Textiles and Fibers, A-Z, pt. II: Waterproofing in cloth diapers

Like I mentioned last week, there are two necessary components of a cloth diaper system: absorbent cloth and waterproof (or water-resistant) cloth. And whether you choose a system with a separate waterproof component (usually called a 'cover' or a 'soaker,' but in the case of gDiapers is a distinctive pouch that snaps into a bloomer-cover) or with a sewn-on waterproof layer, there are lots of great options presented by the inventors and designers behind the modern cloth diaper movement.

Fortunately for you (and for me!), there are fewer textiles commonly used to provide waterproofing than there are to provide absorbency, and they can be grouped into categories that are functionally similar. Laminates and nylons provide waterproofing and feel similar to each other and perform similarly despite their being very different textiles, while fleece and wool are functionally similar in that they are water-resistant, despite being very different in some ways and requiring different styles of laundry care.

If this is information overload for you, don't worry about it! You don't have to care about this stuff to be in the cloth diaper club; not caring to learn the chemical and structural details of the textiles used in your cloth diapers does not mean you are cloth diapering the wrong way. (In fact, I think the only 'wrong way' to cloth diaper is to accept problems as part and parcel of the product instead of reaching out for help from from experienced cloth diapering moms!) But if you're a researcher or even a seamstress yourself, this hopefully comprehensive overview may strike your fancy!

Waterproof textiles

Laminates are textiles that are made waterproof by adding a layer of Thermoplastic Polyurethane (TPU) to an outer fabric that works well to complement the waterproof properties of the polyurethane. Most often, we see TPU laminated to a polyester interlock to create what is commonly called "PUL" in the cloth diapering world.

Polyurethane Laminate (PUL) - PUL is, as mentioned above, most commonly rendered as a compound of some brand of TPU, which is a family of clear, stretchy, waterproof plastics manufactured under more than a dozen name brands, laminated to a polyester interlock or, sometimes, a thickly woven cotton. PUL can be '1 mil' or '2 mil,' which describes its thickness. Thicker PUL is alleged to be less breathable, but more durable, than thinner (1 mil) PUL. PUL is used to create the waterproofing of most pockets and AIOs as well as most wrap-style covers on the market today. 

Many sources claim that PUL was developed to be a medical-grade textile and is thus hardy under 'harsh,' sterilizing laundering conditions like regular exposure to very high heat. However, most cloth diaper manufacturers do not allow their PUL warranties to cover products that have been regularly washed in very hot temperatures--many manufacturers even specify a maximum water temperature that must be used in order to satisfy warranty conditions.

Some manufacturers have claimed that their product is made with "TPU, not PUL," but this is most likely a misunderstanding about some of the technical 'chemistry' terms involved in the world of textiles derived from plastics, which is quite a vast and confusing world! What most manufacturers mean when they say their products make use of 'TPU' is that the manufacturing source from which they purchase their waterproof materials uses a heat (thermal) bonding rather than a chemical bonding process to laminate their outer fabric (usually a polyester interlock, but sometimes woven cotton) with TPU. However, the name "thermoplastic polyurethane" describes how this particular polyurethane (notably different from many other polyurethanes for its elasticity and its transparency) is made, not how it is bonded to its outer fabric.

So why do some PULs feel different than others? There are at least a dozen brands of that clear, stretchy TPU on the market--some are "stickier," some are smoother, and some are more textured. There are also several methods of bonding the polyurethane to the fabric outer, and each method will affect the texture of the finished compound. Additionally, some manufacturers choose to sandwich a "hidden layer" of PUL between other fabrics--the Bummis Super Whisper Wrap, for example, employs a layer of 2 mil PUL bonded to polyester on either side of the polyurethane for extra durability. This makes for a stiffer fabric, and the cover is not slick and "wipe-able," but it is extra leak-proof, and it means that no laminates touch the baby's skin.

Our newest product addition, the bumGenius Freetime, comes in proprietary colors, meaning that the color palette is commissioned by the manufacturer for its own use and cannot be found among other PUL suppliers.

