Organic_Clothing

Permanent Press: Facts behind the Fabrics

Permanent press clothing and wrinkles. Permanent press – aka crease resistant, crease proof, wrinkle-resistant, durable press, wrinkle free – is another of those 1950s brain storms that seemed like a good idea at the time when we were all infatuated with the promise of science to remove toil and strain from our daily lives. We didn’t need balanced, nutritious meals; we just needed our one-a-day Flintstone Multi-Vitamins. As the 1950s rocketed into the Age of Science, it seemed only right that the Stone Age concept of using a hot chunk of iron to smooth wrinkles from clothes should give way to scientific, easy-care garments. Science took aim at the prime culprit in wrinkling - the weak hydrogen bond which cross-linked the cellulose polymers in cotton.

The cross-linked hydrogen bonds keep in place the cellulose polymers in cellulose fabrics such as cotton, hemp and flax. The bad news is that the hydrogen bonds are relatively weak and easily broken by moisture. Once the hydrogen bonds holding the cellulose fibers in place are broken by moisture, then the fibers can shift place and realign themselves and wrinkles are born in cellulose-based fabrics. The 1950s attempt at good news came from Ruth Benerito, the Mother of Permanent Press, at the Physical Chemistry Research Group of the Cotton Chemical Reactions Laboratory of the USDA Southern Regional Research Center when she developed a process to replace the weak hydrogen bonds with stronger bonds that were water-resistant. The bad news was that the new cross-linking agent was formaldehyde – a toxic chemical that not only smelled bad and made the fabric more brittle but was also carcinogenic and a health hazard.

The bad news of using formaldehyde resins to create permanent cross-linked hydrogen bonds for wrinkle-free clothing continues to this day even though the processes have improved. The early formaldehyde-soaked permanent press garments felt scratchy and stiff and smelled funny. The formaldehyde resins also weakened the fabric. Oh, yes … and formaldehyde has also been recognized as a probable carcinogen that can cause a wide variety of health problems such as burning and watery eyes, respiratory complains such as coughing and difficulty in breathing, and allergic contact dermatitis where permanent press clothing comes into contact with the skin.

Regardless of how we might feel about the ethics of dressing millions and millions of people in clothes reeking with formaldehyde, the accomplishments of Ruth Benerito at the U.S. Department of Agriculture in the 1950s and 60s are impressive. During her many years as a research scientist at the male-dominated USDA, Ruth Benerito garnered 55 patents in creating easy-care cotton fabrics which “saved the cotton industry.”

As the Age of Science Infatuation in the 1950s and early 1960s gave way to the Summer of Love and Age of Rebellion in the 1960s and 1970s and then to the Age of Excess Consumerism in the 1980s and 1990s, process improvements were slowly being made in manufacturing wrinkle-resistant cotton textiles to reduce – but not eliminate – the amount of formaldehyde bound on the surface of the fabric.

How the permanent press processes work. There are two basic processes for finishing cotton textiles with wrinkle-resistant properties: the procure process and the postcure process. The procure process goes like this:

1. The conventional cotton or cotton blend fabric is dyed;
2. Garments are sewn together;
3. Formaldehyde resins are applied to the garments;
4. Garments are tumble dried at a low temperature to remove moisture but not cure the formaldehyde resins and cause cross linking of formaldehyde and hydrogen atoms in the cotton’s cellulose fibers;
5. Press the garments to create creases in the clothing were creases are wanted such as pant legs and sleeves on shirts;
6. Oven cure the pressed garments at a high temperature to cross link the formaldehyde and cellulose fibers to create the permanent press properties.

The postcure process is similar except that the formaldehyde resin is applied in step 2 after the fabric is dyed but before the garments are sewn together and made-up. The postcure process goes like this:

1. Dye cotton or cotton blend fabric;
2. Apply formaldehyde resin;
3. Tumble dry to remove moisture;
4. Sew and garment make-up;
5. Press clothing to create creases where wanted;
6. Oven cure to cross link and create the permanent press properties.

Reducing the amount of formaldehyde in clothing. Two improvements were developed in the 1990’s to reduce the amount of formaldehyde bound into clothing. One method consists of soaking conventional cotton fabric in formaldehyde resins, rolling the toxic fabrics between huge rollers to squeeze out excess formaldehyde resins, and then baking in large ovens at 300° Fahrenheit to cure the formaldehyde resins into the fabrics so that it becomes permanent and doesn’t eventually wash out. Some clothing manufacturers, such as the large multi-national Nisshinbo Industries in Japan, will then also treat the formaldehyde-laced fabric with liquid ammonia to reduce shrinkage.

The other permanent press technology improvement that is actively used today consists of exposing garments to formaldehyde gases which permeate the fabric and then are baked into the clothing. This is known as a vapor phase technology. Manufacturers have their own variations of vapor phase treatment for crease resistance, but the basic technology is composed of fabrics of cotton or other cellulose or regenerated cellulose fibers like bamboo and Tencel / lyocell) or cellulose fabrics blended with synthetics like polyesters, an airtight chamber or room, formaldehyde gas, sulfur dioxide gas, and moisture.

Vapor Phase Technology. The basic process works like this. The clothing or fabric is placed in the airtight chamber and is moistened with water or steam until the water moisture in the fabric is about 5% to 20% of the fabric weight. Formaldehyde gas is pumped into the chamber until the concentration of air in the chamber is approximately 40% to 60% formaldehyde gas and then sulfur dioxide gas is also pumped into the chamber. The sulfur dioxide gas acts as a catalyst causing the formaldehyde gas to cross link and bond with the hydrogen atoms in the cellulose polymers which help create not only crease- and wrinkle-resistance but also help protect from fabric shrinking and improved color retention and color fastness. The amount of formaldehyde that cross-links with the cellulose fibers is 0.3% to 0.6% of the weight of the cellulose fibers. You can see that there is a significant amount of formaldehyde bonded into each garment. Steam seems to be the preferred method of moisturizing the fabric as the steam also forces the formaldehyde gas and sulfur dioxide gas to penetrate the fabric which increases the cross-linking of formaldehyde to the hydrogen atom in the cellulose polymers.

