The real answer is that the glue inside the bottle is saturated with solvent which keeps he solids in suspension. If you hold it up to a light you can see the suspense.



When you apply the glue to a surfce or two to be joned together in hol...oh wait. to be joined, the solvent evaporates leaving behind the solid materials which may combine into a matrix and solidify there by holding the parts to be joined solidly coheased or glued. I



it does not require air as the same thing will occur in a vacuum.

It needs air to dry out the solvent.

It needs air to set

its designed to react to the O2 molecules in the open atmostphere

It does.





Try leaving the lid open, and then ask me that question.