Microwave-oven market

A choice of spheres is represented by two ovals, as shown in Figure 18.3. The first covers all the products sold in the Korean market. The second shows one sphere for microwave ovens sold in North America, Latin America, and Europe. One sphere is product-centric another is market-centric. The other dimension, operations, would also need to be defined. For our Korean sphere, it would presumably include all local production facilities that support the market. For the microwave-oven market, it would encompass the existing source for those markets. 

Galanz US 1 billion Home appliances (microwaves, air conditioners, electric rice cookers, electric fans) 30% 40% of Europe s microwave oven market... 

The use of inverter-type power suppHes (63) in place of doubler-type 6O-H2 suppHes results in significant reduction in the weight of microwave ovens. Disadvantages are primarily cost for the consumer market in addition to somewhat less efficiency and increased noise. Their use in commercial or industrial equipment is more attractive. 

A further substantial development, although not on the scale of the bottle and film markets, had been the use of thermoformed PET sheet for menu trays. The high heat distortion temperature of 220°C allows these products to be used in both traditional and microwave ovens. 

It all started almost 60 years ago when P. Spencer, studying high-power microwave sources for radar applications, observed the melting of a chocolate bar in his pocket at least that is the story told. The first patent in this field was filed by him in 1946 and one year later the first commercial microwave oven appeared on the market. We had to wait until 1955 for domestic models, but by 1976 almost 60% of US households already had a microwave oven. 

The domestic microwave oven is a serendipitous invention. Percy Spencer was working for Raytheon, a company heavily involved with radar during World War II, when he noticed the heat generated by a radar antenna. In 1947 an appliance called a Ra-darange appeared on the market for food processing. The first kitchen microwave oven was introduced by Tappan in 1955. Sales of inexpensive domestic ovens now represent a multibillion-dollar (euro) annual market. 

It should be stressed that the majority of literature reports on the acceleration of chemical reactions by microwave irradiation (even more than 1000 fold) come from the initial period of the application of microwaves in organic synthesis (i.e. from late 1980 s and early 1980 s). At this time there were no dedicated microwave scientific reactors available on the market, and most of theses reactions were conducted in household microwave ovens. Recently, applying modern microwave reactors, scientists have verified a number of these reports, and it turns out that the claimed acceleration of the majority chemical reactions were attributed to difficulties with proper temperature measuments rather than to non-thermal micowave effects. Sometimes it was found that these effects were results of faster delivering of energy to the reaction systems [35,38]. 

The main types of microwave power sources are magnetrons and klystrons. Magnetrons which are commonly used in microwave ovens are mass produced thus cheap and easily available on the market. Therefore it is common practice to use the same magnetrons... 

As dedicated microwave instruments appeared rather recently on the market and several interesting applications of microwave irradiation for natural product synthesis were described applying domestic microwave ovens, we decided to include also research performed with domestic ovens, although one could argue that some of these experiments lack reproducibility. On the other hand, the development of safe and reproducible synthetic routes for domestic instruments, which are cheap and at the disposal of every research lab all over the world, is a challenge worth the task as this should tremendously speed up the introduction of microwave irradiation in organic synthesis in general. 

Several small firms market more sophisticated equipment than the domestic microwave oven, and research departments in a number of pharmaceutical companies continue to work with the technology to aid their synthesis of APIs and their intermediates. Several microwave equipment companies70 are developing larger-scale equipment to produce kilogram quantities. Their systems are evolving to meet some of the needs identified by the earlier practioners such as ... 

The recent literature on microwave-assisted chemistry has reported a multitude of different effects in chemical reactions and processes and attributed them to microwave radiation. Some of these published results cannot be reproduced, however, because the household microwave ovens employed often have serious technical shortcomings. Published experimental procedures are often insufficient and do not enable reproduction of the results obtained. Important factors required for qualification and validation, for example exact records, reproducibility, and transparency of reactions/processes, are commonly not reported, which poses a serious drawback in the industrial development of microwave-assisted reactions and processes for synthesis of fine chemicals, intermediates, and pharmaceuticals. Technical microwave devices for synthetic chemistry have been on the market for a while (cf a.m. explanations) and should enable comparative investigations to be conducted under set conditions. These investigations would enable better assessment of the observed effects. It is, furthermore, possible to obtain a better insight into the often discussed (nonthermal) microwave effects from these experiments (Ref. [138] and Chapter 4 of this book). Technical microwave systems are an important first step toward the use of microwave energy for technical synthesis. The actual scale-up of chemical reactions in the microwave is, however, still to be undertaken. Comparisons between microwave systems with different technical specifications should provide a measure for qualification of the systems employed, which in turn is important for validation of reactions and processes performed in such commercial systems. 

Microwave cooking has been available since the 1950s, but, like the electric typewriter, the microwave oven took 20 years to become a common item on the market. 

The frequencies for microwave heating come under the rules of the Federal Communications Commission, which has designated four frequencies— 915, 2450, 5800, and 22,125 mc/sec. The majority of the microwave ovens on the market today use 2450 megacycles. 

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