Looking for B&W sci-fi movie where women are turned into skeletons

I saw a Black and White "B" movie on television in the mid 1970’s. The movie was definitely from the 40’s or 50’s. One scene that sticks in my mind:

Unconscious women are moving on a conveyor belt. The women are covered up to the shoulders in a white sheet.

The women move into a machine. The machine has blinking lights and makes mechanical noises.

When the women come out of the machine, they are skeletons, still covered in the white sheets.

I remember there were 2-3 men in the scene, and I don’t remember whether they ran the machine or were trying to stop it.

edited for time frame