Yep been there done that !
There is no reliable economical repair possible.
Linisher No
Sand Cat No
Any belt sander No (ncluding Festies)
Selleys products ... Fail
Gorilla products... Fail
Signet products ...Fail
all seem to work then when you least expect it a nasty bitch slap occurs!.. definitely ruffles the feathers big time!
The best way is do not hold bulk belts, however if necessary hide then from the sun and elevated temperatures.
Maybe hide them in beer fridge if you have one, but in no circumstances the main food fridge as something bigger than a BS may occur causing a elevated tone in your voice!
I will accept a task to ask my supplier The Sandpaper man if there has been any advances in technology and report back accordingly.
As reported recycling and repurposing is the go currently.
Standby!