Applications advantages over plastics

Thermoplastic elastomers have now been available for over 30 years and the writer recalls organising a conference on these materials in 1969. In spite of considerable publicity since that time these materials still only comprise about 5-10% of the rubber market (equivalent to about 1-2% of total plastics consumption). It is important to appreciate that simply being a thermoplastic material (and hence being processed and reprocessed like a thermoplastic plastics material) is not enough to ensure widespread application. Crucially the material must have acceptable properties for a potential end-use and at a finished product price advantageous over other materials. 

No one steel exceeds the tensile modulus of mild steel. Therefore, in applications in which rigidity is a limiting factor for design (e.g., for storage tanks and distillation columns), high-strength steels have no advantage over mild steel. Stress concentrations in mild steel structures are relieved by plastic flow and are not as critical in other, less-ductile steels. 

Sensors incorporating glass or plastic optical fibers have demonstrated several advantages over electrosensors for biomedical applications. These sensors involve no electrical connections and hence are safe from that standpoint the leads are quite small and flexible they can be incorporated in catheters for multiple sensing where required, they can be implanted for relatively long periods. The fibers are considerably less than 1 millimeter in diameter. Where designed for simplicity, they often can be considered disposable. 

The application of ceramics has infiltrated almost all fields in the last 20 years, because of their advantages over metals due to their strong ionic or covalent bonding. But it is just this bonding nature of ceramics that directly results in their inherent brittleness and difficulty in machining. In other words, ceramics show hardly any macroscopic plasticity at room temperature or at low temperatures like metals. Hence, superplasticity at room temperature is a research objective for structural ceramics. In recent years, many researches have been carried out to investigate nanophase ceramic composites. 

Polyurethanes have several advantages over competing material in the materials field. The major items of competition are metal, other plastics, and rubbers. Ceramics offer some competition to urethanes. Each of the above groups of materials, including polyurethanes, requires its own design adjustments for successful use in any application. 

Similar to these hard plastic applications, the use of elastomers has a number of advantages over silicon as biosensor housing material. Besides fabrication cost and brittleness as described above (PDMS is about 50 times less expensive than siUcon on a per volume basis), moving parts are extremely difficult to make in the stiff silicon material without increasing the overall size significantly. Also, valves, which will be discussed in more detail below, need a soft material as valve seat to close completely (thus, elastomers have to be... 

There is increasing interest in the application of reinforced plastics for metal replacement in the automotive industry to reduce weight and cost. In some applications, reinforced plastics also oner performance advantages over metal. Although the automotive industry is greatly depressed at the present time, a recent report indicates an 11.6% annual growth rate for reinforced plastics in cars and trucks in the next five years (8). 

IMPREGNATION OF SOFT SOUND WOOD WITH MONOMERS, which are then polymerized in situ by 7 radiation, was a method used in many laboratories during the 1960s in an effort to obtain wood-plastic composites. The process was attractive in two respects there was a large choice of consolidants, and radiation-induced polymerization had many advantages. Various vinyl monomers are cured by 7 rays. By proper selection of the polymer or copolymer, materials can be tailor made for specific applications. The radiation process presents several advantages over the chemically catalyzed polymerization of monomers in wood. 

Plastics offer several advantages over traditional materials in automotive applications, namely ... 

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