Frequent Asked Questions

What are the components of a typical disposable diaper?

Most disposable diapers are made with the following basic components:

1) Polyethylene or cloth-like film: This is used as the back sheet, that prevents the liquids from leaking out of the diaper. The back-sheet can also be given a cloth-like look, by adding a thin polypropylene non-woven sheet to the film, using either the hot melt process or the heat and pressure method with direct extrusion to the nonwoven. Contrary to popular belief, the cloth-like back sheet is not cloth -it is made of plastics. Breathable cloth-like material can also be used instead of the film. Not many know that even a breathable diaper with 200 ml of urine loses less than 2.5% of its weight over a period of 24 hours and this evaporation is enough the cool the diaper, which may not be as comfortable at night.

2) Tissue: A special tissue paper that is different from the regular bathroom tissue and has a higher elasticity and wet strength is another important component of a diaper. The tissue essentially serves as a carrier for the pad (the pad is the absorbent core of the diaper) and helps reduce the pin holes created during the compression process carried out by continuous drum forming systems. This tissue, typically at 16 grams/m2 (also abbreviated as GSM) or more, protects the inner plastic from the superabsorbent particles. Instead of tissue, it is possible to use a low gage SMS nonwoven material as the carrier (for the pad), it can be placed right next to the back sheet or as a full wrap material around the core. In order for the SMS carrier to be cost competitive against tissue paper, it needs to be less than 12 GSM.

3) Hot Melts: They are used to glue the different components of the diaper, such as the pad and the elastics. They are made of a mixture of resins, oils and tackifiers. The hot melt adhesive is applied in molten form and when it cools down it provides the required bonding force to glue the materials. Most of the times two types of adhesives are used: a construction adhesive, for the back sheet and the nonwovens, and an elastomeric adhesive, for the leg and waist foam elastics. The elastomeric adhesive has higher elasticity and bonding strength and it is generally more expensive than construction adhesives. When the diaper pad is very thin, another specialty adhesive known as "pad integrity adhesive" is also used to add strength to the diaper core when it is wet. This integrity adhesive is specially useful when SAP loadings exceed 25% of the total pad weight -i.e. when the weight of the SAP is more than a quarter of the weight of the pad. For a list of hot melt suppliers follow this link: Hot Melts.

4) Hydrophobic Non-woven: It is used as a top sheet for the leg cuffs; it prevents water from passing through. It is made of polypropylene resin without any added surface surfactants. The hydrophobic nonwoven prevents leakage out of diaper. By applying a surfactant to a restricted area, it is possible to make a roll of hydrophobic nonwoven only partially philic. This is known as the Zebra process and it is an important feature designed to avoid leakage during leg cuff construction. For nonwoven suppliers use this link: Nonwovens.

5) Hydrophilic Non-woven: It is the main top sheet, the top surface that is in contact with the baby's skin. It allows the liquids to flow into the diaper core. The difference between the two non-wovens (philic and phobic) is the surfactant treatment used in the process. The surfactant treatment reduces the surface tension of the nonwoven, reduces the contact angle with the liquid and allows it to pass. Flow dynamics within the diaper core prevent liquids from returning to the surface. Most nonwovens used in diapers are made with the spun bonding process, though it is possible to use thermal bonded nonwovens also, which are softer but have lower resistance and strength. Trough Air Bonded nonwovens which are more lofty, can also be used. For nonwoven suppliers use this link: Nonwovens.

6) Elastics: Used to improve the fit of the diaper, usually made of polyurethane or polyester foam, synthetic rubber or Lycra (also known with the generic name Spandex). They are used in cuffs, for the waist and the legs; they can also be used as lateral side panels and in tape construction. Most gasketing cuffs use spandex to provide a seal with the baby's legs. Spandex can stretch as much as 400% of its original length before it breaks, however it is typically used at less than 300% stretch. New generations of softer and stronger elastic materials are reportedly in the pipeline. For a list of suppliers use this link: Elastomerics.

