Improving strength properties of recycled and virgin pulp mixtures with dry strength agents

2016 ◽  
Vol 69 (3-4) ◽  
pp. 1600035 ◽  
Author(s):  
Sezgin Koray Gulsoy ◽  
Saduman Erenturk
Keyword(s):  
Strength Properties ◽  
Virgin Pulp

scholarly journals Recycling Mimeograph-Printed Newsprint Paper

2011 ◽  
Vol 28 (2) ◽  
pp. 156
Author(s):  
E. L Mari ◽  
A.S Torres ◽  
C.O Austria
Keyword(s):  
Strength Properties ◽  
Short Fibre ◽  
Original Material ◽  
Paper Properties ◽  
Mechanical Pulp ◽  
Fibre Properties ◽  
Virgin Pulp ◽  
Office Waste

Virgin newsprint paper from thermo-mechanical pulp was subjected to a laboratory recycling scheme, which involved mimeograph-printing, re-pulping, de-inking, washing, refining, and handsheetforming, without adding other fibre in between cycles. Fibre dimension, pulp freeness and paper properties were determined after each cycle until the fifth, at which about 20% of the original material remained. The remaining fibre was then mixed with virgin pulp, the original newsprint and unsorted mixed office waste to determine the proportion necessary for acceptable properties. The results indicated remarkable modification in distribution of fibre properties, a decreasing amount of long fibre with corresponding increase of short fibre in the course of recycling and loss of fibre. Refining generally improved the strength properties of paper from recycled fibre. About 20 % to 30 % of either thermo-mechanical pulp or unsorted mixed office waste was found sufficient for blending with recycled fibre to obtain acceptable strength properties.

scholarly journals KARAKTERISTIK PULP KIMIA MEKANIS DARI KENAF (Hibiscus cannabinus L.) UNTUK KERTAS LAINER

2016 ◽  
Vol 4 (01) ◽  
Author(s):  
Teddy Kardiansyah ◽  
Susi Sugesty
Keyword(s):  
Kraft Pulp ◽  
Sodium Hydroxide Solution ◽  
Strength Properties ◽  
Hibiscus Cannabinus ◽  
Paper Strength ◽  
Physical Strength ◽  
Tear Index ◽  
Virgin Pulp ◽  
Kenaf Bast ◽  
Crush Strength

Liner paper is commonly used for packaging because of its high bursting and ring crush strength. To meet these properties, liner paper strength relies on about 10-40% content of NUKP (Needle Unbleached Kraft Pulp). Currently, Indonesia does not produce NUKP, so it must be imported and the price is expensive. Liners paper in Indonesia is usually made from waste paper (old corrugated containers) that has unacceptable strength properties. To improve the strength properties, virgin pulp should be used. This study aimed to make virgin pulp from kenaf by chemimechanical process. Its physical strength was tested as a NUKP substitute. The results show that Kenaf mechanical pulp from Kenaf bast treated by using 6% sodium hydroxide solution fulfills the NUKP specifications according to SNI- 6106-1999, i.e. a fiber length of 4.24 mm, a freeness of 760 mL CSF, a tensile index of 66.54 Nm/g, a burst index of 5.72 kPam2/g, and a tear index of 18.09 mNm2/g.Keywords: nonwood, chemimechanical pulp, kenaf, bast, core  ABSTRAK Kertas lainer merupakan kertas industri yang digunakan untuk kemasan, dengan sifat ketahanan retak dan ketahanan tekan lingkar (ring crush) yang tinggi. Untuk mendapatkan kedua sifat tersebut maka biasanya kekuatan kertas lainer bertumpu pada penggunaan NUKP (pulp kraft serat panjang belum putih) dengan proporsi sekitar 10 – 40%. Saat ini Indonesia tidak memproduksi NUKP sehingga kebutuhan NUKP harus diimpor dan harganya mahal. Kertas lainer di Indonesia pada saat ini hampir semuanya dibuat dari karton bekas, disamping itu pengolahan karton bekas memiliki masalah pada kekuatan lembaran. Jika pembuatan karton menggunakan serat asli (virgin pulp), maka masalah kekuatan lembaran dapat diatasi. Penelitian ini bertujuan untuk membuat pulp dari Kenaf dengan proses kimia mekanis. Bahan baku nonkayu yaitu kenaf dibuat pulp mekanis dengan menggunakan proses Chemimechanical Pulp (CMP). Selanjutnya pulp mekanis yang diperoleh diuji kekuatan fisiknya untuk melihat potensinya sebagai pulp NUKP. Pulp mekanis kenaf yang berasal dari kulit kenaf dengan penggunaan natrium hidroksida (NaOH) 6% telah memenuhi spesifikasi pulp NUKP sesuai dengan SNI 6106-1999, yaitu panjang serat 4,24 mm, freeness 760 mL CSF, indeks tarik 66,54 Nm/g, indeks retak 5,72 kPam2/g dan indeks sobek 18,09 mNm2/g.Kata kunci: non kayu, pulp kimia mekanis, kenaf, kulit, batang tanpa kulit

