Kraft pulping of white spruce bole and branch

1982 ◽  
Vol 12 (2) ◽  
pp. 299-303
Author(s):  
K. N. Law ◽  
Z. Koran
Keyword(s):  
Tensile Strength ◽  
White Spruce ◽  
Kraft Pulping ◽  
Pulp Yield ◽  
Tear Strength ◽  
Branch Wood

When pulped by the same schedule, barked white spruce (Piceaglauca (Moench.) Voss.) branch wood was comparable in pulp yield to the bole wood. Handsheet made of unbeaten branch pulp showed higher bulk and stretch, comparable tensile and burst strengths, and considerably lower tear strength than bole wood. In the case of beaten pulps, branch pulp gave comparable tensile strength and stretch and lower burst and tear strengths. Inclusion of bark in the cooking increased chemical consumption and degraded sheet cleanliness. Pulping of mixtures containing up to 20% branch wood reduced the tear, burst, and tensile strengths by about 10%). It appeared that the inclusion of branch wood in the furnish within the natural amount limit in kraft pulping would be feasible.

Evaluation of beetle-killed white spruce for pulp and paper

1983 ◽  
Vol 13 (2) ◽  
pp. 246-250 ◽  
Author(s):  
Richard A. Werner ◽  
Erwin E. Elert ◽  
Edward H. Holsten
Keyword(s):  
White Spruce ◽  
Strength Properties ◽  
Kraft Pulping ◽  
Pulp Yield ◽  
Kraft Pulps ◽  
High Quality ◽  
South Central ◽  
Dead Trees ◽  
Standing Trees ◽  
First Results

A kraft pulping study on standing white spruce (Piceaglauca (Moench) Voss) killed by spruce beetles (Dendroetonusrufipennis (Kirby)) in south central Alaska showed no difference in pulp yield between trees dead for 1 year and those dead for as long as 50 years. Strength properties of beetle-killed white spruce remained extremely high in all dead trees regardless of how long they had been dead, so they apparently could be used for producing high-quality kraft pulps. These are the first results reported in which standing trees dead for as long as 50 years produced high-quality bleached and unbleached pulps.

Polysulfide-borohydride modification of southern pine alkaline pulping integrated with hydrothermal pre-extraction of hemicelluloses

TAPPI Journal ◽  
2011 ◽  
Vol 10 (7) ◽  
pp. 9-16
Author(s):  
SUNG-HOON YOON ◽  
HARRY CULLINAN ◽  
GOPAL A. KRISHNAGOPALAN
Keyword(s):  
Loblolly Pine ◽  
Sodium Borohydride ◽  
Kraft Pulping ◽  
Hot Water ◽  
Pulp Yield ◽  
Paper Strength ◽  
Southern Pine ◽  
Two Stage ◽  
Simultaneous Treatment ◽  
Process Modification

We studied three process modifications to investigate their effects on the property and yield recovery capabilities of kraft pulping integrated with hemicellulose pre-extraction of southern pine. Loblolly pine chips were pre-extracted with hot water until the sugar extraction yield reached the targeted value of 10% and then subjected to conventional and modified kraft pulping. Modification included polysulfide pretreatment; polysulfide-sodium borohydride dual pretreatment, and polysulfide followed by polysulfide-sodium borohydride dual pretreatment two-stage pretreatments prior to kraft pulping. In the first modification, about 5% of the lost pulp yield (total 7%) caused by hemicellulose pre-extraction could be recovered with 15%-20% polysulfide pretreatment. Complete recovery (7%) was achieved with simultaneous pretreatment using 15% polysulfide and 0.5% sodium borohydride with 0.1% anthraquinone in polysulfide-sodium borohydride dual pretreatment. Two-stage pretreatment using recycled 15% polysulfide followed by simultaneous treatment of 6% polysulfide and 0.4%–0.5% sodium borohydride with 0.1% anthraquinone also achieved 100% yield recovery. Continuous recycling of 15% polysulfide employed in the two-stage process modification maintained its yield protection efficiency in a repeated recycling cycle. No significant changes in paper strength were found in handsheets prepared from the three process modifications, except for a minor reduction in tear strength.