7) Lateral Tapes: In premium diapers, VelcroR type materials have been used to provide mechanical grip, it is also known as the "hook tape". In lower priced diapers, adhesive tapes made of polypropylene are used. Then there are new versions of elasticized Nonwoven Velcro Tapes. In a few years baby diapers may replace training pants with the help of these new stretchable fastening systems that offer the same characteristics to the consumer but cost less. Some adult diapers use what is called the "target tape" system, where the tape has two adhesive tabs to avoid the need for a frontal tape. This is a cheaper alternative for adult diapers but not as good as the one using a frontal tape which does not require repositioning of the tape on top of the target. For a list of suppliers use this link: Tapes and Clossure systems.

8) Frontal Tapes: This is used to facilitate multiple repositioning of the lateral tape without tearing the back-sheet, it is made of polypropylene film and attached to the front of the diaper with adhesive. Its use has helped to reduce the thickness of the poly film without the risk of potential tears associated with the opening of the lateral tapes from the backsheet. In premium diapers, a special loop system has been developed in order to use of Velcro type fasteners (also called the "hook and loop" system). This loop tape can use a "locked loop" or a "brushed loop" in order to provide a softer texture or a stronger grip. A new generation of nonwoven materials expected to be commercialized in a few years, may eliminate the need for frontal tapes - the whole backsheet will be used to reposition mechanical tapes. The frontal tape can have a printed design which can be random or synchronized, some patents may protect the use of synchronized printing in some markets. Tapes and Clossure systems.

9) Cellulose: Used in the construction of the pad, it gives integrity and absorbing capacity to the diaper. The capacity of normal cellulose pulp is around 10 cc of water per gram of pulp when the diaper is in "free swell" but less than 2 cc when subjected to 5 KPa of pressure; that is why a superabsorbent material is also needed to hold the liquids under pressure. Cellulose comes from pine trees, generally obtained from well managed forests. Liquids are absorbed by the capillaries in the void spaces between the fibers and the surface tension angle between the fibers and the water. Typical fiber length used in diapers is about 2.6 mm. An alternative to pulp is to use air laid synthetic fibers. However, it is still difficult for air laid synthetics to compete with pulp, unless it is a niche market product and thickness is more important for the consumer (as in case of some sanitary napkins and the adult diapers used by active people) than the cost. Cellulose acetate, the material used to make cigarette filters, has been used in some absorbent products. PP synthetic fibers has also been attempted for absorbent core formation. For a list of pulp suppliers use this link: Fluff Pulp.

10) Acquisition and Distribution Layer: Also known with its abbreviation ADL, it is a sub layer used between the top sheet and the absorbent core. Sometimes used in full length but mostly preferred as a patch near the target zone where urine is most likely to be deposited. This sub layer is specially needed when the absorbent core is very thin -the sub layer quickly moves liquids into the absorbent core and reduces potential leakage. The ADL is very important to provide a sense of dryness to the skin, providing additional separation between the wet pad and the skin. ADL's should be used whenever the mix of SAP in the absorbent core exceeds about 15% by weight or when the liquid penetration time requires a boost in order to avoid diaper leakage due to liquid accumulation inside the diaper. ADL's are made either of through air bond (TAB) nonwovens, "curly" fibers such as in P&G's pampers and some Ontex diapers, or some kind of "high loft" nonwoven. An aperture film, made of perforated plastic film, has also been used successfully in some markets. Lower priced diapers sometimes use resin bonded nonwovens, but they do not work as well. For acquisition nonwoven suppliers use this link: Nonwovens.

11) Sodium Polyacrylate: Also known as super-absorbent or "SAP" (super absorbent polymer), Kimberly Clark used to call it SAM (super absorbent material). It is typically used in fine granular form (like table salt). It helps improve capacity for better retention in a disposable diaper, allowing the product to be thinner with improved performance and less usage of pine fluff pulp. The molecular structure of the polyacrylate has sodium carboxylate groups hanging off the main chain. When it comes in contact with water, the sodium detaches itself, leaving only carboxyl ions. Being negatively charged, these ions repel one another so that the polymer unwinds and absorbs water, which is attracted by the sodium atoms. The polymer also has cross-links, which effectively leads to a three-dimensional structure. It has high molecular weight of more than a million; thus, instead of getting dissolved, it solidifies into a gel. The Hydrogen in the water (H-O-H) is trapped by the acrylate due to the atomic bonds associated with the polarity forces between the atoms. Electrolytes in the liquid, such as salt minerals (urine contains 0.9% of minerals), reduce polarity, thereby affecting superabsorbent properties, specially with regard to the superabsorbent capacity for liquid retention. This is the main reason why diapers containing SAP should never be tested with plain water. Linear molecular configurations have less total capacity than non-linear molecules but, on the other hand, retention of liquid in a linear molecule is higher than in a non-linear molecule, due to improved polarity. For a list of SAP suppliers, please use this link: SAP The superabsorbent can be designed to absorb higher amounts of liquids (with less retention) or very high retentions (but lower capacity). In addition, a surface cross linker can be added to the superabsorbent particle to help it move liquids while it is saturated. This helps avoid formation of "gel blocks", the phenomenon that describes the impossibility of moving liquids once a SAP particle gets saturated. Please read the history section for more information. To get more answers about this superabsorbent material, please use the link: Frequent questions about SAP.

