scholarly journals Improvement of linerboard compressive strength by hot-pressing and addition of recovered lignin from spent pulping liquor

2015 ◽  
Vol 21 (1-1) ◽  
pp. 107-112 ◽  
Author(s):  
Motasem Saidan
Keyword(s):  
Compressive Strength ◽  
Hot Pressing ◽  
Black Liquor ◽  
Strength Properties ◽  
Kraft Lignin ◽  
Test Methods ◽  
Attractive Option ◽  
Different Temperatures

This paper evaluates the effect of addition of precipitated lignin, from spent pulping black liquor, to a wet single-ply linerboard handsheet followed by hot-pressing at different temperatures, on the improvement of its compressive strength. Linerboard handsheets for testing the effect of lignin addition were prepared so that the lignin-modified sheets would have the same basis weights as the control handsheets. Both the commercial and the black liquor lignin were added as a powder to wet handsheets after couching from the handsheet mold. The experiments and testing of the physical and strength properties of dried handsheets were conducted according to TAPPI test methods. The results revealed that the addition of the recovered lignin (at pH of 2) to the wet handsheet followed by hot-pressing at 150?C increased the compressive strength of linerboard handsheets by 10% to 20% above that for handsheets made without the addition of lignin. The same results were achieved using purchased lignin. However, with a 16% addition to linerboard, purchased lignin would be too expensive. These results indicate that inclusion of kraft lignin in linerboard sheets could be proved as an attractive option to reduce linerboard basis weight.

scholarly journals The Effects of Different Types of Fly Ash on the Compressive Strength Properties of Briquettes

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Özlem Çelik Sola ◽  
Murat Yayla ◽  
Barış Sayın ◽  
Cengiz Duran Atiş
Keyword(s):  
Particle Size ◽  
Compressive Strength ◽  
Fly Ash ◽  
Strength Properties ◽  
Particle Size Analyzer ◽  
Elemental Analyses ◽  
Compressive Strength Test ◽  
Different Types ◽  
Different Temperatures ◽  
Materials Used

The aim of this study is to evaluate the effect of the different types of fly ash on the compressive strength properties of sintered briquettes. Thermal gravimetric (TG) analysis was carried out. The chemical composition and physical properties of the materials used were determined. Particle size distribution and microstructure elemental analyses of the materials used were carried out by a particle size analyzer (Mastersizer) and a scanning electron microscope (SEM-EDS). Following the characterization of the materials, briquettes were prepared by sintering at different temperatures. Compressive strength test results of the briquette samples indicated that briquettes with a compressive strength value of 47.45 N/mm2can be produced. The results obtained exceed the Turkish standard (TS EN 771-1) requirements (9.8–23.54 N/mm2). SEM-EDS results showed that briquette samples made with Tunçbilek (T) fly ash had a higher percentage of the glassy phase than the other briquette samples. Due to this microstructure, it results in higher compressive strength value.

scholarly journals Direct Observation of Induced Graphene and SiC Strengthening in Al–Ni Alloy via the Hot Pressing Technique

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1142
Author(s):  
Omayma A. Elkady ◽  
Hossam M. Yehia ◽  
Aya A. Ibrahim ◽  
Abdelhalim M. Elhabak ◽  
Elsayed. M. Elsayed ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Thermal Expansion ◽  
Hot Pressing ◽  
Zinc Nitrate ◽  
Oxide Thin Film ◽  
Nitrate Medium ◽  
Ohmic Resistance ◽  
Sic Particles ◽  
Different Temperatures ◽  
Al Matrix

