Unbeaten Pulp Research Articles

Pulp and Paper Characteristics of Five Lesser-known Species in Kalimantan: Effects of Re-beating

Five lesser-known species from natural forests in Central Kalimantan, viz., cempaka (Michelia champaca Linn), mentawa (Artocarpus rigidus Blume), menjalin (Xanthophyllum excelsum Miq.), kempili (Lithocarpus elegans (Blume) Hatus. Ex Soepadmo), and sempori (Dillenia sp.) were evaluated in the laboratory for their specific gravity, fiber morphology, pulping and papermaking properties. In addition, their properties after three-phase beating were also evaluated from a recycled paper point of view. The specific gravity and fiber length range were 0.58~0.68 and 1239~2479 μm, respectively. The highest value in specific gravity was observed in menjalin wood, while the longest fiber was observed in sempori. Kraft pulping with 14% active alkali (as Na2O), 23% sulfidity, 2 h at the maximum temperature showed that the highest screened yield was determined in cempaka wood (44.29%) with a kappa number of 17.6. The freeness ranges of unbeaten pulp were 675~780m mL CSF. The freeness ranges of 1st, 2nd, and 3rd beating were 539~630 mL, 235~275 mL, and 220~230 mL CSF, respectively. The 1st beating exhibited the best mechanical properties. Among the species, cempaka, kempili, and mentawa showed comparatively high tensile (57~60 Nm/g) and burst index (2.6~3.4 KPa m2/g), whereas the highest value for tear index (5.02 mNm2/g) was observed in sempori. A considerable decrease in fiber length, slenderness ratio, and mechanical properties of the paper was observed with an increased beating number. These findings suggest that cutting the fibers or decreasing the slenderness ratio was the main factor causing the strength to decrease.

Adjustment of Strength and Air Permeation Resistance of Low Basis Weight Paper by Separated Beating

This paper reports a method for improving the air permeation resistance and strength of low basis weight paper by applying separated beating. Sw-BKP was beaten to prepare three pulp stocks with three freeness levels (713, 500, and 300 mL CSF), and the fiber properties and one pass retention of the handsheet were analyzed. In addition, using Scheffe’s three-component simplex design, this study investigated the change in the physical properties of paper according to the mixing of the three types of the pulp. The freeness of the pulp, air permeation resistance, and tensile strength of the paper were evaluated. When the freeness of the Sw-BKP decreased, the average fiber length decreased while external fibrillation and WRV increased. When 400 mL CSF pulp was prepared by mixing 300 mL CSF pulp with unbeaten pulp (713 mL CSF), the tensile strength of the handsheet was slightly lower as compared with the case when the same freeness was obtained by mixing 300 mL CSF pulp with 500 mL CSF pulp. However, the air permeation resistance was improved. The formation of the handsheet was improved when 713 mL CSF pulp and 300 mL CSF pulp were blended, and the air permeation resistance increased significantly as the fines increased. However, the tensile strength decreased because of the incorporation of unbeaten pulp, which weakened the bonds between the fibers of the handsheet. Blending pulp with low freeness and unbeaten pulp is advantageous if separate beating is applied during the manufacturing of the low basis weight paper to improve the air permeation resistance regardless of the decrease in tensile strength under certain freeness conditions.

Effects of Recycled Fiber Fines on Hand Sheet Properties of Different Unbeaten and Beaten Pulps

In this study, 5, 10, and 15 % secondary fines of recycled pulp were added to unbeaten and beaten (28 ºSR) samples of recycled pulp, Turkish Calabrian pine (Pinus brutia Ten.) kraft pulp, and European aspen (Populus tremula L.) kraft pulp. The effects of the addition of fiber fines on hand sheets properties were evaluated. The addition of fiber fines to the unbeaten pulps improved the strength properties of hand sheets. The roughness of hand sheets was also decreased with the addition of fines. When fiber fines were added to the beaten pulps, the type of pulp strongly affected the paper strength properties. The strength properties of beaten pulps of Turkish Calabrian pine and European aspen were decreased with the addition of fiber fines, while the strength properties of beaten pulps of recycled pulp were increased. On the other hand, the air permeance of unbeaten and beaten samples was decreased with the addition of fiber fines. Consequently, the addition of fines to unbeaten and beaten pulps had a more pronounced effect on European aspen kraft pulp and recycled pulp than on Turkish Calabrian pine kraft pulp. Also, the strength of paper made of unbeaten recycled pulp with the addition of 15 % fines was higher than that of fines-free beaten recycled pulp.