12) Top Sheet surface add-on lotions: In order to create novelties for product differentiation, several topical lotions are added to the nonwoven top sheet, among others: Aloe Vera, Vitamin E, Petrolatum, Almond Oil, Vitamin D, Oat Extract, Jojoba, etc. There is another trend to use antibacterial lotions (such as tertiary ammonia or silver salt compounds); however, many pediatricians are against its use for obvious reasons.

13) Decorated Films and wetness indicators: For even greater product differentiation, some diapers use decorated films underneath the cloth-like backsheet. Some use as many as nine inks with all kinds of well known characters such as Disney, Sesame Street, Soccer teams, etc. Another gimmick they use is a wetness indicator. This is typically used for adult products but some baby diapers also use it.


How can I test the performance of a diaper?

The best way to measure diaper performance is to evaluate its most important attributes: Absorbent Capacity, Absorbent Retention, Speed of Absorption, Diaper Re-wet, Fit and Comfort. I will refer to the first three because they are more objective and easier to measure. It is important to use a saline solution in all of your experiments because that is the easiest way to simulate urine (think of it as "synthetic urine"). Salts in the water affect the performance of the super-absorbent (SAP) so much, that your data will be meaningless if you use plain tap water. And remember that babies' urine too has minerals - 0.9% is the average minerals content in the urine of a healthy baby.

A performance gain of as much as 35% can be achieved just by using plain water instead of the "synthetic urine", depending on the amount of SAP in a diaper. So if you think that using water will make the test fair to all diapers... STOP! Not all diapers are made with the same amount of SAP and it is only the SAP that is affected by the salts. By showing respect to individual properties of all the components, you are exercising a scientific criterion. Make sure that you record all relevant information in your "experimental record's table". This is what the Science Fair is all about - learning how to have and use a scientific approach. Just to confirm that this is not a simple theory but a hard fact, test one diaper with plain tap water and another with water after adding plenty of salt. You will be surprised by the huge differences in results. Another way to verify this phenomenon without damaging two diapers is to add a tablespoon of salt on top of a used wet diaper. You will see how much liquid is released due to the inability of SAP to retain liquids having highly concentrated dissolved salts. Grown-ups, please skip the following part because it was written just for kids.

A bed time story for little kids not to take too seriously: "Once upon a time, many years ago, there was a nasty wicked old witch who visited supermarkets disguised as a "demo" lady in order to trick innocent mothers into buying low quality diapers. Luckily for us, a handsome prince watched one of her presentations and caught the old witch doing her wicked tricks. The bad witch owned a very large disposable diaper factory. That is why she was conducting diaper tests in front of the consumers to convince them that her diapers were the best in the land. But the trick was that she was using altered water; in one jar she had water with a lot of salt and in another jar she had plain water. She tried to convince mothers that her diapers were the best (using only plain water on her diapers and water with a lot of salt on all other diaper brands, including diapers made by the handsome prince's little diaper factory). Guess which diaper performed better? You are right! Diapers made by the wicked old witch seemed to be better. But you know that it was just a wicked trick. The happy end of the story is that the handsome prince, whose name was Carlos, was able to uncover the fraud and later married the beautiful young manager-in-charge of the diaper department, Adriana, and lived happily ever after. The wicked witch never sold another diaper in town and later moved to New York where she was last seen driving a Taxi!"

