Polyester has quickly but silently taken over many closets. You’d be surprised at how many polyester items you own if you couldn’t be bothered to check tags while shopping for clothes.
It has come a long way from the time it was first introduced. First beloved, it was then labeled ugly, cheap, and even uncomfortable. Textile chemists have since engineered better formulas for polyester to revive its glory and have had remarkable success.
Today, polyester has changed drastically, overtaking the much loved good old cotton in production and sales. The look and feel is everything people have always wanted in garments.
You will find it in socks, gowns, shirts, pants, blankets, upholstery, and pretty much anything. It will be next to luxurious premium fabrics, and you won’t be able to tell the difference.
If you intend to weave, knit, or sew a garment using polyester, you are likely interested in knowing its elasticity to determine its suitability for what you intend to use it for.
Therefore, is polyester stretchy? Polyester doesn’t stretch. However, polyester can be made to stretch, when processed into yarn, fabric, or garments, especially when polyester fibers are blended with, more elastic fibers like spandex. Because of recent treatments and blends, the material has grown in popularity.
This article seeks to explain the stretching abilities of polyester and answer many more questions about it as a fiber, yarn, and fabric to help you work with it better and make informed choices.
Can You Stretch Polyester?
You cannot stretch 100% polyester fiber. It remains taut even after being spun or extruded into yarn. This fiber is not elastic.
Weaving polyester into fabric does not make it stretch either. Woven polyester fabric is equally rigid due to the 90 degrees interlacing of strands. It will stretch only a little on the bias but never along the length or width of the woven fabric.
Knitted polyester has a good stretch across the width and a little less along the length. The stretch has nothing to do with the fiber itself but the matrix of the construction. Stretch is an inherent quality in any knitted garment.
How Do You Stretch Polyester?
Polyester has to be blended with elastic fibers to achieve a considerable amount of stretch in all four directions. A polyester that stretches probably has an element of Spandex or Lycra in it, usually 5%, though it could be more.
You not only get stretch, but recovery too. Recovery is the ability of the stretched fabric to bounce back to its initial shape.
Lots of sports and gym wear as well as form-fitting clothes like leggings are made this way. This has led many to believe that polyester is actually stretchy. But really, it has just been blended with something like Spandex.
Weaving with a poly-spandex yarn will give the weave elastic properties otherwise absent in 100% polyester weaves.
Another way to make polyester stretch is to crimp it industrially. Polyester polymers can be molded and interlaced into a wavy pattern when subjected to hear, which can give it an elastic allowance. However, this process is more expensive than blending in Spandex, so most industries opt for the latter.
Is Polyester a Synthetic Fiber?
Absolutely. Polyester, like nylon and acrylic, is a synthetic or man-made fiber; it is made in a chemical lab using artificial ingredients. This means it does not contain natural components from plant fibers or animal proteins (such as wool, hair, or fur).
What is Polyester Made Of?
Polyester is made from polymers, which are repeating chains of molecular units. The specific polymer for ethylene polyester is PET – Polyethylene Terephthalate.
PET is synthesized by reacting ethylene glycol and Terephthalic acid. Monomers are treated once more with Terephthalic acid to bond chemically and form the PET polymers. These polymers are molten and extruded into ribbons that are solidified and cut into filaments.
The filaments are re-heated into a thick liquid that is passed through a spinneret where it comes out as long strands (think of a running showerhead). These strands are solidified and wound onto a bobbin into yarn. This process is called spinning.
That’s a lot of chemistry jargon right? Well then, to the straightforward question and answer;
Is Polyester Plastic?
Yes, polyester is plastic. The components of PET are petrochemicals derived from refining crude oil or fossil fuels, making most polyesters a kind of plastic.
Some of this PET is also obtained from recycling plastic bottles to make polyester. Plastic bottles are made from PET too so they can be processed back into polymers for making polyester fibers.
Nonetheless, there’s an organic type of polyester which is not plastic. This plant-based polyester derives its ethylene from plant sources such as cane.