A variation on the vapor phase processing is by impregnating the fabrics with an aqueous solution of a weak acid salt such as zinc chloride, ammonium chloride, sodium di-hydrogen phosphate, magnesium chloride or phosphoric acid after exposure of the fabric to formaldehyde and before garment fabrication to facilitate cross-linking. Manufacturers may vary the chemicals used as a catalyst, the temperature in the gas chamber, whether fabrics are gassed before or after being fabricated into garments, the moisture contents, and other factors but the bottom line is that the finishing of easy-care garments is highly chemical and technology-intensive.

Although Ruth Benerito invented permanent press technology in the labs at the USDA in the 1950’s, it wasn’t until the 1990’s that permanent press popularity really took off. Before then the brittleness, fabric yellowing, and unpleasant feel and smell of permanent press clothes from the heavy formaldehyde discouraged wearers. The new and improved finishing technologies were applied to men’s all-cotton trousers and revitalized the industry. It is more than a little ironic that consumers were drawn to buy 100% cotton slacks because they were perceived as being more natural but they also wanted the easy-care low maintenance clothing even if it was impregnated with toxic and possibly carcinogenic chemicals.

All in the (Formaldehyde) Family. Besides process improvements in the 1990’s, chemical scientists at the large garment manufacturers also began scouting for other chemicals which might reduce or eliminate the amount of formaldehyde baked into wrinkle-free clothing. Clothes labeled permanent-press or durable-press have been dipped in a chemical cornucopia of cross-linking resins such as isocyanates, epoxides, divinylsulfones, aldehydes, chlorohydrins, polycarboxylic acids and N-methylol compounds. Popular with today’s textile chemists are resins of N-methylol compounds which include dimethylol urea, dimethylol ethylene urea, trimethylol trazine, dimethylol methyl carbamate, uron, triazone, and DMDHEU.

The chemical DMDHEU (which you might know better as dimethyol dihydroxy ethylene urea or 1, 2-Dimethylol-4, 5-dihydroxyethyleneurea … ever wonder how they make up these names?) has become the most widely used cross-linking agent. The problem is that DMDHEU, like all the other commonly used cross-linking agents, is still a member of the huge formaldehyde family. The National Toxicology Program at the U.S. Department of Health and Human Services still warn that even though formaldehyde off gassing emissions in clothing have been reduced, DMDHEU has been found “to be causal agents in textile-related dermatitis.” Research is continuing into other possible health hazards from DMDHEU and its other formaldehyde-related cousins.

On a sidebar note: the National Toxicology Program is charged with safeguarding public health by evaluating new chemicals released into the public marketplace. More than 80,000 chemicals are registered for use in the U.S. Each year, manufacturers inject an estimated 2,000 new chemicals into our society through all the countless products that Americans buy each year. Many of these new chemicals have not been adequately tested for potential health hazards.

Wrinkle-resistant fabrics are often treated with softeners such as polyethylene to improve the hand and feel of the perma press fabric and for better wash durability. Some manufacturers are also adding fluorochemical additives to increase stain-resistance.

Another formaldehyde resin currently popular with garment manufacturers is DMUG (dimethylurea glyoxal) because it gives a smoother surface smoothness and greater strength and abrasion resistance than DMDHEU but the crease retention of DMUG is not as good as with DMDHEU so sometimes the two are blended together to create a permanent press cocktail.

Fabric is typically dyed before being treated with formaldehyde resins for crease resistance. Sometimes, sulfur-dyed fabrics impregnated with a formaldehyde resin finish will deteriorate due to the generation of acid from the sulfur dye, especially if black sulfur dye was used. Manufacturers use a slightly modified process to reduce the possibility of acid being generated in people’s washing machines and dryers. But the possibility still exists … it’s just been reduced is all.

The science and technology of chemical fabric finishes is astounding and most people have no idea of the vast range of chemicals – some harsh and toxic – that are used to create those easy care clothes that tempt busy consumers. Today’s easy care clothes are the product of a total textile engineering that includes the selection of the fiber, the yarn characteristics, the fabric construction, preparation, dyeing, finishing formulations, and procedures.

While most conventional textile manufacturers would probably take umbrage at the suggestion that their clothes could qualify as toxic Superfunds, there is no doubt that easy care all-cotton clothing has become highly chemical intensive.

 Chemicals in the laundry room. The chemical war on wrinkles doesn’t end in the hi-tech fabric finishing labs of conventional garment manufacturers but is also waged in ordinary laundry rooms everywhere. Beginning in the early 2000’s, the large laundry care chemical companies launched an assault of wrinkle-attacking laundry products such as Downy Wrinkle Releaser and Wisk detergent with Wrinkle Reducer followed by a platoon of gimmicky wrinkle removing spray-on products such as Faultless Wrinkle Remover spray-on, Apparel Press wrinkle-removing spray, and Wrinkle Out Spray by Stanley Home Products.

The basic premise is that these detergents and sprays will cause clothing wrinkles to melt away and “keep your casual clothes looking neat without all the hassle of ironing.” Besides dissolving wrinkles in that crumpled cotton blouse, these products are also supposed work their magic on wools, silks and dry-clean-only garments. How do they do it? Chemicals … lots of chemicals. Manufacturers do not reveal all the chemicals that are used in their products, only the “active ingredients” so determining exactly what is in what is difficult.