Prehydrolysis kraft pulping of jute cutting and caddis mixture for rayon production

TAPPI Journal ◽  
2019 ◽  
Vol 18 (5) ◽  
pp. 287-293 ◽  
Author(s):  
JANNATUN NAYEEM ◽  
M. SARWAR JAHAN ◽  
RAZIA SULTANA POPY ◽  
M. NASHIR UDDIN ◽  
M.A. QUAIYYUM
Keyword(s):  
Kraft Pulping ◽  
Kappa Number ◽  
Pulp Yield ◽  
Solid Residue ◽  
Rayon Production ◽  
Kraft Cooking ◽  
Prehydrolysis Kraft

Jute cutting, jute caddis, and cutting-caddis mixtures were prehydrolyzed by varying time and temperature to get about 90% prehydrolyzed yield. At the conditions of 170°C for 60 min of prehydrolysis, the yield for 100% jute cutting was 76.3%, while the same for jute caddis was only 67.9%. But with prehydrolysis at 150°C for 60 min, the yield was 90% for jute cutting, where 49.94% of original pentosan was dissolved and prehydrolysis of jute caddis at 140°C in 60 min yielded 86.4% solid residue. Jute cutting-caddis mixed prehydrolysis was done at 140°C for 30 min and yielded 92% solid residue for 50:50 cutting-caddis mixtures, where pentosan dissolution was only 29%. Prehydrolyzed jute cutting, jute caddis, and cutting-caddis mixtures were subsequently kraft cooked. Pulp yield was only 40.9% for 100% jute cutting prehydrolyzed at 170°C for 60 min, which was 10.9% lower than the prehydrolysis at 140°C. For jute cutting-caddis mixed prehydrolysis at 140°C for 45 min followed by kraft cooking, pulp yield decreased by 3.3% from the 100% cutting to 50% caddis in the mixture, but 75% caddis in the mixture decreased pulp yield by 6.7%. The kappa number 50:50 cutting-caddis mixture was only 11.3. Pulp bleachability improved with increasing jute cutting proportion in the cutting-caddis mixture pulp.

scholarly journals Utilization of Leather Waste Fibers in Polymer Matrix Composites Based on Acrylonitrile-Butadiene Rubber

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 117
Author(s):  
Le Thuy Hang ◽  
Do Quoc Viet ◽  
Nguyen Pham Duy Linh ◽  
Vu Anh Doan ◽  
Hai-Linh Thi Dang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Polymer Matrix Composites ◽  
Waste Product ◽  
Dynamic Mechanical Properties ◽  
Hammer Mill ◽  
Butadiene Rubber ◽  
Matrix Composites ◽  
Leather Industry ◽  
Tear Strength

In this study, we present the fabrication of nitrile butadiene rubber/waste leather fiber (NBR/WLF) composites with different weight percentages of WLF and NBR (0/100, 20/80, 30/70, 40/60, 50/50, 60/40 wt/wt). WLF was prepared by cutting the scrap leathers from the waste product of the Vietnamese leather industry. Subsequently, in order to make the short fibers, it was mixed by a hammer mill. The characteristics of WLF/NBR composites such as mechanical properties (tensile strength, tear strength, hardness), dynamic mechanical properties, toluene absorption, and morphology were carefully evaluated. As a result, the tensile strength and tear strength become larger with increasing WLF content from 0 to 50 wt% and they decrease when further increasing WLF content. The highest tensile strength of 12.5 MPa and tear strength of 72.47 N/mm were achieved with the WLF/NBR ratio of 50/50 wt%. Both hardness and resistance of the developed materials with toluene increased with increasing WLF content. The SEM results showed a good adhesion of NBR matrix and the WLF. The increasing of storage modulus (E’) in comparison with raw NBR showed good compatibility between WLF and NBR matrix. This research showed that the recycled material from waste leather and NBR was successfully prepared and has great potential for manufacturing products such as floor covering courts and playgrounds, etc.