It also utilizes Cutin from plant cuticles, a wax-like extract whose makeup is polymerized ester. Unfortunately, these non-plastic polyester varieties are rare.
How Did Polyester Become So Popular?
You must now be wondering how we ended up with plastic for clothing and loved it when there’s cotton, hemp, linen and other organic options. How did polyester become more widely used than these traditional options and even other synthetic fibers? Here’s the background of the polyester boom.
History of Polyester
Polyester was born in a UK lab in the 1930s by a man called W. D. Carothers who later sold its rights to DuPont, the company he was working for in 1946.
Many scientists continued working on it, and DuPont together with the American Corporation put it to test by making parachutes and other materials for war during World War II.
It was later introduced to the masses in the ‘50s as clothing fiber. Its popularity soared until the ‘60s when a sharp decline was experienced as a result of youngsters shunning it as cheap, hot, and unbearable.
This ridicule for polyester almost wiped it out by the ‘70s. Thankfully for polyester lovers, the hate fazed out in the ‘80s after a group of world-renown designers launched a polyester line that brought it back into the limelight.
Its popularity once again grew in leaps and bounds as it also improved in quality. Polyester has never stopped spiking in production and sales since the comeback. It currently dominates clothing lines worldwide.
Where is Polyester Produced?
China is the global leader in polyester production. India, Taiwan, Korea, and Japan are some of the next biggest producers.
This polyester, however, does not leave those countries in the raw state. It is made into yarn, fabric, and finished goods which are then exported to the U.K., U.S., and other parts of the world.
The United States also produces polyester, but that accounts for a small percentage of the total production compared to other producers.
Is Polyester Here to Stay?
While it’s still hated and loved in equal measures, polyester is likely here to stay. Sooner or later it will end up on your skin – if it hasn’t already. Here’s why:
The supply of cotton, which is the most preferred natural fiber, is dwindling as it competes with food and other cash crops for land. Also, the amount of time it takes to grow and be processed cannot keep up with the insatiable demand for fabric.
There’s simply not enough cotton to go around. From what it looks like, polyester filled the gap to satisfy this fabric demand arising from people trying to keep up with new fashion trends every season.
But why is polyester beating out so many other man-made fibers like nylon, acrylic, and rayon?
Well, polyester is much cheaper to produce.
Since we can’t grow enough cotton to satisfy the world’s appetite for fast fashion, it looks like polyester is here to stay. So let’s look at the good, bad, and ugly of this material.
What is Polyester Material Like?
This “cheap” fiber is surprisingly so reliable that it keeps pulling crowds. It has some great qualities not present in the natural fibers, which contribute to its popularity. And a few cons too.
Here are some characteristics of polyester:
- It is a very strong and durable fiber. Stronger than cotton but a little less than nylon.
- Polyester is ultra-light. You almost won’t feel its weight. It is also fast drying and has a nice smooth silk-like appearance, a slippery texture, and excellent drape. It is neither rough nor as soft as cotton.
- Polyester is wrinkle-resistant. You can simply wash and wear. Even if you fish it from the furthest corner of the closet, it will quickly straighten out on the body.
- It is resistant to abrasion, but low-quality polyester can pill really badly.
- The fibers are mildew-resistant.
- It keeps color well. Colored polyester stays forever vibrant as it is resistant to fading, unlike natural fibers that turn white with continued exposure to UV light.
- Polyester is resistant to staining. Any soiling will come off easily, but you might struggle more with greasy stains.
- Polyester doesn’t shrink. It is resilient and therefore reliable to use for weaving, knitting, or sewing as it will not change shape.
- It is easy to care for. No special cleaning is necessary. It can be hand or machine washed and tumbled dry without changing shape or form.
- Heat may be used to create permanent designs such as pleats. Notwithstanding, it melts at very high heat with a melting point of about 300°C (572 ℉).
- It is non-absorbent unless woven very loosely. Still, it is often given moisture-wicking properties during production.
- Polyester is static in nature and will, therefore, draw dirt and lint from the surroundings.
