Beyond natural fibers

11 07 2012

It looks like the plastic bottle is here to stay, despite publicity about bisphenol A and other chemicals that may leach into liquids inside the bottle. The amount of plastic used to make the bottles is so enormous that estimates of total amount of plastic used is staggering. Earth911.com says that over 2,456 million pounds of PET was available for recycling in the United States in 2009. Any way you look at it, that’s a lot of bottles.
Those bottles exist – they’re not going away, except perhaps to the landfill. So shouldn’t we be able to use them somehow?
We have already posted blogs about plastics (especially recycled plastics) last year ( to read them, click here, here, and here ) so you know where we stand on the use of plastics in fabrics. All in all, plastic recycling is not what it’s touted to be. Even if recycled under the best of conditions, a plastic bottle or margarine tub will probably have only one additional life. Since it can’t be made into another food container, your Snapple bottle will become a “durable good,” such as carpet or fiberfill for a jacket. Your milk bottle will become a plastic toy or the outer casing on a cell phone. Those things, in turn, will eventually be thrown away.
So the reality is that polyester bottles exist, and using them any way we can before sending them to the landfill will prevent the use of more crude oil, which we’re trying to wean ourselves from, right? Recycling some of them into fiber seems to be a better use for the bottles than land filling them.
Plastic bottles (the kind that had been used for some kind of consumer product) are the feedstock for what is known as “post-consumer recycled polyester”. Even though plastic recycling appears to fall far short of its promise, recycled polyester, also called rPET, is now accepted as a “sustainable” product in the textile market, because it’s a message that can be easily understood by consumers – and polyester is much cheaper than natural fibers. So manufacturers, in their own best interest, have promoted “recycled polyester” as the sustainable wonder fabric, which has achieved pride of place as a green textile option in interiors.
Recycled post consumer polyester is made from bottles – which have been collected, sorted by hand, and then melted down and formed into chips, sometimes called flakes. These chips or flakes are then sent to the yarn spinning mills, where they’re melted down, often mixed with virgin polyester, and and spun into yarn, which is why you’ll often see a fabric that claims it’s made of 30% post consumer polyester and 70% virgin polyester, for example.

But today the supply chains for recycled polyester are not transparent, and if we are told that the resin chips we’re using to spin fibers are made from bottles – or from industrial scrap or old fleece jackets – we have no way to verify that. Once the polymers are at the melt stage, it’s impossible to tell where they came from. So the yarn/fabric could be virgin polyester or it could be recycled. Many so called “recycled” polyester yarns may not really be from recycled sources at all because – you guessed it! – the process of recycling is much more expensive than using virgin polyester. Unfortunately not all companies are willing to pay the price to offer a real green product, but they sure do want to take advantage of the perception of green. So when you see a label that says a fabric is made from 50% polyester and 50% recycled polyester – well, (until now) there was absolutely no way to tell if that was true.
Along with the fact that whether what you’re buying is really made from recycled yarns – or not – most people don’t pay any attention to the processing of the fibers. Let’s just assume, for argument’s sake, that the fabric (which is identified as being made of 100% recycled polyester) is really made from recycled polyester. But unless they tell you specifically otherwise, it is processed conventionally.
What does that mean? It can be assumed that the chemicals used in processing – the optical brighteners, texturizers, dyes, softeners, detergents, bleaches and all others – probably contain some of the chemicals which have been found to be harmful to living things. In fact the chemicals used, if not optimized, may very well contain the same heavy metals, AZO dyestuffs and/or finish chemicals that have been proven to cause much human suffering.
It’s widely thought that water use needed to recycle polyester is low, but who’s looking to see that this is true? The weaving, however, uses the same amount of water (about 500 gallons to produce 25 yards of upholstery weight fabric) – so the wastewater is probably expelled without treatment, adding to our pollution burden. And it’s widely touted that recycling polyester uses just 30 – 50% of the energy needed to make virgin polyester – but is that true in every case? There is no guarantee that the workers who produce the fabric are being paid a fair wage – or even that they are working in safe conditions. And finally there are issues specific to the textile industry:

  • The base color of the recyled chips varies from white to creamy yellow. This makes it difficult to get consistent dyelots, especially for pale shades, necessitating more dyestuffs.
  • In order to get a consistently white base, some dyers use chlorine-based bleaches.
  • Dye uptake can be inconsistent, so the dyer would need to re-dye the batch. There are high levels of redyeing, leading to increased energy use.
  • PVC is often used in PET labels and wrappers and adhesives. If the wrappers and labels from the bottles used in the post-consumer chips had not been properly removed and washed, PVC may be introduced into the polymer.
  • Some fabrics are forgiving in terms of appearance and lend themselves to variability in yarns, such as fleece and carpets; fine gauge plain fabrics are much more difficult to achieve.

