VOA常速英语:Automakers Turn Agro-Waste into Car Parts

Scientists in Brazil are turning fruit fibers into car parts. At a recent meeting of the American Chemical Society, the researchers described their work in making the next generation of automotive parts made from natural fibers from bananas, pineapples and other tropical fruits.

The laboratory that Alcides Leao runs at Sao Paulo State University sees value in such agro-waste waste. "We extract the fibers from the leaves or trunk, and then we separate the cellulose from the other plant components. So basically cellulose is the key raw material." 

This cellulose mixture is used as a bio-based, not petroleum-based plastic for car parts.  While the idea has been around since the early 1990s and championed by Toyota, what’s new in the Sao Paulo lab is the scale. Leaves and stems of bananas, pineapples and other fruit with tough skins are put into a device similar to a pressure cooker. 

Leao says chemicals are added and the result is a fine material that resembles talcum powder. "Basically we are using a very simple process similar to pulp and paper where we are able to go over and over in several cycles. We are able to move from micro-scale to nano-scale" or down to the molecular level.

It is costly - less than one-half kilo of nano-cellulose is needed to produce 45 kilos of super-strong light weight plastic material. However, the nano-cellulose-reinforced plastic is 30 percent lighter and as much as four times stronger than petroleum-based plastic and easily matches carbon fiber and fiberglass. 

Leao says it makes the car more durable, fuel efficient and eco-friendly. "Before it was 50 percent non-biodegradable, non-renewable, that was the plastic based on oil and now we end up with 100 percent bio-degradable, bio-renewable material."

The nano-reinforced plastics have other advantages over conventional plastics including greater resistance to damage from heat, water and spilled gasoline. Leao expects nano-fiber- reinforced car parts to reach the market within two years. He also predicts the product could someday replace steel and aluminum.