There are at least five bands with the name Sink:

1) English punk band formed in London, UK in 1987 around singer Ed (Shred) Wenn after he had left The Stupids. The band played punk, hardcore, melodic pop-punk, with acoustic guitars and blues influences. Recording their last album/7" in 1991, they split in 1992 to form Big Ray. (See below for lineup and discography)

2) Sink is a Finnish underground metal band playing sludge and drone with elements of dark ambient. www.sinkprocess.com

3) SINK is an electronnic music project born in France in 1999. Using analogic and electronic soundspaces with rhythmic processing and improvisation. SINK Electronica website

4) Japanese hardcore band active in the mid-90s. Released a split 7" with Hellnation on Sound Pollution records and a 7" EP on MCR (I think).

5) Berlin based experimental band. Their sound ranges from Berlin-typical echtzeitmusik related sound scape which can, but need not, result in a minimalistic groove fest. Sink was founded in 2004. Sink are Andrea Ermke (mini discs), Chris Abrahams (dx7), Marcello Busato (drums) and Arthur Rother (guitar).
last.fm: sink_berlin homepage: sink