Relationship of Surface Strength and Bulk Strength Properties in Uncoated Woodfree Paper

TAPPI Journal ◽  
2011 ◽  
Vol 10 (2) ◽  
pp. 17-24 ◽  
Author(s):  
ALESSANDRA GERLI ◽  
LEENDERT C. EIGENBROOD ◽  
SANNA NURMI
Keyword(s):  
Tensile Strength ◽  
Calcium Carbonate ◽  
Internal Bond ◽  
Surface Damage ◽  
Strength Properties ◽  
Strength Increase ◽  
Paper Machine ◽  
Precipitated Calcium Carbonate ◽  
Surface Strength ◽  
Tensile Strength Increase

Various uncoated woodfree papers produced on a pilot paper machine were characterized for picking resistance, using an IGT printability tester, and standard sheet properties. The papers were produced with and without surface sizing or a debonding agent, with different filler types (ground calcium carbonate [GCC] or precipitated calcium carbonate [PCC]) and levels (20% and 25%), and by varying the calendering conditions. The goal was to assess the relationship between surface strength of these sheets and their bulk strength properties, such as tensile strength and internal bond. Variables such as the use of a debonding agent or the application of surface size had equal effect on picking resistance and tensile strength. Increase of filler content in paper or replacement of GCC with PCC reduced picking resistance, tensile strength, and internal bond. Increase of the calendering load, for both GCC and PCC sheets, reduced picking resistance but left tensile strength and internal bond unaffected. Picking resistance of the 25% PCC-containing sheets was affected at a significantly larger extent by an increase in calendering load than picking resistance of the 25% GCC-containing sheets. These results point out that the surface of a highly filled PCC sheet is particularly sensitive to surface damage by calendering.

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.

The Use of Controlled Dissolution Glass for the Consolidation of a High Porosity Chalk

2021 ◽  
Author(s):  
Max Olsen ◽  
Ragni Hatlebakk ◽  
Chris Holcroft ◽  
Roar Egil Flatebø ◽  
Asif Hoq ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Colloidal Silica ◽  
Strength Increase ◽  
High Porosity ◽  
Hydrocarbon Recovery ◽  
Filter Screen ◽  
The Matrix ◽  
Core Flood ◽  
Fractured Well ◽  
Tensile Strength Increase

Abstract This paper reports the development and testing, of a Phosphate controlled dissolution glass composition used to strengthen the matrix of chalk whilst retaining the permeability of the rock, facilitating improved hydrocarbon recovery in unstable wells. Multiple versions of the glass solutions and different types of colloidal silica were extensively tested in the laboratory to determine injectability and reactivity with calcium carbonate rocks. The goal of the testing was to determine the best performing solution for use in a field trial in the Norwegian North Sea. The laboratory testing included filtration and core flood tests to determine the injectability of the solutions and post treatment permeability, and Brazilian strength tests to determine the tensile strength of the treated chalk cores. The filterability was tested through filter screen sizes ranging from 5 to 0.6 µm. Core flood testing was performed on 10 cm long chalk cores with 1.5 mD permeability. The glass solutions showed the best results in the filtration and core flood testing, achieving significantly greater invasion depth than any of the colloidal silica samples. The phosphate glass treated chalk cores maintained 70 to 100% of the original permeability while delivering a 3 to 5 fold tensile strength increase. The lab tests demonstrated the potential of a glass based treatment to strengthen chalk formations without impeding permeability.Based on the promising results from the lab tests, it was decided to trial the selected glass solution in a mature vertical proppant fractured well. The test confirmed that the glass solution could be pumped into the well, but the test failed pre-maturely after two months of varied production, and the trial will not be covered in this paper.However, due to the high value in being able to stabilize chalk in the field, the Operator is evaluating a new trial in a horizontal well, and learnings from the first trial will be used to inform further lab tests in the next phase. The glass solution used in this trial is being further developed to be used in other formation types, such as sand and non-calcium containing reservoirs.

Effect of Quantity of Industrial Waste on Eco-Friendly Geopolymer Concrete

2021 ◽  
Vol 1019 ◽  
pp. 102-109
Author(s):  
Endow Mazumder ◽  
L.V. Prasad M.
Keyword(s):  
Tensile Strength ◽  
Polymerization Process ◽  
Strength Increase ◽  
Geopolymer Concrete ◽  
Split Tensile Strength ◽  
Granulated Blast Furnace Slag ◽  
Activating Agent ◽  
Alkaline Activator ◽  
Binder Material ◽  
Tensile Strength Increase

The primary goal of this work is to report the results of the experimental outcome of Geopolymer concrete (GEO-C) which is prepared and cured at room temperature. GEO-C is prepared using a blend of ground granulated blast furnace slag (GGSG) and F Class Fly Ash, and the replacement is ranged from 0% to 100% of binder material, to find the optimum dosage of binder material. Sodium Hydroxide (NaOH) and Sodium Silicate (Na2SiO3) which are alkaline in nature, used primarily as an activating agent for the polymerization process of geopolymer. Experiments were conducted on samples by fixing the NaOH concentration as 14M for optimum strength and the alkaline activator ratio is fixed as one. Mechanical properties of GEO-C like compressive strength, rupture modulus (i.e. flexural strength), and split tensile strength were evaluated at the ages 7, 14, 28 days. From the results, it is observed that with the addition of GGSG in the blend the compressive, flexural, and tensile strength increase but there is a drastic reduction in the workability of the mixture.