Each PUL manufacturer has a contract with a particular brand of TPU (and with a particular brand of polyester interlock as well). Some cloth diaper manufacturers contract with a PUL factory and design proprietary prints and colors (which is why you can't find, say, Thirsties prints or the FuzziBunz color palette on a WAHM diaper); others just purchase wholesale and in bulk, using whatever prints and colors are available to them, and not limiting themselves to PUL manufactured at a single factory, which is why sometimes a single brand will carry prints with PUL that feels just a little different than their solid color palette or some of their other prints.

Laminates are known in the cloth diaper world for 'de-laminating,' which describes the process of the clear, plastic TPU becoming unbonded from the outer fabric. Why does this occur? Sometimes it's a reaction to too much heat exposure, and other times it's a reaction to certain chemicals. Often, though, it's just a product defect. Ever used a laminating machine to laminate paper? How many times has your finished product had a 'bubble' in it? While the process of creating PUL has been refined over the last thirty years, PUL is prone to bubbling and eventually de-laminating if the conditions under which it is bonded are not exactly, perfectly, precisely correct. That's why cloth diaper manufacturers often warranty their PUL for so long.

Pros: PUL is easily laundered, reasonably durable, and definitely waterproof. It can be manufactured in a multitude of colors and prints. Cons: Delamination does happen; fortunately, most manufacturers offer warranties to protect the customer in this event. Additionally, some children are sensitive to the chemicals used in the bonding process of a particular PUL brand or to the plastic itself; others just require more breathability than any laminate can offer.

Nylons that have been treated with a waterproofing agent are also used to create the waterproof layer of some cloth diaper systems, including the gDiapers snap-in gPouch.

Polyurethane-coated Nylon - Polyurethane-coated Nylon is simply another waterproof textile option. It is used to make old-fashioned plastic pull-on pants, like the Dappi, as well as the gDiaper snap-in gPouch. This is integral to what gDiapers terms "gBreathe technology"--because Nylon is more porous and thus more breathable than many of the polyesters used in the outer layer of the alternative, PUL. 

gPouch: coated Nylon

Interestingly, polyurethane-coated Nylon is certified 'food-safe' by the FDA (although when used for reusable food storage products, the 'shiny' side should never touch food), while PUL is not, which leads many to allege that the Nylon alternative is generally less "chemical-ly." Polyurethane-coated Nylon is certified to be mildew- and stain-resistant, although many moms find that gPouches do stain.

Pros: Coated nylon is more breathable than PUL, and there is no equivalent to the 'delamination' that is simply a risk of the PUL manufacturing procedure. Cons: Coated nylon cannot be washed in hot temperatures, which are ideal for killing the bacteria left behind on cloth diapers. Machine washing does break down the polyurethane coating more quickly than PUL is broken down; therefore, products like the gPouches do not have the life expectancy of a PUL cover.

For brevity's sake, we'll cover the water-resistant options, fleece and wool, next week. You think I had a lot to say about PUL? Just wait.

Putting the 'cloth' in cloth diapers: the A-Z on textiles and fibers in CDs

Whether you're researching cloth, you're waiting on an upcoming appointment or workshop with a retailer or consultant, you're just getting started building a stash, or you've been in the thick of cloth diapering for a while, you may find yourself constantly encountering new and unfamiliar textile terminology. 

Does it all confuse you? And do you like what you've got already?

Ain't nothin' wrong with that, my friends. Move right along and ogle something beautiful, like the new gDiaper special releases we just received a shipment of.

But if you've become a diaper nerd--or if you just pride yourself on being the type to research thoroughly enough to know everything there is to know--you may appreciate a handy reference guide to the types of textiles found commonly in cloth diapers.

Textiles 101

So, it's important to know that there are certain terms you'll hear that refer to fibers and raw materials, and there certain terms you'll hear that refer to the way a fiber or raw material is woven, knit, matted, interlaced, or otherwise put together in order to achieve the texture, behavior, and other physical properties characteristic to the textile. Often the resulting textile can be made from a number of possible fibers or raw materials. 

One such example is the term 'fleece.' 'Fleece' does not describe one single type of fabric; it is not in itself a fiber. Fleece is a textile that can be made from many types of fibers and/or raw materials: synthetics like polyethelene (made from a plastic resin) or even the components of recycled plastic bottles, but also hemp and cotton. Microfleece, also known as polar fleece, is a synthetic textile that was invented in 1979 and is a commonly used stay-dry (or "wicking") fabric used in cloth diapers.