As the size of the recycled polyester market grows, we think the integrity of the sustainability claims for polyesters will become increasingly important. There has not been the same level of traceability for polyesters as there is for organically labeled products.

But now there is now a new, third party certification which is addressing these issues. The Global Recycle Standard (GRS), originated by Control Union and now administered by Textile Exchange (formerly Organic Exchange), is intended to establish independently verified claims as to the amount of recycled content in a yarn, with the important added dimension of prohibiting certain chemicals, requiring water treatment and upholding workers rights, holding the weaver to standards similar to those found in the Global Organic Textile Standard:

  • Companies must keep full records of the use of chemicals, energy, water consumption and waste water treatment including the disposal of sludge;
  • All prohibitied chemicals listed in GOTS are also prohibited in the GRS;
  • All wastewater must be treated for pH, temperature, COD and BOD before disposal;
  • There is an extensive section related to worker’s rights.

The GRS provides a track and trace certification system that ensures that the claims you make about a product can be officially backed up. It consists of a three-tiered system: Gold standard – products contain between 95 percent to 100 percent recycled material;Silver standard – products contain between 70 percent to 95 percent recycled product;Bronze standard – products have a minimum of 30 percent recycled content.

I have long been concerned about the rampant acceptance of recycled polyester as a green choice when no mention has been made of processing chemicals, water treatment or workers rights, so we welcome this new GRS certification, which allows us to be more aware of what we’re really buying when we try to “do good”.

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Polyester – to recycle or not to recycle?

12 01 2011

I know it’s hard to imagine that the lovely fabric you’re eyeing for that chair – so soft and supple and luxurious – is just another plastic.

But because 60% of all polyethylene terephalate (PET – commonly called polyester) manufactured globally is destined to be made into fibers to be woven into cloth,  and because  polyester absolutely dominates the market, and because the textile industry has adopted using recycled polyester as their contribution to help us fight climate change, I think it’s important that we keep up with topics in recycling plastic.

”A Tribute to PET Bottles“ by Czech Sculptor Veronika Richterová

If using recycled polyester is good, then using “post consumer” PET bottles  is deemed the highest good.  But an interesting thing is happening with PET bottles and recycling, according to a study published in August, 2010, by SRI Consulting, which is, according to their web site,  the world’s leading business research service for the global chemical industry (www.sriconsulting.com).  The study, PET’s Carbon Footprint: To Recycle or Not to Recycle, caused more than a few ripples because it concluded that in many cases recycling bottles is no better — and could be worse — than landfilling.
The study’s key finding — widely reported — is that a recycling facility needs to recover at least 50 percent of the material it takes in if it is to achieve a more environmentally favorable carbon footprint than simply disposing directly to landfill.  The key is to improve yields , especially in sorting and to a lesser extent, in reprocessing.

This study addresses two key questions:

  • should we recycle plastics?
  • what are the carbon footprints of virgin (vPET)  and recycled PET (rPET)

In order to calculate the carbon footprint of various PET products, the study  calculated the carbon footprint for PET bottles used to package drinks from “cradle to grave,” i.e., extending from production of raw materials (primarily oil and gas) through to disposal of all wastes. The study considers a base case—bottles are used by consumers in northwest Europe, collected in a curbside system and sent on for sorting and recycling—and variations on that theme, including PET-only take-back (as currently practiced in Switzerland) as well as no recycling (with scenarios of “all landfill” and “all incineration”). Sensitivities of all major variables were assessed.

The study concludes that the curbside take-back systems are no better than landfill, in terms of carbon footprint. From a carbon-emissions standpoint, it would be just as well to bury used bottles as to recycle them, and either would be a better option than burning them.  The study found that landfilling PET bottles from certain systems rather than incinerating them could reduce carbon footprint by 30%.  Call it “carbon capture and storage” on an economy budget.  The key is to have the room – and if you read Thomas Friedman’s Hot, Flat and Crowded you may be hard pressed to agree that there could ever be anyplace on the planet with room!

