Fiber Processing
Pulp grades produced through a combination of chemical treatment and mechanical refining offer a balance between strength and high yield. The production of ctmp involves steaming wood chips and treating them with chemicals like sodium sulfite before they enter a pressurized refiner. This softening of the wood structure allows the fibers to be separated with less damage than purely mechanical methods.
Material Property
High bulk and good stiffness are the primary characteristics of the resulting fiber. Because ctmp retains a portion of the lignin, the sheets produced from it are more opaque and have better compression resistance than those made from chemical pulp. The brightness is typically lower but can be increased through bleaching.
Application Suitability
Middle layers of folding boxboard frequently utilize this grade to provide structural rigidity without adding excessive weight. The high bulk allows for the creation of thick board that remains lightweight and cost-effective. It is also used in tissue and towel products where absorbency is a requirement.
However, the presence of lignin means the paper may yellow over time when exposed to sunlight. This makes it less suitable for archival documents but ideal for short-term packaging. The fibers provide a good surface for coating application.
Strength is often enhanced by blending with long-fiber chemical pulps.
