How do YKK zippers self lubricate and zip more smoothly with more use?

Question

I’ve been researching this all morning and keep running into articles that explain why YKK is a great company and what is unique about their zippers, but no article that explains the technical design of the product.

Would love an explanation that goes beyond the very simple “YKK zippers actually lubricate themselves as you zip and unzip them.”

Thank you!

In: 2202

Answer 1

Some materials move much smoother over eachother than others. As an example, rubber on concrete produces more friction than plastic on steel even if all the materials are smooth.

Steel on brass contact actually produces less friction than steel on steel contact without lubricants. When you look at typical cheap manufacturing materials (brass, aluminum, wood, steel, copper) it turns out that brass on steel produces much less friction than the other combinations.

Now, what holds the zipper closed is down more to the shape of the mechanism than the materials, but the materials ensure that they move smoothly over eachother when in use.