Find out about the importance of 3D printers with recycled plastic filament and houses made of inputs like bamboo for a future in which circular economy prevails

The periodic table contains 118 chemical elements that comprise everything that we, human beings, have seen or touched. However, only four are present in living body molecules: Hydrogen (H), Carbon (C), Nitrogen (N) and Oxygen (O). More rarely, though equally important, are Sulfur (S) and Phosphorous (P). All human beings are born, grow, reproduce and die. When life ends, all elements that constitute us are rapidly absorbed by nature, which reinserts them into a cycle that repeats itself, infinitely, neither creating nor destroying matter.

That is the rationale that guides the circular economy principles. The idea is to emulate nature’s efficiency in the supply chain of goods and services. And, to a growing number of experts, plastic 3D-printing and initiatives in biomimicry are the greatest symbols of the circular economy.

See below some examples showing how plastic 3D-printing and biomimicry are vital to the circular future.

Plastic as a 3D printer key element

Humanity has produced over 8.5 billion tons of plastic, and its output keeps growing. Currently, it’s at 335 million new tons every year. As a cheap, versatile and ease of recycling material, plastic has the ideal characteristics to be the input of 3D printers – and, consequently, the revolution generated by the circular economy.

What is a 3D printer

Three-dimensional printers are devices that can print new objects in three dimensions from a two-dimension digital project. Unlike a regular printer, which prints into paper in two dimensions, a 3D printer uses space. That means it can print car parts, for example, among other objects.

In this sense, plastic is, to a 3D printer and new production processes, what carbon is to nature and human beings. They are abundant materials, quickly used, uncomplicated and easily recyclable.  

The logics is simple: plastic is produced on a large scale, and disposed of on a large scale. With an accurate destination, this disposed material can be rapidly reconditioned and become a filament for 3D printers. Gregory Unruh, a professor at George Mason University, in the United States, and one of the main experts in the subject, points out that circular economy will be the next prevailing model in production and consumption of goods, and its management will be based, in large scale, on 3D printer and biomimicry techniques.

Impressora 3D. Crédito: Ines Alvarez/Unsplash

In this sense, a study on domestic waste collected in London estimated that, annually, the capital of England could recover 80 thousand tons of PET plastic for 3D printing. That would generate annual savings of US$ 12.2 million in London’s waste treatment and would supply London’s entire three-dimensional printer industry.

Joshua Pearce, professor and engineer of Michigan Tech, in the United States, and one of the leaders of project RepRap, whose goal is to develop cheap 3D printers, endorses it. According to him, by combining open-source software and low-cost equipment and recycled plastic filaments, “it is very easy to show the economy [with this new technology] for high-end products”.

According to experts’ estimates, with a software license for 3D printing costing about US$ 500 and other US$ 500 or US$ 1,000 for a printer, it’s easy to start producing with potential for greater economic impact and smaller environmental impact. Today, one kilogram of 3D filament costs about US$ 25 to US$ 50, while a ton of recycled plastic costs about US$ 45 to US$ 425.

“If you buy commercial plastic pellets to create your filament, it’s $5 per kilogram. But if you recycle your prints or use waste plastics, the price goes down to about 10 cents per kilogram! Economics like that are hard to beat, even with the scale economies of giant industrial production plants,” says Unruh.

Plastic cars and 3D printer

In 2018 alone, more than ten car makers announced concrete plans or projects to make cars using 3D printers. And their composition is, mostly, plastic. Some vehicles, like the LM3D Swim, by Local Motors, have 80% of its structure made of that material. According to the company, the other 20% are of carbon fiber. The first electric-powered model was made in 2017 and that car is expected to cost about US$ 53.000.

Besides LM3D, Local Motors also makes another vehicle, the company’s main bet for the updated version: Olli. Designed for shared use, Olli is a smart self-driven vehicle, meaning, it transports passengers without any human interaction – other than showing the destination. Olli will soon start running in the streets of Copenhagen and Las Vegas on a trial basis.