Flannel and velour are other examples of textiles that can be made from various fibers.

So what puts the 'cloth' in cloth diapers? 

There are two things a diaper must be to function as a diaper: absorbent and waterproof. After that, some parents may choose a diaper system that pulls moisture away from their baby's skin for comfort reasons as well as to prevent diaper rash; this component is certainly one of the many conveniences of modern cloth diapers, but a diaper can be a diaper without it.

We'll start this week with... 


Absorbent materials

Synthetic textiles are textiles that are manufactured from already manufactured components. Sometimes one component of the raw materials can be found in nature, but, by and large, synthetic textiles are the result of modern chemistry. There is some argument that, despite their association with plastics and plastics manufacturing, their production is 'greener' than textiles woven from natural fibers, which must be farmed, and are often conventionally farmed using pesticides, and then shipped. The cost of synthetic textiles is more easily regulated and slower to rise than the cost of natural fibers, which are in higher demand and lower supply.
 
Microfiber terry - commonly referred to as simply "microfiber," this material is, more accurately, a high-pile, tight-loop version of the synthetic textile microfiber made into a terry (which is why it feels different than, say, your microfiber-covered couch). Terries are absorbent because the loops act as small sponges. Microfiber terry is commonly used to make automobile and kitchen towels! 

The Thirsties Duo AIO uses microfiber terry as its absorbent core material.

Its most common use in the cloth diaper world is as a cut, stacked, and serged-together insert for pocket diapers. It also appears inside All-in-Twos, All-in-Ones, and even in some fitteds. Microfiber terry diapers reach peak absorbency after about 10 washes, although most families find that they are absorbent enough to be usable after only one or two high-agitation washes. Pros: It's inexpensive, durable, and heavily absorbent. Cons: Some mothers frequently express that microfiber terry holds onto minerals from hard water and becomes stinky more quickly than other materials commonly used for absorbency. Microfiber cannot be worn against the skin and is reportedly prone to compression leaking if it becomes saturated.

Zorb and Zorb II - Zorb is a synthetic absorbent textile invented and patented by Wazoodle, an online fabric supplier that specializes in cloth diaper fabrics. It is not all that different than microfiber--it's a blend of poly/micro fibers, viscose of bamboo, and cotton. Pros: According to the manufacturer, it is hemp-free (Wazoodle is an advocate for eliminating hemp from the diaper and healthcare product markets) and trimmer than microfiber terry. It is also manufactured in the US and Canada. Cons: It's weighty, which makes it expensive to ship and thus to source; no mainstream industry manufacturers are using Zorb at this time. Zorb cannot be worn against the skin and is, like microfiber terry, reportedly prone to compression leaking.

Sherpa - Sherpa is a cotton/polyester blend that is processed into a knit terry. It is more commonly used among WAHM cloth diaper manufacturers than mainstream industry manufacturers. Pros: Sherpa can be found in colors other than 'white' and 'natural,' which can be a lot of fun! Cons: Sherpa's plushness makes it, like many other synthetic absorbent textiles, fall prey to that tendency towards compression leaking.

Absorbent minky - Fairly new to the cloth-diaper-absorbent-core scene, absorbent minky is all the rage these days because of its fast drying time and soft feel. "Mothers Against Microfiber" prefer it because it doesn't feel rough on their hands when they're stuffing it into pockets--it feels incredibly soft and luxurious, actually... because it is synthetic mink! 

Tots Bots EasyFit: minky!

Some sources tout absorbent minky as stay-dry, and it is often used as the inner layer of WAHM pocket diapers. However, it is my opinion that a distinction should be made between "quick-drying" and "stay-dry." The fabric that makes up a stay-dry layer (also called a "wicking layer") actually pushes moisture quickly past itself and directs it onto the layer underneath it, the absorbent core. Minky merely dries quickly, so if a diaper is used once and left on the baby over a period of time--say, during a nap--the urine will dry fairly quickly and your baby's diaper may not feel wet unless it is highly saturated. It does not perform the same function that a traditional wicking fabric does. Pros: Though synthetic, it can be safely and comfortably worn against the skin. Cons: Some moms do not find that its typical configuration of three or four stacked layers is absorbent enough on its own and must use a doubler with it.

Bamboozle, made from stretch rayon.

