Today we got taken to visit a diaper and sanitary napkin factory. Bunnie had AQS line this one up because he wanted everyone to be exposed to a non electronics manufacturing operation. The factory was actually quite with only three lines total and one line in operation. The line in operation was a diaper line and we were able to see in detail how diapers were made. I'm not familiar with the exact details of what was happening throughout the process, but the general idea is that paper napkins were being layered on top of each other to form a sort of paper sandwich. Along with that, there were other operations that needed to be done such as adding the elastic bands, some cotton filling, and spritzing the diapers with perfume.
The factory was quite young at only one year old. The owners were formerly paper based product distributors and ran a trading company in that industry. They eventually got to the point where it just made sense for them to own their own factory. What I'm now understanding about Shenzhen is that this is not a difficult undertaking. There is a company that sold them the whole machine as a finished product. Technically, I guess it'd be called something like a "modular paper layering machine" but you can buy one for about $300k USD. This machine can be configured to be used to make diapers, sanitary napkins, or likely any other paper based product that requires layering on paper and there are technicians available that can teach how the machine is used, configure it, and repair it.
The machine that was in use was configured for diapers and could produce
up to 150,000 diapers per day which, at 6 diapers per package, would
have resulted in about 25,000 packages per day. We were doing a rough
analysis of the profitability of the machine. Even if there was a profit
margin of $0.50 per diaper package, the machine would pay for itself
within a year, assuming they were able to move that much diaper. I
wouldn't take the accuracy of those numbers at face value, though.
There were two other machines that were not in operation due to the Chinese New Year holiday and those were configured for sanitary napkins. For those that don't know, that's possibly an overly polite term for what's known in the US as maxi-pads. The machines were basically similar but since they're modular, they were set up with the rollers and everything else in a different configuration to handle the different layering tecnique used in sanitary napkin construction. Bunnie and David Craynor were marveling at the perfume spritzer which gave the napkins a delightful smell, even though they were being made in a slightly dingy factory. In general, all of the guys were very curious about the sanitary napkins because they were like an alien object to us. In the car ride back, Bunnie and I were using one of the napkins to wipe the sweat and oil off our foreheads. We were marveling at how it had a slightly minty, herbal smell, excellent absorbency, and left our foreheads with a cool, menthol feeling.
After the tour, we were taken to lunch by the factory owner, which was at an organic Chinese food restaurant. Since we were surrounded by farm country, there were plenty of farms and that restaurant in particular focused on organic farm produce. Over lunch, we were discussing the possibility of customizing some of the paper products for other uses or perhaps unintended uses. One of the ideas was to drop extremely cheap sensor modules into one of the diaper layers. My purpose in asking this question wasn't that I was really interested in sensor based diapers, but I wanted to know how difficult it'd be to come up with a customized diaper. The factory owner was enthusiastic and was complaining that diapers are a commodity item with low profit margins. She was interested to try something out and said that there was a need to add some type of functionality to let the parents of the child know if the baby pooped or peed in the diapers. Poop was more urgent since it would result in a rash for the baby if left unattended. After some discussion, we all agreed that something like that was possible by using simple paper sensors as a temperature and pH indicator. Temperature indication could be achieved by using a temperature sensitive dye and pH could just use litmus. A temperature change would alert to a potential event that occurred, and the litmus would alert to whether it was pee or not (ammonia is a base).
That was an interesting lunchtime conversation but the more interesting thing is that the factory owner was eager to try something new. I'm pretty sure that if we went up to her with a prototype of what we had just talked about, she'd put her technicians on it and help integrate something like that into the factory line. From there, I would have just needed to slap on a custom FreakLabs embossed label on the top layer and I would have been in the high tech diaper business.