Preparation of CaCO3nanoparticle/pulp fiber composites using ultrafine bubbles

AbstractIn this study, CaCO3nanoparticle/pulp fiber composites were prepared by formation of ultrafine bubbles of CO2gas in aqueous Ca(OH)2solution containing beaten or unbeaten pulp fibers. Scanning electron microscopy images of the fiber/CaCO3composites showed that primary CaCO3nanoparticles with average diameters of 50–80 nm densely formed on the pulp fiber surfaces. The average sizes and morphologies of the precipitated CaCO3nanoparticles can be controlled by controlling the CO2flow rate into the pulp slurry. From dynamic drainage analysis of the CaCO3/pulp slurries with high shear force, retention of the CaCO3nanoparticles on the pulp fiber mats was ∼10 % higher for the slurry formed by the ultrafine bubble method than for that formed by mixing precipitated CaCO3and pulp fiber. Therefore, precipitated CaCO3nanoparticles stably formed on the pulp fiber surfaces in the slurry by the ultrafine bubble method. Compared with reference handsheets, handsheets prepared with the CaCO3nanoparticle/pulp fiber composites had higher CaCO3contents and had consequently higher specific surface areas and surface smoothness values. In contrast, the tensile strength and elongation at break decreased because the sheet density decreased with increasing CaCO3content in the handsheets.

Microwave Assisted-Acid Hydrolysis of Jabon Kraft Pulp

In the present study, microwave assisted acid hydrolysis has been used to produce sugar from Jabon kraft pulp. The pulp behavior during hydrolysis was assessed by observing the changes of morphological characteristics and functional groups on various lignin content after beating. Pulp was hydrolyzed for 5–12.5 min at 180 °C with liquid to solid ratio of 20. The further hydrolysis has been carried out to observe the effect of temperature (180–200 °C) at the best irradiation time. The lignin content reduction and beating obviously has not changed the width and length of fibers. However, the disorganized fiber has occurred after pretreatment with higher damage intensity after beating. Even though the similarity of fiber surface changes has been discovered, some of functional groups disappeared. The reducing sugar yield of pulp with lignin content of 0% lignin content differs significantly with pulp of 4.5% lignin content (α: 0.05). Reaction temperature gives more influence in improving reducing sugar yield compared to irradiation time. Interaction between lignin content and reaction temperature influence significantly on reducing sugar yield (α: 0.05).The highest reducing sugar yield (49.2%) is found in unbeaten pulp without lignin content after being hydrolyzed at 190 °C. It indicates that lignin removal is one of the factors to improve hydrolysis performance in producing sugar.

EFFECTS OF TOTAL CHLORINE FREE (TCF) BLEACHING ON THE CHARACTERISTICS OF CHEMI MECHANICAL (CMP) PULP AND PAPER FROM MALAYSIAN DURIAN (DURIO ZIBETHINUS MURR.) RIND

The effects of bleaching process on the characteristics of pulp and paper produced from durian rind under chemi‑mechanical pulping (CMP) method were investigated. All process and characteristic tests were conducted according to Malaysian International Organisation for Standardization (MS ISO) and Technical Association of the Pulp and Paper Industry (TAPPI). Three (3) stages of peroxide (P‑P‑P) bleaching sequence through the Total Chlorine Free (TCF) bleaching process were applied to the unbeaten and unbleached durian rind CMP pulp. Bleached CMP durian rind pulp drainage time (32s) decreased (faster) and CSF freeness level (172.50ml) increased as compared to a control pulp. It was obtained that overall optical (brightness (66.36 %)) and mechanical characteristics (tensile index (38.33 Nm/g), tearing index (7.56 mN.m2/g), bursting index (2.42 kPa.m2/g), and number of folds (43)) of durian rind CMP 60 gsm paper sheet improved as the TCF bleaching process was applied to the unbleached CMP durian rind pulp.

