Synthetic fibers are
the most popular fibers in the world – it’s estimated that synthetics
account for about 65% of world production versus 35% for natural fibers.
Most synthetic fibers (approximately 70%) are made from polyester, and
the polyester most often used in textiles is polyethylene terephthalate
(PET). Used in a fabric, it is most often referred to as “polyester”
or “poly”.
The majority of the
world’s PET production – about 60% – is used to make fibers for
textiles; about 30% is used to make bottles. It’s estimated that it
takes about 104 million barrels of oil for PET production each year –
that’s 70 million barrels just to produce the virgin polyester used in
fabrics. 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.
The reason recycled
polyester (often written rPET) is considered a green option in textiles
today is twofold, and the argument goes like this:
1. Energy needed to
make the rPET is less than what was needed to make the virgin polyester
in the first place, so we save energy.
2. And we’re keeping bottles and other plastics out of the landfills.
But the game gets a
bit more complicated here because rPET is divided into “post consumer”
PET and “post industrial” rPET: post consumer means it comes from
bottles; post industrial might be the unused packaging in a
manufacturing plant, or other byproducts of manufacturing. The
“greenest” option has been touted to be the post consumer PET, and that
has driven up demand for used bottles. Indeed, the demand for used
bottles, from which recycled polyester fibre is made, is now
outstripping supply in some areas and certain cynical suppliers are now
buying NEW, unused bottles directly from bottle producing companies to
make polyester textile fiber that can be called recycled.
The real problem
with making recycled PET a staple of the fiber industry is this:
Recycling, as most people think of it, is a myth. Most people believe
that plastics can be infinitely recycled – creating new products of a
value to equal the old bottles or other plastics which they dutifully
put into recycling containers to be collected. The cold hard fact is
that there is no such thing as recycling plastic, because it is not a
closed loop. None of the soda and milk bottles which are collected from
your curbside are used to make new soda or milk bottles, because each
time the plastic is heated it degenerates, so the subsequent iteration
of the polymer is degraded and can’t meet food quality standards for
soda and milk bottles. The plastic must be used to make lower quality
products. The cycle goes something like this:
* virgin PET can be made into soda or milk bottles,
* which are collected and recycled into resins
* which are
appropriate to make into toys, carpet, filler for pillows, CD cases,
plastic lumber products, fibers or a million other products, but not
new soda or milk bottles.
* These second
generation plastics can then be recycled a second time into park
benches, carpet, speed bumps or other products with very low value.
* The cycle is
completed when the plastic is no longer stable enough to be used for any
product, so it is sent to the landfill
* where it is incinerated (sometimes for energy generation, which a good LCA will offset) -
* or where it will hold space for many years or maybe become part of the Great Pacific Garbage Patch!
And there is another
consideration in recycling PET: antimony, which is present in 80 – 85%
of all virgin PET, is converted to antimony trioxide at high
temperatures – such as are necessary during recycling, releasing this
carcinogen from the polymer and making it available for intake into
living systems.
Using recycled PET for fibers also creates some problems specific to the textile industry:
* The base color
of the recycled polyester chips vary from white to creamy yellow,
making color consistency difficult to achieve, particularly for the pale
shades. Some dyers find it hard to get a white, so they’re using
chlorine-based bleaches to whiten the base.
* Inconsistency
of dye uptake makes it difficult to get good batch-to-batch color
consistency and this can lead to high levels of re-dyeing, another very
high energy process. Re-dyeing contributes to high levels of water,
energy and chemical use.
*
Unsubstantiated reports claim that some recycled yarns take almost 30%
more dye to achieve the same depth of shade as equivalent virgin
polyesters.[11]
* Another consideration is the introduction of PVC into the polymer from bottle labels and wrappers.
* Many rPET
fibers are used in forgiving constructions such as polar fleece, where
the construction of the fabric hides slight yarn variations. For
fabrics such as satins, there are concerns over streaks and stripes.
Once the fibers are woven into fabrics, most fabrics are rendered non-recyclable because:
* the fabrics almost always have a chemical backing, lamination or other finish,
* or they are blends of different synthetics (polyester and nylon, for example).
Either of these
renders the fabric unsuitable for the mechanical method of recycling,
which cannot separate out the various chemicals in order to produce the
recycled yarn; the chemical method could - if we had the money and
factories to do it.
One of the biggest
obstacles to achieving McDonough’s Cradle-to-Cradle vision lies outside
the designers’ ordinary scope of interest – in the recycling system
itself. Although bottles, tins and newspapers are now routinely
recycled, furniture and carpets still usually end up in landfill or
incinerators, even if they have been designed to be recycled because
project managers don’t take the time to separate out the various
components of a demolition job, nor is collection of these components an
easy thing to access.
Currently, the
vision that most marketers has led us to believe, that of a closed loop,
or cycle, in which the yarns never lose their value and recycle
indefinitely is simply that – just a vision. Few manufacturers, such as
Designtex (with their line of EL fabrics designed to be used without
backings) and Victor Innovatex (who has pioneered EcoIntelligent™
polyester made without antimony), have taken the time, effort and money
needed to accelerate the adoption of sustainable practices in the
industry so we can one day have synthetic fabrics that are not only
recycled, but recyclable.
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Quote: dont hold something in your arms that you can never hold in your heart
Quote: dont hold something in your arms that you can never hold in your heart
