>What is PUL?

>As most of us cloth diaperers well know, diaper covers have come a long way over the years. I myself was a baby clad in the plastic and rubber pants that were the mainstream option of our parents’ generation. To be sure, plastic and rubber pants did the trick in terms of waterproofing, creating a solid barrier layer to keep pajamas and bedsheets dry. These wraps and pull-ons also fit well over the pinned prefolds that were the diapers of yesteryear. However, over the years, rubber and plastic covers have been slowly dwindling in popularity, making way for a new wonder fabric that is replacing them. You’d be hard-pressed to enter a cloth diapering shop, site, forum, or trade show nowadays that didn’t mention polyurethane laminate, or PUL, as it’s known for short.

As its name suggests, PUL is a fabric treatment and refers to any material that has been laminated with a particular waterproof, plasticized substance. We all remember the laminating process from our grade school days, when our teachers would bond plastic wrap to our best class projects and assignments, giving them permanence and safeguarding for years worth of display, storage, and use. Though not quite the same process, laminating fabric does work on a similar principle as laminating paper in that a durable, waterproof layer is bonded to the desired fabric.

A modern cloth diaper shell made of PUL

PUL can be used as a treatment for a variety of fabrics or fabric blends, such as 100% cotton weaves, cotton/polyester blends, or pure polyester knits. For diapering purposes, it is most common to see polyester-based PULs as they prevent wicking in a far superior fashion to cotton (which can suck moisture to the outside of the diaper, causing dampness and leaks). PUL provides a waterproof layer that, while obviously not as breathable as natural fibres, still provides some degree of breathability (moreso than the old-fashioned rubber or plastic pants, at any rate). It is a flexible, resilient, and durable fabric that can stand up to high heat washing and drying.

In fact, prior to its use in cloth diapers, PUL got its start in the medical field for some of the same reasons that diaper users were looking for. Hospitals required a versatile fabric that could prove to be reusable (as an alternative to so many disposable items that were getting discarded daily or even hourly on their wards) as well as one that could still be industrially washed, dried, and sanitized many times over. Thus, they adopted PUL and other plasticized fabric treatments. Laminated backings were applied to everything from incontinence bed pads to the dressings that are applied to open wounds.

For cloth diaperers who are stringent users of natural fibres only, the subject of PUL has been broached with some skepticism. After all, as an artificial fabric, there may be things that we do not yet know about PUL. To be fair, in truth, there have been no comprehensive studies done yet on the use of PUL in diapers; that being said, however, research and scientific information have been shared on the components of PUL and its heat-sealed laminate alter-ego, TPU (thermoplastic polyurethane) and just what goes into their formation and manufacturing process.

It is somewhat of an alarming fact that diisocyanates (which are considered a respiratory hazard) are present in the formation phases of plasticized laminates; these diisocyanates are reacted with polyol during the initial stages of polymerization, when TPU, for example, is formed. That being said, however, any hazardous materials associated with the creation process are well-contained within a regulated factory setting and are no longer present once the TPU, itself an entirely new substance, has been created. The plastic laminate TPU, now its own creation, is void of the diisocyanates which were originally used alongside a catalyst to form it; thus, TPU is said to be an inert substance that is stable with regular use. Only when heated above 428 degrees Fahrenheit does it run the risk of melting and releasing potentially toxic fumes. However, clearly temperatures this high cannot be reached even with extremely high-heat sterilization methods that may be used on cloth diapers or hospital supplies.

PUL comes in many varieties and looks

So, with tests showing them to be stable, safe materials, PUL and TPU can be found in a variety of medical supplies, reusable bags, cloth diaper shells and covers, reusable swim diapers, bibs, wet bags, pail liners, and more. PUL is available in several standard thicknesses (1mm and 2mm, with the thinner gauge allowing for increased stretch and flexibility) and in a variety of fashionable colors and prints. With a little know-how and a few tricks of the trade, it is easy to sew with PUL on any standard sewing machine, applying snaps, velcro, and other embellishments as needed.

All things considered, as with any synthetic material, PUL has its definite upsides for day-to-day convenience and practicality, but, when used for diapering purposes, you may still want to alternate it with some good old natural solutions from time to time as well. While fabulous for waterproofing, PUL still leaves something to be desired in terms of air-flow and breathability. Natural fabrics such as cotton, bamboo, hemp, and wool provide a chance for tiny bums to air out from time to time, and bit of diaper-free time in the fresh air or a sunbeam never hurts either.


Acknowledgments and further reading:

PUL-eez tell me it’s safe! A look at the safety of PUL fabric in Cloth Diapers (New & Green Baby Co.)
What is PUL? (Celtic Cloths)
Artificial Materials and Cloth Diapering (Diaper Pin)
PUL Fabric Information (pulfabricforsale.com)
Is all PUL created equal? (Just Mommies via Dirty Diaper Laundry)

– Image credit (bolts of PUL): Kids In The Garden

6 thoughts on “>What is PUL?

  1. Angela

    >@Beth- Try Joann's if you have one near by. They usually have 3 or 4 colors at mine. I mean, you won't get the variety you'll find online, but at least you get the PUL without the shipping!

  2. Andrea

    >Thanks for the acknowledgment. This is a very well written post about PUL. I would like to grab your button to put on my PUL site. Thanks! Andrea

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