In this study, Al/5 Ni/0.2 GNPs/x SiC (x = 5, 10, 15, and 20 wt%) nanocomposites were constituted using the powder metallurgy–hot pressing technique. The SiC particles and GNPs were coated with 3 wt% Ag using the electroless deposition technique then mixed with an Al matrix and 5% Ni using ball milling. The investigated powders were hot-pressed at 550 °C and 600 °C and 800 Mpa. The produced samples were evaluated by studying their densification, microstructure, phase, chemical composition, hardness, compressive strength, wear resistance, and thermal expansion. A new intermetallic compound formed between Al and Ni, which is aluminum nickel (Al3Ni). Graphene reacted with the Ni and formed the nickel carbide Ni3C. Additionally, it reacted with the SiC and formed the nickel–silicon composite Ni31Si12 at different percentages. A proper distribution for Ni, GNs, and SiC particles and excellent adhesion were observed. No grain boundaries between the Al matrix particles were discovered. Slight increases in the density values and quite high convergence were revealed. The addition of 0.2 wt% GNs to Al-5Ni increased the hardness value by 47.38% and, by adding SiC-Ag to the Al-5Ni-0.2GNs, the hardness increased gradually. The 20 wt% sample recorded 121.6 HV with a 56.29% increment. The 15 wt% SiC sample recorded the highest compressive strength, and the 20 wt% SiC sample recorded the lowest thermal expansion at the different temperatures. The five Al-Ni-Gr-SiC samples were tested as an electrode for electro-analysis processes. A zinc oxide thin film was successfully prepared by electrodeposition onto samples using a zinc nitrate aqueous solution at 25 °C. The electrodeposition was performed using the linear sweep voltammetric and potentiostatic technique. The effect of the substrate type on the deposition current was fully studied. Additionally, the ohmic resistance polarization values were recorded for the tested samples in a zinc nitrate medium. The results show that the sample containing the Al-5 Ni-0.2 GNs-10% SiC composite is the most acceptable sample for these purposes.

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.

A method for measuring the in-plane compressive strength and the compression behavior of coating layers

TAPPI Journal ◽  
2011 ◽  
Vol 10 (7) ◽  
pp. 29-34
Author(s):  
TEEMU PUHAKKA ◽  
ISKO KAJANTO ◽  
NINA PYKÄLÄINEN
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Calcium Carbonate ◽  
Coating Layer ◽  
Test Methods ◽  
Coating Films ◽  
Precipitated Calcium Carbonate ◽  
Coating Color ◽  
Mineral Coatings ◽  
Styrene Butadiene

Cracking at the fold is a quality defect sometimes observed in coated paper and board. Although tensile and compressive stresses occur during folding, test methods to measure the compressive strength of a coating have not been available. Our objective was to develop a method to measure the compressive strength of a coating layer and to investigate how different mineral coatings behave under compression. We used the short-span compressive strength test (SCT) to measure the in-plane compressive strength of a free coating layer. Unsupported free coating films were prepared for the measurements. Results indicate that the SCT method was suitable for measuring the in-plane compressive strength of a coating layer. Coating color formulations containing different kaolin and calcium carbonate minerals were used to study the effect of pigment particles’ shape on the compressive and tensile strengths of coatings. Latices having two different glass transition temperatures were used. Results showed that pigment particle shape influenced the strength of a coating layer. Platy clay gave better strength than spherical or needle-shaped carbonate pigments. Compressive and tensile strength decreased as a function of the amount of calcium carbonate in the coating color, particularly with precipitated calcium carbonate. We also assessed the influence of styrene-butadiene binder on the compressive strength of the coating layer, which increased with the binder level. The compressive strength of the coating layer was about three times the tensile strength.

Pilot-scale combustion studies with kraft lignin in a powder burner and a CFB boiler

TAPPI Journal ◽  
2010 ◽  
Vol 9 (6) ◽  
pp. 24-30 ◽  
Author(s):  
NIKLAS BERGLIN ◽  
PER TOMANI ◽  
HASSAN SALMAN ◽  
SOLVIE HERSTAD SVÄRD ◽  
LARS-ERIK ÅMAND
Keyword(s):  
Circulating Fluidized Bed ◽  
Black Liquor ◽  
Chloride Content ◽  
Pilot Scale ◽  
High Energy ◽  
Kraft Lignin ◽  
High Energy Density ◽  
Alkali Chloride ◽  
Cfb Boiler ◽  
Solid Biofuel

Processes have been developed to produce a solid biofuel with high energy density and low ash content from kraft lignin precipitated from black liquor. Pilot-scale tests of the lignin biofuel were carried out with a 150 kW powder burner and a 12 MW circulating fluidized bed (CFB) boiler. Lignin powder could be fired in a powder burner with good combustion performance after some trimming of the air flows to reduce swirl. Lignin dried to 10% moisture content was easy to feed smoothly and had less bridging tendencies in the feeding system than did wood/bark powder. In the CFB boiler, lignin was easily handled and cofired together with bark. Although the filter cake was broken into smaller pieces and fines, the combustion was not disturbed. When cofiring lignin with bark, the sulfur emission increased compared with bark firing only, but most of the sulfur was captured by calcium in the bark ash. Conventional sulfur capture also occurred with addition of limestone to the bed. The sulfur content in the lignin had a significantly positive effect on reducing the alkali chloride content in the deposits, thus reducing the high temperature corrosion risk.

