As with so many things, chance played a part in the invention of the raincoat. Charles Macintosh was looking for a use for gas works waste products. Then the Scottish chemist noticed that coal tar naphtha dissolves rubber. He took a woolen cloth, smeared one side with the rubber compound, and laid another layer of wool on top – and the result was a waterproof fabric perfect for raincoats.
It’s been 200 years since Macintosh filed his patent number 4804: He claimed the rights to his method of “manufacturing to make the texture of hemp, flax, wool, cotton, silk as well as leather, paper and other substances impermeable to water and air make.” The “Mac” was born. Because Macintosh’s name – over the years with a “k” added to “Mackintosh” – became synonymous with a rain jacket. Later, British soldiers, police officers and railway workers also wore rubberized coats.
Pioneering for the industrial age
The idea of gluing two layers of cotton to a layer of rainproof rubber pioneered production in the industrial age. The “Mackintosh” was by no means the first water-repellent piece of clothing. Southeast Asian peasants wore coats and wide-brimmed hats woven from coconut palm leaves or straw, while European sailors soaked their canvas clothing in linseed oil. The rubberized coat, however, caught on in the 19th and 20th centuries.
In Germany in the 1970s and 1980s, the yellow “Friesennerze” were part of the street scene on rainy days. The manufacturer was Jeantex, originally based in Denmark. Yellow raincoats from domestic production were sold in the GDR.
But rubber – whether natural or synthetic – is not breathable. “Sweat doesn’t get through a rubber coat,” explains Thomas Stegmaier, head of the Competence Center for Textile Chemistry, Environment and Energy at the German Institutes for Textile and Fiber Research in Denkendorf. “After a while, the person is quite damp or wet from their own sweat.” The challenge for the textile industry is that a water-repellent material should also be as breathable as possible.
As a rule, water-repellent finishes are required for the material in question, says Stegmaier. “These are very thin layers that are placed around the fibers.” Chemicals containing fluorine were used in the past, but are no longer used for environmental reasons. “Instead, these ultra-thin coatings are made on the basis of waxes and/or silicones. Depending on the recipe and design, these are more or less durable.” If such a piece of clothing is washed, the coating rubs off over time. “Even the best finishes for workwear can’t withstand more than 40 to 50 washes,” says Stegmaier.
Fluorine-containing substances for water-repellent impregnation are water, dirt and oil-repellent and are known by the acronym PFC – polyfluorinated chemical. “But these are harmful to health, carcinogenic and accumulate in nature,” says a spokeswoman for Vaude, one of the well-known German manufacturers of outdoor clothing. Vaude – and also some other manufacturers – are therefore now doing without impregnation with PFC, company boss Antje von Dewitz is one of the best-known advocates of environmentally friendly textile production in the industry.
Goretex played a key role
The US chemical company Gore played a key role in the development of both waterproof and breathable textiles. In the 1970s, they developed a technology that was widely used under the name Goretex, especially in workwear, hiking and mountaineering clothing. Robert Gore and his collaborators invented a membrane with tiny openings that are vapor permeable but smaller than the smallest drop of water. The membrane is inserted into a textile laminate.
However, outdoor clothing manufacturers also usually impregnate such textile laminates against moisture from the outside. Just as a duck oils its feathers, the owners have to re-impregnate their clothes from time to time. Otherwise, despite the protective membrane, the fabric will become soaked in heavy or continuous rain.
Durability issues notwithstanding, these modern water-resistant textiles eventually prevailed over rubber coats. Although the Macintosh company still makes the famous coats, they have modernized their range. In Germany, the Friesennerz has largely disappeared from the streets, the former manufacturer Jeantex ceased operations years ago. (dpa)