Years and years ago I dumped the soft denim based insulation from a meal delivery service into my home compost. The company bragged that it was compostable.
It was but not in a home compost bin. My compost bin didn’t get to the kind of heat it needed to break down the bio plastics added to the fluff. It only partially broke it down. So my compost bin had these fibrous layers of plastic fluff left from where the denim and cotton had broken down. It was a mess to clean out of the compost.
I’ve also had this happen with a lot of tea bags and other supposedly compostable stuff.
I have recently learned if it’s not compostable in a home compost bin it’s also not great for making paper pulp. My dumbass tested the fluffy paper fiber insulation in my medication package. It partially broke down but not by much. I decided to toss it into my paper pulp bucket and see what happens.
What happens is that if it isn’t shredded down to tiny pieces it tangles up around the mixer and makes a huge mess. Even the sharpened blade of the mixer isn’t enough to break it up. I have hoped it would break down enough to add strength to the pulp. Worse yet it doesn’t even absorb concrete all that well, so I get these wet lumps of fibers in the mix. It made a huge mess of my pulp and the papercrete I was experimenting with. Instead of a smooth mix I had a lumpy mess.
I do think it could be used with a really wet concrete slurry like the draped hypertufa stuff I’ve seen…. I might try something like that. But NEVER in the pulp vat again.