Diaper Tests to do:

Absorbent Capacity: Prepare a few liters of saline solution, mixing water with regular table salt at 0.9% (This is the same as 9 grams per liter of solution, and simulates the minerals in babies urine). Find a large container in which you can immerse the diaper. Start by weighing the dry diaper, using a scale, and record the data. Put the saline solution into the container and place the diaper flat upside down at the bottom of the container, using a chronometer or stop watch set for exactly ten minutes. Do not apply any additional pressure to the diaper as it is soaking the solution. After the ten minutes have elapsed, remove the diaper, holding it from the corners, and let it drip for two minutes. Hang the diaper with cloth pins or something similar (or use your own hands), in such a way that it drips vertically. After the two minutes, measure the weight on the scale. The Absorbent Capacity will be the difference between the two recorded weights. The best diaper for this performance attribute will be the one with the highest Absorbent Capacity. Record the data in your table.

Absorbent Retention: I am going to explain a simplified test that you can carry out without elaborate equipment. You will need only a washing machine. This experiment lets you assess how much liquid a diaper will hold under pressure. First weigh a new dry diaper on a scale and record the data in your table. Then allow it to soak liquid for ten minutes, using the same saline solution and the container you used in the previous experiment. After ten minutes have elapsed, remove the diaper and let it drip for two minutes. Instead of just recording the weight difference (as in Absorbent Capacity experiment), this time we need to place the diaper flat on the inside wall of the washing machine. Important: You will use only the centrifugal cycle. If you are 13 years old or less, please ask permission of your parents before you use the washing machine. A very angry parent once sent me an E-mail complaining about this situation and the thing is that I agree with her - a washing machine can be a dangerous equipment. She made me realize that I could be responsible for anything happening to her child (it seems her kid made a mess with water all over the floor and she was angry with me); yes, even when I was just trying to offer a little help. Life many times is not fair and you should know this by now. It is up to all of us to make it a little better for everybody. Never give up an action when your intentions are good and honorable. It is much better to have your parents involved with the project; this way I am also "off the hook"... By the way, sometimes your parents can also help you with the writing. You will need to improve your negotiating skills. For example, in exchange for cleaning your room ... (ups!!). Enough chat already, let us get back to the experiment ....

Select the centrifugal cycle in the washing machine and let it spin for two minutes. Remove the diaper from the machine and measure its weight. The weight difference will be the total diaper retention. Be consistent by always using the same washing machine with all the diapers you test. The best diaper will be the one with the highest retention. Record the data in your experiment's data table.

Speed of Absorption: You will need a flat table and the means to hold the diaper (pins if you use a cork table, or adhesive tape). You will also need a plastic pipe (or equivalent) with an internal diameter of one inch, about ten inches long, though the length is not so important. You will need to prepare a stand for the pipe, by using a 10 CMS X 10 CMS (4" x 4") Plexiglas square, with a hole in the center where you can attach the one inch pipe. Start by measuring 100 ml of saline solution @ 0.9%. Place the diaper flat on the table, avoiding wrinkles by stretching the diaper before you apply the pins. Put the stand with the pipe on top of the diaper at the target area of the pad. With your chronometer (stop watch?) on hand, start the timer at the same time when you pour the solution into the pipe. Record the time required for all of the 100 ml of liquid to penetrate the diaper. This will be the speed of absorption or First Strike Trough Time. Repeat the test again after ten minutes with an additional 100 ml for a Second Strike Trough. You can also try a Third Insult if you please. The best diaper for this performance attribute will be the one with the least time. The second time is more important than the first, in terms of diaper performance.

These tests are fine for a school project but please be aware that if you want more precise results, you should not use tap water or regular table salt as they have an effect on the performance of the super absorbent due the the variable mineral content of the water. Please visit the following link if you want to download formal instructions on diaper performance: Diaper Performance.

Now that you played with your diapers, let me tell you that if you are looking for a truly professional laboratory to test the performance of your diapers, we will do the testing for you. We are confident that our report will be the best you have ever seen. Please click here if you are interested in our professional Laboratory Services to test your diapers : Diaper Lab.


Can you explain the manufacturing process of a disposable diaper?

Disposable diapers are produced in a continuous process. A baby diaper machine is typically between 20 to 45 meters long, depending on the speed and the complexity of the product to be made. When we take into account the primary peripheral equipment, a typical machine will be from 6 to 13 meters in width. Typical diaper machine speeds range between 200 to 600 diapers per minute, though some of the larger companies have machines running at 1,000 pieces per minute. The fastest machine I have personally seen was running at 950 diapers per minute.