SEM Study of Tension Wood Fiber Morphology and its Effect on Paper Properties

1977 ◽  
Vol 35 ◽  
pp. 308-309
Author(s):  
K. W. Robinson
Keyword(s):  
Tension Wood ◽  
Wood Fiber ◽  
Strength Properties ◽  
Fiber Morphology ◽  
Paper Properties ◽  
Pure Cellulose ◽  
Short Rotation ◽  
Hardwood Trees ◽  
Sem Study

Tension wood (TW) is an abnormal tissue of hardwood trees; although it has been isolated from most parts of the tree, it is frequently found on the upper side of branches and leaning stems. TW has been classically associated with geotropic alignment, but more recently it has been associated with fast growth. Paper made from TW is generally lower in strength properties. Consequently, the paper industries' growing dependence on fast growing, short- rotation trees will result in higher amounts of TW in the final product and a corresponding reduction in strength.Relatively few studies have dealt with the role of TW in the structure of paper. It was suggested that the lower strength properties of TW were due to a combination of factors, namely, its unique morphology, compression failures in the cell wall, and lower hemicellulose content. Central to the unique morphology of the TW fiber is the thick gelatinous layer (G-layer) composed almost entirely of pure cellulose.

Co-cooking nonwoods with hardwoods

TAPPI Journal ◽  
2014 ◽  
Vol 13 (6) ◽  
pp. 19-24
Author(s):  
TROY RUNGE ◽  
CHUNHUI ZHANG
Keyword(s):  
High Performance Liquid Chromatography ◽  
High Performance ◽  
Paper Industry ◽  
Pulp And Paper Industry ◽  
Strength Properties ◽  
Agricultural Residues ◽  
Kraft Pulping ◽  
Pulp And Paper ◽  
Strength Increase ◽  
Xylan Content

Agricultural residues and energy crops are promising resources that can be utilized in the pulp and paper industry. This study examines the potential of co-cooking nonwood materials with hardwoods as means to incorporate nonwood material into a paper furnish. Specifically, miscanthus, switchgrass, and corn stover were substituted for poplar hardwood chips in the amounts of 10 wt %, 20 wt %, and 30 wt %, and the blends were subjected to kraft pulping experiments. The pulps were then bleached with an OD(EP)D sequence and then refined and formed into handsheets to characterize their physical properties. Surprisingly, all three co-cooked pulps showed improved strength properties (up to 35%). Sugar measurement of the pulps by high-performance liquid chromatography suggested that the strength increase correlated with enriched xylan content.

Chemical, anatomical, and technology aspects of Eucalyptus benthamii and Eucalyptus dunii for use in an integrated pulp and paper mill

TAPPI Journal ◽  
2015 ◽  
Vol 14 (2) ◽  
pp. 73-81 ◽  
Author(s):  
GISELY SAMISTRARO ◽  
PETER W. HART ◽  
JORGE LUIZ COLODETTE ◽  
RICARDO PAIM
Keyword(s):  
Energy Levels ◽  
Black Liquor ◽  
Basic Density ◽  
Paper Mill ◽  
Frost Tolerance ◽  
Strength Properties ◽  
Kappa Number ◽  
Pulp Yield ◽  
Chemical Compositions ◽  
Physical Strength

Eucalyptus dunii has been commercially used in southern Brazil because of its relatively good frost tolerance and adequate productivity in the winter months. More recently, interest has grown in cultivating Eucalyptus benthamii Maiden & Cambage, which presents even superior frost tolerance compared to E. dunii and is highly productive as well. The quality of E. benthamii for pulp production is not yet proven. Thus, the chemical, anatomical, and technological aspects of pulp made from E. benthamii were compared with those of E. dunii for unbleached paper production. Samples of E. benthamii chips were obtained and analyzed for their basic density, chemical composition, higher heating value, trace elemental analysis, and chip size distribution. The chips were kraft cooked using conditions that produced a 74 ± 6 kappa number. The pulps were characterized for kappa number, yield, viscosity, and morphologic characteristics (e.g., length, wall thickness, and coarseness). Black liquor was analyzed for total solids, organics, inorganics, sodium sulfide, sodium hydroxide, and sodium carbonate. Brownstocks were beaten at five different energy levels in a Valley beater, and the physical strength properties of 120 g/m² handsheets were measured to develop a beater curve. The results of this study showed differences in delignification between the two woods and lower pulp yield for E. benthamii , which are related to their chemical compositions and basic densities. The E. benthamii studied in this work exhibited higher amounts of lignin and extractives, lower carbohydrate content, and lower basic density. However, cooking a blend of the two woods afforded good results in pulping and in physical pulp properties.