Some of the chemicals commonly used in laundry products to reduce wrinkles include: sodium alcohol ethoxy sulfate, alcohol ethoxylate, sodium linear alkyl benzene sulfonate, propylene glycol, sulphated/sulphonated vegetable oils, zwitterionic surfactants, curable aminosilicones, cellulase enzymes, polyalkyleneoxide modified polydimethylsiloxane, ethoxylated organosilicones, linear aminopolydimethylsiloxane polyalkyleneoxide copolymers, high molecular weight polyacrylamides, betaine siloxane copolymers, alkylactam siloxane copolymers – PLUS tons of artificial fragrances and perfumes to create the chemical illusion of “Morning Fresh”, “Spring Morning”, “Clean Breeze”, “Mountain Spring”, Tropical Clean”, lavender, vanilla, and all the other countless chemical smells that they use to saturate clothes.

Chemicals in the fragrances of consumer products have been identified to the allergens and worse. The Scientific Committee on Cosmetic Products and Non-Food Products (SCCNFP) issued a position paper highlighting the use of allergens in the chemical fragrances often used in consumer detergents. Their position stated “A person sensitised to a certain fragrance material will elicit an allergic response when exposed to this fragrance from any product whether cosmetic or detergents under similar exposure conditions. Thus, it is important that consumers have information on the presence of fragrance chemicals in the respective products.”

Sidebar conversation: For a well done overview of chemicals used in laundry detergents and laundry fragrances, check out the 5-part series in the Bright Hub reporting on the environmental and health impact of conventional and environmentally responsible laundry products. The Bright Hub is a good resource that attempts to "share knowledge about how the simplest scientific idea evolves into tomorrow’s technology.”

Laundry products are often loaded with chemical ingredients that can be unhealthy for people and the environment. A patent application by laundry product giant Unilever on “Wrinkle Reduction Laundry Product Compositions” outlines commonly used chemicals in laundry products such as liquid fabric softeners for reducing wrinkles in cotton and cotton blend fabrics. The Unilever patent application mentions “Additional materials typically used in these formulations include preservatives, pH control agents, viscosity modifying salts, perfumes, optical brighteners, colorants and color care agents.” Unilever is the maker of Wisk with Wrinkle Reducer laundry detergent which spectacularly failed to live up to expectations and marketing hype.

Getting back to how chemists deal with wrinkles, laundry room wrinkle removers reduce wrinkles by “relaxing” the fibers which actually means that wrinkle-relaxing products penetrate fabrics and apply a find coat of lubricate to the fiber surfaces so that the fibers can slide more easily relative to each other and can be pulled straight, resulting in less wrinkles. The ingredients used to coat fabric fibers so that wrinkles can be smoothed out are usually a polyolefine type softener such as polyethylene and polypropylene or a curable amine functional silicone.

Many consumers have reported after using some of these wrinkle-relaxer and fabric softening products that their clothes felt like they have a film on them that builds with continued use. Consumer tests have also questioned the effectiveness at eliminating or reducing wrinkles. Don’t expect these products to allow you to toss out that rusty old steam iron.

The future of wrinkle-reducing textile manufacturing and laundry products: Don’t expect the unnatural laundry products industry to rollover and give up. The laundry care market is an $11+ billion industry and growing at a rate of more than 5% annually. The big names are spending big bucks to develop and roll out new chemical additives and new technologies to improve the garment and textile markets. Proctor & Gamble spent over $100 million just to build a new fabric and home care research and development center. Proctor & Gamble also developed a new cellulosic Liquifiber technology which is used in Tide Ultra powder under the trademark WearCare. Liquid Detergents - Second Edition, edited by Kou-Yann Lai from CRC Press describes the Liquifiber technology as hydrophobically modified cellulosic polymers that binds to cotton fibers and effectively glues the cotton fibril in place so that they do not break lose causing fraying, microscopic pills, color degradation, and wrinkling. Curiously, the basic concept is the same as that used in Proctor & Gamble’s Pantene Pro-V Restoratives Time Renewal shampoo and conditioner collection for hair. I guess that fiber is fiber in the R & D labs.

The use of enzymes in all phases of textile manufacturing and especially garment finishing will continue to grow. Expect enzyme use in detergents and laundry products to also grow. GMO (genetically modified organisms) technology is also becoming more prevalent as new enzyme cocktails are being developed for use in the textile and home laundry product industries. Genencor is one of the largest of the biotechnology companies providing textile enzymes for textile manufacturing and finishing.

Look also for growth in nano-technologies for textiles. Nanotech textiles have quietly been infiltrating the textile manufacturing industry with new fabrics which are touted as having anti-wrinkle, anti-static, anti-stain, and anti-bacterial. Because nano-textiles have the potential to be a high tech tsunami on the textile industry we will explore the potential impacts in the next post.Stay tuned...

Enjoy.

Michael

How to Keep Natural Fiber Clothes from Wrinkling

“WARNING! Never iron or steam clothes while they are being worn.” – an actual warning in the operating instructions booklet for the high-end Rowenta electric steam clothes iron.

Resist the urge! Even when you are frantically late and you slip on that freshly laundered – but not ironed – organic cotton shirt or bamboo skirt and the wrinkles jump out like the back side of the moon, don’t even think the thought that maybe you could just ever so quickly iron out the more visible areas while just standing there.  Some people obviously have given in to the impulse which is why corporate liability lawyers now place the warning prominently in their operating manuals.  Never mind that anyone who would try such a clueless feat would also never, ever read an operations manual.

While ironing and pressing are the avenue of last resort to remove wrinkles from natural fiber and organic clothing, you do have a laundry basket of options which can greatly reduce or eliminate wrinkles from your clothes before they ever reach the ironing board. Here are some of the best.

