Uses of Fillers

Fillers are used for packaging, mainly for food. These are used to fill either a bottle or a pouch, depending on the product. There are several types of fillers used by the packaging industry, those listed below are the most common. 

Using adsorptive properties, explain the application of clay minerals in medicine. 

In aesthetic medicines, what is the usefiilness of clay minerals. 

Abdel-Halim, Rabie E. (2006). Contributions of Muhadhdhab Al-Eteen Al-Baghdadi to the progress of medicine and urology. Saudi Medical Journal, 27(11) 1631-1641. 

Addison, K., Braden, J.H., Cupp, J.E., Emmert, D. et al. (2005). (AHIMAe-HIM Work Group on the Legal Health Record) Update Guidelines for Defining the Legal 

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Although the use of simple diluents and adulterants almost certainly predates recorded history, the use of fillers to modify the properties of a composition can be traced as far back as eady Roman times, when artisans used ground marble in lime plaster, frescoes, and po22olanic mortar. The use of fillers in paper and paper coatings made its appearance in the mid-nineteenth century. Functional fillers, which introduce new properties into a composition rather than modify pre-existing properties, were commercially developed eady in the twentieth century when Goodrich added carbon black to mbber and Baekeland formulated phenol— formaldehyde plastics with wood dour. 

Fillers. These are used to reduce cost in flexible PVC compounds. It is also possible to improve specific properties such as insulation resistance, yellowing in sunlight, scuff resistance, and heat deformation with the use of fillers (qv). Typical filler types used in PVC are calcium carbonate, clays, siHca, titanium dioxide, and carbon black. 

For many electronic and electrical appHcations, electrically conductive resias are required. Most polymeric resias exhibit high levels of electrical resistivity. Conductivity can be improved, however, by the judicious use of fillers eg, in epoxy, silver (in either flake or powdered form) is used as a filler. Sometimes other fillers such as copper are also used, but result in reduced efficiency. The popularity of silver is due to the absence of the oxide layer formation, which imparts electrical insulating characteristics. Consequently, metallic fibers such as aluminum are rarely considered for this appHcation. 

Of these methods the first gives only marginal improvements whilst the second approach has far too severe an effect on the softening point to be of any commercial value. The use of fillers has been practised to some extent in the United States but is not of importance in Europe. Deliberate orientation is limited to filament and sheet. 

During the past 30 years considerable research has been undertaken that has led to electrically conducting polymers that do not rely on the use of fillers, the so-called intrinsically conductive polymers. Such polymers depend on the presence of particles which can transport or carry an electric charge. Two types may be distinguished ... 

Another advantage of the addition of inorganic filler is the significant increase in density of the silicone, which helps the dispensing process. The use of fillers also reduces the total cost of the product, as the expensive high performance silicone does not require 100% volume occupancy to fulfil its function. 

The main reasons for this lie in feasibility. Conducting fillers are rather expensive and their use increases the cost of an article. Besides, filled polymers have worse physical-mechanical properties, especially impact strength and flexural modulus. The use of fillers is also detrimental to the articles appearance and calls for additional treatment. The continuous development of electronics has also contributed to a loss of interest to conducting composites as screening materials the improvement of components and circuits of devices made it possible to reduce currents consumed and, thereby, noise level a so called can method is practised on a wide scale in order to cover the most sensitive or noisy sections of a circuit with metal housings [14]. 

There are different techniques that have been used for over a century to increase the modulus of elasticity of plastics. Orientation or the use of fillers and/or reinforcements such as RPs can modify the plastic. There is also the popular and extensively used approach of using geometrical design shapes that makes the best use of materials to improve stiffness even though it has a low modulus. Structural shapes that are applicable to all materials include shells, sandwich structures, and folded plate structures (Fig. 3-8). These widely used shapes employed include other shapes such as dimple sheet surfaces. They improve the flexural stiffness in one or more directions. 

Source R. Bown, Physical and Chemical Aspects of the Use of Fillers in Paper , in Paper Chemistry , ed. 

Table 6.2 Theoretical multiplication factors for anisometric particles with an aspect ratio r 1. (Note For a disc-shaped particle the aspect ratio is the ratio of disc diameter disk thickness and for a rod-shaped particle it is the ratio of rod length rod diameter). (Source R. Bown, Physical and Chemical Aspects of the Use of Fillers in Paper , in Paper Chemistry , ed. J.C. Roberts, Blackie, Glasgow, 1992, pp. 162-196).

