摘要:

The increasing use of synthetic organic polymers as insulation for wire and cable has led to some concern regarding the flammability of these materials, which may contribute to propagation of an electrically initiated fire. An analysis of statistical data for 1977–1979 reported through the National Fire Incident Reporting System (NFIRS) to the National Fire Data Center of the U.S. Fire Administration [1] has revealed that wire and cable insulation is involved in 59% of the fire incidents in which a plastic material is ignited first, accounting for a considerable percentage of the “civilian injuries” recorded by the data system for plastic products' fires. Wire and cable insulation thus poses a significant, albeit unusual flammability hazard, as well as complex technical problems relating to the selection of materials and designs for improved flame resistance. The magnitude of these problems is reflected, for example, in the proceedings of workshops held under the aegis of the National Research Council, with contributions from many experts in the field. Technical reports covering these workshops have been issued by the National Materials Advisory Board [2] and by the Electric Power Research Institute [3], and they demonstrate that overviews of materials and technology employed in wire and cable insulation, and approaches to flame resistance, can provide only an introductory discussion of a difficult and multifaceted subject. In the context of these limitations, the present paper presents a brief review of the polymeric materials and flame retardants currently used in the industry, and of some advanced state-of-the-art approaches that have been developed to enhance fire resistance in wire and cable products.

ISSN:0360-2559    

DOI:10.1080/03602558208067716

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

For years, plastics processors have been attempting to make polymers resistant to UV light degradation through addition of carbon black or chemical UV inhibitors. However, with the advent of litter legislation to clean up the environment, many government officials, at the urging of environmentalists, have been tacking on laws which require the plastic rings connecting beverage cans to be either, bio, photo, or chemically degradable. Since spontaneous chemical degradation does not seem feasible and attempts to make plastics truly biodegradable have not been successful, photodegradation was explored, particularly since plastics are already susceptible to UV degradation. Now, relatively quick photodegradation has been achieved by copolymerizing ethylene and carbon monoxide. This results in a polymer having processing characteristics and physical properties similar to low density polyethylene.

ISSN:0360-2559    

DOI:10.1080/03602558208067717

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The service life of a machine component is determined by three factors-breakage, obsolescence, and wear. Most engineers have traditionally directed their attention to avoiding breakage since, once broken, the machine component ceases to function. The breakage usually has an immediate, and sometimes embarrassing, effect. Obsolescence occurs over a period of time and is usually accepted as a fait-accompli. With it comes an opportunity to buy

ISSN:0360-2559    

DOI:10.1080/03602558208067718

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

In 1980, plastic in the United States has overtaken steel on a volume basis as the dominant material. Though recycling of iron and steel goes back to the early years of United States history, plastics recycling is in its infancy. Today, plastics recycling is an urgent necessity as petrochemical raw materials, energy, and disposal become more costly.

ISSN:0360-2559    

DOI:10.1080/03602558208067719

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The role of aluminum trihydrate as an arc suppressant has long been recognized in the plastic industry. As early as 1953 an application by Jones and Wilkinson [29] was received at the U.S. Patent office for an arc-suppressing device. This consisted of a shield made up of an organic-type binder such as phenolic, urea, melamine, silicone, or polyester. With these binders were included asbestos along with aluminum, magnesium oxide, or hydrate as a filler. The study of Jones and Wilkinson showed that hydrates are more effective arc-suppressing substances than were oxides. Similar behavior was observed by Kessel and Norman [30] in electrical equipment subjected to contaminating atmospheric conditions such as moisture, dust, fog, and salt. This scrubbing action of aluminum trihydrate was described by Norman and Kessel as the most important function of this type of filler electrical application [31]. This use of aluminum trihydrate as an arc suppressant involves the release of the chemically combined water at a temperature of ∼250°C. All grades of aluminum trihydrate contain 3 moles of combined water per mole of alumina. When this water of hydration is released, the surface temperature is lowered, thereby reducing the tendency of the substance to carbonize and form a conductive path.

ISSN:0360-2559    

DOI:10.1080/03602558208067720

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Filament winding is a reinforced plastic process that employs a series of continuous resin impregnated fibers applied to a rotating mandrel in a predetermined geometrical relationship under controlled tension.

ISSN:0360-2559    

DOI:10.1080/03602558208067721

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The petrochemicals industry in India is just about 25 years old, the major milestone being the commencement of manufacture of the first thermoplastic, polystyrene, in 1957 with technical collaboration of Dow Chemical Co. U.S.A. The initial capacity of the plant was only 7500 tons/yr. This was followed by the manufacture of LDPE by I.C.I. and Union Carbide, HDPE in collaboration with Hoechst, and PVC in collaboration with Shell and a few other overseas companies. There is an installed capacity to manufacture 300,000 tons of the above plastics per year. Among the range of thermosets, PF, UF, MF, polyester, and epoxies are manufactured in the country.

ISSN:0360-2559    

DOI:10.1080/03602558208067722

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The application of various polymers, both synthetic and natural, for biomedical purposes has made such tremendous progress during the last two decades that a wide variety of biomaterials and blood-contacting devices are currently being used in cardiovascular, orthopaedic, and dental applications throughout the world. Implantation of heart valves, catheters, etc. has become more or less a routine affair in cardiovascular surgery. Most of these devices are being fabricated from polymers, and the basic requirements for developing such a biocompatible polymer are very rigid. It has to be sterilizable, nontoxic, easily fabricable, highly resistant to mechanical strains, should not produce allergy or hypersensitivity, not incite any inflammatory response, and also should not degrade chemically [1].

ISSN:0360-2559    

DOI:10.1080/03602558208067723

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0360-2559    

DOI:10.1080/03602558208067715

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor