Home Cosmetic Science Talk Formulating How does a capsule in a toilet work?

  • How does a capsule in a toilet work?

    Posted by Ryoo on December 28, 2016 at 3:53 pm

    Hi everybody reading,

    I’m new the science world, and strangely I saw my dad put in a toilet tablet into our cistern system. I dont understand how this sits in water and doesnt react, but then every time we flush it, it does. Could anybody explain please, my dad doesnt know.

    Sorry for the lame question.. just found it interesting.

    Ryoo

    johnb replied 7 years, 10 months ago 3 Members · 36 Replies
  • 36 Replies
  • johnb

    Member
    December 28, 2016 at 4:15 pm

    These “tablets” are usually one of two types:

    1. A cast mixture of a high melting point nonionic detergent (perhaps stearyl 25-ethoxylate) and a lower melting point ethoxylate such as stearyl 5-ethoxylate. The lower ethoxylate is relatively insoluble in water and gives the longevity, the high melting point ethoxylate enables the tablet to have sufficient “body” to withstand handling. They can contain up to 5% of colorant such as FD&C Blue No1. Often wrapped in a PVA film to protect against colour transfer whilst handling.

    2. A hard pressed mixture of conventional toilet cleaner alkalis or of trichloroisocyanuric acid. This last has a low water solubility and can last several weeks in a toilet cistern slowly releasing its contained chlorine. TCCA is a  VERY POWERFUL OXIDISING  AGENT and must be handled with great care and the manufacture of blocks should only be attempted by specialist manufacturers. It cannot be mixed safey with other materials.

  • belassi

    Member
    December 28, 2016 at 7:22 pm

    We certainly don’t want exploding toilets. No sir. (A friend tried to clear his drains by flushing a chunk of sodium metal. The explosion blew a manhole cover in the road into the air, and showered a passing pensioner with the brown and smelly)

  • Ryoo

    Member
    December 28, 2016 at 11:26 pm

    @johnb incredible. That makes perfect sense. Would I be able to make one at home? Or something similar that creates bubbles and a nice smell to begin with??

  • johnb

    Member
    December 29, 2016 at 7:57 am

    You could make the coloured ones at home  - if you are able to obtain the ingredients - which may not be easy for you. To be honest, it isn’t really worthwhile doing-it-yourself.

  • Ryoo

    Member
    December 29, 2016 at 9:44 am

    What would the ingredients be? I should give it a go.

    See I thought it was like making a bath bomb, but more complex. I’ve actually got some ingredients from bath bombs from a while back.. citric acid, SLS, Sodium Bicarbonate and cream of tartar. Any of them of use??

  • johnb

    Member
    December 29, 2016 at 4:06 pm
    Any of them of use??

    No.  They will dissolve far too quickly.

    I described suitable ingredients in my first reply. Whether these are available to a small user in your country, I don’t know.

    Do NOT try to make any of the TCCA products. It is very unlikely that a home user would be able to obtain the materials but, in case you are, heed this warning ver

  • Ryoo

    Member
    December 29, 2016 at 6:29 pm

    Got you. Is option 1 more than the  two ingredients you mentioned?
    stearyl 25-ethoxylate
    -  stearyl 5-ethoxylate

    Do these include the bleach that kills bacteria, as well as the chemical to create the bubbles? I guess ultimately thats what a toilet tablets purpose is right?

    Thanks

  • johnb

    Member
    December 30, 2016 at 8:21 am

    A most important part of option 1 is the dyestuff - in fact it is THE most important. These products do little more than provide colour and a slight foam to the water from the cistern. The dilution rate is so vast (just think, a 50gram block slowly dissolving in probably hundreds of litres of water - almost homeopathic in concentration).

    Similarly with the chlorine releasing blocks , they do little more than release a chlorine type odour, the amount of chlorine released per unit volume is miniscule.

  • Ryoo

    Member
    January 2, 2017 at 9:42 am

    Hi John, Happy New Year!

    I’m finding this difficult to understand in all honesty. Is there a simplified way you could explain to me what I need to make one please? I’m not quite getting what it is I need or what to do next? Thanks

  • johnb

    Member
    January 2, 2017 at 10:34 am

    You need to make a mixture of stearyl alcohol (5 or 6)-ethoxylate (this is a soft solid) and stearyl alcohol 25 ethoxylate (this is a hard waxy material). The first item gives longevity to the block, the second the hardness and handle-ability. The more of item one, the longer it will last but the softer it is. That is the reason that some of the longer lasting blocks are wrapped in a water soluble wrapper. The colour is most commonly given by FD&C Blue No1 (CI42090).

    These materials are not commonly available to the home user. Do you have a source of supply? If not, there is little point in me going further.

  • Ryoo

    Member
    January 5, 2017 at 12:07 am

    I have found a few suppliers. However, they dont call their items those specific names. For example, I’ve found a ‘fatty alcohol ethoxylate’ and ‘cetyl stearyl alcohol’ (boosts foam, which I’d be interested in doing I think)

    Is this because there are various types of ethoxylates, and depending on the number, it is a different type?? Noticed here http://www.saibabasurfactants.com/products.html

    I also found two UK suppliers, but having searched, believe they only supply the stearyl 5-ethoxylate;

    http://www.bonnymans.co.uk/

    https://mistralni.co.uk/

  • belassi

    Member
    January 5, 2017 at 6:40 am

    Before you actually make this, I suggest you check your cost of ingredients against the cost of buying one in the supermarket . . .