The process starts at the mill, where a sheet of pulp is fed into a rotary mill and is converted into fibers (from 2.3 to 2.7 mm in length). These fibers are transported into a forming pocket using a vacuum generator that is also called the "dust collector". As the fibers are produced, they are mixed with a super-absorbent within the drum former. The drum former usually holds between 8 to 12 pockets, depending on diaper size and the diameter of the drum. The mix of pulp and powder coming out from the drum is called "the pad" or "the absorbent core". Once the pad is formed, a layer of tissue (or light weight non-woven) is placed on the top, bottom or around the whole pad. The pad is then compressed using a debulker roll and then it is cut into individual pieces of pad (unless the pad was made in a non continues drum former). In the next step, a poly film or cloth-like material is added at the bottom of the pad (or laminated on line) and non-woven material is added at the top.

Frontal tape is glued to the poly film or cloth-like backsheet, using a cut and place applicator, before it is added to the bottom of the pad. In order to glue all these materials, hot melt is used in the form of multi-lines or spray. Specialty glue is also used for pad integrity, particularly when the pad is very thin; this help reduce incidence of breaking apart of the diaper when it is wet. Elastomerics are also added at this point to provide stretch to the waist and the leg area – they are glued with hot melts. Typical elastomerics used in a diaper are Lycra (Spandex), polyurethane or polyesther foam.

The non-woven top sheet can be made of one or more pieces, depending on the features to be added to the diaper. For example, diapers can be with or without leg cuffs. Typical nonwovens used in a diaper are Spunbond and Thermobond or a combination, such as SMS (spunbond-meltblown-spunbond). The top sheet is made of hydrophilic nonwoven and the leg cuffs are always phobic, in order to provide water resistance and to stop leakage. The next step in the manufacturing process is addition of lateral tapes. They are applied using another cut and place applicator. Tapes can be the standard adhesive type, made of polypropylene, or they can be mechanical tapes, like the hook and loop (originally called and patented as "Velcro") tapes. After the tapes are added, a die cutting system trims the leg area of the diaper and discards the waste, using a vacuum system. These trims are later recycled in a different process to make plastic pellets, to be transformed into garden houses or even funeral caskets inside linings.

A visual system is frequently used for automatic inspection just after trimming, before the folding of the diaper. The diaper is carried on to a folding process and then it is cut into individual diaper pieces, is inspected and is finally stacked into a plastic bag for its final sealing and packing. You can visit "Machine Photos" if you want to take a look at pictures of baby diaper machines from different vendors. If you want to learn how to control quality in the process of diaper manufacture, click: Quality Control Systems. If you want to see a process chart, please click: Diaper process. If the language is starting to be a bit technical, here you can find a list of technical definitions to help you better understand the language used in the diaper industry: Technical Dictionary. For a nice short video showing an actual diaper factory in operation, please use this link: diaper machines. If you want to really understand the diaper manufacturing process in great detail, you may want to hire my consulting services. I have an intensive three day seminar that includes everything you need to know to understand the diaper manufacturing process, with many pictures and videos where I explain all comparative technologies and provide Excel and Power Point presentations to help you with your diaper factory economic feasibility project. With many such presentations in 4 Continents, I am the world expert in this topic. For more information please visit: Richer Investment.


I have been told that cloth diapers are better for the skin of my baby....?

This is simply not true! There are many diaper washing services that confuse the consumer using very "old medical reports" that claim that cloth diapers are better for the skin of the baby. They argue that cotton diapers breath. A close analysis of these reports shows that mothers did not use the same pattern of changing diapers. Disposable diapers were used for extended times between changes while cloth diapers were changed because they leaked. Most of such reports have compared very old disposable diapers (with modern cloth diapers), even from before they had started adding super-absorbent in the diapers (just look at the date of the report). Many disposable diapers are also breathable now. Please read another question in this section to learn more about breathability. Do not be tricked. I have explained how to test the performance of a diaper in this website, just carry out the tests for yourself: Test Methods The best experiment I have found to convince cloth diaper "fanatics" is actually a very simple experiment. Wear the best cloth adult diaper you can buy for yourself and allow it to be wet for a few hours. Now compare your personal experience against wearing a good (does not need to be the best) disposable adult diaper and do the same. You will find out the cloth diaper is just the same as keeping a wet swimming suit and then putting dry cloths on top of it after you get out from the pool. In a few hours you will not be able to stand it and you will feel a real treat once you put something dry instead. This is why older babies using cloth diapers try to run naked from their mothers when she tries to put a new one.