Rayon from bamboo - Also known as "viscose of bamboo," this is a synthetic textile, despite its derivation from a plant. Bamboo itself is farmed in a comparatively green and sustainable way, although the manufacturing process is no more or less green or toxin-free than the process associated with any synthetic textile; some of the chemicals used to process rayon include lye and carbon disulfide. The plant contains anti-microbial properties, but the resulting fabrics do not. 

Rayon from bamboo (or from any plant) can be made to mimic silk, wool, cotton, and linen. The version of the fabric that appears in cloth diapers, HVM rayon, is usually napped, giving it more textural similarity to a fleece or even a terry than to a smooth, woven fabric. It can also be made into a velour.

Rayon from bamboo is reported to be slower to absorb than terries, which are made from large loops and thus act more effectively as 'sponges.' Because of this, it is often paired with or layered underneath microfiber terry to catch what is 'squeezed out' of the microfiber layers. HVM rayon is more durable and retains its appearance for longer than the conventionally processed version. Pros: Rayon from bamboo is soft, thin, and absorbent. It does not compress as profoundly when layered like a high-pile fabric such as microfiber does. It can be worn against the skin. Cons: Claims that this is a naturally anti-microbial, natural-fiber material simply are not true.

Natural fiber textiles are often considered more "high-end" than their synthetic counterparts. Some families find that they are more difficult to clean than diapers made from synthetics, while others find that they are more easily cleaned; this is so dependent upon the makeup of a household's water supply that a generalization really can't be made fairly or accurately. 

Natural fibers can be configured in several different ways to form the absorbent textiles that become the absorbent core of a cloth diapering system--they can be woven and smooth, knotted into a velour or French terry, and even blended together. Natural fibers are farmed and then shipped to factories where they are made into various usable textiles, including the types of textiles used in cloth diaper manufacturing. There is concern among fair trade activists that most of the labor on these farms falls to severely underpaid workers and even to slaves.

All diapers made from natural fibers require additional "prepping" before first use. This prep process is accomplished in a number of ways, usually involving hot water and often a de-greasing agent. The goal of prepping is to remove as much of the natural oils and waxes inherent to the fibers as possible in order to achieve maximum absorbency and prevent repelling. 

Cotton - Who doesn't know about cotton? Cotton, like other natural textiles, has the benefit of being, well, natural. Absorbent cotton is made by removing the fiber's naturally occurring wax. 

It's rare to run across a cotton allergy, and there's a reason cotton has been used for diapering for centuries. It's highly absorbent and highly durable. It can be made into a number of textiles: flannel or a flannelette, a fleece, or even a velour, but a simple birdseye weave is its most common manifestation in the cloth diapering world. It is typically bleached, which is effective in removing its oils and waxes, but it can also be purchased unbleached. Pros: Woven cotton, like birdseye, is porous and breathable while still being highly absorbent. Most cotton products, especially Chinese or Indian cotton prefolds and birdseye flats, are inexpensive. Cons: Conventionally farmed cotton is regarded as a problematic crop for a number of reasons, both environmental and human rights-related. Because of this, many consumers feel ethically convicted not to purchase it.

Organic cotton - Cotton that has been farmed according to certified organic farming practices, using minimal to no chemical pesticides, is classified as organic cotton. Because it is more rare than conventionally grown cotton, it is often more expensive. It is considered less durable than conventional cotton and is prone to tearing or forming holes near its seams when it is sewn or serged. Pros: There are significantly fewer environmental concerns regarding the farming and harvesting of organic cotton than conventionally grown cotton. Cons: Fair Trade organic cotton can be darned near impossible to source; even organically grown cotton is associated with labor practices that would not fly in the United States. Additionally, its sustainability as a crop remains a concern--while grown without chemicals, organic cotton still carries a hefty footprint because of the amount of land and water its farming requires.

Hemp - Hemp is a little controversial in the textile world, but it is certainly popular in the cloth diapering world. To be softened enough to be usable as a textile, hemp fibers must be blended with cotton fibers. According to some sources, this hemp/cotton blend is up to eight times more absorbent than cotton alone, and it is regarded as more durable.
 

Thirsties hemp prefolds.

