Browsing by Subject "paper industry"
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(2022)The use of recycled fibers in paper production has increased during recent years. Recycled fibers are a more sustainable alternative compared to virgin fibers made from wood. However, paper mills utilizing recycled fibers have more microbiological problems compared to mills using only virgin fibers. Especially, anaerobic bacteria are harmful for papermaking processes utilizing recycled fibers. Bacteria of the class Clostridia comprise a very diverse group and have many different metabolic properties. Bacteria of class Clostridia can ferment different substrates, for example cellulose and starch, crucial in paper mills utilizing recycled fibers. Fermentation does not only decrease material efficiency, but also the acids produced during fermentation deteriorate papermaking processes. Volatile fatty acids are odorous compounds causing bad odors in the mills and in the final products. Clostridia can also produce, for example, hydrogen which is an explosive gas endangering the safety of the mill employees. Quantitative PCR is a feasible detection method for microbes. Here, a qPCR method was developed for the detection of most abundant bacteria in the class Clostridia in the recycled fiber mills. The designed primers targeted the most harmful bacteria from the genera Clostridium, Ethanoligenens, Fonticella and Ruminococcus identified in the recycled fiber mills. Three primer sets were designed for the target bacterial group. Positive controls of each target bacterial genus was included and close relatives from class Bacilli were used as negative controls. The designed primer sets were compared in efficiency, specificity and performance with process samples collected from paper mills using recycled fibers. One of the primer sets was found the most potential for the qPCR detection method for the diverse target bacterial group. All positive controls were amplified with the designed qPCR assay, whereas the designed primers discriminated well each negative control in vitro. The applicability of the designed qPCR assay was yet confirmed with process samples collected from mills utilizing recycled pulp. Even though the efficiency of the designed primer set was not optimal, the designed assay was determined feasible for the detection of the target group in the recycled fiber mills usually high in bacterial density.
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(2017)The paper industry is one of the largest industrial sectors in India. In general, wood procurement processes play an important role in the operations of the paper industry, but there is very less research on India in this topic. The purpose of this study was to evaluate the present state of wood procurement in the Indian paper industry and finally to detect possible bottlenecks in the system. The data was collected by interviews from a total of 10 paper mills in India. Paper industry in India is entirely based on a plantation forestry, where private farming plays a very large role. Wood procurement begins with planning. The field officers cooperate with the vendors in the field. The vendors are private operators who trade directly with up to thousands of farmers and are therefore necessary for the successful operations. Wood is almost always harvested manually by axes and rarely with chain saws. Long-distance transport is mainly carried out by trucks which can carry about 15 to 20 tons of wood at a time. At the reception, the quality of the raw material and the papers are checked, and the load size is weighed. After reception, the wood is transported either to the wood yard or alternatively directly to the chipper. The load is unloaded either by loaders, or sometimes, but rarely, by hand. The results show clearly that the mills are dissatisfied with the present state of wood procurement. The biggest problem is that there the domestic supply is insufficient, which makes the wood raw material price very high and forces the industry to buy wood from abroad and longer distances which affect negatively to transport costs. In India, land ownings of farmers are also small and it complicates efficient wood procurement processes. In addition, farming trees does not interest the local people. Infrastructure is also weak and the use of trains in wood transport is difficult. Some mills stated that the policy plays too big role in determining the price of the raw material. In addition, expertise in supply chain management is weak and no suitable software is available.
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