There are some adults that like wearing diapers "just for fun" (I swear it is true it is called "infantilism"). They even have their own well organized clubs, impressive. I am not going to judge them as they are free to do whatever they want with their time and with their body, my respectful greetings to all of them (I beg for your pardon and I hope you do not take my comment in a bad manner). By the way, you can see a few of the photos of adults wearing diapers that I have received over the years (I filtered only the cute ones): diaper models.

I took the liberty to ask a few adults how they feel after wearing a wet diaper for a long time. All of them have the same answer - the dryer the diaper the better they feel. This is another reason why I am so sure about what I am saying. Please: Next time a cloth diaper fanatic sends me an offensive letter, at least do the last experiment that I suggested. If you want to send me a strong counter statement, please present arguments. I love intelligent conversations and even a good discussion but I also try my best to avoid stupidity. Please do not send more pictures, I have more than enough. And no, I will not send or post more pictures.

Disposable Nappies - No Worse for the Environment Than Cloth Nappies A Government commissioned life cycle assessment (LCA), co-ordinated by the UK Environment Agency, has been published today (May 18) and shows through independent analysis that disposable nappies have no greater impact on the environment than cloth nappies.


Are disposable diapers safe to use for the skin of my baby?

There are many diaper washing services that are truthful in their claims. I have the greatest respect for all the diaper services that have managed to survive. It is hard not to feel sad for them when their market share has dropped so suddenly and so dramatically. Did you know that less than 4% of all babies in the U.S. use a diaper service? The fact of the matter is that even when we can recognize some marginal benefits of a highly breathable diaper, it is even more important to have a dry environment for the health of the skin. Nothing comes close to the dryness that a good disposable diaper can give to the baby's skin. I dare the best cloth diaper in the world to challenge the re-wet and dryness of premium diapers. I would pay a reward of $100 if anybody can beat the best disposable diaper with a commercial cloth diaper (rewets after a 200 ml or a 300 ml urine insult).

There are still a few disposable diapers in the market that claim to be safer because they are made without any SAP. Some of them even go so far as to try to claim (indirectly, of course) that SAP is not good for the baby's skin. In my opinion, this is an attempt to justify the lack of novelty in their own diapers -17 years ago all diapers were made without SAP! Wow, so much of novelty! A diaper without SAP! .

And the statement that SAP is bad for the baby’s skin is a big lie! Do not be fooled or tricked by it. Read what contemporary pediatricians have to say about SAP: "The important thing is that parents can feel reassured that these technologies, especially superabsorbent material, improve skin health and hygiene and that they have undergone rigorous testing to ensure safety. It is because of SAP that diapers use much less pulp (much less volume); SAP can replace as much as four times its weight of fluff and that is good for the environment. A disposable diaper without SAP is just poor intelligence and a poor marketing gimmick. To learn more about the health benefits and environmental aspects of disposable baby diapers, please follow this link for a free report: www.hapco.edana.org/publications/ .


Which disposable diaper is the most friendly for the environment?

Natural Baby ("Earth Pure" diaper sold by Amway in the USA until 2004) was the first degradable diaper in the world, launched in the year 2000. It was made with a new technology called T.D.P.A. ("totally degradable plastic additive" -a trademark of Environmental Products Inc.), a new kind of additive that changes the molecular properties of plastics, thereby degrading the outside shell of the diaper. There is no better disposable diaper for the environment at this time. Please understand that this does not mean that the whole diaper will bio-degrade. However, tests show that TDPA facilitates bio-degradation of the outside shell, converting it into fine dust. Unfortunately, this diaper is not commercially available anymore due to its limited sales volume and the high cost its producer had to incur to defend it from law suits. It is extremely expensive to prove that the diaper will bio-degrade in every single landfill in the United States. Some landfills are so poorly managed that in these few places, not even a banana peel will bio-degrade. For this reason, though we could claim degradation on a ASTM active landfill simulator, we could not print the claim on the diaper bag – i.e. without being confronted by powerful enemies. You can find more about this remarkable technology at: Insight2000.htm

