Used coffee grounds, plastic waste from the ocean, cork and car seats are all materials used to make eco-friendly fashion showcasing at a trade fair in Berlin.

Sustainable fashion trade fair Neonyt is taking place from 14 – 16 January on the sidelines of Berlin Fashion Week.

More than 210 brands came to the disused Tempelhof airport in the center of the German capital to show their products to the environmentally conscious.

Jackets made from recycled plastics found in the ocean, shoes made from used car seats and t-shirts made with coffee grounds are only some of the hundreds of products on show.

The companies and brands, which all need to be certified as sustainable, hope to provide alternatives to the mainstream fashion world.

One company attending the fair is Ecoalf which was founded in Spain in 2013 and now has over 70 stores worldwide.

Ecoalf's jackets, just one of their products, are made from plastic waste that has been taken out of the sea off the coast of Spain.

"There is so much plastic in the seas, especially on the coast of Spain, so we said that this needs to be removed somehow," Niels Garbe, director of communications at Ecoalf, told the Associated Press (AP).

"Normally the fishermen would go out and then they would throw the plastic back that was caught in their nets. But we started paying them for it instead. And the plastic is turned in to yarn and the yarn is turned in to clothes," Garbe explains.

German high-end fashion company Like a Bird is another brand grabbing attention with its use of unusual waste materials.

The company's new product is a T-shirt made with a mix of cotton and fiber from coffee ground. 

"The coffee carbon fiber is a waste material from the coffee industry that has been processed," Tanja Kliewe-Meyer, founder of Like a Bird, told AP.

"The special thing about it is that it has a natural UV protection. It acts like a deodorant. And it protects the skin. And of course, it is recyclable which is very important for us," Kliewe-Meyer said.

Another unusual material used to create sustainable fashion was showcased by Portuguese company Steelground.

Steelground showed footwear that was made using textiles from car seats. 

"Why not use that? So, we need to use the waste that we make in all sorts of ways," says Linda Teles, Steelground sales manager.

Steelground also had footwear made from cork on display.

The mainstream fashion industry is often accused of not being environmentally friendly, with some designer brands coming under fire for their products' harmful effects on the environment as well as wildlife.

From the thousands of liters of water it takes to make a pair of jeans, to the carbon footprint of "fast fashion" - clothes that are made to last for a year or less - fashion is often considered to be an environmental problem.

According to a study by the Ellen Macarthur Foundation, the fashion and textiles industry has a larger carbon footprint than the airline industry.

But growing climate change activism globally, with demonstrations held in major cities across the globe, means that sustainable fashion is becoming mainstream.

"The whole Fridays For Future movement, the mindset of the generation that comes now is very different from the previous generation. There has been a huge step. Five years ago there was almost no interest. Now you can't avoid it," Ecoalf's Garbe said.