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Packaging Wrappers for products; wrappers may be made of a variety of materials: plastic, cardboard, paper, metal, glass, wood, and ceramics.

Packed tower Also known as packer tower scrubber. Air pollution control device. Contaminated air is circulated through a tower containing materials that have a large surface area. The contaminants are absorbed into a liquid flowing over the tower materials. The liquid falls downward and the air is forced upward through the tower. The vapors or particulates contained in the air go up through the surface area. The fumes come into contact with the surface and take up the material releasing the air and cleaning it. See also: Absorption process; Scrubbers; Ventury scrubber

Packed tower aeration Process to remove organic contaminants from groundwater. Groundwater flows downward in a tower filled with material over a large surface. Air is introduced at the bottom of the tower and is forced upward past the falling groundwater. Organic contaminants are transferred from the water to the air.