PAPER making! FROM THE PUBLISHERS OF PAPER TECHNOLOGY INTERNATIONAL Volume 7, Number 3, 2021
benefits. The corrugated paper keeps items protected through long-distance logistic processes and constant shipping and handling. The corrugated boxboards are ideal options for any industry’s shipping, packaging and storage needs. Papers and cardboards are quite a low cost and also provide environmental-friendly solutions, using recyclable materials such as used corrugated cartons and old newspapers. Recycling offers a reduction in environmental impact in densely populated regions and a large production of paper and board products. Generally, the use of recycled fiber produces paper with poorer mechanical properties due to the decrease in interfiber bonding. The recycled pulp must be treated to restore its bonding strength, for which there are six methods possible: mechanical treatment, chemical additives, chemical treatment, fractionation, papermaking process modification, and blending with virgin fiber. Although some mills produce 100% recycled paper, the majority augment their used pulp with some virgin fiber. Paper properties can be tailored within some ranges by modifying the properties of fibers, but the influence of fine quality on the structure, strength, and optical properties of paper can be even greater. The properties of papers are essentially determined by their raw materials. Most of these raw materials are made from 100% recycled fiber, but as the quality of the waste fiber varies, different chemicals must be used to provide the desired or expected properties. From an environmental and economic point of view, the use of primary fibers can be an alternative. PAPERMAKING “ Development of Post Hybrid Calcium Carbonate for High Loaded Paper ”, Min Woo Lee, Dong Suk Kang & Yung Bum Seo, BioResources , Vol.16(4), pp.7716-7728 (2021). In papermaking, pre-flocculation of fillers such as ground calcium carbonate (GCC) improves the tensile strength of paper sheets. However, the pre-flocculated fillers mostly suffer from the instability of the floc shape such as the decrease in floc diameter with time elapse after preparation and no improvement of bulk and stiffness. The addition of calcium compounds such as calcium oxide or calcium hydroxide to the preflocculated GCC, and injection with carbon dioxide caused pre-flocculated GCC flocs to be covered with newly formed calcium carbonate. This product, called post hybrid calcium carbonate (pHCC), was found to be more stable in size and gave better sheet strength than the pre- flocculated ones. Furthermore, pHCC gave remarkably higher bulk and stiffness than the pre-flocculated flocs did without impairing smoothness that was essential in printing paper. The proper use of pHCC in papermaking could allow the production of high loaded paper with more than 10% higher filler contents, which could reduce paper production cost and save drying energy. The proportion of the newly formed calcium carbonate in pHCC, turbulence intensity at preparation stage, and the effect of storage time were investigated. “ Data-driven method for monitoring and diagnosis in energy system of papermaking process ”, Yanzhong Zhang, Zhiqiang Zeng, Jigeng Li & Huanbin Liu, Drying Technology , online 23 Aug 2021. This study proposes a data-driven model for monitoring and diagnosis in energy system of papermaking process based on kernel component analysis (KPCA) and the kernel slow feature analysis (KSFA). Four different abnormal patterns are designed, while the false alarm rate (FAR) and the missed detection rate (MDR) are used to evaluate the validity of the proposed model. The performance of KPCA is better than that of conventional PCA and KSFA. The online monitoring and diagnosis analysis of energy utilization are achieved based on the historical data and the proposed model. The production status and the energy consumption level across the whole process can be acquired. The results demonstrate that the proposed method is effective. It can provide the valuable reference foundation for further energy analysis and optimization in papermaking process.
Technical Abstracts
Page 8 of 13
Made with FlippingBook Online document maker