Very soon, European capitals will see plastic-made vehicles. A joint creation by companies Polymaker, from China, and XEV, from Italy, the LSEV appears as a real possibility for cars made in large scale with 3D printers. The vehicle is already a hit: more than 7 thousand units have been ordered. Its small size, light weight and low power consumption requirements make it attractive to buyers, with a speed limit of about 70 km/h and autonomy of 145 km.

To reach LSEV’s final version, Polymaker developed hundreds of types of plastic which, when combined, sustain the car design. Despite being a difficult process, the production of this vehicle takes just a fraction of time usually required by the conventional car industry: R&D process for a model takes about 3-5 years, but only 3-12 months to finish a new XEV design. Each unit requires only three days of printing, and will reach consumers for about US$ 7.5 thousand.

In building, bamboo is the revolution

Cement production accounts for about 5% of all the planet’s greenhouse gas emissions. In Brazil, each ton of produced cement is equivalent to 600 kg of CO2 released into the atmosphere – and the global average is even higher, 900 kg of CO2 by ton of produced cement. Therefore, finding an alternative for the product is helping to combat climate changes in a meaningful sense.

Again, the solution may lie in observing and emulating nature.

Over 40 years ago, Khosrow Ghavami, emeritus from PUC-Rio (Pontifical Catholic University), noticed the need for seeking unusual materials and technologies for the building industry and developed researches on natural fibers, unploughed land, recyclable materials and sugar cane bagasse, among others. Bamboo leads the ranking for these materials.

Ponte produzida de bambu. Crédito: Dil/Unsplash

“Bamboo has a low cost, high productivity, good mechanical resistance (especially traction resistance), and low energy consumption during production when compared to conventional materials, like steel,” says Ghavami. “Energy consumption during bamboo production is fifty times higher than the consumption of energy during steel production,” says Ghavami.

Bamboo has, in its favor, the fact that it is produced by photosynthetic processes – which fixate carbon through chemical reactions triggered by solar energy -, in addition to a stable structure. It is also light and has an efficient mechanical resistance three years after sprouting, making it highly productive. According to estimates by the Associação Brasileira de Materiais e Tecnologias Não Convencionais (Brazilian Association of Unconventional Materials and Technologies), replacing conventional cement with bamboo may reduce the cost of building by 30%.

No wonder, in 2011, Act 12,484 was enacted in Brazil, which created the National Policy on incentives for Sustainable Bamboo Cultivation and Management. The goal was to encourage the use of this material.

Three emblematic projects made of bamboo

In Brazil, it was used in Santos Dumont’s 14 Bis, and it is a common tool in buildings. It is also largely used worldwide. Check three examples of bamboo works that impress by their size, resistance and durability.

The bamboo bridge that holds 90 tons

In the Chinese province of Hunan, for example, in ten days, a 3.4-meter width bridge with capacity to hold up to 90 tons was built. That was in 2007 – the bridge is still there and its useful life is estimated in more 18 years.

The 2 thousand-square meter factory

Bali island, in Indonesia, has the largest bamboo construction of all time. The “bamboo cathedral” is, in fact, a chocolate three-story factory within a space of more than 2 thousand square meters amidst paddy fields and palm trees. “Each cane is worth three dollars” told Benjamin Ripple, one of the Big Tree Farms owners, to EFE agency at the opening, in 2012. “Definitively, building with bamboo is way cheaper than any other material. It’s one of the most ecological components for construction ever,” he says.

The Colombian bamboo cathedral

Nave central da Catedral Alterna Nuestra Señora de la Pobreza. Crédito: Javier Herrera Zuñiga/Wikimedia Commons

Even true architecture masterpieces can be made out of bamboo. In the city of Pereira, in Colombia, lies the shrine Catedral Alterna Nuestra Senora de la Pobreza (Our Lady of Poverty Cathedral). Signed by highly praised architect Simón Vélez, the construction withstood a strong earthquake, in 1999, which damaged more than 50 thousand constructions in the region.

Content published in March 19, 2019

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