Commercial products, radiation processing

Nevertheless, the field of radiation processing is growing, and an increasing number of products or processing methods are achieving commercial status (3). With increasing awareness and confidence by both the processor and the consumer in the use and safety of radiation sources and facilities, as well as of the end product, the field of process radiation is assured a further growth. In the field of food irradiation, for instance, the... 

Radiation Process. Commercial production of wood-polymer composites began in the mid 1960 s using the radiation process. 

Presentations by D. Meisel, G. Hug and J. LaVeme, underscored the relationship between fundamental research in radiation mechanisms and the emerging uses in applied technology.. Investigations into the concerns over hydrogen gas evolution and other by-products involved in nuclear waste storage were found to shed light on mechanisms found in commercially viable uses of radiation processing. 

Principles and Characteristics As already indicated in Chp. 1.2.3, Raman scattering induced by radiation (UV/VIS/NIR lasers) in gas, liquid or solid samples contains information about molecular vibrations. Raman specfioscopy (RS) was restricted for a long time primarily to academic research and was a technique rarely used outside the research laboratory. Within an industrial spectroscopy laboratory, two of the more significant advances in recent years have been the allying of FT-Raman and FTIR capabilities, coupled with the availability of multivariate data analysis software. Raman process control (in-line, on-line, in situ, onsite) is now taking off with various robust commercial instrumental systems equipped with stable laser sources, stable and sensitive CCD detectors, inexpensive fibre optics, etc. With easy interfacing with process streams and easy multiplexing with normal (remote) spectrometers the technique is expected to have impact on product and process quality. 

The bulk of worldwide annual commercial production of ethylene is based on steam cracking. In this petrochemical process saturated hydrocarbons are broken down into smaller, often unsaturated, hydrocarbons. It is the principal industrial method for producing lighter alkenes, mainly ethylene and propylene. The steam cracking operation involves heating the hydrocarbon (ethane, propane, butane, naphtha or gas oil) in radiant coils in the presence of steam in a furnace. The heat is transferred to the coils by radiation. This technology has been commercially practiced since early 1940s. Hydrocarbon feed is heated with steam up to 1050°C and fed to Cr-Ni reactor tubes. Cracked products exit at 850°C and are rapidly quenched to 300°C to prevent secondary reactions. The product is scrubbed to remove H S and CO, and then dried. and Cj components are separated by low temperature fractional distillation. 

One of the most important properties of commercial glasses is their great resistance to corrosion any chemical laboratory apparatus, any window or windscreen provides an excellent illustration. Windows remain virtually unchanged for centuries, resisting the influences of atmosphere and radiation. A vast range of products may be safely stored in glass for decades at ordinary temperatures, and the fact that gleiss can be used with alkaline, neutral and acid environments allows the same equipment to be used for a variety of processes. 

After aflatoxin contamination, perhaps the next most important factor that has a negative effect on human health and food quality is the presence of food borne bacteria. Several routes for reduction of the risk are currently under extensive investigation. One such means of risk reduction is the utilization of ionizing radiation treatments on meat food products. Ionizing radiation has been demonstrated to be an effective method to reduce or eliminate several species of food borne human pathogens such as Salmonella, Campylobacter, Listeria, Trichinella, and Yersinia Chapter 23). If proper processing conditions are used, it is possible to produce high quality, shelf-stable, commercially sterile muscle foods. 

Larger 3- and 4-m.e.v. Dynamitron electron beam accelerators are likewise available commercially. Service capabilities increase with the m.e.v. level of the electron beam accelerator. A 3.0-m.e.v. Dynamitron electron beam accelerator furnishes radiation capable of penetrating a maximum 370 mils of a unit density material or 185 mils of 2.0-density material other performance capabilities are doubled as well. The overwhelming majority of polyolefin plastic products now being manufactured have section thicknesses which can be penetrated safely even by a 1.5-m.e.v. electron beam accelerator. Two possible exceptions would be printed circuit board and thick-walled pipe. A 3-m.e.v. accelerator could readily meet such requirements. The performance capabilities of the 3-m.e.v. accelerator (12-ma. power supply) are increased not only with respect to maximum depth of penetration but also processing capability, which amounts to 14,000 megarad-pounds per hour at 50% absorption efficiency. 

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