An evaluation of ECT sample height for small flute board grades and Box Manufacturer’s Certification compliance

TAPPI Journal ◽  
2009 ◽  
Vol 8 (6) ◽  
pp. 24-28
Author(s):  
CORY JAY WILSON ◽  
BENJAMIN FRANK
Keyword(s):  
Compressive Strength ◽  
Compressive Load ◽  
Test Sample ◽  
Test Methods ◽  
Test Method ◽  
Initial Development ◽  
Sample Height ◽  
Relationship Of ◽  
The Relationship ◽  
Corrugated Fiberboard

TAPPI test T811 is the specified method to ascertain ECT relative to box manufacturer’s certification compliance of corrugated fiberboard under Rule 41/ Alternate Item 222. T811 test sample heights were derived from typical board constructions at the time of the test method’s initial development. New, smaller flute sizes have since been developed, and the use of lighter weight boards has become more common. The T811 test method includes sample specifications for typical A-flute, B-flute, and C-flute singlewall (and doublewall and triplewall) structures, but not for newer thinner E-flute or F-flute structures. This research explores the relationship of ECT sample height to measured compressive load, in an effort to determine valid E-flute and F-flute ECT sample heights for use with the T811 method. Through this process, it identifies challenges present in our use of current ECT test methods as a measure of intrinsic compressive strength for smaller flute structures. The data does not support the use of TAPPI T 811 for ECT measurement for E and F flute structures, and demonstrates inconsistencies with current height specifi-cations for some lightweight B flute.

New Research on the Use of Hardening Plastics for Aircraft Construction

1940 ◽  
Vol 44 (349) ◽  
pp. 44-73
Author(s):  
Wilhelm Kuech
Keyword(s):  
Strength Properties ◽  
Dynamic Loads ◽  
Absorbed Energy ◽  
Good Strength ◽  
Different Temperatures ◽  
Bonding Properties ◽  
Static And Dynamic Loads ◽  
Impact Bending ◽  
New Research ◽  
Laminated Materials

Laminated materials incorporating plastics seem to be especially well suited lor highly stressed aircraft components, by reason of their good strength properties. Paper, fabric and wood veneers treated with plastics on a phenolic basis were tested with regard to their strength, especially in bending, shear, absorbed energy in impact bending, notching strength and in their resistance against moisture. Further, the behaviour of compressed plastics was studied at different temperatures under static and dynamic loads. A part of the research was extended to pure phenol resin and to thermoplastics based on methacrylate and polyvinylchloride. The bonding properties of laminated compressed plastics were established. Concluding, some experiments relating to the practical manufacture of aeroplane components are communicated.

scholarly journals Influence of Bitumen Type and Asphalt Mixture Composition on Low-Temperature Strength Properties According to Various Test Methods

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2118 ◽  
Author(s):  
Marek Pszczola ◽  
Cezary Szydlowski
Keyword(s):  
Tensile Strength ◽  
Low Temperature ◽  
Cooling Rate ◽  
Strength Properties ◽  
Test Methods ◽  
Asphalt Mixtures ◽  
Bending Test ◽  
Mixture Composition ◽  
Tension Stress ◽  
Strength Reserve

In regions with low-temperatures, action transverse cracks can appear in asphalt pavements as a result of thermal stresses that exceed the fracture strength of materials used in asphalt layers. To better understand thermal cracking phenomenon, strength properties of different asphalt mixtures were investigated. Four test methods were used to assess the influence of bitumen type and mixture composition on tensile strength properties of asphalt mixtures: tensile strength was measured using the thermal stress restrained specimen test (TSRST) and the uniaxial tension stress test (UTST), flexural strength was measured using the bending beam test (BBT), and fracture toughness was measured using the semi-circular bending test (SCB). The strength reserve behavior of tested asphalt mixtures was assessed as well. The influence of cooling rate on the strength reserve was investigated and correlations between results from different test methods were also analyzed and discussed. It was observed that the type of bitumen was a factor of crucial importance to low-temperature properties of the tested asphalt concretes. This conclusion was valid for all test methods that were used. It was also observed that the level of cooling rate influenced the strength reserve and, in consequence, resistance to low-temperature cracking. It was concluded that reasonably good correlations were observed between strength results for the UTST, BBT, and SCB test methods.

Sign in / Sign up

Export Citation Format

Share Document