Kraft pulping and bleaching of Eichhornia crassipes (Mart.) Solms (water hyacinth)

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 9243-9264
Author(s):  
Luis Fernando Pintor-Ibarra ◽  
José de Jesús Rivera-Prado ◽  
Sarai Ramos-Vargas ◽  
Teófilo Escoto-García ◽  
Nancy Eloisa Rodríguez-Olalde ◽  
...  
Keyword(s):  
Water Hyacinth ◽  
Eichhornia Crassipes ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Pulp Yield ◽  
Inorganic Elements ◽  
Wood Fibers ◽  
Pulp Bleaching ◽  
Cellulosic Pulp ◽  
Unbleached Pulp

Eichhornia crassipes (water hyacinth) was pulped by means of a kraft pulping process with reagent loads of 10 and 20% on a dry matter basis to determine yield, rejects, kappa number, and ash. Fiber classification, brightness, opacity, and viscosity were measured in the brown pulp. Bleaching was performed by means of an O1O2D1(PO)D2HD3 sequence. Yield, kappa number, pH, ash, brightness, opacity, and viscosity were evaluated in the bleached pulp. Finally, a microanalysis of inorganic elements was carried out in both the bleached and unbleached pulp ash. The highest kraft pulp yield was 26.4%, with a 10% reagent load at 120 °C and 30 minutes cooking. It was determined that E. crassipes cellulosic pulp contains large amounts of fines. Results of the bleaching sequence indicate low brightness (58.0 %) and low viscosity (6.43 cP). The most abundant inorganic elements in the ash of both bleached and unbleached pulp were Ca, Mg, P, and Si. These results suggest that E. crassipes biomass might complement cellulosic fibers in pulping processes of low yield, such as the wood fibers used to produce handmade paper.

Application of Chelating Agents as Cooking Aids in Bamboo Pulping

2013 ◽  
Vol 750-752 ◽  
pp. 1520-1523
Author(s):  
Hong Xia Gao ◽  
Wen Hua He ◽  
Xiu Qiong Guan ◽  
Chun Liu ◽  
Bo Yuan
Keyword(s):  
Phosphonic Acid ◽  
Chelating Agents ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Pulp Yield ◽  
Diethylene Triamine ◽  
Bamboo Pulp ◽  
Kraft Cooking ◽  
Pulp Strength

The effect of chelating agents Diethylene Triamine Penta Methylene Phosphonic Acid in bamboo kraft cooking was studied. The results show that the bamboo pulp yield was 49.52% when DTPMPA dosage is 0.4%, at the same time the Kappa number was lower. With the increasing of DTPMPA dosage in bamboo kraft pulping, the bamboo pulp strength was increased.

scholarly journals Chemical characteristics and Kraft pulping of tension wood from Eucalyptus globulus labill

2012 ◽  
Vol 36 (6) ◽  
pp. 1163-1172 ◽  
Author(s):  
María Graciela Aguayo ◽  
Regis Teixeira Mendonça ◽  
Paulina Martínez ◽  
Jaime Rodríguez ◽  
Miguel Pereira
Keyword(s):  
Eucalyptus Globulus ◽  
Lignin Content ◽  
Strength Properties ◽  
Kraft Pulping ◽  
Pulp Yield ◽  
Chemical Characteristics ◽  
Kraft Pulps ◽  
Opposite Wood ◽  
Alkali Consumption ◽  
Pulp Strength

