Too much foam, or none

The property customers judge cleaning by, and one of the few that has almost nothing to do with cleaning.

Foam is a perception and a problem

Customers read foam as strength. A dish soap that does not foam is judged weak whatever it does to the grease.

And foam is a genuine nuisance in several applications: it has to be rinsed, it interferes with machines, and it makes a floor slippery.

So foam level is a product decision rather than a side effect, and it should be specified.

Where foam is wanted

Hand dishwashing, where it is the entire perceived performance and where its collapse signals that the water is spent.

Hand soap and foaming dispensers.

Anywhere the customer's judgment of the product is the point.

Anionic surfactants foam; amphoterics boost it; a foam stabilizer holds it.

Where it is a fault

Floor cleaners, where foam leaves residue and makes a surface slippery.

Anything used in a machine: a foaming product in an automatic dishwasher or a carpet extractor is a failure and sometimes a damaged machine.

Anything rinse-free, where foam means residue.

Spray-and-wipe products, where foam obscures the surface and slows the job.

Nonionic surfactants are the low-foam answer, with a defoamer where needed.

Controlling it

Choose the surfactant system for the foam profile you want, first, rather than adding a defoamer to fix a choice.

Test foam the way the product is used: shaken in a bottle is not a floor, and a dilution matters more than the concentrate.

Specify it, so a batch can be checked against it.

And write the dilution instruction with foam in mind, because an over-concentrated dilution is the commonest cause of a foam complaint on a product that is correct.

References