Difference between revisions of "Team:UChile-OpenBio/Practices"

When we presented our project, Andres Briceño agreeded that although prices can vary a lot according to the country of origin, it is expensive to buy PLA. He added that if we could demonstrate our fabrication process is cheaper than the current ones, the project would turn very attractive for many digital fabrication laboratories, for he gave us his support at the end of the visit, sending us another letter of inquiry.

Discussion about the impacts of PLA production

In order to evaluate those impacts, the positive and negatives ones, we met with Claudia Mac Lean, in charge of the Sustainability Office of the Faculty. She made us present our project to her pupils in the context of a Sustainable Project Workshop and she gave us some pieces of advice, like developping a Life Cycle Assessment analysis or asking us the functionality of our plastic; will it be used for every kind of plastic objects? What consequences could have such a production? This was useful to wonder, for example:

We infer PLA can be degraded into lactate, which could enter into the metabolic cycle of anaerobic bacteria, generating CH4 (methane) and/or CO2[2] . Environments without oxygen could be found in typical landfills, so in a hypothetical situation where PLA would be established in our society (it means PLA would have totally replaced plastic from fossil origin), huge amounts of PLA could worsen the global warming (due to greenhouse gases emissions)[3] . Nevertheless, a controlled degradation of PLA would allow to take advantage of CH4 generation by producing energy from its combustion and would help to reduce the effects of climate change[4]. If we implemented our project in the long term we would promote cultivation of macroalgae which could contribute to economic development of Chile. Also, macroalgae don’t require any farmland, fertilizer or fresh water and is a renewable resource, so it is a better alternative than corn cultivation (which is one of the main current production modes). Nevertheless, the Chilean regulation of macroalgae uses should be constantly checked to avoid overexploitation and imbalance of natural ecosystem where macroalgae live.

On the other hand, the big problem of fossil plastic is its accumulation[5] . For example, if we suppose a constant production of the same amount of PLA and PET (a fossil plastic), after 5 years, higher amounts of PET would b expected to be found because a percentage of PLA should be degraded in the first two years[5] . But if PLA had a short degradation time, we guess people would replace it more frequently by buying more PA products, so higher amounts of PLA could be thrown away and the accumulation rate would increase. We think the trade off between replacing fossil plastics and avoiding an overproduction of PLA should need further analysis to evaluate the real impact of the PLA production process. According to the previous reflection, we recommend to use PLA for products which will have a short life-time (<2 years), for example plastic cups or bags. On the contrary, for long life-time products such as pipes, chairs or big structures, it would be appropriate to keep using fossil plastics. On the particular case of medical use, we think PLA should be used like suture, because sutures need to be degraded in a short time. Moreover, the degradation would have no nefast consequences on the organism as PLA is a biocompatible material.[6]