EFFECT OF MICROCRYSTALLINE CELLULOSE AS A FILLER AND/OR FILLER RETENTION AID ON THE MECHANICAL PROPERTIES OF BAGASSE PAPER SHEETS

Microcrystalline cellulose (MCC), as a green material derived from bagasse, was investigated as an additive (0-3 wt%) in the preparation of bagasse paper sheets, in comparison with cationic starch. The effect of MCC addition, in the presence of 15% kaolin or 15% calcium carbonate as paper filler, was also studied. The properties of bagasse paper sheets loaded with MCC or cationic starch, in the presence or absence of 15% kaolin or 15% calcium carbonate as paper filler, were evaluated in terms of breaking length, burst, tear, opacity and filler retention values. Also, SEM and thermal analyses of the paper sheets were performed. It was found that all the properties of the bagasse paper sheets were improved as a result of MCC or cationic starch addition and, in general, the observed improvement increased as the percent of addition increased. Calcium carbonate and cationic starch, in general, gave superior properties, compared to kaolin and MCC, respectively. Overall, MCC could be considered as an alternative economically viable paper additive.

Effects of In-Situ Filler Loading vs. Conventional Filler and the Use of Retention-Related Additives on Properties of Paper

In the present paper, aspects concerning the obtained and characterization of additive systems used for maximizing filler retention, and the effects on paper properties, were investigated. The effects of retention additives over properties of paper, containing fibers from in-situ loading (IS-CCP), were analyzed against the effects of additives over properties of paper containing fibers from conventional loading, obtained by the addition of calcium carbonate in precipitated form (CCP). The physico-mechanical properties were analyzed by various analyses and investigations: calcium carbonate content, X-ray diffraction, scanning electron microscopy (SEM) images, optical and mechanical properties, in order to develop the best systems of retention additives for obtaining higher retention loads for making paper with high content of nano-filler material. The obtained results reveal that at the same level of calcium carbonate content, all paper samples with in-situ loading had higher the optical and mechanical properties than the paper obtained by conventional loading in all cases the additives studied. For all studied properties, nanoparticles had a positively influence over paper properties.

Composite filler by pre-flocculation of fiber fines and PCC and its effect on paper properties

A composite filler was developed by pre-flocculation of fiber fines and precipitated calcium carbonate (PCC) particles with flocculants such as cationic polyacrylamide (cPAM) and bentonite. The composite filler was compared with a conventional loading method in terms of physical properties of handsheet and filler retention. The handsheets using the composite filler showed higher strength properties than that using a conventional loading at a similar paper ash content level, implying that paper ash content can be increased maintaining same level of paper strength. Optical properties such as opacity and brightness of the paper with the composite were quite similar with the paper with the conventional loading. Filler retention of the composite filler was slightly higher than that of the conventional loading even though retention aids were not used for the composite filler. Paper formation of the composite filler was better than the case of the conventional loading. However, the sheet with the composite filler showed lower bulk than that with the conventional loading. Conclusively, the composite filler technology by pre-flocculation of fines and filler has a potential to be utilized to produce a high loaded paper.

New Diatomite Filler for Improvement of Paper Strength Properties

In this work, diatomite particles were modified to improve the bondability of diatomite particles with pulp fibers and filler retention via a complex of cationic starch-sodium hexametaphosphate coating method. The particle size, FTIR spectroscopy characteristic and morphology of the resulting modified diatomite were studied to confirm the successful modification. The SEM results illustrated that the surface of modified diatomite particles was covered by the complex coatings. The coating efficiency of the complex of cationic starch-sodium hexametaphosphate on diatomite surface was up to 98%. Compared with the handsheet filled unmodified diatomite, the handsheet filled with modified diatomite had higher strength properties and lower bulk. When cationic starch dosage was 7%, and filler dosage was 25% , the resulting tensile strength of filled modified diatomite handsheet was 22.1% higher than the handsheet filled unmodified diatomite. Furthermore, with the filler loading of 30%, compared with that of unmodified diatomite, filler retention of modified diatomite was increased by 20.4%. The larger particle size and higher zeta potential of modified diatomite were benefitial to increase retention of modified diatomite filler.

Filler modified by a sequential encapsulation and preflocculation method and its effect on paper properties

Increasing the filler content of sheet tends to decrease filler retention and paper strength properties. To overcome this problem and make better use of fillers, development of new methods on filler modification has never been stopped. In this study, filler modification was carried out by sequentially adding an anionic polyacrylamide, a cationic starch and a cationic polyacrylamide. It is believed that in this process, multiple polyelectrolyte complexes are formed which can not only encapsulate filler particles but also preflocculate the particles. The results showed that, compared to the single preflocculation treatment, the sequential encapsulation and preflocculation (SEP) treatment brought significantly larger particle size and higher surface charge potential of the filler, thus higher filler retention was achieved. When the modified fillers were used for papermaking and paper ash contents were controlled at the same level, the SEP modification was better in improving the tensile index, internal bond strength and tearing index of paper than the single preflocculation method, in addition, it maintained better paper formation, caused insignificant change on opacity of paper. It is believed that this newly developed SEP method is worthy of being applied to industrial scales in making various grades of filled paper.