SRI report author Eric Johnson told FoodProductionDaily.com that transportation and processing costs, as well as low yields of pure PET (of below 50 per cent) from curbside recycling collections such as Germany’s DSD ‘Green Dot’ programme,  warranted SRI’s conclusion. (read article here)

Johnson said: “In terms of resource squandering [of oil in particular], if it takes more resources to recycle bottles …  than to produce units from virgin PET then this is irresponsible. If you’re going to recycle…do it properly.”

Jane Bickerstaffe, director of the UK Industry Council for Packaging and the Environment, concurred with Johnson’s point that rPET purity was a significant hindrance to worthwhile recycling, given that it affected recoverable PET levels: “Quality of recyclate is a big issue because the energy costs to separate out contaminants and clean the polymer are significant,” she said. (1)

As you might expect, there was a bit of an uproar over the study.

Casper van den Dungen,  EuPR PET working group chairman,  condemned SRI Consulting’s report:  “By applying SRI Consulting’s results we would …  lose valuable [rPET] material in landfills. The model used is intrinsically wrong, as in reality landfill should be avoided as a starting principle.”  (2)

Antonio Furfari from EuPR added: “The wrong signal is that landfill is good for environment. Landfilling is not acceptable for environmental and resources efficiency reasons, and CO2 is not the only environmental variable.” (3)

And yet, Jane Bickerstaffe had this comment: “It’s worth noting that landfilling inert materials like PET is just like putting back the sand, granite etc. that was dug out of a hole in the ground in the first place.  Inert materials are benign, whereas biodegradable materials such as cabbage leaves and potato peelings generate methane in landfill and have a negative impact on climate change.” (4)

The findings of this study hinge on how the plastics are collected.  Recycling programs using curbside collection typically displace less than 50% of new PET (polyethylene terephthalate). Community programs with plastic bottle take-back, mandated separate collection, or deposits on bottles tend to report much higher displacement rates. For regions that already have a recycling infrastructure, the aim should be to boost recycled PET (rPET) displacement of virgin PET (vPET) significantly above 50%.   The key seems to be in increasing yields rather than improving collection rates.  In countries where there is no recycling infrastructure, the best choice may well be to landfill bottles.”

It seems to me that, in consideration of “should we recycle plastics”  –  the answer is (as it almost always is): “it depends”.   Should we use only carbon footprint as a yardstick?  Sometimes you have to pull back and take in the big picture; as one blogger put it, “It’s unconscionable to pay out the nose for foreign oil so that we can produce more soda bottles to package up products that make our population fat and unhealthy.”

And how does all that trash get into the oceans?  How does that figure into this equation?

Hey, I never promised answers.

(1)  Bouckley, Ben; “Plastic recycling body slams report advising countries to landfill PET bottles”, FoodProductiondaily.com, September 2, 2010

(2)  Ibid.

(3)  Ibid.

(4)  Ibid.





Will the antimony in polyester fabric hurt me?

17 02 2010

Synthetic fibers are the most popular fibers in the world with 65% of world production of fibers being synthetic and  35%  natural fibers. (1)  Fully  70% of that synthetic fiber production is polyester. There are many different types of polyester, but the type most often produced for use in textiles is polyethylene terephthalate, abbreviated PET.   Used in a fabric, it’s most often referred to as “polyester” or “poly”.  It is very cheap to produce, and that’s a primary driver for its use in the textile industry.

The majority of the world’s PET production – about 60% – is used to make fibers for textiles; and about  30% is used to make bottles.   Annual PET production requires 104 million barrels of oil  – that’s 70 million barrels just to produce the virgin polyester used in fabrics.(2)  That means most polyester – 70 million barrels worth –  is manufactured specifically to be made into fibers, NOT bottles, as many people think.  Of the 30% of PET which is used to make bottles, only a tiny fraction is recycled into fibers.  But the idea of using recycled bottles – “diverting waste from landfills” – and turning it into fibers has caught the public’s imagination.  There are many reasons why using recycled polyester (often called rPET) is not a good choice given our climate crisis, but today’s post is concentrating on only one aspect of polyester: the fact that antimony is used as a catalyst to create PET.  We will explore what that means.

