Tuesday, October 29, 2013

Water use and the textile business

I mentioned in my last post that the textile industry uses huge amounts of water. Because a large section of this blog is devoted to waterway pollution, I thought I'd explain that a little more detail, even though it's not directly linked to the microbe question.

What you see in the photograph is a digital textile printer that is being assembled right at this very moment. It represents a revolution that most people will never see or understand — but it is a very important one.

I can't tell you exactly where this printer is being installed, because it's privileged information, but I can tell you that it is in a foreign country — most textile business in the world is outside the US these days — and that the machine is costing its owner  $4 - 5 million in investment. Many of these new digital machines are now going into production.  Unlike everything that has ever been done in textile printing over the last several thousand years, these machines operate exactly like the computer printer you have at home. They just do it on fabric. This particular machine is one of the most advanced machines in the world, capable of printing king-sized sheet widths and operating at speeds of up to 75 m/m (that, FYI, is almost twice as fast as many of the high-tech rotary printing machines in the world today.)

 The machines can achieve resolution of imagery on fabric that rivals what you see printed on sheets of paper on a good laser printer. That is, the results are nothing short of incredible.

 So why is this a revolution? Besides, of course, the fact that the printing is of much higher quality than almost anything that has ever been achieved before on fabric.

Textile printing and finishing uses an enormous amount of water. Screens need to be loaded with ink before they are used, and washed clean between each printing run so that new ink colors can be introduced. The use of the water itself is  already a huge burden on the environment, because  the water has to be clean and, generally speaking, pH neutral (in other words, treated in order to be free of impurities) in order to be used. It is, in other words, probably at about the grade of drinking water, if not better. Water chemistry, after all, is pretty critical to fabric treatment and dyeing. If the water is off, technical processes can't be completed properly.

After the water is used, it needs to go through extensive water treatment to remove the chemicals that are introduced by the inks. 20 and 30 years ago, when I started my career, one routinely used to see the majority of this water runoff being discharged untreated into creeks and streams in Taiwan, Thailand, China, and other countries. The effects on the waterways were disastrous, to say the least; and the short-term gain that these countries realized by keeping prices low while ignoring environmental problems has been dramatically offset by long-term ecological disasters that the governments are now recognizing. Consequently, water treatment has become one of the major priorities and requirements for textile businesses in almost every nation.

Textiles has always been water intensive; but one of the counterintuitive developments in the textile business over the last 20 years has been the development of huge, staggeringly expensive textile industries in countries such as Pakistan, which is already water challenge. The contradictions in situations like this are glaring, and US consumers are generally unaware of the fact that the garments and sheets they are wearing and using are being produced at the expense of water resources everywhere.

The good news is that the digital textile printer is going to eliminate the need for many screens and constant interchanges. The technicians of the factory words being installed told me they estimate it will reduce water usage associated with a printing end of the business by about 80%. This is an enormous advance. Finishing processes, of course, will still need a lot of water — fabrics need to be  bleached before they are printed, and steamed afterwords. But because the bleaching process involves a more limited range of chemistry than the pigment and ink process, water treatment efforts can be more focused and effective, since the plants can narrow the range of their treatment to the finishing chemistry.

Printing machines of this kind will come to dominate the textile industry within the next 20 years, revolutionizing the way in which textiles are produced. There will be a great many other implications for consumers following this revolution, but I won't go into it here. I just wanted to let readers know that there are people out there that are thinking about ways to change our macroscopic impact on water resources, and that some of them are being successful.

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