A lot of good qualities there, but does it match up to natural fibers in aspects such as sustainability, breathability, and heat resistance? Let’s find out.
Is Polyester Breathable?
There’s a lot of contrarian views on whether polyester is breathable or not. But first, let’s explain what fabric breathability means. Breathability is about the moisture vapor transmission rate of a fabric. A fabric is breathable when perspiration is allowed to escape, making the wearer more comfortable.
If a fabric neither absorbs nor releases moisture, or is absorbent but does not allow humidity to be released, then it is not breathable. Plastic or PET, the main constituent of polyester fibers, is not breathable. It is known to be hydrophobic which is moisture resistant.
However, it is not the fibers that really make a fabric breathable but rather the construction. Tighter knits or weaves are less breathable. Weight also plays a major role in the breathability of fabrics.
The recent construction of polyester makes it breathable. It is lightweight and will not soak moisture but let it evaporate quickly. It is woven with moisture-wicking properties. The weave matrix is made to be permeable allowing the free flow of air and water molecules to the exterior surface for evaporation.
Cotton is more breathable and absorbent, but a bit heavy. Polyester, in contrast, is ultralight, breathable, but non-absorbent. A polycotton blend is the best of both worlds and a popular choice of fabric in top activewear labels.
Is Polyester Flammable?
Polyester is highly flammable, and this is perhaps one of the biggest downsides of the fiber. It ignites so easily thanks to its plastic contents and cannot be ironed on high heat. If you must iron it, you’ll need to wet it first and switch to a low or medium setting.
The good thing with polyester is that it is crease-resistant. Ironing is not necessary unless for a different purpose like pleating. That said, the damage caused by polyester on the skin should it catch fire and melt is far worse than most fibers.
Unlike cotton, wool, or other fibers that char on flames, polyester will melt as is expected of polymers when heated. This kind of burn is too severe to be reconstructed and does terrible damage to skin tissue.
How Sustainable is Polyester?
If you are an eco-conscious yarn crafter or needleworker, you might also be interested in knowing how sustainable polyester is. What environmental impact does it have?
Polyester is created from petrochemicals, and it is no news that refining petroleum and processing plastics impact the environment negatively. Synthesis of polyester pollutes the environment by emitting greenhouse gases.
The disperse dyes used to color it are not water-soluble. Their chemical structure is so complex and will not disintegrate even after treating the industrial wastewater that ends up in waterways.
Also, the production of polyester uses a lot of energy and takes up a lot of water. It involves many heat processes that need copious amounts of water as a coolant.
Some studies also revealed that washing polyester releases microscopic plastic fibers into the water which enters the waterways.
Can growing more cotton eliminate this problem? Not by itself. Even cotton has its own share of contribution to environmental degradation through fertilizers, pesticides, water usage, and even production of the fabric.
Is Polyester Biodegradable?
Polyester is not biodegradable. Most polyesters are petroleum-based plastic and non-biodegradable. If your polyester garment ends up in the landfills, it will take a couple of decades to decompose fully.
There are a few polyesters that are biodegradable and sustainable according to scientific research. They are made from plant bases, like how the US utilizes corn oil instead of fossil fuels. Still, the cost of manufacturing them is extremely high, making them very rare.
The fact that many of these may still be blended with resin polymers makes them not entirely biodegradable, but far better and faster at decomposing.
Biodegradable polyesters include aliphatic polyesters such as PCL-Polycaprolactone, PHB-Polyhydroxybutyrate, and PLA-Polylactic.
Other fabrics and fabric blends are increasingly being designed and tested, so perhaps one day sustainable polyesters and cottons will be big players on the market.
Is Polyester Recyclable?
Polyester is recyclable. Instead of synthesizing more virgin PET, it can be obtained from plastic waste, recycled and made into usable fiber. When recycled, it is known as rPET.
Clear single-use plastic bottles are collected, cleaned, and shredded into fine confetti-sized chips. These are then molten, dyed, and transformed into filaments that undergo extrusion to make yarn.
