R&D behind everyday products: Making diapers superabsorbent

In our daily lives, we have many products that we take for granted, but that actually require a great deal of R&D. Take diapers, for example. Diapers are a fascinating technology, if you think about it. How can something be so cheap, thin and lightweight, and superabsorbent at the same time?

I did a little diaper reading on Wikipedia. From this I learned that the materials that make diapers so absorbent are called superabsorbents, or, more specifically, superabsorbent polymers. These superabsorbent polymers come as powders, looking like this…

Superabsorbent polymer powder. Image from Wikipedia.
Superabsorbent polymer powder. Image from Wikipedia.

…and when they are filled, they look like little paint balls:

Expanded, filled, superabsorbent polymer balls. Image from Wikipedia.
Expanded, filled, superabsorbent polymer balls. Image from Wikipedia.

Diapers consist of superabsorbent polymer that can absorb 300 times its own weight.

wikipedia article on superabsorbent polymers

Isn’t this impressive? I used Mergeflow to discover more about the R&D that makes this possible.

How I searched

I used two very basic and general search strategies:

  1. I searched for “diapers” in order to get some broad spectrum information, and perhaps discover some unexpected things as well.
  2. In order to zoom in on the materials aspect, I searched for “superabsorbent”. I deliberately did not include “polymer” in my search query. After all, there might be other superabsorbent materials as well.

A short 360° view on diaper tech and business

In order to read more about how you can do a 360° search in Mergeflow, you can read this FAQ article. In our blog, we also have articles describing 360° views on other topics.

For my “diaper tech” 360° search, i very generally searched for “diapers” first.

Venture fundings

Yes, there are diaper-related venture capital investments. But they focus on the purchasing, marketing, and logistics side of things, not on the materials. For example, Starship Technologies raised $40M in 2019 for its autonomous delivery robots (yes, they deliver diapers, among other things).

Another example is SessionM, who received $23.8M in 2018 for their customer data analytics platform. One of their customers is diaper maker Huggies, who use SessionM to deliver purchasing tips. For example, if you switch to the next diaper size, SessionM will email you product tips related to baby-proofing your house. You can read more about this here.

Then there is kwik, who in 2016 received $3M funding. kwik describe themselves as “self-learning IoT technology for automatic ordering”. Huggies uses their platform to implement one-tap diaper delivery.

Markets

When you search for a topic, Mergeflow shows you market estimates that are related to your query. This can be a good way of discovering the broader context of your search. For example, my search on diapers in Mergeflow also showed me related markets. For example, breathable films.

Why is this interesting? Because this alerted me to another tech aspect of making diapers. They do not only have to be superabsorbent but breathable as well. Otherwise you’d basically be wrapping your baby into a plastic bag. While this seems obvious after the fact, I did not think of this at first. And breathable films are yet another high technology product in their own right (which we may explore in another blog post in the future). Notable suppliers of breathable films include Arkema, Mitsui Chemicals, Nitto Denko, and Toray.

Emerging technologies

Mergeflow has semantic models that detect emerging technologies across its data sets, 24/7. For example, I also zoomed in on technology blog posts that talk about diapers. From these blog posts, Mergeflow identified “alternative fuels” as a related emerging technology.

Alternative fuels and diapers? Yes:

In 2017, New Atlas reported that “British Airways plans to turn trash into jet fuel”. This trash includes plastic food containers, as well as other things consumed during flights. This includes diapers. Fast-forward to 2019, and British Airways, Shell, and renewable fuels partner Velocys announced plans for a commercial plant that makes sustainable jet fuel from waste.

Illustration of the Altalto Immingham sustainable jet fuel plant. Image by Velocys.
Illustration of the Altalto Immingham sustainable jet fuel plant. Image by Velocys.

Let’s put the 500,000 tons of solid waste into perspective. According to a 2018 estimate, the city of London produces 3.1 million tons of household waste and 5 million tons of commercial waste every year. So in order to just process the London household waste, we’d need more than six such factories.

R&D funding

One of Mergeflow’s data sets includes updates on publicly funded research projects from the US, UK, and the EU. And these R&D projects included some related to diapers as well.

For example, CellSorb, an EU-funded project, aims at the development of cellulose-based absorbent materials. The goal is to use these materials in diapers, among other products. In other words, the idea is to replace synthetically produced superabsorbent polymers by more sustainable materials. Project coordinator is the Swedish company Cellcomb.

A US-funded R&D project has a similar goal: “Bioproduction of super absorbent polymers”. Funding agency is SBIR in this case, and the money comes from the US Department of Energy. The awarded company is Zymochem. Zymochem engineers microbes so that they produce chemicals that traditionally are made from petroleum.

Why all this research on making sustainable superabsorbents?

A discarded disposable diaper takes approximately 450 years to decompose.

Quote from WIKIPEDIA article on diapers

Let this sink in. 450 years ago, in 1570, Galileo Galilei was a 6-year-old child. So if he’d had disposable diapers, and if the 450 years are an approximation plus or minus a few years, his diapers might just have decomposed by now.

I thought about this, and about how many diapers people use every day. The result is a huge waste problem. So next, I zoomed in on R&D on how to make more sustainable superabsorbent materials.

R&D on more sustainable superabsorbent materials

R&D aimed at making more sustainable superabsorbents basically seems to follow two approaches:

Protein-based superabsorbents

For example, research at the Universidad de Sevilla, led by Estefanía Álvarez-Castillo, investigated soy protein as feedstock for superabsorbents:

“Optimization of a thermal process for the production of superabsorbent materials based on a soy protein isolate”.

They say that their method would not require chemical modification of the soy protein in order to make it superabsorbent.

Polysaccharide-based superabsorbents

Examples of polysaccharides are starch, cellulose, chitin, or chitosan. Starch and cellulose can be derived from plants. Chitin or chitosan can be made from crustaceans.

Research on making superabsorbents from polysaccharides so far has focused on cellulose and chitosan.

For example, Josefina Patiño-Masó and colleagues from the University of Girona have investigated….

“TEMPO-oxidized cellulose nanofibers: A potential bio-based superabsorbent for diaper production”.

They argue that their cellulose-nanofiber-based aerogels showed even better absorbent properties (swelling capacity) than traditionally-made disposable diapers.

At the Indian Institute of Technology Madras, Abathodharanan Narayanan and colleagues made a polymeric gel from chitosan, citric acid, and urea:

“Super water absorbing polymeric gel from chitosan, citric acid, and urea: Synthesis and mechanism of water absorption.”

They also argue that their biodegradable polymeric gel has better absorption capabilities than the traditional super absorbent polymers.

Using superabsorbents beyond diapers

Interestingly, chitosan is not only proposed for making diapers. Another application is wound care. Chitosan has antimicrobial properties and also promotes blood clotting. Apparently this was used for wound treatment in ancient China already. In 2015, Oregon-based health technology company RevMedx received FDA approval for its XStat device. This device can be used for treating hemorrhage caused by deep wounds. Initial studies have also investigated the device for treating postpartum hemorrhage.

What every day product should we explore next?

I hope that you found this little discovery tour into “diaper tech” interesting. Now I’d like to hear from you. The R&D behind what other everyday product should we explore next? If you have a proposal, please send us an email, or leave a reply below. Thank you!


Featured photo by Corryne Wooten on Unsplash.

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