In the store. The wild, woolly world of wrinkling woes begins in the store or recycled and pre-worn clothing shops. Not only do some fibers wrinkle more than others but some fabrics and weaves also so a greater propensity for wrinkles. If wrinkle-control is a big issue for you when shopping for new or recycled natural fiber clothing:

• Choose fabric weaves that are more immune to wrinkles like knits for cellulose fibers such as cotton, hemp, bamboo and Tencel / lyocell.
• Silk is a notorious wrinkler, but some silks are less prone to wrinkling. Chose silk crepe de chine, habotai, noil and charmeuse silks to tame the wrinkle monsters. Ahimsa silk – also known as Peace Silk because the silk worms are allowed to live and are not destroyed as they are for conventional silk – is also reputed to be more wrinkle resistant.
• Because of the elastic nature of wool fibers, wool fabrics are less likely to wrinkle … but they still can and do. Worsted wools are more tightly woven and more resistant to wrinkles while loosely woven woolens are more prone to wrinkling.
• Tightly woven garments with a high thread count are less susceptible to wrinkling. This is true for most fibers including organic cotton and the cellulose-derivatives like bamboo, Tencel / lyocell and modal.

In the laundry room. Here is where the real wrinkle-trouble blossoms. Many people – myself included – have laundry habits that maximize the potential for wrinkles. Besides blooming wrinkles, the laundry room also has a huge impact on the size of the environmental footprint created by clothing.

We have written a handful of posts about the environmental, ethical and health impacts of the clothing industry – including the time in the laundry room. The study “Well dressed?” from the University of Cambridge in the UK discovered that electric and gas clothes dryers use about 60% of the “use phase” energy consumed to keep clothes clean, ironed and pressed. Many advocate the use of clothes line drying indoors or outdoors to reduce the use of electric and gas clothes dryers. The excellent sustainable blog Green Living Tips has several articles exploring ways to incorporate clothes lines into the laundry lives of house and apartment dwellers. Originating in Australia and oozing with Down Under sensibilities, GreenLivingTips.com is definitely worth visiting frequently.

Washing machines use large amounts of water and energy to heat the water. The new high efficiency (he) washers are a significant environmental improvement that uses 50% or more less water, energy and detergent than conventional clothes washing machines.

Regardless of the type of washing machine or if you line dry or tumble dry, there are steps that you can take in the laundry room to win the war on wrinkles. Remember that it is heat and moisture that feed those wrinkle appetites so learn how to use them to deflate those wrinkle tendencies. Here are some tips:

• One popular home remedy is to add one cup of white vinegar to the final rinse of wash cycle. The white vinegar can be added to the fabric softener reservoir. This is supposed to help eliminate static cling and wrinkles. The theory is that the white vinegar helps keep the fabric fibers soft and flexible so that wrinkles don’t set into the fabric.
• As soon as the last spin cycle of the washing machine finishes, remove the clothes immediately - don’t let them sit in a big damp clump. Take out each garment individually, shake it out to remove all the twists, and place it in the dryer or hang it on a clothes line.
• When using a tumble clothes dryer, don’t stuff your dryer so that clothes are unable to open up and dry evenly. If your clothes dry in a wad, all those wrinkles will be trapped in the fabric. Some people suggest adding five or six tennis balls to the load. The tennis balls will help prevent the clothes from clumping together which will keep air flowing over all surfaces of the clothes. This will also help reduce the time to dry. The tennis balls will make some additional noise as they tumble around but they won’t cause any harm to the dryer drum or to the clothing.
• Remove clothes from the dryer as soon as they are dry. Leaving clothes tumbling in a hot dryer after they are dry just bakes in wrinkles … besides creating the conditions for shrinking and increasing static cling. This also means that a dryer load should contain fabrics of a similar weight so that they dry in roughly the same amount of time. Don’t plop a couple of heavy bath towels, which will take a long time to dry, in a dryer with light cotton shirts, which will dry more quickly.
• Hang or fold clothes as soon as the clothes are dry and removed from the dryer. Don’t leave them in a big heap in the laundry basket waiting to cool down. Remember about the glass transition temperature? When clothes cool down, the cellulose polymers will slip below their glass transition temperature and they will tend to retain whatever shape they are in. If they cool down in a crumpled heap, they will look it.
• If you are hanging clothes on a line to dry rather than using a tumble dryer, give each garment a good shake and smooth the fabric when placing on the line to dry. The smoother the clothes when hanging them, the less wrinkles after they dry.
• When drying on a line whether outside or indoors, a breeze blowing on the clothes will not only help them dry more quickly, but will also help remove stiffness and give a softness to the fabric. When line drying indoors, you can even use an electric fan to create a breeze on the clothes. The motion will keep the fabric fibers flexible as they dry which not only helps prevent wrinkles but gives a softness to the fabric. This is also one of the effects of the tumbling action in clothes dryers.
• For 100% bamboo fabrics, line or flat drying is generally recommended. Tumble dryers can cause 100% bamboo clothes to loose their shape and even shrink.

On the ironing board. After choosing your fabrics wisely and laundering correctly, if there are still wrinkles that you must flatten, then the electric steam iron is your trick of last resort. The steam iron combines the two primary factors in wrinkling – heat and moisture – to undo wrinkling.

Wrinkles will generally fall out of woolen fabrics if left to hang overnight, especially if they have been lightly steamed. Warm steam will help the tight, crinkly wool fibers to relax and loosen. If the woolen clothes are hanging, the weight of the garments will naturally pull most wrinkles out if left to hang overnight. For stubborn wrinkles, use a steam iron set to the wool setting which should provide a light, moist steam. Tips for ironing woolens:

• Don’t iron woolens when they are totally dry;
• If possible, iron the back side of the fabric to avoid a shine. If you must press the visible side of the woolen fabric, use a press cloth or thin towel on top of the fabric;
• Lower and lift the iron when pressing rather than sliding the iron back and forth.

In the closet. The battle against the wrinkle doesn’t end in the laundry room. When hanging clothes in the closet, give them a little room to hang. If clothes are tightly smushed together then any creases or twists will effectively get pressed back into the clothes. Shirts are best hung on plastic or wood hangers (not metal like the ones you get from the dry cleaners) and pants are best using clamp-style hangers on the bottom cuffs.

