corrugator

Corrugator is a term that can refer to two distinct things: a machine used in the production of corrugated cardboard and a facial muscle involved in frowning.

In manufacturing, a corrugator (also called a corrugating machine) forms the fluting of paper to produce corrugated board. The process typically combines a corrugating medium with one or two liner sheets. A single facer creates one corrugated sheet with a paper flute that is glued to a liner; a double backer adds another liner to form final board. The machine uses heated rollers to shape the flute and adhesives (usually starch-based or hot melt) to bond the layers. The product may be single-wall or double-wall and is used for packaging. Modern corrugators include automated drying, glue application, moisture control, cutting and stacking equipment, and can run at high speeds. The corrugator is central to the packaging industry, producing a range of cardboard thicknesses and strengths to suit shipping and display needs.

Corrugator muscle: The corrugator supercilii is a small facial muscle located deep to the orbicularis oculi, beneath the eyebrow. It originates near the frontal bone at the orbital rim and inserts into the medial portion of the eyebrow. Contraction draws the eyebrows downward and toward the center, producing vertical and horizontal wrinkles above the nose—commonly associated with frowning. It is innervated by branches of the facial nerve (cranial nerve VII). Clinically, activity in this muscle is involved in expressions of concern or worry and can be assessed in neurological and cosmetic contexts.