Pasta blanqueada y azúcares fermentables a partir de médula de bagazo de caña

La médula del bagazo de caña es un residuo subaprovechado que se produce en gran cantidad en los ingenios azucareros y en las fábricas de papel. Es una mezcla de células de parénquima, vasos y pequeñas fibras. Su contenido de carbohidratos y lignina es similar a la fracción fibra. Con el propósito de aprovechar este considerable contenido de carbohidratos, se aplicaron a la médula dos procesos distintos: Pulpeo-blanqueo, hidrólisis enzimática. El primer caso se aplicó prehidrólisis, pulpeo químico, blanqueo y refinación, obteniendo pulpa de médula blanqueada con 68% ISO de blancura y 0,38% de lignina residual. El mayor incremento en resistencia (77,6% de aumento en índice de tensión, IT) fue con la incorporación de 30% de pulpa de médula blanqueada sin refinar, mientras que con 10% de pulpa de médula blanqueada refinada, el IT se incrementó en 43,8%. En el segundo caso, se trató enzimáticamente la médula. Con 6 h de hidrólisis se obtuvo 86,6% de rendimiento en azúcares fermentables tanto para pulpa de médula cocida como para pulpa de médula blanqueada, lo que representa cerca del 100% de hidrólisis de los carbohidratos presentes en el sustrato, lo cual es significativo ya que el rendimiento en azúcares fermentables de médula sin tratar fue de solo 26,1%.

The effect of eucalypt tree overaging on pulping and paper properties

Overaged trees of Eucalyptus globulus were evaluated to determine their aptitude for pulping with industrial chips as reference. The overaged wood was separated into sapwood and heartwood. Compared with industrial chips, the overaged E. globulus heartwood and sapwood contained approximately 1.5 times more extractives (3.8 vs. 5.2 and 5.9 %), similar amounts of lignin (21.4 vs. 23.3 and 19.9 %) and the holocellulose ranged from 69.5 % (heartwood) to 74.5 % (industrial chips). Overaged heartwood and sapwood produced kraft pulps with 44.6 % yields (48.4 % from industrial chips). The unbeaten pulps from overaged heartwood and sapwood compared with industrial chips have wider cells (19.5–20.7 vs. 17.7 µm), and higher coarseness (0.066–0.097 vs. 0.060 mg m−1) and more primary fines (27.4–27.5 vs. 16.6 %). Overaged wood produced handsheets with lower bulk density and higher water retention value (2.25–2.93 vs. 1.12 g/g). The refining behavior was similar as well as the tensile and tear strength development. The results show that overaged E. globulus trees with large diameters may be introduced into the pulp feedstock without extensive impacts on the pulp characteristics.

Soda Anthraquinone Pulping of Oil Palm Male Flower Spikes

This study was carried out to investigate the characteristics of pulp and paper produced from oil palm oil male flower spikes (OPMFS). The evaluation of the pulping process was studied based on the chemical Soda Anthraquinone pulping process. 60 gsm papersheet of oil palm male flower spikes were prepared from unbeaten and unbleached OPMFS Soda-AQ pulp. All optical, physical and mechanical characteristics were investigated according to TAPPI and MS ISO standards. OPMFS pulp recorded value of 6.42 s, 353 ml, 76.5 %, 36.7 % and 9.35 for drainage time, freeness, moisture content, screened yield percentage and Kappa number respectively. OPMFS paper sheet recorded value of 56.99 g/m2, 131.11 µm and 0.43 g/m3 for grammage, bulking thickness and apparent bulk density respectively. Unbleached OPMFS paper also recorded 26.49 % and 43.50 % for brightness and opacity. For mechanical characteristics, OPMFS paper recorded 39.10 N.m/g, 8.32 mN.m2/g, 3.15 kPa.m2/g and 38.50 for tensile index, tear index, burst index and folding endurance (no.) respectively. This research demonstrate some potential characteristics of oil palm male flower spikes (OPMFS) paper to be investigated as a newly explored non-wood based raw material for papermaking.

