Hope you are well. We haven't checked in for a while and felt like it's time to tell you more about luumi :)
please check out this video we made to show off our unique, secure, watertight seal :)
We are still chugging along on our mission to Unplastic the World with our bags lids and straws, and it turns out what makes us unique in the marketplace is our purity and our ability to seal securely, in other words, our clamp.
Right from the beginning of luumi, people have asked to incorporate a seal into the bag, to make a zipper style seal rather than the clamp, which I understand would be awesome because of the smaller carbon footprint of a single item, single material, and it would be easier to use than two pieces, BUT it just doesn't work very well :(
A zipper made of silicone is just too darn squishy to maintain a strong seal, and that truth of that fact is being called out on one competitor's design as we speak with the majority of feedback saying the seal doesn't work well enough; not airtight or watertight is what they say.
Some of the competition has added filler to their bags to make them more rigid so they can make a slightly better seal with a more rigid zipper, but the filler does not actually bond to the silicone, and is loose in the composite and given off easily (pinch and scratch a composite bag with your fingernail and you will see the problem).
The silicone strength is also severely compromised by the lack of bonding between the silicone and filler. Compounding the issue, silicone cut with filler can be made to extremely thin tolerance which is more attractive for manufacturing cost (cheap filler + thinner tolerance = cheaper manufacturing), but exacerbates the overall durability issue (thin walled composites tear easily).
Pure platinum silicone tends to stretch and break when demolding designs with tolerances under 1mm, but the more rigid composite materials peel off the mold easier due to the lack of flex of composites (they don't stick to the mold quite as much). After being pulled from the mold, the lack of flex causes it to tear quickly, so what you gain in zipper strength, you lose in overall durability, and one only needs look at the many complaints about breakage of these kinds of super thin silicone zipper bags on Amazon (filter to the most critical reviews of these designs) :(
So there are now two basic models of silicone bags available today; ones with a built in zipper that make an iffy seal at best, and ones with a clamp ;)
There are a few plastic clamps showing up out there in the marketplace, one with a sliding plastic rail that seems to be very hard to slide, and one with a 4 piece, semi built-in plastic clamp that breaks very easily and makes the bag hard to use or clean.
Now I know the clamp is more work, I know there is a learning curve, but it comes down to intention and ours is to give people a long life product that actually works as described, so they can reduce their consumption of plastics rather than increase our consumption of short lived or non-useful silicone stuff.
The clamp also allows for easy cleaning. The bag itself is simple and easy to turn inside out, no hidden corners or zippers to trap stuff, just flat, easy to reach surfaces that come clean with a wipe...
Luumi bags are kinda end of the world bags that aim to help stop the whole end of the world cycle of plastics. Thick pure platinum silicone with a button system that has not failed in the 6 years I have been manufacturing them, and a hard anodized aluminum clamp that does not bend or warp or become useless.
We also want to influence the market, not corner the market, so I'm OK with the role of slower growth although I'm worried that all the issues with my larger competitors may turn the public away from the opportunity we have to use pure platinum silicone to replace our plastic food delivery and storage problem, so I thought I would let you know.
Hope you are having a wonderful day!