BANGALORE: Narendra Modi may have never heard of Sidhant Pai , but if the young MIT graduate’s plans remain on track then the 21-year-old may unwittingly become an ally in the Indian prime minister’s push to clean up Indian cities. In the run up to the general election, Modi had made making Indian cities world-class one of his key poll promises. Along with impressive skyscrapers and airports, cleanliness is a common factor of all great cities.Which is where a startup like Pai’s Protoprint with its innovative solution to transform plastic waste into raw material for 3D printers makes a difference. The Pune-based startup, the first of its kind in India, has tied up with ragpickers who bring in waste they collect from various parts of the city to a site run by Protoprint.At the site, the plastic materials are segregated and fed into the FlakerBot, a machine built from scratch by Pai to shred the plastic. From there, the shredded plastic moves to the RefilBot, also built by Pai, which converts it into filaments that is used as raw material to print objects in a 3D printer.“We designed them (the machines) specifically to be low cost,” said Pai, who started up through grants and the fellowship money that he received, apart from his work on projects like building an affordable solar cell phone charger in Nicaragua and pedal powered butter churn in Tanzania during his first two years at Massachusetts Institute of Technology in the United States. “As an environmental engineer I wanted to bring technology to the masses.”Of the total investment of $110,000 in the startup, non-profit global investment firm Echoing Green put in about $80,000, said Pai. So far, different commercial 3D printers used filaments of various sizes as raw material. Pai is now trying to change this by standardising the sizes and quality of the filaments.Deepak Raj of Bangalore-based 3D printing design factory Df3d said there is a certain chemical composition that has to be met for a filament to work in a particular 3D printer, stressing on the difficulty in developing a standardised filament. “It’s very interesting how this (standardisation of filament) is being done. It is quite difficult,” said Raj.Protoprint is working as the first officially certified producer with UK-based charity organisation Techfortrade’s The Ethical Filament Foundation, an initiative that partners with organisations worldwide to aid the manufacturing of ethical 3D printer material from recycled plastic waste.Globally, there are a few precedents. While Italy-based Ewe Industries has developed a machine that turns any recycled plastic into filament, UK’s Omnidynamics recently raised £64,369 on crowdfunding platform Kickstarter to develop its filament maker.