Viscometer

RenKBRenKB Member, PCF student
Can anyone recommend a viscometer that's not going to cost an arm and a leg but still effectively get the job done? 

Comments

  • GuntherGunther Member
    You can build one yourself:

    1 Buy plastic graduated cylinders (IMO 50-100 ml work fine)

    2 Drill a hole in the bottom. The hole diameter depends on the viscosity range you're willing to test.
    Even wikipedia 'Flow cups' article gives great info
    https://en.wikipedia.org/wiki/Flow_cups

    3 Get a stopwatch (even a smartphone app can work fine)

    4 Fill it up with the bottom hole plugged.
    Unplug and measure the time it takes to partially empty by gravity
       i.e. from 50 to 5 ml. You may want to paint the cylinder marks to make them easily readable.
    don't allow to fully empty as it ain't accurate there.

    You may wish to buy a bottle of your favorite commercial product with the proper viscosity you're looking for, or get some liquid with a known viscosity as a "calibration standard".
  • BelassiBelassi Member
    Gunther's idea works well.
    Or you can measure the time for a (eg) marble to sink a given distance.
    Or measure the time taken for an air bubble injected from a pipette to rise a given distance.
    Cosmetic Brand Creation. Concept to name to IMPI search to logo and brand registration. In-house graphic design inc. Pantone specs. Cosmetic label and box design & graphics.
  • RenKBRenKB Member, PCF student
    Thank you! I will try that. And good point about it not emptying all the way. 

    Can you tell me what I should expect to pay for a decent one on the market after I have a chance to save toward its cost?
  • GuntherGunther Member
    @RenKB price depends if you want a "mechanical" or a digital one
    You can start here:
    https://www.labx.com/v2/adsearch/search.cfm?sw=viscometer&sort=p&sortDir=a

    Hint: choose one that's easy to clean up. Most aren't, especially those made of curved glass.
  • svensven Member
    @Gunther, i just want to get a little more clarity on your article above. Since i make shampoos all who are around 1200 - 3000 mpas then i should use a 8mm hole at the bottom of the cup?
  • GuntherGunther Member
    edited May 2018
    Yes, but you'd need something to compare flow-times to
    either

     A. Reference fluid with the desired viscosity. Either lab-grade reference standards like these
    https://www.sigmaaldrich.com/analytical-chromatography/analytical-products.html?TablePage=113813044
    or a bottle of your favorite commercial shampoo (not very accurate, but allows a better comparison to commercial products).

     B. A professional viscometer with viscosity tables like these
    https://www.thomassci.com/Equipment/Viscometers/_/FORD-VISCOSITY-CUPS

    You can always start smaller, say 6mm hole and then drill it bigger, if flow is too slow.
  • DuncanDuncan Member, Professional Chemist
    If you want cups pre-made try looking at places that sell automotive refinishing products - they're used for checking paint viscosity before spraying, or google "Ford cups"
    UK based, Over 20 years in Toiletries, After a 5 year sabbatical doing cleaning products, back in the land of Personal Care
  • svensven Member
    Thank you @Gunther and @Duncan
  • GuntherGunther Member
    Just check the paint cups specs
    Paint, especially those meant to be sprayed are way thinner than shampoo
    https://www.hallmach.co.nz/public/db_files/1504567179.pdf
  • svensven Member
    @Gunther, reached out to a lab supplier and the following is their oem supplier response "Afternoon Sven

     Herewith feedback from our supplier.

     Hope this helps

     Mpas is the same as centipoise.

    Cups measure Centistokes.  To convert from centistokes to centipoise, the density of the liquid is required.

    Assuming the shampoo is a similar density to water (1) then centipoise and centistokes are equal. 1200 to 3000 is outside the range of all cups.

    I suspect the shampoo is thicker than water so I would need to know the density to be sure, but don’t believe a No 4 cup would be suitable for this application. Maybe no cup will be in this range.

    Which type of cup is it?

  • GuntherGunther Member
    You need to read the specs for that cups manufacturer.
  • PerryPerry Administrator, Professional Chemist
    Interesting discussion. 
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