Let’s say I want to make a ginormous ziplock sammich bag. I have a big sheet of 3 mil plastic and plan on attaching a giant plastic pressure sealing zip-lock type thing to it.
Can I get the zipper stuff in bulk? Like on a big spool?
I’ll try to get a contact at 3M. If they can’t do it, I would be willing to bet they know who can.
Considering that Ziploc™ is an S. C Johnson & Son product, you’d be better off starting with them, I should think.
Zip Lock and similar self sealing bags are all one manufactured molded piece, the “zippers” are part of the mold process and aren’t sold separately so far as I know.
They make long tubes for bundling cables that close with a zip-lock. If you can’t find bulk zipper, you might be able to split one of these in two and at least have a very long length. I have no idea where to buy them though, and I have only ever seen them in opaque black material.
No, they do make rolls of the stuff–it’s an extrusion. But, the only suppliers I’ve been able to find seem to be all in China for some reason. Like this one.
I realize 3M doesn’t make Ziploc, but I believe that the OP was referring to more industrial-sized proportions, since I’ve never met a sandwich that requires 3mil plastic. 
Thanks Dewey! Nice work.
I don’t know a damn thing about zip-lock plastic.
But , man, I just gotta ask what kind of a sammich you’re planning to eat 
In that case, I have a contact over there I can put you in touch with if you’d like.
Sounds like a home-made body bag. Not that it would be, of course.
How long is “Long?” For my nefarious purposes I need one that is at least 35-40 feet long. And very strong.
And no, truthbot, it’s not a body bag. But the concern that it could accidentally become one…sort of…is always a vexing issue.
Zipped enclosures aren’t really all that strong. In my experience they pop open under pressure. Have you considered just heat-sealing the bag shut, or using an adhesive? As it is, you’ll need to adhere the zipper lock to the plastic sheeting.