Fine fillers

Summary This chapter describes research into magnetic silicone composite properties. The main components of this composite are silicone matrix and magnetic fillers (fine iron and ferrite powders). Composites with changing elasticity can be obtained by modifying matrix composition and the content of fillers. These products are smart materials , and it can be expected that they will have wide application in electronics and electrical engineering... 

Fillers Finely dissolved solids added to polymer systems Calcium carbonate, kaolin, talc, alumina... 

Poor retention of fillers and fines caused by the poor retention and/or wet-end imbalance can also result in deposits of filler/fines/size at the presses and press felts and pre-dryer doctor blades. 

This is a fines/filler retention related problem. Fines/fiUer are removed from the sheet on the wire and as they have size attached to them the size will be proportionally greater in the top side of the sheet. This will give harder sizing on the top side. The solution is to improve the filler/fines retention. This may involve an ionic imbalance, use of a more efficient retention system, or even reduction of wire vacuums and foils. 

The term retention refers to the holding back of the components of the stock during dewatering. The fibers are retained on the wire whereas fillers, fines, and additives of colloidal size may be washed through the mat formed... 

As a medical product in work used antibacterial means furacilinum (m.f.). Filler fine grained schimgite technical specifications 2169-001-5773937-natural formation, on 30% consisting of carbon and 70% of silicates, the Zagozhinsky deposit [4]. 

Add hard fillers (fine furnace blacks or silicas)... 

The introduction of chemical cross-links into an uncross-linked polymer converts it from a viscoelastic liquid to a viscoelastic solid in the sense of the definitions of Chapter 1 and the classification of Chapter 2 the viscosity becomes infinite and the material acquires an equilibrium modulus and compliance, so the properties in the plateau and terminal zones change profoundly. However, the properties in the transition zone may change very little. The effects of cross-linking are discussed in this chapter, as well as the effects in the plateau and terminal zones of incorporating fillers (finely divided particles, usually of high modulus) or other combinations of more than one phase. 

The abrasion potential of fillers is influenced by the particle stracture, the particle fineness and the particle hardness. Relatively coarse platy pigments tend to be less abrasive than non-platy ones of similar size. Increasing the filler fineness decreases the wire abrasion potential significantly. This is particularly pronounced when testing non-platy pigments. Large size non-platy impurities such as quartz increase the wire abrasion excessively. Any pigment which is harder than the synthetic wire, commonly installed in the paper machine, potentially initiates wear on the wire. 

---