While traveling or other occasions when clean clothes become wrinkled. The travel wear industry has a firm foundation in fashioning clothing that travels easily … and wrinkles hardly … through a combination of wrinkle-resistant weave, fibers and chemical support. Travel wear is often the intersection of fashion and easy care garments which often depends upon blends of natural fibers, regenerated cellulose fibers and synthetic fibers such as polyesters, and upon chemically enabled permanent press fabrics. We’ll talk more about this because it is central to many health related clothing issues. Here are tips for how to smooth out wrinkles in clean clothes during traveling or even at home.

• Hang the wrinkled clothes in the bathroom while you take a hot, steamy shower. You will need to balance this with the sustainability issues of taking hot, steamy showers … but then issues of balance are frequently woven into sustainability. When your shower is finished, gently stretch your clothes by hand to pull out the wrinkles. Let them cool down and dry while hanging before wearing or folding them.
• If you have access to a dryer, toss the clean clothes in tumble dryer with a wet sock or wash cloth for 10 minutes. The wet sock or cloth will provide the moisture and the tumble dryer will provide the heat and motion to coax out the worst of the wrinkles. Or, instead of using a wet sock, you can use a spray bottle and lightly spritz the clothes before putting them in the dryer.
• Travel accessory companies like Magellan’s sell clothes steamers that are priced at about $30. They are relatively light (generally less than 25 oz.), compact and can be used while traveling or at home. The Jiffy Steamer is an excellent brand manufactured in the US since 1940 and produces a wide range of clothes steamers for home, business and travel. The reality is that a clothes steamer is much more effective that a hot, steamy bathroom and probably has a significantly lower environmental impact.

A clothes steamer works best on wool suits and slacks.  The hot steam relaxes the crinkly wool fibers and the natural weight of the garments as they are hanging pulls out most wrinkles. The wrinkles in many types of silks will melt away with a little bit of steam … except for smooth finish silks like charmeuse which respond better to a warm iron. Steam, either from a clothes steamer or electric steam iron, works well on cotton fabric but often leaves spots or rings on 100% bamboo fabrics. Oh, yes - just another reminder to not be wearing the clothes that you are trying to steam.

During the day … or evening. OK, it is possible to become totally crazy and completely obsessive / compulsive about wrinkles. Personally, I believe that there is no reason to disturb your composure or wa over a few random creases in your clothing. Keep things in perspective. But if you are one of those people who feel that a little inconvenience or even discomfort are worth the price of peace of mind knowing that your appearance is smooth and unrumpled, then these tips are for you:

• When sitting for more than a few minutes, remove sports jacket or suit coat and hang, don’t toss over the back of a chair. Never place a suit coat in the overhead compartments of an airplane. Ask the flight attendant to please hang in a closet for you. Unless you are in business class, you will either receive a cross look or hysterical laughter.
• When sitting, don’t pull up trouser legs slightly to give a bit of room. Rather, as sitting, pull trouser legs down to remove excess fabric. Excess fabric behind the knees or in the seat is a prime opportunity for wrinkling.

That smelly, toxic elephant in the china closet. The topic of permanent press clothing will soon force its way into any discussion about avoiding and removing clothing wrinkles. We will explore the technology and health concerns of permanent press clothing in the next post. Stay tuned…

Enjoy
Michael

Why Natural Fiber Clothes Wrinkle

Why clothes wrinkle and how to stop clothes from wrinkling have befuddled people from the time when mirrors were invented.  The world of fabrics is littered with many incorrect myths about what causes fabrics to wrinkle and what to do about it. Let’s take a journey together through all the wrinkles of fabric lore to see what we can do about removing wrinkles from clothing.

Why do clothes wrinkle? The two primary causes of wrinkling in fabrics are water moisture and heat. Heat and moisture can remove wrinkles (think ironing and steaming hanging clothes), but they are also the leading causes of that ferociously wrinkled organic cotton shirt. As we’ll see, many other factors can contribute to wrinkled clothing and there is much that you can do to reduce wrinkles that will also reduce the total amount of energy that you will invest in your clothing over their life cycle from when you first go clothing shopping until you are finally ready to send it to the thrift shop, homeless shelter or recyclers.

Which fabrics are more prone to wrinkle? Sometimes it seems as if an organic cotton shirt will sprout contact wrinkles if you just look at it and crinkle your nose while a polyester dress can survive a train wreck and still be ready for a night on the town. Generally, clothes using fabrics made from natural cellulose – cotton, hemp, linen (flax) – are the most prone to wrinkle. Clothes made from regenerated cellulose – bamboo, rayon, Tencel / lyocell, Modal – or from regenerated plant protein – soya, Ingeo – are less likely to wrinkle and wrinkles are easier to remove. Animal fibers – wool, alpaca, cashmere – are generally the least likely to wrinkle. Silk tends to fall in the middle category of wrinkle-ocity.

But, this doesn’t mean that just because a favorite organic cotton skirt is made from organic cotton or hemp that it is going to have more wrinkles than Shar Pei puppies. The tendency of a garment to attract or repel wrinkle is affected by many qualifications such as: weave – knits are less likely to show wrinkles than woven fabrics; fiber blends – wrinkles will easily fall out of a woven yoga top of 95% organic cotton blended with 5% lycra (spandex); quality of fibers – other factors being equal, high quality long staple organic cotton fibers are less likely to wrinkle than lower quality conventionally grown short cotton fibers; quality of manufacturing – a dress of tightly woven, high thread count cotton finished with tightly sown seams will last longer, look better and often require less ironing than a low quality garment; fabric finishes – this is tricky as chemical fabric finishes can be added during manufacturing or during laundering that will reduce the propensity for wrinkling, more about this later; and laundering – which can make all the difference between having your clothing look like the surface of the moon during a solar eclipse or the smooth, shiny backside of a new baby … well, maybe not the best metaphor but you get the idea.

