I recently bought a pack of Sony IBM formatted high density floppy disks, the same pictured below. There's a "Special Cleaning Mechanism" logo displayed on the box, and the only information I can find about it is on the back which states:

Sony's Special Cleaning Mechanism protects your diskette and reduces chances of error with features that clean the diskette surface.

What "mechanism" was being marketed here, and how did it protect the floppy disks?

  • 5
    probably some brush inside that would catch dust... Opening (i.e. sacrificing) a floppy could give the answer probably. Commented Jan 1, 2023 at 11:06
  • 2
    Perhaps patent JPH0562415A is applicable. Using <your favorite search engine> to search for "sony" diskette cleaning patent may turn up other patents of interest.
    – HABO
    Commented Jan 1, 2023 at 15:34
  • 1
    A few years back I had to destroy a pile of floppy disks (different manufacturers). I took them apart and they all had a felt strip inside.
    – Sep Roland
    Commented Jan 1, 2023 at 16:18

1 Answer 1


Heeded advice to take apart one of the floppies (I was apprehensive of this at first as I don't have the largest amount of them). As other commenters suggested, there's simply fabric inside spanning the circumference of the magnetic disk. A little dinky for what the branding suggested, although notably more elaborate than a simple strip of felt!

A taken apart 3.5" floppy disk. White fabric is inside on either side of where the magnetic disk would be.

  • 2
    The fabric disks? I think that's standard stuff. At least, I've seen it in other brands. I just now disassembled a noname-floppy (last used in 1995) and it had a similar feature.
    – dave
    Commented Jan 2, 2023 at 16:08
  • Yeah. My understanding is that having a single strip is a cost-cutting measure introduced around the end of the production lifespan of floppy disks.
    – ssokolow
    Commented Jan 2, 2023 at 18:43
  • Take the cleaning fabric off. I recall from reading from a box of Sony floppies decades ago, the lifter, which applies pressure to the cleaning pad and media is metal and not plastic as standard. The other side of the shell where the lifter presses against has angled tracks which sweep debris out of the data area.
    – user71659
    Commented Jan 4, 2023 at 5:36

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