Materials: oily film on old unused rubber

Self-tutoring about materials: the tutor investigates the oily deposit on an old rubber mat.

In a closet yesterday, while doing some general searching, I encountered an old bath mat not used for decades. It’s the kind with suction cups on the bottom.

I reached up to grab the bath mat to look underneath it, but felt an oily film on it. Pulling it down from its place, I saw it was covered with flat droplets of oil. The oil seemed too thick to flow.

There was no evidence of a spill, so I decided the oil had oozed from the rubber mat itself. Why, and what is said oil, I wondered.

It turns out such a phenomenon might be called “rubber bloom” and occur as ingredients added to the rubber gradually escape it.

Apparently, said bloom can possibly be cleansed away, possibly with an alcohol wipe, for instance. In this case I disposed of the rubber mat. My thought was that, having changed thus, it may no longer perform as it should.

Source:

echosupply.com