Two new products recently launched into the market are the Bio Baby made by Mabesa in México, and Safeties, the first diaper to claim it is 100% biodegradable, made by Senevens in New Zeland. You can visit their links here: http://www.senevens.com.au/home.htm and http://www.pimabe.com/ Another interesting new product also claiming ecological benefits is the gdiapers a simple diaper insert made with soluble materials that you can flush directly into the toilet: http://www.gdia.net/


What is your opinion regarding the use of disposable diapers inside the pool?

Since the introduction of the "little swimmers" by Kimberly Clark, parents are inclined to believe that it is OK to swim with your baby in the pool; after all, he/she is wearing a disposable diaper. The only problem is that diapers are designed to absorb and retain liquids, an impossible task when underwater.

There are very few things that are more enjoyable for a baby (and for that mater for the parents too) than playing with parents in the pool, specially on a hot summer day. Unfortunately diapers are not designed to contain liquids while they are submerged in water. Because of this reason, the risk of water contamination is huge, specially if you are planning to swim in a large public swimming pool. The only advantage of "little swimmers" or similar products is that they do not contain any SAP so you will not end up finding SAP gel floating on the pool. However the problem is not finding SAP on the pool or weather or not SAP is toxic, the real problem is the water contamination. The risk of getting an infection is far greater from feces than by the ingesting of residual amounts of SAP.

I was recently told of a particularly embarrassing situation (as a matter of fact I am not even sure if it is all true or if it has been exaggerated), the final result of which, according to the hotel manager who told me about the situation, was the need to remove and refill 150,000 liters of water - a two year old baby wearing a diaper had decided to "use it" when his father was jumping him up and down (I call it "the melting log" syndrome). He told me that they tried to get the stuff out of the pool but it just dissolved in front of everybody, making the situation even worse.

When the temperature of the water is cool, I believe the probability of such an event to happen is quite low, as the human nature is to contract the sphincter; however, when the water is warm, as it was in this particular case, anything is possible. So be careful when you mix a warm water pool with a baby. You may be laughing now but it was not so funny for the people who were using the same pool in the hotel – they all had to get out of the pool.

Please play all you can with your baby and also teach your baby how to swim (a very important lesson for a lifetime), but please do it in a small private pool, not in a large public swimming pool. Many hotels now offer a small pool with an independent filtering system, that would be OK. Do not do unto others what you would not like done unto you. ("El respeto al derecho ajeno es la paz"... Benito Juárez, former Mexican President 1872).


What is the origin of the word "diaper" or the word "nappy"?

Diaper was originally the term used for an overall pattern of small repeated geometric shapes, and then a white cotton or linen fabric with such a pattern. So the first babies' diapers were made from diaper fabric, meaning fabric with a repetitive pattern.

A "nap" is a hairy surface of cloth formed by short fibers; it was the preferred material to make "nappies". The word "diaper" is used in America and most other countries that speak English, while a "nappy" is used in England, New Zealand and Australia.


What is the pH of Urine of a typical Baby or Adult?

Contrary to popular belief, the pH of urine is actually light acidic, in the range of 4.5 to 6.5 The kidneys maintain normal acid-base balance primarily through reabsorption of sodium and tubular secretion of hydrogen and ammonium ions. Urine becomes increasingly acidic as the amount of sodium and excess acid retained by the body increases. Alkaline urine, usually containing bicarbonate-carbonic acid buffer, is normally excreted when there is an excess of base or alkali in the body.

Some medications for urinary infection work best on alkaline urine but this is not typical of a healthy adult who is not taking any medication. In a typical diaper, it is possible to see an increase in the pH value. As urine biodegrades due to time and oxidation, ammonium hydroxide is generated, increasing the pH values to 8, 9 or as high as 10 (generating a hazardous condition known as "diaper ammonia dermatitis".

In addition, it is well known that superabsorbent performance is reduced due to the higher pH, making it even worse for the patient. Diaper should be changed before there is a risk of diaper rash associated with ammonia. Diapers should not be used for more than 8 hours at a time without a change. Diaper with feces should be immediately removed.