Core catchers
The tube rim seats on the catcher shoulder,and both are pop-riveted together.  The upper helix of thin blades spreads open during tube entry, then collapses to seal the tube during withdrawal.  The larger hole through the lower part is use to pry the catcher off the filled core tube.  These catchers must be cleaned (decontaminated?) between cores.
Plastic leaf catcher (AScI design) for 4-in. diameter unlined plastic tubes, both made of butyrate (CAB) or polycarbonate material.  The catchers, mass-produced flat with curving "fingers", are rolled and pop-riveted into the tube end.  The orange caps (and duct tape) are used to seal the tube after coring.  Both tubes and catchers are disposable.
"Leaf" or "orange peel" stainless steel catcher (Rossfelder design) of the type used with 4-in. diameter unlined metal tubes.  Another version for lined tubes (at right) has an extra shoulder for seating the plastic liner.
AScI Corporation
Rossfelder Corporation