  • johnb

    Member
    January 5, 2017 at 8:33 am

    As it appears that you are in the UK, stearyl alcohol 21-ethoxylate is available from The Soap Kitchen https://www.thesoapkitchen.co.uk/acatalog/emulsifying-wax-steareth-21.html#SID=119

    Although not quite 25 ethoxylate, the difference will not be noticed in a product of this type.

    Cetyl stearyl alcohol (or anything similar) will NOT boost foam.

    Please heed the advice from Belassi and from me earlier>

    To be honest, it isn’t really worthwhile doing-it-yourself.

  • Ryoo

    Member
    January 6, 2017 at 10:30 am

    It’s just something I’d like to attempt as a hands on hobby. All of your help is so appreciated as well, looking forward to making it.

    Thanks for the 21-ethoxylate John. That site doesnt seem to have he 5-ethoxylate though.

    Which of these make the foam then?

    You reckon it’ll be an easy case of mixing together right proportions then making it into a tablet??

  • johnb

    Member
    January 6, 2017 at 11:32 am

    The materials are mixed and melted together with the dyestuff.
    Both materials contribute to the foam.

  • Ryoo

    Member
    January 6, 2017 at 12:34 pm

    Ok great.

    Could you check these for me please?

    FD&C Blue No1 (CI42090
    https://www.thesoapkitchen.co.uk/cgi-bin/sh000002.pl?WD=ci42090%20no1%20blue%20fd&PN=fcf%2dblue%2dpowder%2ehtml#SID=47

    Strearyl 5-ethoxylate
    Could you tell me the alternative name if one? As I cant find a place that have this?

  • johnb

    Member
    January 6, 2017 at 2:53 pm

    That is correct for the dyestuff.

    Regarding the stearyl-5-ethoxylate, you already told us that you have a source (Bonnymans or Mistral)

  • Ryoo

    Member
    January 6, 2017 at 5:16 pm

    Great!
    I’ll check again once on my personal laptop. But I believe it was this I presumed was Stearyl 5-ethoxylate?
    http://www.bonnymans.co.uk/products/product.php?categoryID=1417&productID=6498

  • johnb

    Member
    January 6, 2017 at 6:02 pm

    No, that is not the required material.

  • Ryoo

    Member
    January 11, 2017 at 10:33 am

    Hi John,

    Finding these aren’t easy, but persevering.
    Are there any additional ingredients required for this? Would these ingredients bring in the element of medium thick foam and the cleaning properties?

    Thanks

  • johnb

    Member
    January 11, 2017 at 1:47 pm

    Are there any additional ingredients required for this? Would these
    ingredients bring in the element of medium thick foam and the cleaning
    properties?

    The ingredients for a basic “blue block” are as given. Some have had perfumes included but, as the dilution ratio is so vast, these are ineffectual. Similarly with cleaning power. All that can be expected from this type of product is a blue colour in the flush water and some fairly transient foam.

    If you find it impossible to obtain stearyl 5-ethoxylate, it is possible to substitute coconut monoethanolamide (cocamide MEA). This may give improved foaming. It was not used in the original commercial formulations because of relatively high cost. It is available in small quantities from several suppliers.

  • Ryoo

    Member
    January 12, 2017 at 2:43 pm

    It’s proving difficult for those items. stearyl 21-ethoxylate and FD&C Blue are good. But even cocamide MEA is not easy to find.
    Do you have any recommended suppliers? Not looking to buy a tonne however!?

  • johnb

    Member
    January 12, 2017 at 2:57 pm
  • Ryoo

    Member
    January 12, 2017 at 3:13 pm

    I just wanted to let you know that I have just found cocamide MEA, great success (ignore my last post).

    Should I buy that, and the Stearyl 21 which is available and then the FC&D? Would that be ok to make these capsules?

    As I mentioned, I really want to ensure I have a good ‘solid’ foam from the capsule, and so hope these ingredients can create it. I noticed yesterday, my supermarket bought capsule gives little foam. That’s something I’d like to improve on my version.

    Would I also need to purchase the paper wrap? Maybe you could advise on next steps before I purchase so I know what’s in store?

    Ever so thankful for your advice and guidance.

  • johnb

    Member
    January 12, 2017 at 3:30 pm

    Those three materials are all you need to make a high quality product. Ensure you have cocamide MEA and not DEA (which has completely different properties.

    You will have to do some experimental work trying different ratios of detergent to check which gives the longest life and best visual effect.

    The dye content is about 2% - 5%.

    Regarding the amount of foam generated, the cocamide MEA is a very good foam stabiliser and will most likely give a superior foam compared to that of a commercial product.

    The steareth21/cocamide MEA block will be much harder in texture that commercial ones and may well not require a wrapper. If you want, you can get a suitable product from Amazon https://www.amazon.co.uk/s/?ie=UTF8&keywords=soluble+film&tag=googhydr-21&index=aps&hvadid=155853298232&hvpos=1o2&hvnetw=g&hvrand=6922649303676878326&hvpone=&hvptwo=&hvqmt=b&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9041127&hvtargid=kwd-1033397470&ref=pd_sl_2wndqe1c97_b

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