Recycled polyester has many benefits. It reduces the number of plastic bottles that end up in landfills, oceans, and other water bodies, for one thing. It also utilizes less energy and water to respin and produces lower greenhouse gas emissions.
Not to mean that recyclable polyester is the answer to plastic pollution, or has no negative environmental impact. It is only a lesser evil compared to virgin polyester. Every fiber has some degree of negative environmental, social, and health impact, whether natural or synthetic, virgin, or recycled.
What Certification is Available for Polyester?
OEKO-TEX provides safety and non-toxic certification for polyester products generally. Intertek and Global Recycled Standard provide recycled polyester or rPET certification.
There is no certification for biodegradable or plant-based polyester. Its organic properties are null and void since it is chemically processed at some point.
What Are Some Popular Uses of Polyester?
There are certainly hundreds of potential polyester applications, but we’ll go over a few common ones.
Polyester yarn is soft, colorful, strong, and resilient. The possibility of things you can knit, weave, or crochet with it are near-infinite.
It is commonly used for children’s handmade apparel which requires high tenacity yarn that is resistant to stains. Kids can get very dirty very fast during play and meal times.
It is also good for handcrafting baby items like toys, hats, mittens, sweaters, socks, and clothes for the same reasons. Besides, babies outgrow outfits really fast, so it makes sense to go cheap on everyday wear.
Polyester yarn is good for warmth and makes throw blankets, afghans, and other heavy, difficult to handwash articles. They can go into the washing machine without worries.
It is used for weaving wall hangings, crocheting potholders, making yarn crafts, in embroidery, making coasters, etc.
Polyester fabric is used to sew and tailor anything from high-fashion gowns to tops and bottoms. It is popular for uniforms too as these require regular washing.
Polyester is also used for household and commercial sewing of curtains, cushion covers, and light draperies as well as curtains, mats, rugs, and other upholstery.
Its hydrophobic characteristics make it useful for industrial manufacturers of swimwear, wet weather jackets, raincoats, umbrellas, and other clothing and equipment for wet conditions. Poly-Cotton blends are popular for making beddings.
Bags, footwear, conveyor belts, cords, ropes, tents, fishing nets are a few among the many other industrial applications of polyester.
Polyester fiberfill is the common stuffing for toys, pillows, cushions and duvets. When we said polyester is popular, we meant it!
How to Care For Polyester
Caring for polyester is simple. Being a resilient fabric, it can handle many things well, except for heat. It is therefore critical that you avoid high heat when laundering polyester.
- Always set your washing machine to a cool or warm cycle setting but never hot. You can also handwash your items at the same temperature.
- Use an all-purpose detergent and fabric softener to maintain the quality of the fibers and lower its static power.
- Hang or tumble dry at a cool temperature.
- Polyester does not need pressing as it is crease-resistant. But if you must iron it, use low or medium heat and wet it a little if not using a steam iron.
Polyester is one of the most versatile fibers you will ever find. It has lots of desirable properties for making a variety of things, but can be modified to make it work for nearly any application.
It has high tenacity, is durable, vibrant, drapey, lightweight, and resistant to fading, wrinkling, staining, abrasion, and shrinkage. However, heat is its greatest enemy.
Is it absorbent? Not quite, but with the latest technology, it is often given some moisture-wicking properties in manufacturing. It can also be blended with cotton to make up for that.
Is polyester stretchy? No, it isn’t, But may be woven or knitted loosely to give the resulting textile a small stretch. Or it can be blended with Lycra or Spandex for incredible elasticity.
Polyester is no doubt just plastic and is non-biodegradable. Still, there are many efforts to make it easier to break down using catalysts and blends with bio-based polyester.
Recycling polyester also lowers the negative environmental impact of its production. The undeniable fact, however, remains that it is still bad for the environment, whether virgin or recycled.
The qualities of polyester make it usable in a wide variety of applications and compete on the same level as the likes of cotton despite not being a sustainable option.
Going by statistics, it is already the choice of fiber for nearly half of the global clothing and textile industries. The stigma is still there but clearly, polyester is the future, and savvy fashion industries are already both feet in.