Binder penetration

Changes in particle-size distribution affect the pore distribution of the powder. Large pores between particles enhance the rate of binder penetration, whereas they decrease the final extent. In addition, the particle-size distribution affects the ability of the particles to pack within the drop as well as the final degree of saturation [Waldie, Chem. Engin. ScL, 46,2781 (1991)]. 

Heterodisperse extenders have a smaller binder requirement than homodisperse extenders because their interstices can be filled with fine particles. In homodisperse systems the binder penetrates the interstices. 

The number range for each sample is the binder penetration grade, and the small peak at zero time is a polystyrene standard. (Reproduced from Reference 31, p. 29, by courtesy of... 

Deposition of carbon inside the pores of activated carbons or various carbonized materials though the carbonization of additives, such as resins, coal tar pitch and sulfate pulp waste liquor [32,33,38,39], to reduce pore size. In these processes the starting material is ground and the powder is mixed with the appropriate binder and extruded in the form of pellets. Pellets are then heated to temperatures up to 1000°C. In this way, the binder penetrates the surface of the starting material and decomposes to form a carbon crystallite, growing on the inner surface, thus improving selectivity to gas mixtures. 

A test method was designed in NWSP 150.1.R0 (15) (equivalent to ASTM D5908-96) to analyse polyester nonwoven fabrics for resin binder distribution and binder penetration. 

A specimen of the nonwoven fabric (in full width and 0.6 m in length) was dyed in a dye (C.I. Basic Red 14) solution of 60 L with a concentration of 0.2% at 120—140°F for 15 min. After resin and dry, the stained specimen is examined and rated for binder distribution on the nonwoven fabric surface and binder penetration through the fabric thickness by comparison to photographic rating standards, using the binder... 

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