There is a word for a particular commercial product that becomes so well knownthat the entire line of products may be refered to by it;s business name.
Such as KLEENEX, COMET, JELLO, Etc. YOu just go to pick up some Kleenex, Or "May I have a Kleenex" REgardless of the actuall mfgr. brand.
I heard the word once and lost it. It is distinct from something that is named after a person, as in a Dikensian sttatement
Can you help please.

Generic?

As in "The proprietory brand 'Kleenex' has been used as a generic for tissues for some years"

Metonymy?

Welcome to the nuthouse, K.D.

I've been told that, in Business Law, this is called generification.