Silica wicks can have the tendency to some apart and can leave some slivers, it's just the nature of the silica wick, doesn't always happen, but if the wicks them selves are messed with much they will come apart, this is a reason why some people when they built new coils and replace the wicks they use untreated cotton as the wick, those you have to be careful with as to not let them dry out, if you do they will burn and no saving them at that point, they will need to be replaced.
I know you didn't ask for all that, but well I have too much time on my hands right now!