The lightweight plastic carrier bag made headlines across the globe during 2008 – but, unfortunately, for the wrong reasons. Far from being recognised as an example of engineering genius, the T-shirt carrier bag has been vilified. And not for what it does, but for what people do not do with it; use it and dispose of it responsibly.
Thankfully, criticism of the lightweight carrier bag has been directed at the invention rather than the inventor. It is unlikely that Sten Gustaf Thulin had environmental harm in mind at the beginning of the 1960s when he came up with his idea for forming a simple one-piece bag by folding, welding and die-cutting a flat tube of plastic. Far more likely, the Swedish engineer saw his new idea freeing the planet from the environmental cost of paper production.
Sten Gustaf Thulin’s concept yielded a simple, strong bag with a high load carrying capacity. It was patented in 1965 by Celloplast, a long-standing producer of cellulose film based in Norrkoping, in Sweden, and a pioneer in plastics processing.
Celloplast’s patent position gave it a virtual monopoly and the company set up manufacturing plants across Europe and in the US. However, others saw the attraction of the bag, too, and US petrochemicals group Mobil overturned the Celloplast US patent in 1977.
The Celloplast business went into decline and was split up during the 1990s, with the Norrkoping site now the headquarters of Miljösäck, Sweden’s largest producer of waste sacks from recycled PE.