Why do some fibers wrinkle more than others? The differences are in the structural and chemical natures of the fibers that make the fabrics. Let’s quickly first look at how the chemical nature of fibers affect how they respond to wrinkling.

Polymers are the key to understanding wrinkling. Polymers form the basic structure of many fibers which form fabrics. The cellulose found in cotton, bamboo, hemp and linen flax and the proteins that comprise the new eco-fibers Ingeo and soya are natural polymers. Nylon and PET (PolyEthylene Terephtahalate) are examples of synthetic polymers that have been used in clothing. Polymers help hold fibers together and give stability to fabrics.

The energy in heat, whether the heat comes from hot water during washing, hot air in a clothes dryer or even body heat, weakens the covalent bonds that bind polymers together but different polymers of different fibers have different transition points at which the bonds weaken. The polymers of natural cellulose fibers such as cotton, hemp and flax, which is used to make linen, have a much lower transition level and therefore require less heat energy to break the stable covalent bonds than nylon, polyester or regenerated polymers of bamboo, rayon, Tencel / lyocell, Modal, or Ingeo which means that they wrinkle more easily.

This transition point where a polymer’s covalent bonds become weaker is also known as the “glass transition temperature.” An interesting research paper by J.M. Maxwell at the University Of Melbourne, Australia, found that cotton fibers pass through a glass transition at about 72 degrees F (22C) at a relative humidity of 78% which shows the connectedness between heat and water for fabric wrinkles. Different types of fibers have different glass transition temperatures with natural cellulose fibers such as organic cotton, hemp and linen on the lower end of the spectrum making them more susceptible to wrinkling. Research from other sources suggests that moisture and humidity also lower the glass transition temperature, at least for natural cellulose fibers.

Heat is only half of the wrinkle equation. Heat’s partner in growing or removing wrinkles in clothes is water moisture. Using a scanning probe microscope, Maxwell found that water moisture caused cotton cellulose fibers to swell and soften making it easier for the fibers to move and change shape which are all part of the wrinkling or wrinkle removing processes. These are the chemical processes involved in wrinkles.

Mitsuhiro Fukuda of the Textile Materials Science Laboratory at Hyogo University has researched the “dimensional stability” like wrinkling caused by moisture on hydrophilic and hygroscopic fibers such as cellulose and cellulose derivatives (regenerated cellulose). Fukuda documents that a 1% increase in a fiber’s moisture content causes a decrease of about 10 degrees C in the glass temperature for many polymer fibers. The lower the glass temperature of a fiber then the more likely that the fabric will wrinkle.

The structural factors in natural cellulose fibers involve fiber fibrils which are bunches of cellulose chains all lined up together and twisted together into threads that are woven or knit into clothes. The cellulose fibers are held in place through chemical bonds between hydrogen atoms across cellulose fibers. Both heat and water weaken these hydrogen bonds which help keep the fibers in fabrics together and this can happen during washing, drying, while wearing (your skin releases a lot of heat and moisture even if you aren’t sweating), or even while hanging in a closet during a hot, humid day.

To see how wrinkles develop in your cotton, hemp or linen clothing, look through a microscope at the fabric threads and you will see lots of rough little fibers that stick out from the woven threads and become intertwined with other fibrils from other threads. During laundering or even during wearing on warm, humid days, the heat and moisture help weaken the chemical bonds helping to hold fibers in place and the moisture softens the fibers and allows them to slide around more easily. When the fabric dries and cools, the rough little fibers become intertwined with other fibers in different locations and the chemical bonds reform and give rise to the wrinkles. This is why those natural cellulose fiber fabrics have a greater propensity to wrinkle.

Regenerated cellulose fibers, such as bamboo, Tencel / lyocell, Modal, and rayon, are more immune to wrinkling than natural cellulose fiber clothing for two reasons. First, they tend to have a slightly higher glass transition level. Second, regenerated cellulose fibers are born by being shot from a spinneret head into a chemical bath which gives the fibers a smooth surface without small fibers sticking out to snare and become tangled with other fibers during washing or wear.

Fabric weaves and wrinkling. The type of fibers, the temperature and the moisture absorbed by a fiber all contribute to fabric wrinkling, but wrinkling is also influenced by the type of weave and construction of fabrics. Generally, loosely woven fabrics are more susceptible to wrinkling than tightly woven fabric. A high thread count, tightly woven cotton shirt or bed sheet will tend to wrinkle less than a low thread count, loosely woven cotton shirt or bed sheet. The tight weave tends to hold the threads and therefore the fibers in place without as much freedom to move around and give rise to wrinkles.

Knit fabrics tend to wrinkle less than woven fabrics because of the inherent elasticity of a knitted fabric compared with a woven fabric.

Blended fabrics and wrinkling. Stretch woven clothes, which are typically 90% to 96% natural fibers such as cotton blended with 10% to 4% spandex / lycra threads, also tend to be more wrinkle-free due to the elastic quality of the spandex / lycra threads. To reduce nasty wrinkles, clothing manufacturers sometimes blend natural fiber fabrics – cotton, hemp, bamboo, rayon, Tencel / lyocell and even silk – with more wrinkle resistant fibers like polyester. There is an ecological case that states that the total lifecycle environmental cost of synthetic clothes made from polyesters can be significantly less than for natural fibers such as organic cotton and hemp. It’s up to eco conscious and health sensitive consumers to decide where their consuming edges really are.

