scholarly journals The rheology and microstructure of acicular precipitated calcium carbonate colloidal suspensions through the shear thickening transition

2005 ◽  
Vol 49 (3) ◽  
pp. 719-746 ◽  
Author(s):  
Ronald G. Egres ◽  
Norman J. Wagner
Keyword(s):  
Calcium Carbonate ◽  
Shear Thickening ◽  
Colloidal Suspensions ◽  
Precipitated Calcium Carbonate

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.

Transjøen, a Groundwater Influenced Lake with Special Redox and Sulphate Conditions

1976 ◽  
Vol 7 (5) ◽  
pp. 307-320 ◽  
Author(s):  
G. S. Bremmeng ◽  
A. E. Kloster
Keyword(s):  
Calcium Carbonate ◽  
Chemical Composition ◽  
Lower Layer ◽  
Calcium Content ◽  
Meromictic Lake ◽  
Redox Potentials ◽  
Precipitated Calcium Carbonate

Transjøen, a lake in S.E. Norway investigated hydrographically from October 1969 to October 1971, consists of two basins, both of which are meromictic (lake with lower layer which does not participate in the periodic circulations). The lake has a large influx of groundwater of very varying chemical composition. The calcium content is high and precipitated calcium carbonate and electrolyte rich groundwater is assumed to be the main reason for the meromictic stability. The redox potentials of monimolimnion (the lower layer which does not participtate in the periodic circulation) are extremely low, but in spite of this fact the content of sulphate is high.

scholarly journals Shear thickening behavior in dense repulsive and attractive suspensions of hard spheres

Soft Matter ◽  
2021 ◽  
Author(s):  
Vikram Rathee ◽  
Alessandro Monti ◽  
Marco Edoardo Rosti ◽  
Amy Q Shen
Keyword(s):  
Flow Curve ◽  
Hard Spheres ◽  
Shear Thickening ◽  
Colloidal Suspensions ◽  
Thickening Behavior ◽  
The Stability

Shear thickening in stable dense colloidal suspensions is a reversible phenomenon and no hysteresis is observed in the flow curve measurements. However, a reduction in the stability of colloids promotes...

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