Care+ Hygiene Expert: The Development Story of Blue Ag+

Mothers with babies are very busy washing and
keeping things hygienic every day

I drew on my own parenting experiences when developing this Blue Ag+ bacteria elimination function.
At the time, washing baby clothes was a really troublesome task. After separating items from other laundry and pre-washing them, I washed them again with a special detergent for baby clothes. Then I rinsed them one extra time to make sure there was no remaining detergent residue.

Baby clothes soon get dirty, so there's always a lot of laundry. It must have been hard work.

Yes, and babies put everything in their mouths, so I always wanted to keep things clean. I was also worried about bacteria.

You don't have to worry about common everyday bacteria harming a baby's health. But if you leave dirt on anything, bacteria may multiply.

I was trying really hard to be a good mother. But one day, I realized that if I spent too much time doing laundry, I wouldn't have enough time to look after my children.

I wanted a washing machine that can eliminate bacteria while washing.
That's when I started developing Blue Ag+.

At the time, the only ways to eliminate bacteria in laundry were either to wash with high-temperature water or use chlorine bleach.
But if I wash with high-temperature water, clothes shrink and get damaged. And it takes time. Chlorine bleach can only be used to eliminate bacteria on white clothes. After all, it's not something I can easily do every day.
There wasn't a function that enabled easy bacteria elimination with any item of clothing.

Didn't you dry clothes outside in the sun? Ultraviolet rays from sunlight also have a powerful sterilizing effect. But bacteria are only eliminated on the surface of clothes that are irradiated, so every part of an item has to be irradiated.

Yes, I knew that but I couldn't dry clothes outside. My daughter had bronchial problems, so I was worried that air pollution and pollen might become attached to clothes and cause her to develop allergies.

That's why you needed a washing machine with a function that can easily eliminate bacteria on clothes.

Yes. That's why I wanted a washing machine with Blue Ag+.

Searching for a simple, safe and reliable hygiene technology

The development team read a huge amount of material looking for new sterilization technologies.
It was at that time I came across your thesis concerning silver ions.
They can be easily used to sterilize any clothes, even colored items, and there's no problem with safety. I knew at once that this was what we'd been looking for!

I've been conducting research into silver ions for many years. It's been experimentally proven that silver ions have a strong, safe sterilizing effect.

And silver ions are relatively easy to make through a reaction with water, so it made sense to use them in a washing machine.

OH radicals, the key to 99.99%* bacteria elimination

What we paid the most attention to was the discovery of OH radicals, which have an extremely powerful sterilizing effect. They can be produced by exposing silver ions to ultraviolet light.

The mechanism of OH radical generation and bacteria elimination

* Images are for illustrative purposes only.


 

OH radicals, also called hydroxyl radicals, are a type of reactive oxygen. They work in the same way as the substances released by macrophages and natural killer cells, which are related to white blood cells, that attack bacteria and viruses entering the body.

Silver ions alone have a sufficiently strong bacteria elimination effect, but we needed something even more reliable.
There's no such thing as "100%" in the world of technology, but we had to get as close to it as possible.
The good thing about OH radicals is that they have the same mechanism of action as the body's immune system, so they're safe and reliable.

But OH radicals have an extremely short lifetime.

We overcame this problem by coming up with a way to continuously generate them.
Ag ions dissolved in rinse water stick to clothing. UV-A irradiation of these ions during the rinse cycle successively generates OH radicals to enable continuous bacteria elimination.

I see. Irradiating clothes with UV inside the tub is a great idea.
Because the clothes are agitated, the OH radicals are evenly distributed.
 

It was difficult, though, and it didn't work well at first.
Through repeated trial and error, we finally figured out the best balance between UV wavelength and intensity, lamp mounting position, irradiation time, timing and other factors.

Stable performance is a must in any home

Applying my research results for a washing machine must have posed some difficult problems.

There's a difference between the lab and a regular household. During a wash, a washing machine constantly splashes water and detergent, and vibrates. This affects the bacteria elimination effect. In theory it may seem easy, but in fact it isn't.

Were there any other difficulties?

Water pressure, which differs from home to home. If water flow is too powerful, the concentration of dissolved Ag ions decreases. To deliver stable performance, the design had to be able to maintain an Ag concentration above the standard level under any water supply conditions.

I followed this up in my university lab, and the presence of OH radicals was confirmed. And 99.99%* bacteria elimination performance has also been certified by a third party evaluation organization.

We're confident that our design will produce reliable results under any conditions.

Even if bacteria elimination performance is achieved, technological innovation doesn't end, does it?

No. There are endless challenges, such as how to make washing more stress-free, and how to help mothers raising children.
We're constantly improving our products to make them more convenient, safer and more durable.
We believe that this commitment and technological prowess is the cornerstone of Panasonic's Japan quality.

Making silver ions in rinse water and irradiating them with UV-A radiation to eliminate bacteria. It's a ground-breaking approach.

Ag+ Case
The Ag ion device releases Ag ions into the rinse water.

UV Light
Blue UV light at the upper part of the drum eliminates bacteria.

After being rinsed twice as usual, bacteria on clothes are eliminated during a third rinse.
(Rinsing three times also makes sure there's no remaining detergent.)

The Ag+ case is a cartridge type so it can be replaced, right?

The silver ion device has also been improved.
At the beginning of development, ions were generated by passing an electric current through an electrode plate, but we refined this into a simpler cartridge type device. This lets users replace the device themselves.
We also improved the shape of the case to make it easier for water to flow through it. And it's designed with safety in mind, so users can't directly touch the antibacterial agent.

Third party evaluation certification test results confirmed that 99.99%* of bacteria were eliminated.

Of course I was confident about its performance, but I'm relieved that it's been officially proven to be effective in eliminating bacteria.
And the bacteria elimination effect continues after washing.

Let Blue Ag+ do the hard work of eliminating bacteria so that all mothers can spend more quality time with their children. That was my goal.

Applying my research results to improve people's quality of life will make researchers very happy.