It Scales…

I tell people “We can only make closures 4 mm small [height].”

Partial Lies.
…because I predicted my competitor’s actions. They would attack the height.

But, I really like a ZS closure height of 6 mm because, per testing, that is a good optimization of size, tensile strength, water tightness, and just overall durability.
6 mm is the height of 4 pennies stacked on top of one another.
If your waistline increased 6 mm then would you notice?
Well…the optimal (in my opinion) ZS zipper will stick out 6 mm from your body.

That’s the smallest size (4 mm) we can make with heavy gauge sheet metal- 0.5 mm and above metal thickness.
But, we can use medium weight sheet or heavy foil, which is anything above 0.10 mm. Or, said differently, 5 mil foil.

If the metal is bent and holds the shape, then we can use it. This also depends on metal hardness. So, 1/4 hard steel will be weaker than full hard steel.

And, using around 50% less thick endoskeleton material results in a thickness decrease of 0.25 mm on each half of closure, 0.5 mm overall. But, there’s also the thickness of polymer exoskeleton to consider.

We can get to 2.5 mm tall closures. This is the height of a YKK size 5 metal zipper.
Oh, and the YKK size 5 metal zipper has a tensile strength of well under 180 lbF. The maximum crosswise tensile strength of a size #10 YKK zipper is 800 Newtons or 180 lbF.
Whereas the Zipr Shift closure is above 180 lbF in tensile strength. The closure with 0.5 mm thick, half hard (steel) metal had a tensile strength of over 400 lbF.

I believe this is already happening, competitors attacking the perceived height of my closure.
There’s an interesting action from YKK. They’re trying to update the ASTM D2061 standard to include the dimensions of zippers.
(It’s a publicly available link via the Free Standards Tracker email  or RSS so I’m not in violation of copyright- it’s a free AND public link.)

After their 83 years of zipper use, they (YKK) now think it’s reasonable to include specific dimensions in the standard.
When all zippers are the same, this wouldn’t matter.
All zippers are the same = All zipper dimensions are the same.
I’m sure most companies who use zippers don’t know the tensile strength of zippers. They never had a choice of zipper strength.
If they did then they’d know that YKK’s perceived superior strength is false.
There is no significant difference in strength between the zippers of any mainstream zipper maker- SBS, YKK, Ideal, Dunlop, etc.

I laugh because that’s a predictable response.
Adding dimensions to the standard will serve to further make the standard specific to their zipper type. (Because there’s more than one type now with ZS.)

But, I’m sorry. Sheet metal is extremely versatile as far as tensile strength.
And, ZS’s closure depends on material stiffness (force to bend) and not shape (tiny parts slipping past one another.)

Extra full hard puzzle piece zipper teeth will slip past one another just as easily as dead soft puzzle piece zipper teeth.
The separation or gaps between the teeth and coils (i.e. not being a continuous structure) is what hurts the tensile strength.
That’s why it’s a design weakness.

The shape and size doesn’t matter for the ZS closure.
Only the stiffness of the metal endoskeleton matters. No matter how tall I make it, the trend of changing size doesn’t drastically alter the strength.
A 0.5 mm thick half hard metal endoskeleton and 10 mm tall closure has roughly the same strength as a 0.5 mm thick half hard metal endoskeleton with 4 mm tall closure.
There are no interlocking parts so the size of the parts doesn’t really matter.
You have to bend metal so only the metal matters.

Changing the metal to make it stiffer is the only thing that changes the strength.

The exoskeleton is merely functional to keep the structure continuous, hermetic, and inert.

Give them hope and then snatch it away…






I’m so good at this.
Predicting the Army’s awful corruption and now (potentially) predicting the plight of my competitors.

But, it doesn’t matter anyway.
I’m not interested in updating the standard because I’d have antitrust issues if my closure sets/becomes the standard.

Plus, people don’t notice two extra millimeters anyway. Especially not when they realize it’s watertight under pressure and much stronger than its predecessors.
(Per my focus groups, people noticed when my closure was 8 mm tall but not before that. And, that’s smaller than the size of a YKK BDM zip which is 9.5 mm tall.)





It’s funny how business works. Everything you say could end up in your competitors ears…


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11 thoughts on “It Scales…

  1. Right. When the standard mentions say size 5 that implies dimensions.
    But not when you have a new kind.

    Specifying more defeats the point of a standard. It eliminates having new kinds by honing in on the current design.

    1. Well the designation “Size 5” implies the dimensions already is my point.
      Every zipper maker (until me) has made the same “Size 5” within 0.5mm difference.

      Size 5 = 5 mm tape width
      And, the standard currently has this distinction.
      The only dimension left out of the standard is height.

      Why after 83 years (oh and the standard hasn’t been altered in 4 years) of selling zipper are they now wanting to include the height of the zipper in the standard?

      No zipper company makes any zipper of a significantly different height!

      And, I’m 100% certain their customers having to “look elsewhere to understand the expected strength of the closure” (Quoted from the ASTM revision link) is NOT a new problem.