Denitrogenation behavior and tensile strength increase during carbonization of stabilized pan fibers

Carbon ◽  
1998 ◽  
Vol 36 (9) ◽  
pp. 1327-1330 ◽  
Author(s):  
J. Mittal ◽  
H. Konno ◽  
M. Inagaki ◽  
O.P. Bahl
Keyword(s):  
Tensile Strength ◽  
Strength Increase ◽  
Tensile Strength Increase ◽  
Pan Fibers

scholarly journals Effect of the Alkalized Rice Straw Content on Strength Properties and Microstructure of Cemented Tailings Backfill

2021 ◽  
Vol 8 ◽  
Author(s):  
Shi Wang ◽  
Xuepeng Song ◽  
Meiliang Wei ◽  
Wu Liu ◽  
Xiaojun Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Rice Straw ◽  
Low Cost ◽  
Strength Properties ◽  
Hydration Reaction ◽  
Strength Increase ◽  
Improvement Effect ◽  
Naoh Solution

The tailings and rice straw are waste by-products, and the storage of tailings on the ground and the burning of rice straws will seriously damage the ecological environment. In this study, the effect of different contents of alkalized rice straw (ARS; rice straw was alkalized with 4% NaOH solution) on the mechanical properties and microstructure of cemented tailings backfill (CTB; ARSCTB) was studied through uniaxial compressive strength (UCS), scanning electron microscopy (SEM), and X-ray diffraction (XRD) tests. The results indicated that 1) the UCS of ARSCTB could be improved by ARS. However, with the increase in the ARS content from 0.1 to 0.4 wt%, the UCS showed a monotonous decreasing trend. The UCS improvement effect was best when the ARS content was 0.1 wt%, and at 7, 14, and 28 days curing ages, the UCS increased rate was 6.0, 8.3, 14.7% respectively. 2) The tensile strength of ARSCTB was generally higher than that of CTB and positively correlated with the ARS content. The tensile strength increase rate was 24.1–34.2% at 28 days curing age. 3) The SEM test indicated that the ARS was wrapped by cement hydration products, which improves its connection with the ARSCTB matrix. ARS performed a bridging role, inhibited cracks propagation, and provided drag or pulling force for the block that is about to fall off. Therefore, the mechanical properties of ARSCTB were enhanced. However, under high ARS content, the inhibition of ARS on hydration reaction and the overlap between ARS were not conducive to the improvement of the UCS of ARSCTB. 4) The post-peak residual strength and integrity effect of ARSCTB were greater. It is recommended to add 0.1–0.2 wt% ARS to the backfill with high compressive strength requirements such as the empty field subsequent filling mining method and the artificial pillar. 0.3–0.4 wt% ARS is incorporated into backfill with high tensile strength requirements such as high-stage filling with lateral exposure and artificial roof. This study further makes up for the blank of the application of plant fiber in the field of mine filling and helps to improve the mechanical properties of backfill through low-cost materials.

The effects of TMP and filler stratifying on wet web runnability and end product quality of fine paper

2012 ◽  
Vol 27 (1) ◽  
pp. 130-136
Author(s):  
Antti Oksanen ◽  
Kristian Salminen ◽  
Jarmo Kouko ◽  
Elias Retulainen
Keyword(s):  
Mechanical Properties ◽  
Filler Content ◽  
Length Distribution ◽  
Fibre Length ◽  
Strength Properties ◽  
Raw Material ◽  
Paper Machine ◽  
Precipitated Calcium Carbonate ◽  
Purity Analysis

Abstract Increase of filler content in paper improves quality of the final product and reduces raw material costs. However, this is often accompanied by deterioration of paper machine runnability. In this paper the effects of stratifying PCC (precipitated calcium carbonate) and TMP on fine paper quality and the mechanical properties of dry and wet paper were studied. In addition, a new method was introduced for evaluating the layer purity of pulp and filler stratifying by measuring the fibre length distribution in the thickness direction of the paper. The filler addition reduced the mechanical properties of paper more with chemical than mechanical pulps, with similar dry tensile indices. Stratifying filler onto paper surfaces gave higher dry tensile strength properties than samples with mixed structures, whereas only a small positive effect was detected for wet tensile and relaxation properties as a result of stratifying. Stratifying fillers only had a small negative effect on the internal bond strength. Stratifying or mixing TMP with a chemical pulp blend was shown to enable an increase in the filler content of 10% without significant changes in the residual tension (tension after 0.475 s of relaxation) or tensile index of wet samples. Based on layer purity analysis, stratifying TMP and filler was found to be successful in these trials.

