How are wood logs prepared before they are turned into pulp?

Before wood logs are converted into pulp, they undergo several preparation steps to ensure the material is suitable for processing:

• Sizing: Pulpwood typically arrives at the mill as full-length logs or bolts approximately 1.2 meters (4 feet) in length. These are sawn to the appropriate size required for the specific pulping machinery.1
• Debarking: The logs are tumbled in large, revolving drums to remove the bark, which is considered an undesirable material in the pulping process.12
• Chipping: For chemical and semichemical pulping, the wood is reduced to chips. This step is critical, as the quality of the final pulp depends on the careful selection and cleaning of these chips to remove contaminants like knots, dirt, and remaining bark.342
• Moisture Control: For mechanical (groundwood) pulping, the moisture content of the wood is essential for both the ease of grinding and the quality of the resulting pulp. Ideally, the moisture content should be between 45 and 50 percent; wood that is too dry is presoaked in a pond or sprayed with water before being sent to the grinders.1