Hemp, like bamboo, is an anti-microbial plant, but once it is manipulated and processed and blended with other fibers to become a textile, there is no evidence that it retains any anti-microbial properties. In fact, because hemp is so strong and absorbent, it is prone to stinking if it is not 100% cleansed and subsequently dried completely before its next use. Pros: Hemp's tensile strength and durability make it a great candidate for workhorse diapering. Cons: Because its production is limited to certain countries (in light of its association with marijuana), hemp fabrics are expensive for manufacturers to source, and that cost gets added to the price tag. Hemp blends that have less cotton in them, while more absorbent, are prone to stiffness.

Wool - Wool deserves a mention. It's most frequently used as a water-resistant outer, but wool makes an appearance from time to time as an insert or part of an insert. Why? Because it is absorbent! In fact, wool, an animal-derived fiber, can hold up to 30% of its own weight in liquid without feeling damp--that's because it consists of overlapping cuticles that repel water, but beneath those cuticles is a porous absorbent core. Pros: Wool is breathable and (it's true!) somewhat self-cleaning, and the types of wool used in diapering (like merino) are usually hypoallergenic. Wool is a fantastic option for babies who present a reactive sensitivity to other textiles popularly used in cloth diapers. Cons: Even machine-washable wools require some special laundry care. Wool is also more costly than plant-derived or synthetic fibers, and if you are passionate about animal rights, then wool presents a problem.

So is there a perfect absorbent textile for cloth diapers?

The perfect absorbent material for your cloth diapers is the textile that you like the best. It's what functions well for your child and cleans well in your washer, with your water. It's what your budget can handle, and it's what fits into your family's consumer ethics. 

Chances are, you'll love whatever you try first, because there's nothing popular on the market that just plain doesn't work. And if, like many mamas, you start with microfiber terry and then get the itch to try new things, well, that's great, too!

(Next time, we'll talk about waterproof textiles! Laminates and nylons, fleeces and wools--ever wondered what "interlock" means? Or what the difference between PUL and TPU is? Check back to find out!)

Double the fluff!

So I have some news, dear readers.

Monday, my husband and I went to a diagnostic imaging center to see our third baby on ultrasound for the first time and to find out if this little womb inhabitant was our second daughter or our second son. We did things a little unconventionally--we knew our dates with certainty, so we had opted out of the first-trimester dating confirmation ultrasound. I am currently 16 weeks and 4 days pregnant.

Almost as soon as she placed that wand on my belly, our ultrasound technician asked us, "And you said this is your... first ultrasound?"

Yep.

That was at 12:45 pm on Monday. I don't think I've blinked since then. My sweet husband's reaction? "Good thing we bought that minivan."

Then he said words that were music to my ears. "Hey! I guess this means you get to buy more newborn cloth diapers."

And, you know what? He's right. I'd already started building a new newborn stash--right around the time I was working on that Newborns in Cloth series (sneaky, right?). But I'm thinking that, just like all my other plans for this "baby," the game plan will have to be tweaked a little.

Come March, I'll have four children at home, ages newborn, 2.5, and newly 4. Anyone who feels inclined to volunteer to change one of these sweet girls (two girls!), then, will be welcomed to--and that means I need easy-peasy newborn diapers.

That's right: I'm scratching the prefolds and AI2s completely for the sake of convenience. I don't want to have to call out instructions from my rocking chair throne: "Please don't put the cover in the wet bag! I need to reuse it later!" ("And so which part are you calling the 'cover,' now?" is a real question I've heard more than once, and while I'm usually thrilled to get to do a little CD education, I'm not sure that newly postpartum after birthing twins is the best time for me to step up to the proverbial blackboard.)

Cloth diapered twins. Copyright Stacy Mitchell 2010.

Beyond that, I'm not sure I even have a plan or a concept in mind. I have no doubts that we'll be cloth diapering these babies full-time from birth. If they were babies #1 and #2, that might not be the case, but at this point, cloth is all we know. We've also discovered that there's a 90% chance that the girls are identical. They may need color-coded diaper stashes.

We've received an outpouring of love and support and lots of sweet, funny comments about how many cute cloth diapers will be flowing from our nursery to our laundry room! 

You can go ahead and join my husband in his gushing and fist-pumping and Awwwws. I really do appreciate it.

I'll just be in the corner, rocking back and forth on my heels, muttering a rosary under my breath, and sucking down a protein shake.