Retention and drainage aids are chemicals which are added to the fibre and filler suspension to assist the efficiency of the filtration process. Growth in recent years in the use of retention aids has been greater than that of almost any other paper chemical additive. It has been caused by a combination of factors increased machine speeds, the increased use of filler in alkaline systems, the increased use of recycled paper and the growing tendency to use fillers in newsprint. Retention aids are water-soluble polymers which may be cationic,... 

A minimum shrinkage of 5% or less, more typically 1% or less, has been specified in order to maintain excellent seal transference in the cured mass. This requirement has been met through much experimentation involving various levels of filler. Fillers typically result in lower shrinkage with lower bulk viscosity. Fillers also present difficulty in this application due to the inherent problem presented by a fibrous mass with its high surface area. The present formulation has avoided the use of fillers. 

The need to minimise production costs and hence the selling price of mineral fillers is a dominant theme running through the technology. Although compound cost reduction was one of the principal reasons for using fillers in the past, this is of less importance now, due to the fall in the cost of the commodity thermoplastics. Indeed, the cost in use of fillers (taking into account volume costs and the cost of incorporation) can now lead to a rise in overall compound costs and it is often the minimisation of this cost increase that has become important. 

One of the emerging technologies that is showing great promise is the use of hydrated mineral fillers such as aluminium and magnesium hydroxides, as such materials can provide high levels of flame retardancy without the formation of smoke or corrosive and potentially toxic fumes. The use of fillers as flame retardants has recently been reviewed by Rothon [23]. Essentially the key features are an endothermic decomposition to reduce the temperature, the release of an inert gas to dilute the combustion gases and the formation of an oxide layer to insulate the polymer and to trap and oxidise soot precursors. 

KatzHS,MUewski JV (1987) Introduction and guide for the selection and use of fillers. In Katz HS, MUewski JV (ed) Handbook of fillers for plastics. Van Nostrand, New York,... 

Uses of Fillers, Reinforcing Agents, and Chemical Additives... 

Compounds for oil field service typically have higher compression set values due to use of fillers and compounding ingredients dictated by the oil field service requirements. 

The modification of plastics with inert fillers of various kinds is long-established, particularly with thermosetting materials. The use of fillers and reinforcements now also is frequent practice with thermoplastics, not only for making items in the field of engineering2 but also for the more common products. 

Fillers are relatively nonadhesive substances added to the adhesive formulation to improve its working properties, strength, permanence, or other qualities. The improvements resulting from the use of fillers are listed in Table 1.8. Fillers are also used to reduce material cost. By selective use of fillers, the properties of an adhesive can be changed significantly. Thermal expansion, electrical and thermal conduction, shrinkage, viscosity, and thermal resistance are only a few properties that can be modified by the use of fillers. Common fillers are wood flour, silica, alumina, titanium oxide, metal powders, china clay and earth, slate dust, and glass fibers. Some fillers may act as extenders. 

TABLE 1.8 Adhesive Properties That Can Be Modified by the Use of Fillers... 

Fillers and extenders are used in epoxy adhesive formulations to improve properties and to lower cost. Properties that can be selectively improved include both the processing properties of the adhesive as well as its performance properties in a cured joint. However, the use of fillers can also impair certain properties. Typically, the formulator has to balance the improvements against property decline. The advantages and disadvantages of filler addition in epoxy formulations are listed in Table 9.1. Common fillers used in epoxy formulations and the properties that they are used to modify are shown in Table 9.2. 

An improvement in strength can allow a potential reduction in refining. Usually, any strength increase in an alkaline sheet is taken not as a reduction in refining but rather as a quality improvement or offset in some other area such as increased use of filler or cheaper fiber. 

Another important distinction is based on (1) filled and reinforced plastics, and (2) foams. (1) When any family of polymers is combined with particulate inorganic fillers, this produces major increase in density, modulus, dimensional stability, heat transfer, dielectric constant, and opacity, and frequently a decrease in cost. When the fillers are reinforcing fibers, they can further produce a great increase in strength, impact resistance, and dimensional stability. Thus, these properties may depend more upon the use of fillers and fibers, than upon the choice of the particular polymer in which they are used. 

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