EFFECT OF USING WHEY POWDER ON THE PROPERTIES OF PULP AND PAPER OBTAINED FROM STORED BAGASSE

The aim of this study was to investigate the effect of using whey powder (different concentrations and treatment repetitions) as a probiotic agent on the quantitative and qualitative properties of stored bagasse intended for use in the pulp and paper industry. For this purpose, whey powder was added in three concentrations and the treatment was applied once or twice. After that, soda pulp was prepared under conventional conditions. Then, handsheets (80 g/m2) were made and tested in terms of paper properties, and the results were compared. The findings revealed that increasing the concentration of whey powder and the number of treatments significantly improved the pulp and paper characteristics, thus, using the treatment with 2% whey powder twice and 0.4% whey powder once led to the best results for bagasse protection in terms of quality of the raw material, pulp and handsheets.

The Effect of a Sustainable Technology of Delignification and Tcf Bleaching on Physical Properties of Recovered Cardboard

Old Corrugated Containers (OCC), also known as waste corrugated cardboard, multilayer packaging and wrapping sacks are complex and heterogeneous materials composed of various sources of unbleached cellulose pulp derived from several raw material processes. However, OCC pulp have a high proportion of long fiber because are mainly manufactured from softwood pulp by the kraft process. OCC are the main category of recovered paper; however, due to their high lignin content, hornification and other problems resulting from the pulp to cardboard conversion processes, additives and pollutants, their physical properties decrease with each recycling which justifies evaluating various treatments with existing technologies to improve it. The objective of this work was to obtain improved unbleached and bleached old corrugated container (OCC) pulp more ecologically justifiable than wood for higher grade papers using sustainable processes evaluated in pilot scale tests OCC were collected from a landfill, cleaned, repulped, and treated with extended delignification with the alkaline soda process, obtaining a pulp with significant physical-mechanical improvements in relation to the original material, such as tensile strength, tearing resistance, bursting strength and folding endurance. The OCC soda pulp was bleached by a sequence totally free of chlorinated compounds (TCF), obtaining bleached pulp with optical and mechanical properties comparable to virgin pulps of annual plants such as bagasse but with improved drainage properties and lower processing costs. According to their properties, it is a competitive pulp obtained with existing technologies, available for use in various grades of printing and writing paper replacing totally or partially bleached wood pulp.

Comparison of wood and non-wood market pulps for tissue paper application

A comparison among ten market pulps at a laboratory scale using uncreped tissue handsheets was performed to study the performance of wood and non-wood pulps for tissue manufacturing, evaluate what fiber features are desired for a specific tissue property, and determine how non-wood pulps can be used to replace or complement wood pulps in tissue products. A characterization of the fiber morphology and handsheet properties (softness, water absorbency, and strength) was performed at different mechanical refining levels. The results showed that the fiber morphology had a major impact on tissue properties. Market pulps with a combination of long fibers, high coarseness, and low fines content can provide superior bulk and water absorbency. Short fibers with thin cell walls and low fines content can impart superior softness. Bleached bamboo soda pulp can replace hardwood and softwood pulps to provide an excellent combination of water absorbency and strength. Bleached bamboo soda pulp can also replace Northern bleached softwood kraft (NBSK) pulp to impart strength without sacrificing softness. Bleached and semi-bleached wheat straw soda pulps presented a similar combination of softness and strength as Southern bleached hardwood kraft (SBHK) pulp. The wheat straw pulps can be used to replace deinked pulp (DIP) pulp to impart intermediate levels of water absorbency and strength.

PRODUCTION OF PRINTING AND WRITING PAPER GRADE PULP FROM ELEPHANT GRASS

ABSTRACT The main goal of this study was to characterize chemically and morphologically elephant grass (Pennisetum purpureum), and evaluate the potential of its fibers for production of printing and writing paper grade pulp. The elephant grass was chemically and morphologically characterized and cooked by the soda process to two different degrees of delignification (kappa 17.5 and 10.6). The resulting pulps were fully bleached by the O-D*-(EP)-D sequence and characterized for their beatability, drainability and physical-mechanical properties. The lignin content (20.2%) was low, indicating that this grass should be easier to pulp. The morphological analyses of the elephant grass indicated a short fiber material, similar to hardwoods. The soda pulp from elephant grass cooked to kappa number 17.5 presented higher screened yield than 10.6 kappa pulp, with alkali demands of 15.0% and 20.0%, respectively. The total active chlorine required by the 17.5 and 10.6 kappa pulps, were 42.1 and 35.1 kg/odt pulp, respectively, to achieve an ISO brightness of approximately 90.0%. The bleached soda pulps cooked to 17.5 and 10.6 kappa number showed similar refinability and resistance to drainage, but the tensile and burst index were highest for the 17.5 kappa pulp at beating energy consumptions in the range of 0-6 Wh. It was concluded that both 10.6 and 17.5 kappa pulps from elephant grass are suitable for the production of printing and writing paper grade pulps, but the highest kappa 17.5 pulp is more economically attractive given its highest pulping yield, despite the significantly increased of chemical demand for bleaching A produção de papel para impressão e escrita Grau de celulose a partir de capim-elefante.

Properties of bleached pulp sheets of avocado wood (Persea americana Mill.) pulped by Kraft and Soda processes

Chips of avocado wood (Persea americana Mill.) were pulped by means of conventional Soda and Kraft pulping processes. The pulps were bleached with an elemental-chlorine-free sequence OD1-Eop-D2, pre-setting reaction conditions for the first chlorine dioxide stage (D1) . The results show that during the chemical pulping process, avocado wood is easier to cook than other hardwoods such as eucalyptus. The avocado pulp also showed a very good bleachability, reaching brightness levels of up to 92% ISO compared to 84% for eucalyptus after the ECF bleaching sequence. The avocado Kraft pulps required more chemical input in the bleaching sequence than the Soda pulps. On the other hand, the physico-mechanical properties of the pulp were not notably reduced by the bleaching process, the Kraft pulp being stronger than the soda pulp. Strength properties of avocado are similar to those of eucalyptus; therefore this raw material constitutes a worthwhile choice for cellulosic fiber supply.

Application of Enzyme for Bleaching of Wheat Straw AQ-Soda Pulp

Pulp and paper industry is one of the major contributors to environmental pollution due to its toxic and carcinogenic discharges during its various processes e.g., chlorinated bleaching of the pulp. Use of alternative bleaching chemicals e.g., enzyme and/or elemental chlorine free (ECF) or total chlorine free (TCF) agents are the best option to reduce the load of carcinogenic chlorinated compounds on our environment. Present study was carried out to highlight the application of enzyme during bleaching of wheat straw anthraquinon (AQ)-soda pulp to considerably reduce the toxic load on the environment. Wheat straw AQ-soda pulp was treated with acid (A) to reduce its metal contents followed by oxygen (O) delignification. Delignified pulp was then subjected to enzymatic (X) treatment with xylanase prior to bleaching to increase the effectiveness of successive bleaching with hydrogen peroxide (P). Handsheets were prepared from the treated pulp after each experimental trial to study its various optical, physical and chemical properties. Brightness of bleached pulp was improved up to ISO 73% with AOXP1P2 bleaching sequence. The improved brightness up to ISO 76% was achieved when alkali extraction stage was incorporated before bleaching with hydrogen peroxide (AOXEP1P2). TDS, COD and BOD5 of effluent samples during different experimental stages was monitored and compared with NEQS. It was evident from the results that enzymatic treatment not only helped to reduce the effluent load but also reduced the consumption of bleaching chemicals to achieve good brightness values.