Dear everyone,
So it's a project to make a machine that can wash reusable cups. However, there are quite a few problems, like how to get rid of lipstick, using brushes (they get dirty easily, silicon ones are an alternative but I am not really sure) I am thinking of having a vertical gravity system to reduce the number of moving parts so that cups could drop and get washed. But there is a problem of washing the cups just enough to remove the coffee stains without wasting water. Does anyone know anywhere where such a system has been applied, or if anyone has some experience with dishwashers, please do give suggestions that might be relevant.
Any help is appreciated.

Thanks a teratonne!
yashvini

 

Hi Yashvini,

Have you looked into industrial/commercial glasswashers like those used in restaurants and bars?

I worked in bars for quite a few years as a student and our glasswashers were pretty heavy duty. There were occasional items that weren't fully clean but they mostly do a great job.

 

I think it should be a washing chamber with high pressure vats.
The cup should be immersed in the chamber and several jets of water under high pressure wash away the dirt, while the cup should be in motion, for example, a swinging chamber or a vibration chamber.
how many cups will be washed at the same time?

 

To remove lipstick easier, you may want to add a bit of ammonia in your washing solution. That is not to say that standard dish detergent shouldn’t do the job really. Now for the jets, I have seen industrial solutions using rotating jet heads to clean glass bottles from the inside, so that would be your best bet. The rotation guarantees adequate coverage on the inside and combined with enough pressure it should do the job. I would say that it is safer to keep the cups steady and have the jet heads moving back and forth and rotating instead. If you have the cups dropping, you’ll most likely have trouble from excessive residue stuck on one side for example. If you pre-wash, then you’ll be ok, but that kind of beats the purpose of “saving water” right?

 

I don’t know if my suggestion makes any sense or not, because I don’t know for what reason you would want to use this cup washer. But I am going to blurt it out anyway, instead of designing a better washing machine, why not just change the cups.

For example, there are cups that are very easy to wash (they’re coated with Teflon or hydrophobic coatings) and as soon as the water touches the cup all the coffee and dirt just washes off.

So if this was a machine that would be used in a office environment where everyone would drink the coffee and leave the cups on a rack, then the rack could be dipped in a huge tank of soap water and give a shake. Then flushed with clean water ( and the clean water can be stored in the soap water tank for future use) and the cups also dry really fast with a wiper.

However, if this machine is to be used in a dormitory, where everyone has their own cup to wash then this solution makes no sense at all.