan and reuse of any bag is manipulated by its strength. Paper bags have a lower lifespan due to its deterioration upon contact with any liquid. In order to increase a bag's durability and strength, heavy chemical processes need to occur, but these processes are normally not eco-friendly, not cost effective, and can release hazardous toxins when recycled or broken down in landfills. Tripathi believes that exploring non-chemical options for increasing its strength when wet can be done, and using ‘torrefaction’ is one of the main ways.
Torrefaction is the slow heating, or thermal, pretreatment process that reduces the water content in biomass, in turn leaving a more solidified and uniformly composed product. This process is extremely popular in recycling processes and the manufacturing industry has seen an increase in the usage of this procedure. In relation to paper bags, Tripathi conducted multiple experiments using this process–the process of torrefaction decreased the glucose yield within the raw sheets of paper, in turn decreasing its durability, but she found that by treating the torrefied samples with alkaline sodium hydroxide, the glucose yield increased all while keeping the moisture at an all time low. This accidental finding has increased their viable studies and their hope in creating more durable alternatives that can be used in the packaging and consumer industry.
"I was looking into something else, studying how torrefaction impacts cellulose for glucose yield for use as a biofuel substrate. But I noticed that the paper's strength was increasing as we torrefied the cellulose. That made me think that it probably would be good for packaging, an entirely different application," concluded Tripathi.