Plastics in action: The Invention of Rainwear

18,000 invisible guards per square centimeter

It's familiar: it's drizzling in the morning, you grab your rain jacket or raincoat. After eight hours of commuting, meetings and errands, you're still dry - and not just on the outside. No clammy skin, no sweating. But how exactly does this actually work?

The answer lies in the textile coating or membrane: a Gore-Tex membrane in a modern rain jacket has around 1.3 billion microscopically small pores per square centimeter. Each one is 20,000 times smaller than a raindrop, but 700 times larger than a water vapor molecule. This is not magic - this is material science. And there is a 200-year history of chemistry behind it, in which foul-smelling tar was turned into high-tech textiles.

Scotland, early 19th century. The Scottish physician and chemist Sir James Syme experimented with dye production and obtained a by-product from coal gasification: Coal Tar Naphtha, a solvent that does not mix with water. This substance aroused the interest of Charles Macintosh, a chemist from Glasgow. He saw the potential: rubber can be dissolved in Coal Tar Naphtha - and this in turn can be applied to cotton fabric. Combined with two layers of fabric, the result was a waterproof material - the basis for the first functional raincoat. Macintosh patented his method in 1823.

The price? Today we would call it a designer piece. Which is surprising when you consider the smell. Because it was pungently chemical and tar-like. Not for sensitive noses. Did it detract from its popularity? No, the demand was enormous - especially among the British army.

It was the American Charles Goodyear who solved the odour problem: by treating natural rubber with sulphur - known as vulcanization - he made it suitable for everyday use. Elastic, durable, and you could wear it without passers-by changing sides of the street. Today, we tend to think of car tires when we hear the name Goodyear. You can read here in K-Mag why vulcanization was also an accidental find.

Fast forward to the 1970s: the bright yellow, so-called “Friesennerz” becomes a cult item in northern Germany. PVC on polyester - practical, robust, highly visible. Not only fishermen wore them, but also city dwellers and children. The problem? After an hour of cycling, you're swimming in your own juice. The simple logic behind it: What doesn't let rain through from the outside doesn't let sweat out from the inside either.

The solution came from space travel. Well, almost. In 1969, a chemist named Robert W. Gore (that's right, the guy from Gore-Tex) accidentally developed a material that changed everything: expanded polytetrafluoroethylene (ePTFE). He stretched PTFE so much that a structure with billions of tiny pores was created.

The result? A membrane that doesn't let water through, but lets water vapor (i.e. sweat) out. For the first time, it stayed nice and dry under a rain jacket or coat.

Modern rain jackets are sandwich constructions with several layers:

• Outer fabric: usually polyamide (nylon) or polyester - robust and lightweight. A DWR (“Durable Water Repellent”) coating sits on top, which allows water to roll off like on a lotus flower.
• The membrane: the centerpiece. Polyurethane (PU), thermoplastic polyurethane (TPU) or the aforementioned ePFTE with microscopic pores. The choice today is huge.
• Inner lining: Protects the membrane and transports moisture to the outside. Often made of polyester or nylon, sometimes also cotton.

“Is it sustainable?” - The question hangs over the entire outdoor industry like a storm cloud. The honest answer: it's getting better, but it remains complicated.

The good news:

• Many manufacturers now use recycled polyester. Your new jacket? It might be made from 15 old water bottles.
• PFC-free impregnations are on the rise. The old perfluorinated and polyfluorinated chemicals - practically indestructible and bioaccumulative - are slowly disappearing from products. Look out for the label: “PFOA-free” or “PFC-free”
• Quality pays off: A good rain jacket lasts 10+ years. This is circular economy in practice.

The bad news:

• Microplastic fibers dissolve during washing. This can amount to hundreds of thousands of particles per wash cycle, which end up in the wastewater.
• Recycling remains difficult: multi-layer composites can hardly be separated by type.

What you can do: Use wash bags against microplastics (filter up to 90% of the fibers), wash less often (airing is often enough), and pay attention to repairability when buying.

Work is already underway in laboratories around the world:

• Self-cleaning surfaces based on beetle armor that repel dirt and water in equal measure
• Adaptive textiles that self-regulate their breathability depending on temperature and humidity

Research is focused on developing membranes from renewable raw materials that offer the same performance as materials already in use.

Next time you cycle to work in the fall rain and arrive dry - think about this for a moment: a piece of scientific history lies on your shoulders.

Synthetic products have revolutionized weather protection. Not despite, but because of their unique properties. The challenge for the next 200 years? To combine this functionality with ecological responsibility.

Textile technology, polymer chemistry, materials science - the plastics industry is looking for creative minds who can combine functionality and sustainability. At the K trade fair, you can find out about training and study opportunities and talk to professionals from the industry. Click here for the Young Talents of the K trade fair!

Who knows - maybe you will develop the first completely compostable high-tech membrane. The industry is waiting for you.

This article was created with additional AI tools.