Tension (TW) and opposite wood (OW) of Eucalyptus globulus trees were analyzed for its chemical characteristics and Kraft pulp production. Lignin content was 16% lower and contained 32% more syringyl units in TW than in OW. The increase in syringyl units favoured the formation of β-O-4 bonds that was also higher in TW than in OW (84% vs. 64%, respectively). The effect of these wood features was evaluated in the production of Kraft pulps from both types of wood. At kappa number 16, Kraft pulps obtained from TW demanded less active alkali in delignification and presented slightly higher or similar pulp yield than pulps made with OW. Fiber length, coarseness and intrinsic viscosity were also higher in tension than in opposite pulps. When pulps where refined to 30°SR, TW pulps needed 18% more revolutions in the PFI mill to achieve the same beating degree than OW pulps. Strength properties (tensile, tear and burst indexes) were slightly higher or similar in tension as compared with opposite wood pulps. After an OD0(EO)D1 bleaching sequence, both pulps achieved up to 89% ISO brightness. Bleached pulps from TW presented higher viscosity and low amount of hexenuronic acids than pulps from OW. Results showed that TW presented high xylans and low lignin content that caused a decrease in alkali consumption, increase pulp strength properties and similar bleaching performance as compared with pulps from OW.

APPROACHES TO CONTROLLING MICRO-ORGANISMS IN COTTON AND COTTON/ELASTANE CLOTHINGS

2021 ◽  
Vol 16 (3) ◽  
pp. 124-135
Author(s):  
Nilüfer Yıldız Varan
Keyword(s):  
Mechanical Properties ◽  
Antimicrobial Activity ◽  
Tensile Strength ◽  
Untreated Control ◽  
Physical And Mechanical Properties ◽  
Emergency Rooms ◽  
Tear Strength ◽  
Antifungal Properties ◽  
Micro Organisms ◽  
Control Samples

Antimicrobials are substances or mixtures of substances used to destroy or suppress the growth of harmful microorganisms such as bacteria, viruses, or fungi on inanimate objects and surfaces. In this study, an alternative method is presented using triclosan agents that can kill bacteria and viruses to help keep patient, operating, and emergency rooms free of germs. Samples were treated with triclosan to achieve antimicrobial/antiviral/antifungal properties for further designs to help comfort and bacteria, virus, fungi (BVF) resistantance during use. The physical, and mechanical properties of triclosan treated cotton and cotton/elastane fabrics in comparison with untreated control samples was investigated. The results showed that a small significant decrease was observed for tensile strength (strip and grab methods), tear strength and seam strength. Besides, statistically a small significant decrease was observed with the increase in triclosan concentration for all samples. The panama weaves showed the lowest tensile strength and the highest tear strength and statistically small significant decrease was observed for all treated samples. The antimicrobial tests showed that all treated samples have a very good antimicrobial activity which can also lead to antivirus protection by providing hygienic environment for the users during future designs.

Effect of abrasive particle size on tribological behavior of elastomers

2019 ◽  
Vol 234 (3) ◽  
pp. 373-385 ◽  
Author(s):  
F Hakami ◽  
A Pramanik ◽  
AK Basak ◽  
N Ridgway ◽  
MN Islam
Keyword(s):  
Particle Size ◽  
Tensile Strength ◽  
Wear Rate ◽  
Coefficient Of Friction ◽  
Abrasive Particle ◽  
Tribological Behaviour ◽  
Elongation At Break ◽  
Tear Strength ◽  
Wear And Friction ◽  
Abrasive Size

Effect of abrasive particle size on tribological behaviour of different elastomers was investigated experimentally in this study. The size of abrasive particle size was varied from coarse (425 µm) to fine (82 µm). Wear rate and coefficient of friction were calculated and analyzed accordingly followed by the examination of worn surfaces by a scanning electron microscope to unravel the wear mechanism. Experimental results showed that abrasive size had a significant effect on wear and friction behaviour of the elastomers. As the abrasive particle size increased, wear rate and coefficient of friction also increased at different rates and exhibited different wear mechanisms that changed from friction to fatigue and roll formation. Mechanical properties of elastomers such as hardness, tensile strength, tear strength, and elongation at break also contributed to wear and friction. The effect of elongation at break and tensile strength on wear rate is more pronounced at lower abrasive particle size, whereas hardness and tear strength play a pivotal role at the higher abrasive size.

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