Quote Originally Posted by AgX View Post

Before reading your post I was looking at the coating head again. It seems it consists out of two acrylic plates screwd onto each other, with one having been milled out, so that a small volume is made which at the same time forms the slit at one end. Thus the coating, except for base velocity, is mainly controlled by the pressure in that coating head chamber.
You are pretty much correct as is Steve. The cascade coater is the only one that can do multiple layers at the same time. It is called a 'slide hopper' at Kodak. The other hopper is called a 'curtain coater' and is entirely different from either a slide hopper or an extrusion hopper.

What you see in the picture is commonly called an X-hopper or an extrusion hopper at Kodak and functions as you describe.