Screw caps often look simple until orientation and chute control matter.
Plastic screw caps are one of the most common closure types, but reliable feeding still depends on skirt depth, cap height, tamper band style, diameter and the way the capper receives the cap.
Some screw caps can be elevated and sorted with a relatively simple route. Others need bowl tooling or additional orientation features to keep the threaded side, open side or decorated side in the correct position.
The feeder should keep the capper supplied without overloading the chute or causing caps to bridge in the hopper.