Help with paper pulp closure!

Hi guys,

I’m currently working on compostable paper pulp bowls and lids and need to figure out a way to close them tightly.
It will be used for salads and food so it needs to be tightly secured. We tried using tabs, inner lid, etc but the pulp to pulp connection don’t seem to work very well as the lid just pops out in transit or paper bag. We’re currently using PLA lid but we’re trying to get rid of it.

Is it also possible to add threads or twist lock on paper pulp? My guess is no but would be great to figure out some sort of secured lid.
Another option would be adding a sleeve, rubber band to secure the lid but it is not ideal as we’re trying to use the least amount of materials and have every packaging to be compostable.


Seems to me you need to keep exploring. Think outside the box…well, maybe do think more about boxes.
Don’t know your specific requirements or challenges so a bit hard to give you a solution. Plenty of cardboard boxes have locking features (tabs, holes, snaps, etc.) that I assume could be tweaked to work with paper pulp and it’s process. I think your features will have to grow in order to work with the rough tolerances and flexing of paper pulp.
Polly’s pie boxes have some side tab features that are pretty good. PIzza boxes, happy meal boxes, etc. Maybe you need to work with Holes & Tabs or a re-imagined mortise and tenon type of closure specific for paper pulp.

Good luck.