Silk and wrinkling. For such a simple fiber forced out of the lower lip of the silkworm, the processing into fabric and then into clothing is often complex and chemical intensive. Silk clothing manufacturers often use a wide variety of chemical finishes and manufacturer processes to improve the easy care properties of silk including making silk more wrinkle-free. One chemical process for making silk clothing more wrinkle resistant is by bathing silk in “an aqueous solution containing a water-soluble epoxy compound in a catalyst which may be selected from alkali metal or alkali earth metal salts of dicarboxylic acids, tricarboxylic acids, and amino carboxylic acids.”

 Another chemical finish for more wrinkle free finish uses glyoxal resin with ethylene urea and a metal-acid catalyst. Machine-washable silks commonly use urethane resins with or without formaldehyde. And, of course, there is nothing on a garment label that gives a clue as to what chemicals that new silk blouse might have been soaked in. To bad clothing isn’t like Campbell Soups that list all their chemical ingredients.

But, silk naturally has a wide variety of wrinkle and care tendencies depending upon what kind of silk it is. Silk crepe de chine, habotai, noil, and charmeuse are generally easy care silk fabrics less prone to wrinkling. Ahimsa silk, also know as Peace Silk because it is made from silkworm cocoons in which the silk worms were not killed, also wrinkles less than other silks.

Wool and wrinkling. Wool does wrinkle and, like other fibers, the propensity to wrinkle depends upon the weave and type of wool. There are basically two categories of woven wool garments: woolens and worsteds. The distinction between the two categories of wool garments depends upon how the wool fibers are prepared which results in different degrees of snugness in the weave. Woolens are more loosely woven and more prone to wrinkling while worsted wools are more tightly woven and more resistant to wrinkles.

Wool will wrinkle like clothes made from cellulose fibers for most of the same reasons – heat and moisture affecting the glass temperature of the fibers and allowing hydrogen bonds in the fiber molecules to disconnect and reconnect to create wrinkles.

Wool is more wrinkle-resistant and recovers more quickly from wrinkles because of the more elastic nature of wool fibers. The elastic filaments and viscoelastic properties in wool fibers help the fiber stretch and then return to its original state when the force which contorts the fabric into a wrinkle is removed. Low Friction between the yarns in wool fabrics also helps wool garments recover quickly from being wrinkled back to their original state. Wool clothes will wrinkle when the wrinkled state is held for a long period of time in a hot and humid environment.

Wrinkle wrap up. All natural fibers – and synthetic fibers also – have a greater or lesser propensity to wrinkle and the twin enablers that encourage wrinkles are heat and moisture. Both heat and moisture help break weak molecular bonds that bind fibers to each other within fabrics. This allows fibers to shift within the fabric and to be reshaped by other forces such as laundering or wearing clothes in hot, humid conditions. When the temperature is lowered and the moisture dried out, the fibers reform new bonds which give the fabric a wrinkled look.

A fiber’s wrinkle destiny is affected by other factors also such as the type of weave, thread count and tightness of weave, and fabric quality.

In the next post, we will examine how you can help your natural fibers resist the urge to wrinkle.

Enjoy.

Michael

Bamboo Sprouting Green Myths

"Advertising is the 'wonder' in Wonder Bread." - Jef I. Richards, Professor of Advertising, University of Texas at Austin

Bamboo fabric is becoming the Wonder Bread of sustainable textiles. This isn’t to say that bamboo doesn’t have many exceptional qualities. I’m just saying that the green hype is starting to lead to a loss of credibility. Let’s take a short walk through the bamboo green claims and see what’s real and what’s green spin.

Anti-bacterial & UV Protection. “Bamboo fiber has particular and natural functions of anti-bacteria, bacteriostasis and deodorization” due to a “a unique anti-bacteria and bacteriostasis bio-agent named bamboo kun." The mysterious anti-bacterial component has also been called “bamboo chinone”. This unique claim of bamboo fabric is bolstered by studies performed by the Japan Textile Inspection Association; National Textile Inspection Association in China (NTIA), and the Shanghai Microorganism Research Institute. The theory goes that somehow the bamboo kun is chemically bound closely to the bamboo cellulose fibers and this chemical binding survives the harsh chemicals used to free the bamboo cellulose from the lignin and other components found in bamboo when the bamboo cellulose is regenerated into bamboo fiber.

There are two problems to bamboo’s claim for being a uniquely anti-bacterial fabric. The first is that bamboo fabric’s anti-bacterial claim was recently repudiated by research conducted by Colorado State University chemists Subhash Appidi and Ajoy Sarkar, Ph.D., investigating UV-resistant and anti-bacterial fabrics. They reported at the 235^th national meeting of the American Chemical Society that “bamboo fabric did not live up to antimicrobial expectations.” Their research also indicated that bamboo fabric is low in UV-resistance and that most damaging ultraviolet rays pass through bamboo fabric to the skin. The research at the Colorado State University directly contradicts many claims and research performed in China and Japan. We need more independent and transparent research to ferret out why the differences.

The second problem is that claims for being an anti-bacterial fabric are not unique to bamboo fabric. Other regenerated cellulose fabrics also claim to have anti-bacterial properties. According to the Lenzing AG web site, “Bacterial growth was observed in various fibers, and TENCEL®, with its rapid absorption of moisture and high absorption capacity proved most effective in inhibiting growth” and “The result demonstrates that TENCEL® is the most naturally hygienic fiber. TENCEL® prevents the growth of bacteria naturally without the addition of chemical additives.”

Unique Bamboo Properties? Thermal-regulating, Anti-static, Biodegradable, Natural UV Protection, Super Soft. Regenerated cellulose fabrics share many common properties. “Green & biodegradable, breathable and cool, soft had feeling, luxurious shiny appearance” are properties commonly found in regenerated cellulose fabrics such as Tencel® / lyocell, Modal®, Viscose® … and bamboo. And this shouldn’t be any surprise as they all derive from cellulose that has been extracted from plants using similar chemical processing and then excreted through spinnerets to form fibers for textiles and clothing.