Tensile Strength of Filled SBR Vulcanizates

1959 ◽  
Vol 32 (3) ◽  
pp. 680-691
Author(s):  
F. Bueche
Keyword(s):  
Tensile Strength ◽  
Calcium Carbonate ◽  
Carbon Black ◽  
Strength Properties ◽  
Carbon Black Concentration ◽  
Molecular Behavior ◽  
Concentration Degree ◽  
Observed Behavior

Abstract The molecular behavior responsible for the observed tensile strength properties of unfilled rubbers has been studied in a recent paper from this laboratory. In the present paper we intend to extend that work to the case of rubbers which are filled with carbon black. Measurements of the tensile strength of hot and cold SBR as a function of carbon black concentration, degree of vulcanization, and temperature are reported. An attempt is made to interpret the observed behavior in terms of molecular concepts. Some additional measurements with resin and calcium carbonate fillers are shown to lend support to the conclusions reached.

scholarly journals Small Pilot System for the Manufacture of in Situ Precipitated Calcium Carbonate in the Presence of Pulp Fibers

2021 ◽  
pp. 118-123
Author(s):  
Klaus Dölle ◽  
Bardhyl Bajrami
Keyword(s):  
Calcium Carbonate ◽  
Calcium Hydroxide ◽  
Pilot Scale ◽  
Production Costs ◽  
Pulp Fiber ◽  
Paper Machine ◽  
Precipitated Calcium Carbonate ◽  
Paper Properties ◽  
Eucalyptus Pulp

Paper fillers materials are less expensive than fiber, allowing reduced production costs and improvement of paper properties. A small pilot scale in-situ laboratory calcium carbonate filler precipitation unit was developed and designed with the objective to provide enough pulp fiber containing in-situ precipitated calcium carbonate for a small 12-inch (304 mm) wide laboratory paper machine. The in-situ precipitation system requires the reactants calcium hydroxide and carbon dioxide and was tested with a eucalyptus pulp fiber pulp suspension. The final precipitated in-situ filler content achieved was 38.2%, 55.5% and 66.6% based on initial eucalyptus pulp fiber content. The precipitation time from an initial pH of 12.77, 12.76 and 11.98 to an final pH of 7.29, 7.55, and 7.28 for the 3 kg, 6kg, and 9 kg of calcium hydroxide reactant addition was 45 minutes for the 3 kg and 9 kg calcium hydroxide addition and 40 min. for the 6 kg calcium hydroxide addition.

Tensile Strength of Cu Sheets Welded by Ultrasonic Metal Welding

2013 ◽  
Vol 658 ◽  
pp. 202-208 ◽  
Author(s):  
Dong Sam Park ◽  
Ho Su Jang ◽  
Woo Yeol Park
Keyword(s):  
Tensile Strength ◽  
Manufacturing Industry ◽  
Ultrasonic Welding ◽  
Welding Parameters ◽  
Strength Increase ◽  
Ultrasonic Metal Welding ◽  
Experimental Parameters ◽  
Tensile Strength Increase ◽  
Metal Welding ◽  
Welding Pressure

This paper gives a description of an experimental study on the ultrasonic welding of metals. In ultrasonic metal welding, high frequency vibrations are combined with pressure to join two materials together quickly and securely, without generating large amount of heat. Horn, a key part of ultrasonic welding machine, should be designed very accurately to get the natural frequencies and vibration mode required. In this study, a horn is designed and developed for ultrasonic welding of Cu sheets. The tensile strength of welded parts is investigated for evaluation of weldability. Experimental parameters of welding test is set as follows; welding time 0.4s ~ 3.4sec. and vibration amplitude 40%, 60%, 80% and welding pressure 1.5bar, 2.0bar, 2.5bar. Samples are Cu sheets of 0.1mm thickness. Experimental results showed that the tensile strength increase as welding parameters increase, but when welding pressure is excessive, the tensile strength decrease due to fracture of the Cu sheets caused by over-welding. These results could be successfully applied for ultrasonic metal welding in various fields of manufacturing industry.

PBA/P (MMA-MAH) Core-Shell Particles Toughening Reinforced PA6

2013 ◽  
Vol 750-752 ◽  
pp. 136-139
Author(s):  
Wen Jie Mei ◽  
Yu Zhu Xiong ◽  
Zhen Yu Liu ◽  
Jin Zhong Luo
Keyword(s):  
Tensile Strength ◽  
Layer Structure ◽  
Butyl Ester ◽  
Core Shell ◽  
Strength Increase ◽  
The Core ◽  
Unique Nature ◽  
Shell Particles ◽  
Tensile Strength Increase ◽  
The Impact

Polyacrylic acid butyl ester (PBA) / poly (methyl methacrylate - maleic anhydride) [P(MMA-MAH)] was synthesized by emulsion polymerization. We got three core-shell particles of core-shell ratio 2/8,3/7 and 4/6 by the method, and blend them with PA6 in proportion of 5%,10% and 15%. Two-layer structure under the TEM proves the existence of core-shell particles, and the core-shell particles disperse uniformly under the SEM. The core-shell rate is 4/6 and PA6 ratio in the 10%, toughening effect is the best. The impact strength and tensile strength increase by 187% and 13.8% respectively, showing the unique nature of the core-shell particles.

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