The removal of bark prior to pulping wooden logs or sticks for use in papermaking. Wood is pulped in order to liberate cellulose fibers from non-fibrous materials. Bark contributes no fibrous material and adds dirt and other contaminants to the pulp, so must be removed. (But see also Whole Tree Utilization.) Pulpwood logs are debarked either mechanically in a drum-type barker, in which logs are sent through a rotating barking drum and the impact and abrasion experienced by the logs as they roll over each other knocks the bark off, or hydraulically, where logs are rotated beneath high-pressure water jets (at 1,300 pounds per square inch) which strip the bark away. Bark is then used as a fuel source or for garden mulch. The debarked logs are sent to a chipper, in which they are cut into small chips ready for pulping. (See also Pulping.)
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