NANOFIBRILLATED CELLULOSE AS PAPER ADDITIVE IN EUCALYPTUS PULPS

In this work, the physical and mechanical properties of bleached Eucalyptus pulp reinforced with nanofibrillated cellulose (NFC) are compared with those of traditional beaten pulp used in the making of writing/printing and offset printing papers. For this purpose, three different types of hardwood slurries were prepared: beaten pulps, unbeaten pulps reinforced with NFC, and slightly beaten pulps also reinforced with NFC. Physical and mechanical tests were performed on handsheets from these different slurries. The results showed that adding NFC to unbeaten pulps results in physical and mechanical properties similar to those in pulps used for printing/writing papers. Nevertheless, the best results were obtained in slurries previously beaten at slight conditions and subsequently reinforced with NFC. These results demonstrate that the addition of NFC allows a reduction in beating intensity without decreasing the desired mechanical properties for this specific purpose.

A study on some properties of thin biocomposites made from unbeaten wood and non-wood pulps

AbstractA number of thin biomaterials were prepared via a wet formation method from seven different unbeaten plant fibers without using any chemical additives. It is noted that sheets made with short fibers (Flax-B: 0.32 mm and Straw-UB: 0.36 mm) and high fine content (Flax-B: 9.77% and Straw-UB: 10.64%) showed higher tensile index values (Flax-B: 27 Nm/g and Straw-UB: 25 Nm/g) than those made from long fibers. Despite having the longest fibers (1.11 mm) in studied samples, the tensile index values of sheet sample made from Pine-S-UB was just 12 Nm/g, which is just half of short-fibered (0.36 mm) straw sheets. Air permeability of sheets made from Pine-S-UB and Straw-UB were 5322 and 917 ml/min, respectively. Densities of the same sheets in the same order were 493 and 539 kg/m3. It is concluded that long cellulose fibers actually produce bulky materials with limited interfiber contacting areas, while short ones give biocomposites with higher density values indicating a firmly compacted internal structure in the case of utilizing plant fibers without beating and refining. Results would be usable when producing biocomposites from plant fibers via wet formation followed by various resins and polymer moldings.

TCF bleaching sequence in kraft pulping of olive tree pruning residues

The aim of the present work was to find a suitable Kraft cooking process for olive tree pruning (OTP), in order to produce pulp of kappa number about 17. The Kraft pulp produced under optimized conditions showed a viscosity of 31.5mPa·s and good physical, mechanical, and optical properties, which are suitable for paper production. The physical–mechanical and optical properties were measured before and after bleaching. Although the OTP pulp was bleached to 90.9% ISO brightness (kappa<1), the process demanded a long sequence of stages, OZQPOZQPO. The bleached pulp showed a brightness reversion equal to 1.3%. Furthermore, this bleached pulp did not need a high intensity of beating due to high drainability degree in the unbeaten pulp. So that, OTP is suggested as an interesting raw material for cellulosic pulp production because its properties are comparable to those of other agricultural residues, currently used in the paper industry.

Effect of beating on recycled properties of unbleached eucalyptus cellulose fiber.

The effects of beating on recycled properties of eucalyptus cellulose fiber were studied by analyzing the changes of morphological parameters (fiber length and the fines content), physical properties (tensile strength, breaking length and the stretch), WRV, crystal structure of cellulose and pore structure of cellulose fiber. The results showed that beating caused the fine content increase. Tensile strength, breaking length and the stretch increased with the increasing beating time. WRV of the first cycle beaten eucalyptus pulp was increased by 32.1%, compared to the first cycle unbeaten pulp. WRV increased with the increase in beating degree. However, crystallinity of cellulose increased, and then decreased with an increase in beating degree. FTIR spectra showed that there were no drastic changes in the functional groups of the eucalyptus pulp cellulose during beating. Fiber pore size was gradually diverted into macropore with the increase in beating degree, resulting in the mean pore volume increased.

Biokraft pulping of European black pine with Ceriporiopsis subvermispora

European black pine ( Pinus nigra Arn.) chips were treated with the white-rot fungus Ceriporiopsis subvermispora for periods ranging from 20 to 100 days. The effects of pretreatment on the chemical composition of wood and kraft pulping were investigated. The results showed that fungal pretreatment reduced the lignin and extractive content of wood chips. Also, weight losses occurred. Kappa number, viscosity, and reject ratio of biokraft pulps decreased. Biokraft pulps gave better response to beating, which led to significant energy saving during refining. The tear index, burst index, and tensile index of biokraft pulps were found to be lower than those of kraft pulps. However, the tensile index and burst index of 20-day biotreated and unbeaten pulp was higher than those of kraft pulp. Also, the tear index of 20-day biotreated and beaten pulp was higher than that of kraft pulp. The brightness of biokraft pulps decreased irregularly with increasing incubation time.

The pulp and paper properties of Sirex noctilio infested and fire-damagedthermomechanically pulped, South African grown Pinus patula

Pinus patula is the softwood species most extensively planted in South Africa. However, large portions of these plantings are under threat from Sirex noctilio infestation and occasional forest fires. In this exploratory investigation, the effects of tree age, Sirex noctilio infestation and fire damage to wood from Pinus patula trees on their pulp and paper properties were evaluated. Pulp was produced using the thermomechanical pulping (TMP) process. The energy consumption required to pulp the different pulpwood materials was determined. Pulps were beaten for five different time periods to investigate the development of the fibre properties in response to increasing energy input. Paper properties such as burst, tear strength and breaking length were determined on handsheets manufactured from unbeaten and beaten pulps. Box and line plots and canonical variate analysis biplots were used to statistically analyse the data. It was found that the burst strength of paper produced from healthy trees was significantly higher than that from sirex-infested or fire damaged (burnt) trees. Similarly, the tear strength of paper from healthy and burnt trees was significantly better than from sirex-infested or young trees. No significant differences in breaking length were evident between the pulpwood materials and an increase in beating time did not lead to any improvements. From this study it can be concluded that wood from dead or dying, sirex-infested and young trees produced paper with consistently lower strength properties compared to wood obtained from healthy 12-year-old trees.

Sorption of corn cob and oat spelt arabinoxylan onto softwood kraft pulp

Abstract Arabinoxylans from corn cob and oat spelt were studied in sorption experiments onto bleached and unbleached softwood kraft pulp. The corn cob (CC) xylans were produced by steam extraction (SE-CC) and alkaline extraction (NaOH-CC), while the oat spelt xylan (NaOH-OS) was obtained by alkaline extraction. Both alkaline extracted xylans exhibited a high degree of polymerization (DP) (230–240), whereas the steam extraction induced a significant degradation resulting in DPs around 36. Investigation of the xylan addition mode revealed that adding xylan before beating of pulp is most effective for increasing the beating degree and the strength properties. The tensile and burst indices are improved by xylan addition over the whole range of beating degrees. In contrast to that, the tear strength is increased significantly for unbeaten pulps but declines after beating, compared to the reference. Xylan sorption rates are increased with prolonged beating. Highest sorption rates are observed for the NaOH-OS (12–32%) and lowest for the SE-CC xylan (6.6–14%). In general, the alkaline extracted xylans have a better performance, most likely as a result of their higher molar masses.

Effects of processing on zeta potential and cationic demand of kraft pulps

The zeta potential and cationic demand of various kraft pulps—unbleached, bleached and beaten to different wetness levels—were determined in the laboratory. The magnitude of zeta potential of pulp where the final stage was a lignin degrading and dissolving treatment, such as alkaline extraction or hypochlorite, was lower than that of unbleached pulp. The cationic demand of bleached pulp was lower compared to that of unbleached pulp. Beaten pulps showed larger cationic demands than the unbeaten pulps, which can be attributed to the larger specific surface area of pulp components. Fibres become increasingly electronegative when beaten, and therefore, cationic demand of pulps increases with beating. When the zeta potential method is used with pulp furnishes of different wetness, an almost linear relationship is observed between added polyamine and attained zeta potential. However, the slope of the curve is decreased with the increase in wetness of the pulp.

Upgrading of recycled paper with oil palm fiber soda pulp

Recycled fibers, in comparison to its virgin counterpart, generally have reduced conformability and interfiber bonding capability due to irreversible hardening or hornification of these fibers. The extent and reversibility of the reduction is dependent on the original pulp type and on the papermaking process. Various methods are used to recover the lost potentials of the recycled pulp such as mechanical beating, use of chemical additives, physical fractionation and blending; the latter being the subject of this study using oil palm fiber virgin soda pulp as the upgrading strength material. With as little as 20% addition of virgin unbeaten pulp and considerably lesser amount of ca. 10% of beaten virgin pulp is sufficient to completely restore the strength of the recycled paper. The major mechanism of strength improvement is probably due to increase of interfiber bonding as a result of substitution of inactive secondary fibers with active virgin fibers.

THE EFFECT OF A CHELATOR MEDIATED FENTON SYSTEM ON THE FIBER AND PAPER PROPERTIES OF HARDWOOD KRAFT PULP1*

ABSTRACT Research was conducted into the effect of a chelator-mediated free radical treatment (CMT) on drainage rate, strength properties, optical properties, and fiber morphology for a fully bleached hardwood kraft pulp. The nature of the pulp furnish, specifically the fines and microfibril content, and its gross fiber characteristics, had a significant effect on the final fiber and paper properties. This was primarily due to an increase in the specific surface area of small fibers and fines in the beaten pulp. Treatments with high concentrations of Fenton reagents displayed severe damage to the cellulose fibers in both the beaten and unbeaten pulp. However, under relatively mild reaction conditions, fiber surface fibrillation of the unbeaten virgin fibers occurred. This observation was confirmed through results showing increased pulp tensile strength after treatment. *This is paper 2582 of the Maine Agricultural and Forest Experiment Station.

Sorption of dissolved galactoglucomannans and galactomannans to bleached kraft pulp

Sorption of mannans onto bleached kraft pulp (BKP) was investigated withreference to other interactions of mannans in mechanical pulping andpapermaking. O-Acetyl galactoglucomannans (GGM) isolated from thermomechanicalpulp (TMP), as well as enzymatically modified guar gum galactomannans (GM) wereused in the study. The results showed that deacetylation of TMP GGMs, alsooccurring during peroxide bleaching of TMP, dramatically increased thesorption.A higher sorption was also achieved after salt addition, while temperature hadno effect. Sorption of guar gum GMs onto BKP fibres was, on the other hand,quite unaffected by external conditions such as temperature, pH and saltaddition. The degree to which the pulp was beaten did not notablyinfluence the sorption either – only unbeaten pulp gave a clearly lower mannansorption. A lower number of galactose side groups, however, strongly affectedsorption – the lower the number of side groups, the higher the sorption.The molar mass did not seem to affect the rate of sorption to any higher extentat ambient temperature. At higher temperatures the rate of sorption of smallerGM polymers was, nevertheless, slightly increased. Low-molar-mass GMs alsosorbed at a higher rate onto unbeaten pulp compared to high-molar-mass mannans.GM sorption appeared to be virtually irreversible.