Kraft Pulping Digester
A large pressure vessel used in the kraft process to cook wood chips with chemicals to separate lignin and produce pulp from fibrous cellulosic material. It operates under high temperature and pressure to break down the wood structure. Classified under HTS 8439.10.00 as machinery specifically for making pulp from cellulosic fibers.
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More Specific Codes
This product may fall under a more specific subheading:
Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If used primarily for chemical reactions rather than pulp extraction
Machinery of heading 8419 covers chemical reaction vessels; pulp digesters are specifically excluded and classified here.
If sold as a complete pulp production line set
Unspecified industrial machinery in 8479 may apply to assembled systems, but individual pulp digesters stay in 8439.
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Import Tips & Compliance
• Verify pressure vessel certification (ASME or equivalent) for customs clearance and safety compliance
• Provide detailed process descriptions to confirm classification under pulp-making machinery, not chemical reactors
• Include material safety data sheets for alkaline chemicals used in kraft process to avoid misclassification
Related Products under HTS 8439.10.00
Continuous Wood Chip Digester
An automated digester that continuously feeds wood chips through cooking zones for efficient pulp production from cellulosic fibers. It features stratified impregnation and cooking stages for optimal lignin removal. Falls under HTS 8439.10.00 for specialized pulp-making equipment.
Batch Pulp Digester
A cylindrical vessel loaded in batches with wood chips and cooking liquor to produce chemical pulp through intermittent cycles. Commonly used in smaller mills for flexible production. HTS 8439.10.00 covers this core pulp-making machinery from fibrous cellulosic material.
Sulfite Pulp Cooker
Machinery using calcium or magnesium bisulfite solutions to cook wood chips for sulfite pulp production, yielding high-brightness pulp for specialty papers. It maintains acidic cooking conditions for fiber separation. Classified in HTS 8439.10.00 as pulp-making equipment.
Defibrator for Mechanical Pulp
High-speed rotor machinery that mechanically separates wood fibers through grinding and refining to produce mechanical pulp without chemicals. Used for newsprint production from cellulosic material. HTS 8439.10.00 includes mechanical pulping equipment.
Wood Chip Impregnator
Equipment that pre-treats wood chips by impregnating them with cooking liquor before digestion, improving pulp yield from fibrous cellulosic material. Features downflow or upflow liquor penetration systems. Falls under HTS 8439.10.00 for pulp preparation machinery.
Pulp Washing Drum
Rotating vacuum drum that separates cooking liquor from pulp fibers post-digestion, recovering chemicals and cleaning cellulosic pulp. Twin-roll design for multi-stage washing. Classified under HTS 8439.10.00 as integral pulp-making machinery.