Pilot trials of hemicelluloses extraction prior to thermomechanical pulp production: Part 1

TAPPI Journal ◽  
2011 ◽  
Vol 10 (5) ◽  
pp. 21-28 ◽  
Author(s):  
CARL HOUTMAN ◽  
ERIC HORN
Keyword(s):  
Oxalic Acid ◽  
Energy Savings ◽  
Wood Chip ◽  
Strength Properties ◽  
Thermomechanical Pulp ◽  
Sugar Solution ◽  
Bisulfite Treatment ◽  
Pilot Trials ◽  
Pulp Production ◽  
Production Part

Pilot data indicate that wood chip pretreatment with oxalic acid reduced the specific energy required to make thermomechanical pulp. A combined oxalic acid/bisulfite treatment resulted in 21% refiner energy savings and 13% increase in brightness for aspen. A low level of oxalic acid treatment was effective for spruce. Energy savings of 30% was observed with no significant change in strength properties. Adding bisulfite did not significantly increase the brightness of the spruce pulp. For pine, the optimum treatment was a moderate level of oxalic acid, which resulted in 34% energy savings and an increase in strength properties. For all of these treatments 1–3 w/w % carbohydrates were recovered, which can be fermented to produce ethanol. The extract sugar solution contained significant quantities of arabinose.

Does kraft hardwood and softwood pulp viscosity correlate to paper properties?

TAPPI Journal ◽  
2016 ◽  
Vol 15 (10) ◽  
pp. 643-651 ◽  
Author(s):  
ROBERT J. OGLESBY ◽  
HUMPHREY J. MOYNIHAN ◽  
RICARDO B. SANTOS ◽  
ASHOK GHOSH ◽  
PETER W. HART
Keyword(s):  
Physical Properties ◽  
Strength Loss ◽  
Strength Properties ◽  
Clear Correlation ◽  
Paper Properties ◽  
Physical Strength ◽  
Pulp Viscosity ◽  
Softwood Pulp ◽  
The Impact ◽  
Related Paper

The impact of commercially prepared, fully bleached pulp viscosity variation on handsheet physical properties was evaluated at different levels of pulp refining. Hardwood pulps from the same brownstock species mix, cooking parameters, and kappa numbers were processed through two different commercial bleach plants: one with a D0(EP)D1D2 sequence and the second with an OD0(EOP)D1 sequence. Additionally, a commercial softwood (predominately Scotts pine) brownstock pulp bleached by an OD0(EP)D1D2 sequence was employed in this study. Pulps with viscosities ranging from 14 to 21 mPa∙s were refined in a Valley beater to two freeness levels, and the associated handsheet physical properties were measured in this study. Over the pulp viscosity range of 14 to 21 mPa∙s, no clear correlation was found to exist between pulp viscosity and related paper physical properties. Finally, a series of laboratory prepared bleached pulps were purposely prepared under non-ideal conditions to reduce their final viscosities to lower values. Handsheets made from these pulps were tested in their unbeaten condition for physical strength properties. Significant and rapid strength loss occurred when the measured pulp viscosity dropped below 12 mPa∙s; overall strength properties showed no correlation to viscosity above the critical 12 mPa∙s value.

A novel predictive method for filler coflocculation with cellulose microfibrils

TAPPI Journal ◽  
2019 ◽  
Vol 18 (11) ◽  
pp. 653-664
Author(s):  
IGNACIO DE SAN PIO ◽  
KLAS G. JOHANSSON ◽  
PAUL KROCHAK
Keyword(s):  
Negative Impact ◽  
High Strength ◽  
Strength Properties ◽  
Cellulose Microfibrils ◽  
Paper Strength ◽  
Flow Loop ◽  
Cationic Starch ◽  
Reflectance Measurement ◽  
Drainage Rate ◽  
Complete Study

Different strategies aimed at reducing the negative impact of fillers on paper strength have been the objective of many studies during the past few decades. Some new strategies have even been patented or commercialized, yet a complete study on the behavior of the filler flocs and their effect on retention, drainage, and formation has not been found in literature. This type of research on fillers is often limited by difficulties in simulating high levels of shear at laboratory scale similar to those at mill scale. To address this challenge, a combination of techniques was used to compare preflocculation (i.e., filler is flocculated before addition to the pulp) with coflocculation strategies (i.e., filler is mixed with a binder and flocculated before addition to the pulp). The effect on filler and fiber flocs size was studied in a pilot flow loop using focal beam reflectance measurement (FBRM) and image analysis. Flocs obtained with cationic polyacrylamide (CPAM) and bentonite were shown to have similar shear resistance with both strategies, whereas cationic starch (CS) was clearly more advantageous when coflocculation strategy was used. The effect of flocculation strategy on drainage rate, STFI formation, ash retention, and standard strength properties was measured. Coflocculation of filler with CPAM plus bentonite or CS showed promising results and produced sheets with high strength but had a negative impact on wire dewatering, opening a door for further optimization.

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