Profitable pulp production begins with high-quality, even-sized wood chips. In pulp mills, all the raw material passes through the wood chipper, and its ability to deliver top-grade chips is paramount to digester or refiner performance, pulp quality, raw material yield, and end product quality.

The critical role of knife condition in wood chip quality

In the chemical and mechanical pulping process, the size distribution of wood chips is crucial for a smooth process in subsequent stages. Variations in chip thickness lead to uneven penetration of cooking liquors and, as a result, less efficient impregnation.

In addition to wood quality, the chipper knife system has the greatest impact on final chip quality. Keeping the wood chipper running with knives in good condition is the most effective and cost-efficient way to maximize pulp yield and quality. Dull or damaged knives typically result in increased and inconsistent chip sizes, leading to lower-quality pulp. Contaminants such as rocks can damage the knives, particularly during winter. Blunt blades also cause greater impact forces on the machine. However, the ideal time to replace the knives is not easily identifiable, and this assessment often relies on operator experience.

Informed decisions, better results: boosting quality and minimizing waste

SPM’s knife wear monitoring solution provides insights into the condition of chipper knives and offers decision support on managing chipper knife replacement. In a web-based dashboard, clear and easy-to-understand graphs indicate whether a knife is damaged, becoming dull, detached, or missing from the knife holder: