Fillers particle sizes

For large amounts of fillers, the maximum theoretical loading with known filler particle size distributions can be estimated. This method (8) assumes efficient packing, ie, the voids between particles are occupied by smaller particles and the voids between the smaller particles are occupied by stiH smaller particles. Thus a very wide filler psd results in a minimum void volume or maximum packing. To get from maximum packing to maximum loading, it is only necessary to express the maximum loading in terms of the minimum amount of binder that fills the interstitial voids and becomes adsorbed on the surface of the filler. 

The abihty of fillers to improve paper brightness increases with their intrinsic brightness, surface area, and refractive index. According to the Mie theory, this abiUty is maximum at an optimum filler particle size, about 0.25 pm in most cases, where the filler particle size is roughly one-half the wavelength of light used for the observation. 

This is the probability that failure will occur due to the propagation of one tip of the initial defect c under stress o, where is the critical stress intensity factor of the filler particle and a is the filler particle size. 

Chow demonstrated theoretically [143] that for anisodiametrical particles, the ultimate tensile stress is inversely proportional to square root of the effective or characteristic filler particle size (in this case by effective particle size the ratio of particle volume to surface area is implied). 

Effect of Filler Particle Size and Shape on the Rheological Properties of Composites... 

It is well known that the particle size, structure, and surface characteristics are important parameters that determine the reinforcing ability of filler particle size is important because a reduction in size... 

Filler Particle size (mass %) n2bet surface area (m2/g)... 

Fig. 3. Effect of filler particle size on the adhesion and shear forces acting during the homogenization of PP/CaC03 composites. Symbols (O) shear, (A) adhesion [25]... 

Figure I. Reinforcement of silicone gums by carbon blacks (including nonrreinforcmg NR), silica powder (both surface-treated T and untreated NT), and titanium dioxide. The increase in modulus per unit dose and filler concentration depends on filler particle size.

This property depends on filler particle size and filler loading. Higher filler loading gives lower resilience. Rubber type plays a great role here in that no synthetic rubber can match the characteristic of high resilience of natural rubber. 

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