Biro pens

[flirty41]

What causes the ink in (probably cheap) biros to go all gloopy and blobby all of a sudden? You know, you put pen to paper one day and get a great big blob of ink that then smears all over the paper and your fingers too! Why does it do this?

[wildwood]

Biros seem to have a mind of their own... they only leak when they are in a shirt pocket or handbag:-)
When a lot of ink comes out, it is probably because the tube has been damaged by dropping the pen, letting false air into it. Quite often there is a small blob of ink on the end which is really a bit of fluf which has been saturated with ink. I noticed that the sort of ballpoint pens with a cover cap never seem to get that blob.
Happy New Year.

[WendyW]

Thought this may be useful as it seem most Biro's leak. If you get biro on washable clothes then milk will remove it. Don't know why but it does.

[Cactus]

Milk is an alkali - not sure if biro ink is an acid, but alkalis neutralise acids, could be why it gets it out. Useful tip though WendyW, thanks.

[sft42]

Milk is an alkali...really i always thought that milk contained lactic acid?? Can anyone tell me for def if i am wrong then?

[Andromeda]

Sft42 - the four main constituents of milk are water, proteins, sugar (lactose) and fat. MIlk is slightly acidic though (around pH 6.8 for fresh milk as opposed to pH 7 neutral) due to the presence carbon dioxide, protein, phosphates and citrates, but lactic acid is present in milk as it gets older due to the fermentation of lactose by bacteria. A high measure of acidity in milk implies a high lactic acid component and therefor a higher bacterial content. As milk gets older there is more breakdown - it gets more acidic The making of cheese requires the inclusion of acids to coagulate the casein in cheese and so you can observe that as your milk gets older it starts to look a bit cheesy.

Andy

[flirty41]

How did a question that started off being about gloopy biro ink end up being a lesson on the constituents of milk??!! (How do you know all that Andy?) :-) Anyway, thanks for all your suggestions and tips! I think I've found the solution to my problem though - I've bought a fountain pen!!!

[Andromeda]

Flirty, I was trying to work that one out too! Seems I answered sft42's question! Beware your new pen - fountain pens do have a propensity to the same problem - it is a problem of all emulsions I am afraid. However it won't be as bad as fountain pens are more expensive on the whole than biro's and therefore the problem won't be as bad. To answer your last question, I like science, and spent a few minutes trawling internet sites to make sure I had got my facts right before posting (though I didn't manage to find the approximate percentages for milk constituents. :-( )

Andy

[flirty41]

Thanks Andy! I nearly went back to my gloopy biro today when my fountain pen leaked black ink everywhere because the cartridge hadn't gone in properly! What could I try next - rollerball!!!!???