Why, in print, is the word "dumpster" capitalized?

Question

I'm an avid reader and I've always wonder what the logic is. I don't recall learning anything about it being a proper noun in school.

Answer 1

"Dumpster" is a propernoun, the trademarked name of a product made by the Dempster Corporation.

Answer 2

Because it's a brand name, like Kleenix.