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Too good to be true? This plastic made from corn could solve the plastic waste crisis

Too good to be true? This plastic made from corn could solve the plastic waste crisis Polylactide, known as PLA, is a fully biodegradable plastic substitute that''s made using fermented plant starch, usually from corn. It can be used to wrap vegetables, and be turned into cups for cold drinks. Afterward, it can be turned into fertilizer. Environmentalists tout the use of PLA as a way to cut plastic pollution and to lower greenhouse gas emissions. But this bioplastic is far from being a truly green solution. Our Sunday special report. ##A thin film is rolled up and inserted into the machine. After it''s heated, the material is cooled quickly and pressed into the shape of a cup. One machine can produce 300,000 cups a day. Seventy percent of these cups made with PLA are sold to Europe and the U.S., where markets are hungry for eco-friendly solutions.Su Kuo-tseEPA waste departmentPLA is one of those materials we spoke of, one of those biodegradable materials. It''s a replacement for petroleum-based materials. It is relatively environmentally friendly. PLA is made with plant starch, such as starch from corn. PLA pellets can be used to make bags and containers. Via the industrial composting process, PLA packaging can be fully broken down and used to fertilize plants.Chen Ming-chunResearcherBecause PLA is highly biocompatible, its earliest application was in medical equipment. Taiwan does not produce its own PLA. Most of the PLA used to make bags is imported from the U.S.Chen Ming-chunResearcherAs for where the finished product goes, the ratio is roughly seven to three. That is to say, 70 percent is exported. About 30 percent is used domestically, primarily to make egg containers and other packaging for fresh foods.Currently about 90 percent of PLA packaging is used for cold beverages and fresh produce. This is because PLA plastics are not resistant to heat. Pan Wei-chihPlastics supplierThis cup over here is made from polypropylene. It can withstand temperatures up to 100 degrees Celsius. Now on the left is a cup made from PLA, which can withstand up to 54 degrees Celsius. So when you pour hot water into the PLA cup, it turns soft instantly.PLA doesn''t just deform under high heat. It''s also very expensive.Lee Miao-lingSupermarket managerPLA bags are two to three times the price of standard plastic bags.In Taiwan, about 77 percent of products sold at grocery stores are packaged in plastic. Chang Kai-tingGreenpeaceThere is a certain need to have plastic packaging. It does provide an advantage in that it prolongs the freshness of food products, and it can reduce damage during transport. However, plastic packaging has one major problem - 95 percent of it is used only once.This problem is why one organic foods retail chain turned to PLA.Lee Miao-lingSupermarket managerWe thought we could completely replace all the plastic with PLA. But then we found that PLA as a material is not actually very breathable. In terms of its ability to ward off oxidation, PLA is actually not very good.Poor heat resistance and protective properties have hampered the adoption of PLA as a plastic substitute. Another major problem with PLA is their disposal.Lee Miao-lingSupermarket managerAfter the PLA bags are used … we discovered that recycling used bags was relatively difficult under the current waste management system.The Environmental Protection Administration classifies PLA as a category 7 recyclable plastic. However, given the low rate of PLA use, Taiwan has yet to establish any facilities to process recycled PLA. That means PLA ends up at recycling plants that deal with general plastic waste. PLA has to be separated out by hand, so that they don''t degrade the quality of processed plastic.Chen Ming-chunResearcherIf PLA gets into the recycling system for PET bottles, it will lower the quality of the processed PET and affect subsequent production processes.Studies show that PLA releases less carbon dioxide than other plastics when burned, although environments say that burning PLA is still not an ideal solution. PLA can be composted, but the EPA has not established a national system for composting PLA.Su Kuo-tseEPA waste departmentOther countries have gone the way of composting PLA. But in Taiwan, as you know, composting facilities are reviled.Unwilling to let PLA burn, managers at this supermarket set up a box to collect discarded bags and containers from customers.Lee Miao-lingSupermarket managerWe send the waste back to our supplier. We found a place where the bags can be composted and returned to the earth.PLA bags put through industrial composting break down into thin strips after only one month. Within three months, the PLA is no longer visible to the naked eye. At that point, the soil is ready to be used as fertilizer.They can also be used as fuel. These pellets were developed by the EPA as a way to add value to PLA waste.Su Kuo-tseEPA waste departmentWe can use it to make refuse-derived fuel pellets to be used in a...

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