PENINGKATAN MUTU BAHAN PENGISI KERTAS GROUND CALCIUM CARBONATE MELALUI MODIFIKASI DENGAN TAMARIND KERNEL POWDER (QUALITY IMPROVEMENT OF GROUND CALCIUM CARBONATE AS FILLER IN PAPERMAKING THROUGH MODIFICATION WITH TAMARIN KERNEL POWDER)

Ground Calcium Carbonate (GCC) as the filler required in paper making that is intended to reduce production costs thus providing a profit opportunity for the paper industry. However the usage of GCC affected decreasing of paper strength and effectiveness of sizing process. In order to reduce the negative effect, this research has been conducted through the modification of filler using Tamarind Kernel Powder (TKP) which is a natural polymer obtained from local tamarind seeds. The results of high performance liquid chromatography (HPLC) analysis, showed that TKP contained 64-68% xylose, glucose, maltose and arabinose. Filler modification was conducted with mixing the TKP into CaCO3 and addition of cationic polyacrylamide and sodium polyphosphate dispersant at composition ratio of 100: 0.4 : 0.1: 1.0. Filler application with added the retention aid of cationic polyacrylamide 0.1%, resulted the filler retention value on sheet of 26.9 %. The modified filler shows an increase in filler stability and is easy to form emulsions when compared to commercial fillers. Modification of GCC filler with higher number of TKP usage gives increased filler retention value on sheets, improved sheet formation properties and optical properties.ABSTRAKGround Calcium Carbonat (GCC) sebagai bahan pengisi (filler) dalam pembuatan kertas untuk mengurangi biaya produksi sehingga memberikan peluang keuntungan bagi industri kertas, namun peningkatan jumlah GCC dapat berpengaruh pada menurunnya kekuatan kertas dan efektivitas proses pendarihan. Untuk mengurangi pengaruh negatif telah dilakukan penelitian modifikasi filler menggunakan Tamarind Kernel Powder (TKP) yang merupakan polimer alami dari bahan lokal biji asam jawa. Hasil analisis kromatografi cair kinerja tinggi (KCKT) menunjukkan bahwa TKP mengandung silosa 64-68 %, glukosa, maltosa, dan arabinosa. Modifikasi filler dilakukan dengan mencampurkan TKP ke dalam CaCO3 dengan penambahan poliakrilamida kationik dan dispersan natrium polifosfat pada komposisi 100 : 0,4 : 0,1 : 1,0. Aplikasi filler dengan penambahan zat peretensi 0,1 % poliakrilamida kationik diperoleh nilai retensi filler pada lembaran 26,9 %. Filler yang termodifikasi menunjukkan peningkatan stabilitas filler dan mudah membentuk emulsi jika dibandingkan dengan filler komersial. Modifikasi filler GCC dengan jumlah TKP yang lebih tinggi memberikan peningkatan nilai retensi filler pada lembaran, peningkatan formasi dan sifat optik lembaran.

Role of particle size and preflocculation of talc in improvement of paper properties

Mineral fillers are added during papermaking to improve the optical and printing properties of paper and decrease energy costs. Filler loading using conventional approaches has some disadvantages, such as reduction in paper strength. The finer filler, the more the strength loss. Several methods and materials have been reported to overcome or alleviate the same, but with higher costs. Our approach provides an economically viable solution to the problem, using conventional papermaking materials. Talc filler of different particle sizes, preflocculated using different doses of cooked amphoteric starch, were used for papermaking. Relatively higher filler retention, paper strength, and hydrophobicity of paper were obtained with preflocculated talc compared to native talc. The optical properties of paper were unchanged on the loading of similar talc after preflocculation. The preflocculated talc of finer particle size provided higher opacity at similar ash, as well as paper strength, than the native talc of coarser size.

Effect of Xylanase-Aided Refining on Wet-End Chemistry and Bleachability of Masson Thermomechanical Pulp

The Masson thermomechanical pulp (TMP) which was obtained from the first stage refiner was pretreated with xylanase followed by refining with PFI refiner. The impact of enzymatic refining on wet-end chemistry and bleachability of pulp were studied. The results showed that the enzymatic pretreatment could improve the wet-end chemistry properties and enhance the bleachability of masson TMP. In contrast to the control pulp sample, the beating degree, the zeta potential, the dissolved charge, the filler retention, and the sizing degree was increased respectively by 18.8%, 17.5%, 10%, 19.6%, and 18.8% at the xylanase dosage of 0.3 AXU/g (o.d. pulp); the tensile index, the tearing index and the brightness was increased by 2.3 N·m2/g, 0.19 mN·m2/g, and 1.3%ISO, respectively.