This presents a very simple and effective design for a face shield frame.
It can be printed within 2 hours, is light weight and comfortable.
The materials needed to make the complete face shield are:
3D printed frame
Clear Plastic sheet of appropriate size (as per requirement)
Nylon Elastic Band (or any kind of fabric fastening device like elastic or Velcro)
Binder Clips.

Print instructions

Rafts:
Doesn't Matter

Supports:
No

Resolution:
0.25

Infill:
50

Filament_color:
White

Filament_material:
PLA