PAPER making! FROM THE PUBLISHERS OF PAPER TECHNOLOGY INTERNATIONAL Volume 7, Number 3, 2021
“ Characterization of retention chemicals and their effect on the paper forming process on machine P M4, Billerud Korsnäs Gävle Mill”, Therese Alm, 2021 (English) Independent thesis Basic level (degree of Bachelor). In the papermaking industries spots in the finished product is a recurring problem. Billerud Korsnäs have in earlier studies identified poorly optimized retention systems as one of the reasons for these spots. Poorly optimized retention systems will allow for detrimental substances to flow freely in the system, which may cause agglomeration into larger particles that could end up as darker spots in the finished product. The aim of this thesis is to investigate a number of retention systems, consisting of a retention polymer and retention microparticles, and characterize the polymers. The retention aid systems task is to flocculate fibres, fines and fillers along with the colloidal material to improve process parameters. To investigate the retention systems three different retention polymers with different charge densities have been investigated alongside one microparticle. The parameters investigated in this thesis were the retention systems effect on drainage time, turbidity, charge demand and zeta potential. Pulp and white water from PM4 was used to imitate mill conditions. The results showed that the drainage time and turbidity was most effected by the retention aid systems. The polymer with the highest charge yielded the best results. Only minor effects could be detected on charge demand and Zeta potential. PULP “ How Different Carryover Pitch Extractive Components are Affecting Kraft Paper Strength ”, Jussi Lahti, Roman Poschner, Werner Schlemmer, Andrea Hochegger, Erich Leitner, Stefan Spirk, & Ulrich Hirn, ACS Omega 2021, 6, 44, 29350 – 29359. We present how harmful different wood extractives carried over to paper mill with unbleached softwood Kraft pulp are for the strength of packaging papers and boards. The investigations were done by simulating industrial papermaking conditions in laboratory- scale trials for handsheet production. It was found that fatty acids are the most relevant compounds in the carryover pitch extractives (CPEs), as they readily interfere in fiber – fiber bonding strength, control the properties of CPE micelles, and are furthermore the most abundant compounds. Addition of cationic starch improved strength and evened out the strength differences of handsheets with different CPE compounds. Oleic acid (unsaturated fatty acid) was an exception, as it was above average harmful for paper strength without cationic starch and also heavily impaired the functioning of cationic starch. As a whole, these findings demonstrate that fatty acids, especially unsaturated ones, are the most relevant CPE compounds contributing to the reduced efficiency of cationic starch and decreased strength of unbleached softwood Kraft paper. This makes the cleaning of process waters by precipitating CPEs on the pulp fibers harmful for paper strength. “ Utilization of c orn husk for tissue papermaking”, Natalia Suseno, Marisca E. Gondokesumo, & Puspita R. Permatasari, AIP Conference Proceedings 2338, 040019 (2021); https://doi.org/10.1063/5.0067417. The demand of tissue papers is increasing with the population increase. This will definitely increase the need of wood fibers as the main raw material. However, due to the wood shortages, there have been many attempts to use non-wood fibers as substitutes for papermaking. In Indonesia, corn production has gradually increased for the last 5 years, hence it also has an impact on the raising in the amount of corn husk waste. Corn husk has a high cellulose content which suitable to be used as a raw material for tissue papermaking. In this experiment, soda pulping process was conducted to remove out lignin. The resulting tissue paper will be added with additives that have antimicrobial properties of chitosan and mangosteen peel for the purpose of increasing the tensile strength or absorption of water. The aim of this research is to study the effect of depending variables (temperature and NaOH concentration) on
Technical Abstracts
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