While organizing my workshop, I labeled a lot of things with my label maker (Brother P-Touch PT-D400) and used up a cartridge. A common complaint with these TZe label tape cartridges is that they are really expensive. So now that I have an empty cartridge, I thought I would take it apart to see if I can see anything that justifies its expense. It turned out to be far more sophisticated than I had originally expected, but I still don’t know if I would call its cost “reasonable”. Plus I found an interesting security concern. Don’t use label makers for confidential information!
The only thing we can really see from the outside is a horizontal window designed to let us see how much tape is left. When full, there’s white visible behind the light blue area. That white spool’s diameter decreases as the tape is consumed, gradually running to what we see in this picture where very little white is visible behind the blue.
Looking around the perimeter, I see several little clips holding the lid to the body plus this white tag telling me what label tape is inside. I expect that I would have to cut this white tag along the seam, pop those little clips loose, and it should fall apart.
It did not.
Majority of holding force actually came from these posts that fit very tightly into their sockets, not the clips or the sticker. Dimension precision in injection-molded plastic is directly correlated to cost, so that’s where some of the money went: it’s pretty expensive to keep these posts and their corresponding sockets within the exact dimensions to fit and grip tightly.
After I opened up the cartridge, I see I had drastically underestimated the complexity inside. There are actually four spools, a few rollers, and many guides to keep three tapes of materials flowing properly.
Here are all the components of the cartridge. Multiple spools, and a few springs to maintain tension. I had expected a single spool of tape that gets spit out, so this is far more complex than I had anticipated. There are actually three spools of material: The white adhesive backing, the black ink (with take-up reel), and the clear laminate layer.
Here is a closeup of the clear laminate spool and the white adhesive backing spool. The clear laminate spool has black stripes in this picture because that’s how the cartridge signals the end. There were ~20cm left of this zebra stripe, not that I can think of much I could do with it.
Here is the other side, showing the adhesive backing still usable on what’s left of the white reel. It looks like remaining white backing can still function as double-sided tape if I wanted to put it to work.
The black ink tape was a surprise. It is a pair: a dispenser reel for fresh material and a takeup reel for used ink. What’s super interesting here is that the takeup reel has a clearly legible negative image of everything that has been printed. Unspooling the takeup reel a bit, we can clearly see that my most recent label was for a batch DC buck converters showing their adjustable voltage range and maximum of 5 amps capacity.
A valuable lesson from this teardown: avoid confidential information when using a label maker, because a motivated dumpster-diver can read that information off your discarded empty label tape cartridges.