The What Nobody Tells You Files: Starting solid foods

It's that six-month milestone that first-time parents seem to universally look forward to. You know. Food.

I mean, whether you plan to go with the baby-led, self-feeding-from-the-start model or you want to catch that classic "open wide for the choo-choo!" moment on camera, you know there's going to be some mega-cuteness associated with introducing your baby to solids.

And you're mostly prepared for the thing that everyone does tell you about. You know the thing. The poop. You can't ever truly prepare for the thrills to come, but if you're cloth diapering, you probably have your diaper sprayer installed. You did that right after you bought new batteries for the camera. You're all set!

But there are certain Things That Nobody Tells You about heading down the flavorful and textured path of Babies Eating Food:

1) If you don't have a dog, keep your mop handy. This is the beginning of a years-long foray into food-on-the-floor frustration. 

At first, your baby will accidentally drop lots of food on the floor. Who could be mad about that? Her fumbly little fingers are so cute picking up that slippery, slobbered-up banana chunk. 

She'll get a little neater as time goes on, but then she'll learn... to throw. Throwing food is FUN. It gets a great reaction from grown-ups: laughter the first few times, that trademarked "I'm pretending to ignore you" face that moms can be so bad at, and, after several weeks, complete and total frustration, which is even better than laughter. After a 200-comment thread that begins with you asking your Facebook friends if it's all normal, you'll either get the throwing game under control or (more likely) she'll outgrow it.

But by then she's doing two new things: wanting to use a utensil (sort of) and rejecting the high chair. Standing in it. Leaping out of it. Refusing to eat and reverting back to food-throwing unless she's seated elsewhere. And 'elsewhere' usually means somewhere messy, especially when spoons are involved.

Some moms find that 'splat mats,' washable mats that protect the floor, work well to combat this problem. Not having to clean the floor aside, you still have to clean the mat. I think that I would be a lazy splat mat mom, and my splat mat would have to be replaced every couple weeks due to mold growth.

2) Starting solids probably won't cut down on the number of times your baby wants to nurse or drink a bottle per day (or night). Some well meaning family members might tell you that the secret to getting more sleep or more time away from your baby is starting solids. This isn't necessarily true, especially in the very early stages of food introduction. Your baby should be getting most of his calories from breastmilk or formula until his birthday, and getting too many calories from food before the developmentally appropriate time has been linked to eventual obesity and diabetes.

As they say, "Food before one is just for fun!" If your six-month old baby's solids intake corresponds to longer stretches of sleep at night, it could be coincidence, just an age thing. Or it could actually mean your baby is taking in too many calories from a source that isn't complete nutrition for him, and he's having some trouble digesting it. The latter is more likely if you're spoon-feeding (and watching the measurements on the jar rather than your baby) than if the baby is using his own hands to experiment with food (because rarely will a baby be able to instinctively overeat). Note: plenty of parents who prefer to spoon-feed are careful to read their baby's cues and always stop when the baby is ready to, so if that's your preferred method for introducing foods, don't fret. You're doing this parenting thing just fine.

3) Once they start eating, you can kiss your own plate goodbye. Practice saying this now and get used to it: Everything looks better on my plate. Everything tastes better from my plate. Everything that I put in my hand is a swiping target. What's mine is yours, darling. Even my fork. Which just fell on the floor. Oh! There's the dog.... These things just happen.

4) Food battles happen anyway. There are certainly ways to introduce your babies to flavors and textures to avail them of good chances to develop an adventuresome foodie spirit, but there's a certain level of confirmation bias involved when anyone tells you, "Well, I just did __________, and Little Jack eats everything." Sometimes your baby eats everything, but that same baby becomes a toddler and preschooler who does not. And some babies will simply reject anything green from the onset.

Bottom line: you are not a failure if your child is a picky eater or is resistant to trying (or continuing to eat) certain foods. Your friend's anecdotal advice based on her own Perfect Snowflake's preference for Cuban cuisine is not proof that you didn't introduce enough variety during infancy. As your baby grows up, you can try all kinds of methods to encourage your picky child to develop an adventuresome palate (or at least learn to choke down what's served at a friend's house even if it does have parsley on top), but some people just don't branch out until adulthood.

(Confession: I didn't eat tomatoes until I was 23.)

Special thanks to all the moms to gave us permission to use their cuties' likenesses in this post!