Research by Y. Xu, Z. Lu and R. Tang at the Testing and Analysis Center at Suzhou University in China used scanning electron microscopes (SEM), Infrared Spectroscopy (IR), and thermoanalyzers (TA) to analyze the physical structure and properties of bamboo viscose, Tencel® and viscose fibers. Their results, which are reported in the Journal of Thermal Analysis and Calorimetry, Vol. 89 (2007), found that all three fibers belong to the cellulose II category and that, while there are variations in the regenerated cellulose fibers that affect fiber properties, the similarities in structural properties are striking. Among their findings was that Tencel® consists of longer molecules and has a greater degree of crystallinity, while bamboo viscose fiber has a lower degree of crystallinity. Differences in fabrics from regenerated cellulose are a combination of factors – some differences in the cellulose cellular structure between the different sources, differences in the mechanical spinning processes when the fibers are formed and the specific chemicals used, and the finishing processes and the enzymes and chemicals used.

Grown on Environmentally Friendly Bamboo Plantations. Bamboo fabric is spun from bamboo pulp manufactured from bamboo grown on bamboo plantations primarily in China. Because bamboo has so many uses and derived products, growing bamboo has become a significant industry in China. The book Rehabilitation of Degraded Forests to Improve Livelihoods of Poor Farmers in South China by Liu Dachang published in 2003 by the Center International Forestry Research researches in depth the environmental and social damage that have been created by poor and over-harvested forests of all kinds, not just bamboo, in China. Chinese government forest policy reforms within the last twenty years have transferred ownership of most forests to private citizens and businesses. The result has been a lack of government regulations for controlling forest land use and many forests were clear-cut to plant money-making mono-cultures such as bamboo plantations.

The adverse environmental impact associated with bamboo plantations replacing natural forests was also documented in a paper by Dr. Jim Bowyer titled “Bamboo Flooring – Environmental Silver Bullet or Faux Savior?”. Because of the severity of the problems, there are now broad initiatives underway in China to rehabilitate degraded forest lands by restoring biodiversity and improving soil and forest conditions. Because bamboo has so many different economics uses such as food products, paper, furniture and housing materials, and textiles, the opportunity and temptation for exploitation of land and resources is great and it is difficult to determine where and under what conditions the bamboo was grown. This is especially a problem for bamboo textiles which are made from regenerated cellulose bamboo pulp because bamboo fiber manufacturers buy their bamboo pulp from suppliers. They don’t manufacture it themselves and there is little transparency in the supply chain.

Here is one example. On their web site, BambroTex proclaims “Bamboo Fibre is a kind of regenerated cellulose fiber, which is produced from raw materials of bamboo pulp by our sole patented technology. Firstly, bamboo pulp is refined from bamboo through a process of hydrolysis-alkalization and multi-phase bleaching. We then process Bamboo pulp into bamboo fiber.” At the same time, Tenbro is declaring “Shanghai Tenbro is the earliest and most specialized bamboo fiber manufacturer in China, and the only patent holder of both material and products of bamboo fiber accredited by State Intellectual Property Bureau.” Both the claims of BambroTex and Tenbro to being the sole patent holders of bamboo fiber are misleading. It seems that Jigao Chemical Fiber Co., Ltd. of China is the actual holder of the patent for manufacturing bamboo fiber in China and the Jigao Chemical Fiber Company produces all the bamboo fiber which Shanghai Tenbro Bamboo Textile Company, China BambroTextile Company, Hebei Jigao Import & Export Company, Jilin Chemical Fiber Import & Export Company, Shanghai Worldbest Company and Minmetals Shanghai Pudong Trading Company export bamboo fiber globally according to the Jigao Chemical Fiber Company.

Things with bamboo fiber are seldom what they seem at first blush. The tens of thousands of tons of bamboo fiber produced by Jigao Chemical Fiber Company for export by its licensed agents such as the Shanghai Tenbro Bamboo Textile Company and the China Bambro Textile Company are manufactured from hundreds of thousands of tons of bamboo plants raised on many thousands of bamboo plantations across China under a wide variety of environmental farming conditions. How can any manufacturer claim that their bamboo fabric is only produced from bamboo grown on environmentally sustainable farms? How do they know where their bamboo was grown and under what conditions? Given the intense emphasis on profits and the lack of transparency in Chinese business and that one company manufacturers the bamboo fibers used in the majority of exported bamboo fabric, claims that only environmentally sustainable bamboo plants are used ring as hollow as a bamboo flute.

The processing of bamboo plants into textile fibers is relatively harmless because caustic soda is the “main chemical used.” Caustic soda, aka sodium hydroxide - NaOH, is one of the ingredients used to reduce bamboo plants to pulpy goo in a process known as hydrolysis alkalization. Caustic soda is a harsh alkaline chemical that must be handled carefully, especially at high levels and under the high temperature and pressure needed for hydrolysis alkalization. As the old saying goes “The poison is in the size of the dose.”

Another toxic chemical in the processing of bamboo rayon is carbon disulfide which has been linked to serious health problems. Breathing low levels of carbon disulfide can cause tiredness, headache and nerve damage. Carbon disulfide has been shown to cause neural disorders in workers at rayon manufacturers.

In Summary. Bamboo fabric has much to offer but much remains to be done before the growing of bamboo can have significant environmentally positive impacts. Here are some steps to produce a more sustainable bamboo fabric:

• The Chinese Government must strengthen their forest reform policies.
• Organic bamboo certifications must be enacted to insure that bamboo plantations are sustainably managed.
• Bamboo rayon fiber manufacturing must be transformed into a closed-loop process to reduce the escape of harsh and toxic chemicals into waste waters, the air and the textile workers environment.
• Commercialize natural bamboo bast fiber processing such as that promised by Litrax so that we can get away from chemically regenerated bamboo viscose rayon.
• And please, make sure that marketing claims match the facts and don’t mislead the consumer.

Enjoy.

-Michael