scholarly journals Effects of phosphogypsum whiskers modification with calcium stearate and their impacts on properties of bleached softwood paper sheets

TAPPI Journal ◽  
2021 ◽  
Vol 20 (9) ◽  
pp. 567-578
Author(s):  
HAITANG LIU ◽  
XIN JIN ◽  
LIN CHEN ◽  
XIAOCHEN CHANG ◽  
JIE LI ◽  
...  

By combining the structural properties and characteristics of phosphogypsum whiskers, a preliminary study on the modification of phosphogypsum whiskers and their application in papermaking was carried out. The effects of reaction temperature, reaction time, and reaction concentration on the solubility and retention of modified phosphogypsum whiskers and the effects of phosphogypsum whiskers on the physical properties of paper under different modified conditions were explored. The research results show that, after the phosphogypsum whiskers are modified with calcium stearate, a coating layer will be formed on the surface of the whiskers, which effectively reduces the solubility of the phosphogypsum whiskers. The best modification conditions are: the amount of calcium stearate relative to the absolute dry mass of the phosphogypsum whisker is 2.00%; the modification time is 30 min, and the modification temperature is 60°C. The use of modified phosphogypsum whiskers for paper filling will slightly reduce the whiteness, folding resistance, burst resistance, and tensile strength of the paper, but the tearing degree and retention of the filler will be increased to some extent.

2019 ◽  
pp. 152808371987700 ◽  
Author(s):  
Laila Sajid ◽  
Oussama Azmami ◽  
Zakia El ahmadi ◽  
Abbès Benayada ◽  
Said Gmouh

The aim of this work is the production of new nonwovens materials based on wool, polyester and palm fibers ( Washingtonia). The extraction of palm fibers was achieved by the combination of alkaline and bleaching treatments. Chemical composition, mechanical and physical properties of the extracted fibers were first determined. Then, two types of blended nonwovens based on Palm/Wool (P/W) and Palm/Polyester (P/PES) mixtures were produced using the needling technique. The physical and structural properties of produced nonwovens were studied such as surface density, tensile strength, porosity and thermal properties. The results showed that the porosity lies between 83.81% and 86.93% for (P/W) mixtures and between 78.01% and 86.93% for (P/PES) mixtures. The air permeability was found to be between 61.56 m3.m−2.min−1 and 129.01 m3.m−2.min−1 for P/W blend nonwovens and between 22.75 m3.m−2.min−1 and 129.01 m3.m−2.min−1 for P/PES blend ones. The thermal conductivity varies between 36.45 mW/m.K and 43.88 mW/m.K for P/W nonwovens and between 36.45 mW/m.K and 47.70 mW/m.K for P/PES nonwovens. Moreover, the tensile strength of blended nonwovens is found to be higher than that of non-blended ones.


1977 ◽  
Vol 47 (9) ◽  
pp. 584-590 ◽  
Author(s):  
G. M. Venkatesh ◽  
R. J. Berni ◽  
W. F. McSherry ◽  
A. R. Markezich

Core crosslinking has been shown to enhance abrasion resistance; the extent of improvement depends on the method employed to remove the surface resin. To better understand the relationship between types of crosslinking and abrasion resistance and other physical properties, resin-treated fabrics were produced by pad-dry-cure, core crosslinking, and skin crosslinking techniques. At comparable bound-resin levels the core-crosslinked fabrics, especially those produced by treatment with ammonia gas, exhibit higher abrasion resistance and tear and tensile strength, with little sacrifice in crease recovery or tensile recovery, than do the pad-dry-cure and skin-crosslinked fabrics.


TAPPI Journal ◽  
2011 ◽  
Vol 10 (7) ◽  
pp. 29-34
Author(s):  
TEEMU PUHAKKA ◽  
ISKO KAJANTO ◽  
NINA PYKÄLÄINEN

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.


Alloy Digest ◽  
2007 ◽  
Vol 56 (2) ◽  

Abstract Durimphy is a maraging steel with 1724 MPa (250 ksi) tensile strength and a very high yield strength due to precipitation hardening. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: FE-140. Producer or source: Metalimphy Precision Alloys.


Alloy Digest ◽  
1981 ◽  
Vol 30 (8) ◽  

Abstract CENTRI-CAST GRAY IRON 50 is a centrifugally cast gray iron with a nominal tensile strength of 50,000 psi. It is cast in the form of tubing which has a wide range of uses in applications where size and shape are of paramount importance and freedom from pattern cost is an important consideration. Among its many applications are farm machinery, seals, bushings, machine tools and general machinery uses. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, tensile properties, and compressive and shear strength as well as fatigue. It also includes information on casting, heat treating, machining, and surface treatment. Filing Code: CI-51. Producer or source: Federal Bronze Products Inc..


Alloy Digest ◽  
1979 ◽  
Vol 28 (9) ◽  

Abstract CENTRI-CAST GRAY IRON 55 is a centrifugally cast gray iron with a nominal tensile strength of 55,000 psi. It is produced in the form of tubing which has a wide range of uses in applications where size and shape are of paramount importance and freedom from pattern cost is an important consideration. Typical applications are seals, bushings, farm machinery, casings and general machinery uses. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, tensile properties, and compressive and shear strength as well as fatigue. It also includes information on casting, heat treating, machining, and surface treatment. Filing Code: CI-48. Producer or source: Federal Bronze Products Inc..


Alloy Digest ◽  
2011 ◽  
Vol 60 (8) ◽  

Abstract Wieland-FX9 is a high-manganese bronze alloy that has good strength and is available in numerous cold work tempers related to its minimum tensile strength. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: Cu-801. Producer or source: Wieland Metals Inc..


Alloy Digest ◽  
2010 ◽  
Vol 59 (12) ◽  

Abstract Dogal 600 and 800 DP are high-strength steels with a microstructure that contains ferrite, which is soft and formable, and martensite, which is hard and contributes to the strength of the steel. The designation relates to the lowest tensile strength. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on forming, joining, and surface treatment. Filing Code: CS-160. Producer or source: SSAB Swedish Steel Inc. and SSAB Swedish Steel.


Alloy Digest ◽  
1969 ◽  
Vol 18 (12) ◽  

Abstract Columbium 15W-5 Mo- 1Zr is a columbium-base alloy capable of retaining usuable structural properties up to 2500 F. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Cb-17. Producer or source: Fansteel Metallurgical Corporation.


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