      This is just speculation but I’m pretty darn sure YKK is trying to tailor the standard to fit specifically the current zipper, leaving no room for other zipper technologies.

      And, this is a new problem because before 2016, there were no other zipper technologies strong enough for durable goods.

      But, as I said in the post, I don’t even care.
      I don’t want antitrust issues from setting the standard.

  2. Did not know size 5 was 5 mm width.
    But I said, “Specifying more defeats the point of a standard. It eliminates having new kinds by honing in on the current design.”

    So we agree and the fact that it already has the width but just not the height aids your speculation.

    P.S. I’ve never read the standard but have noticed the number on the back of a zipper slider.

  3. The first testing I’d done a year ago…it’s certified.

    I tested size #10 YKK brass metal zippers (the 173 lbF values.)
    And one size #15 brass zip (193 lbF value)

    By now, I’ve tested all major companies’ zippers.
    I found out coil zippers are somewhat stronger but nothing incredible.

    Also, no matter what they do with the standard, the military already knows their technology is inadequate. And, really this is what standards are for.

  4. I don’t think it was sole rationale.
    However, after using same standard for years why specify strength by molded, metal, and coil plus dimensions now?

    I agree. Not new problem.

    1. Yeah. But, hopefully in doing this, zipper buyers will realize that there is no great difference in strength between any zipper on the market.
      And, with that, I hope the feelings of “YKK makes the strongest zipper” dies.
      But, I want people to stop putting faith in all of these ~200 year old zippers.

      Even I, before tensile testing, thought metal zippers were the strongest.
      But, coil zippers are because of the amount of touching surface area- they’re the most continuous zipper. The gaps between coils are really small.
      This is also why my closure is so much stronger. It’s like having metal coil with 90% of the surfaces touching one another. The metal endoskeleton acts as a wall.

  5. So you didn’t tell the truth about the sizing and you think a competitor is up to no good with changing ASTM standards.
    Well at least youre honest about speculation.
    What is your aim?

    1. Haha. Yes.
      My aim is this: get the world to switch to a better zipper.
      I want to do it honestly but I’m feeling out my market, my competitors, and everyone and everything else!
      I like the taller zipper of mine so I wanted to see everyone’s reaction to a ~4mm height increase even though I can make a smaller zipper.

      And, my not wanting to get involved in antitrust issues means I don’t want to have to forcibly license my technology to my competitors.
      If my tech is veritably the chosen zipper then I’d like to put everyone else out of business. Because as an inventor, I’m trying to give the world new, beneficial tech when they’ve been stuck with no options and the same ~200 years old tech in the 21st century where robots are beating people at particular work functions. The brands should die with the company…like Netflix and Blockbuster (Blockbuster, who? oh right. nothing about it exists anymore).

      Honestly, publicly speculating about competitors is iffy. But, I’m looking for a discussion. My blog creates an open forum. Or, at least that’s my hope.

      Thank you for your comment. 🙂

      I want to be honest about my startup journey and the struggles that I face so everything that people see here on this blog will NOT be happy and nice.
      But, I’m respectful. For instance, my opinion (the speculation) is stated as such. Of course I’m biased. But, determine what you will!

      I’d just like to say that…

        No large company likes to be overtaken by a startup
        …and typically their actions border on corruption once they begin trying to squash the little guy.
        This is just my opinion on the situation. Anyone is free to feel how they want.


      YKK is the only zipper company on the ASTM committee.
      I speculate it’s because they want to SET the standard.
      They want to be known as the maker of the strongest zipper.
      If there’s something in the standard that they didn’t specify before then they probably had good reason.
      This new proposed change the standard further specifies the standard to zipper size and strength.
      They’ve been selling zippers for nearly a century and they are just now specifying more.

      I’m just going to make sure as best as I can that the people who test the zippers test the zippers from other major zipper companies.
      Then, the whole world will see that every zipper is the same size and strength and that YKK was hardly ever ‘better’ from a quality perspective.

      And, when people are buying zippers, they’ll ask “Can you meet this standard size and strength?” and I think YKK will lose business right then because pretty much every other zipper company makes the same size and strength zipper as YKK.
      They all tailor their zippers to the standard, produce the zippers the same way, and use the same materials.

      It’s a mature industry. Everyone is selling the same thing (except me.) The current D2061 standard is just for show basically. Whoever enters the market won’t sell zipper until they meet the standard. Even Chinese knockoffs have the same strength and size as YKK zips. Chinese zipper maker SBS is proving that Chinese zippers are awesome quality…and taking tons of market share from YKK!

      To me, it’s akin to a hypothetical floppy disk standard where the standard once just said how much storage the floppy disk has.
      But, the prime floppy disk manufacturer hears about a jump drive stanrtup and changes the standard so that it reads: “Storage devices are 5 inches length by 5 inches width and 0.15 inches height.”
      Thus, making a hurdle for the 1 inch length by 2.5 inches width and 0.5 inch height jump drive.

      It’s taller so it doesn’t fit within the standard. (just an example)

      Remember how thin floppy disks were compared to jump drives?

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