Applications for Plastics

In recent years a whole new generation of high performance engineering plastics have become commercially available. These offer properties far superior to anything available so far, particularly in regard to high temperature performance, and they open the door to completely new types of application for plastics. 

In structural applications for plastics, which generally include those in which the product has to resist substantial static and/or dynamic loads, it may appear that one of the problem design areas for many plastics is their low modulus of elasticity. The moduli of unfilled plastics are usually under 1 x 106 psi (6.9 x 103 MPa) as compared to materials such as metals and ceramics where the range is usually 10 to 40 x 106 psi (6.9 to 28 x 104 MPa). However with reinforced plastics (RPs) the high moduli of metals are reached and even surpassed as summarized in Fig. 2-6. 

This chapter reviews the design of different current and potential applications for plastics. Plastics are used uniquely in these applications because of factors such as availability of their extensive capability in material modifications to meet specific material and processing requirements. By incorporating some innate behaviors of the materials and adapting them to operate in unusual environments, low cost products are produced as well as some of the most significant and sophisticated problems of man-kind are being solved by the use of plastics. 

Capacitor There are several applications for plastics in electrical devices that use the intrinsic characteristics of the plastics for the effect on the electrical circuit. The most obvious of these is the use of plastics particularly in the form of thin films as the dielectric in capacitors. TP polyester films such as Mylar are especially useful for this type of application because of the high dielectric strength in conjunction with a good dielectric constant. 

Electret Another application for plastics which uses the intrinsic properties is in elec-trets (a dielectric body in which a permanent state of electric polarization has been set up). Some materials such as highly polar plastics can be cooled from the melt under an intense electrical field and develop a permanent electrical field that is constantly on or constantly renewable. 

A number of areas in which plastics are used in electrical and electronic design have been covered there are many more. Examples include fiber optics, computer hardware and software, radomes for radar transmitters, sound transmitters, and appliances. Reviewed were the basic use and behavior for plastics as an insulator or as a dielectric material and applying design parameters. The effect of field intensity, frequency, environmental effects, temperature, and time were reviewed as part of the design process. Several special applications for plastics based on intrinsic properties of plastics materials were also reviewed. 

The application for plastics most widely known, based on the transparency and clarity of plastics, is their use as a window or... 

The ophthalmic applications for plastics lenses include contact lenses which are now made of acrylic plastics. Another material for this application is a special hydrophillic acrylic polymer used in soft contact lenses. These lenses are much more comfortable than rigid contact lenses. 

There are two major areas of application for plastics in bioscience. The plastics make interesting materials to be used for... 

Plastics have a unique contribution to make in exploring new environments. Their applications in space vehicles are well known and are generally of a mechanical nature. Plastics are used extensively in equipment for exploring under the sea. One unique application for plastics used in the sea environment and which is important in other areas that range from packaging to space is in filtering... 

Another important application for plastics is thermal insulation. Without plastic insulation, major appliances would consume 30-50% more energy. From 1972 to 1995, the energy consumption of major appliances decreased by up to 40%, and energy efficiency increased 50-100% (19). 

One final thought before the minefield is tackled management codes are guidelines only and differing opinions and business pressures can cause considerable discussion inside companies. It is possible for untrained or very focused minds to err from the path of righteousness and for the sake of our industry I urge real caution in this area. There are many examples of both deliberate and accidental errors in the area of food contact application for plastics and none of them are justifiable if the spirit of Responsible Care, product stewardship and consumer safety become, as they should be, the number one priority in a company. 

While the relatively young polymer industry was learning much from the modification of natural polymers, production figures were small. As the purely synthetic polymers came on stream, the range of valuable applications for plastic materials rapidly increased. Today, the annual mass of polymeric... 

By 1985, it has been predicted that interior applications for plastics will amount to 108 lb./car and exterior applications for plastics, to 154 lb./car, giving a total of 262 lb./ car (excluding under the hood applications), of the exterior applications it can be expected that the combined RIM and RRIM markets for steel replacement will amount to approximately 7% of the total and 12% of the exterior applications. 

Engineering plastics, particularly thermosets, are also used in composite materials. Their excellent technological properties make them suitable for applications in cars, ships, aircraft, telecommunications equipment, etc. In recent years, important new areas of application for plastics have emerged in medicine (fabrication of artificial organs, orthopaedic implants, and devices for the controlled release of drugs), electronics (development of conductive poly-... 

Selecting, combining and matching colors is a complicated art that only well-trained individuals are able to perform correctly. There are hundreds of different colorants used in the plastic industry, and there are as many types of colorants as different applications for plastics. Similarly to measurement of optical properties of paper and paperboard, the characterization of a color for plastics is based on the measurement of color (hue), brightness, and opacity. Other important variables to be considered in colorant selection include dispersability in the plastic, migration, toxicity, light stability, and chemical resistance. 

World War II increased both the demand and the number of applications for plastics. Just prior to the war, plastics were not only developed as substitutes for materials which were in short supply, notably rubber and gutta percha, but also to out-perform the then available plastics. Wartime demands encouraged scientists to develop polymers that could meet the demands of the military, electronics and food industries. Before 1940, plastics had mainly been used to make decorative and ephemeral pieces, but the war demanded more performance-based... 

High torque and high speed applications for plastics compounding High volume applications for adhesives, sealants, chemicals... 

One of the applications for plastic materials is to resist atmospheric corrosion. In addition to being able to resist attack by specific corrodents in plant operations, they are also able to resist corrosive fumes that may be present in the atmosphere. Table 2.5 provides the resistance of the more common thermoplasts to various atmospheric pollutants, and Table 2.6 gives the allowable temperature range for thermoplastic polymers. 

Traditionally, incineration has been used to reduce waste volume. It has also been used to produce inert residuals from hazardous waste. Emissions in the form of combustion gases and solid residuals from conventional incinerators have lead to much resistance to the widespread use of incineration. Nowadays, incineration technology is available which avoids the production of such emissions [25]. It would seem that the use of clean combustion technology to recover energy from waste otherwise destined to landfill has been accepted by European governments in and attempt to reduce landfill [57]. Two of the applications for plastics waste under investigation are the co-combustion of plastics waste with municipal solid waste as the main fuel and the use of... 

Large body of information is available on the plasticization of cellulose acetate beearrse of the long history of the polymers and the wide spread applications for plasticized eellrrlose acetate. " The following plasticizers and plasticizing compounds are frequently rrsed ... 

Ease of processing is an important advantage in all branches of polymer technology, and one that has been important in developing applications for plasticized PVC Unlike the more conventional rubbers listed above, plasticized PVC is a thermoplastic elastomer, which can be extruded, calendered, or melt-coated on to fabrics and other substrates. Without the support of a fabric or other base, it suffers from a relatively low tensile strength and tear resistance. On the other hand, it is a good electrical insulator, and is inexpensive there is little difference in price between plasticized and unplasticized grades of PVC. Applications include cable insulation and interior trim for cars. 

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