Antimony is present in 80 – 85% of all virgin PET.  Antimony is a carcinogen, and toxic to the heart, lungs, liver and skin.  Long term inhalation causes chronic bronchitis and emphysema.  The industry will say that  although antimony is used as a catalyst in the production process, it  is “locked” into the finished polymer, and not a concern to human health.  And that’s correct:   antimony used in the production of  PET fibers becomes chemically bound to the PET polymer  so your PET fabric does contain antimony but it isn’t available to your living system. (2)

But wait!  Antimony is leached from the fibers during the high temperature dyeing process.  The antimony that leaches from the fibers  is expelled with the wastewater into our rivers (unless the fabric is woven at a mill which treats its wastewater).  In fact, as much as 175ppm of antimony can be leached from the fiber during the dyeing process. This seemingly insignificant amount translates into a burden on water treatment facilities when multiplied by 19 million lbs each year –  and it’s still a hazardous waste when precipitated out during treatment. Countries that can afford technologies that precipitate the metals out of the solution are left with a hazardous sludge that must then be disposed of in a properly managed landfill or incinerator operations. Countries who cannot or who are unwilling to employ these end-of-pipe treatments release antimony along with a host of other dangerous substances to open waters.

But what about the antimony that remains in the PET fabric?  We do know that antimony leaches from PET bottles into the water or soda inside the bottles.  The US Agency for Toxic Substances and Disease Registry says that the antimony in fabric is very tightly bound and does not expose people to antimony, (3) as I mentioned earlier.    So if you want to take the government’s word for it,  antimony in  PET  is not a problem for human health  –  at least directly in terms of exposure from fabrics which contain antimony.  (Toxics crusader William McDonough has been on antimony’s case for years, however, and takes a much less sanguine view of antimony. (4) )

Antimony is just not a nice thing to be eating or drinking, and wearing it probably won’t hurt you, but the problem comes up during the production process  – is it released into our environment?  Recycling PET is a high temperature process, which creates wastewater tainted with antimony trioxide – and  the dyeing process for recycled PET is problematic as I mentioned in an earlier post.   Another problem occurs when the PET (recycled or virgin) is finally incinerated at the landfill – because then the antimony is released as a gas (antimony trioxide).  Antimony trioxide  has been classified as a carcinogen in the state of California since 1990, by various agencies in the U.S. (such as OSHA, ACGIH and IARC)  and in the European Union.  And the sludge produced during PET production (40 million pounds in the U.S. alone) when incinerated creates 800,000 lbs of fly ash which contains antimony, arsenic and other metals used during production.(5)

Designers are in love with polyesters because they’re so durable – and cheap (don’t forget cheap!).  So they’re used a lot for public spaces.  Abrasion results are a function not only of the fiber but also the construction of the fabric, and cotton and hemp can be designed to be very durable, but they will never achieve the same abrasion results that some polyesters have achieved – like 1,000,000 rubs.  In the residential market, I would think most people wouldn’t want a fabric to last that long – I’ve noticed sofas which people leave on the streets with “free” signs on them, and never once did I notice that the sofa was suffering from fabric degredation!  The “free” sofa just had to go because it was out of style, or stained, or something – I mean, have you even replaced a piece of furniture because the fabric had actually worn out?  Hemp linens have been known to last for generations.

But I digress.   Synthetic fibers can do many things that make our lives easier, and in many ways they’re the true miracle fibers.  I think there will always be a place for (organic) natural fibers, which are comfortable and soothing next to human skin.  And they certainly have that cachet: doesn’t  silk damask sound better than Ultrasuede? The versatile synthetics have a place in our textile set – but I think the current crop of synthetics must be changed so the toxic inputs are removed and the nonsustainable feedstock (oil) is replaced.  I have great hope for the biobased polymer research going on, because the next generation of miracle fibers just might come from sustainable sources.

(1) “New Approach of Synthetic Fibers Industry”, Textile Exchange,  http://www.teonline.com/articles/2009/01/new-approach-of-synthetic-fibe.html

(2) Polyester, Absolute Astronomy.com: http://www.absoluteastronomy.com/topics/Polyester and Pacific Institute, Energy Implications of Bottled Water, Gleick and Cooley, Feb 2009, http://www.pacinst.org/reports/bottled_water/index.htm)

(3)  Shotyk, William, et al, “Contamination of Canadian and European Bottled waters with antimony from PET containers”, Journal of Environmental Monitoring, 2006.   http://www.rsc.org/delivery/_ArticleLinking/DisplayHTMLArticleforfree.cfm?JournalCode=EM&Year=2006&ManuscriptID=b517844b&Iss=2

(4)   http://www.atsdr.cdc.gov/toxprofiles/phs23.html

(5)  http://www.victor-innovatex.com/doc/sustainability.pdf

(3) http://www.greenatworkmag.com/gwsubaccess/02mayjun/eco.html