Domestic appliances

The important features of rigidity and transparency make the material competitive with polystyrene, cellulose acetate and poly(methyl methacrylate) for a number of applications. In general the copolymer is cheaper than poly(methyl methacrylate) and cellulose acetate, tougher than poly(methyl methacrylate) and polystyrene and superior in chemical and most physical properties to polystyrene and cellulose acetate. It does not have such a high transparency or such food weathering properties as poly(methyl methacrylate). As a result of these considerations the styrene-acrylonitrile copolymers have found applications for dials, knobs and covers for domestic appliances, electrical equipment and car equipment, for picnic ware and housewares, and a number of other industrial and domestic applications with requirements somewhat more stringent than can be met by polystyrene. 

Polycarbonates have proved attractive in domestic appliances. Examples include food processor bowls, coffeemaker cold water reservoirs, vacuum cleaner housings, food mixer housings, power tool housings, hair drier and electric razor housings, and microwave cookware. 

Electrical engineering, including wiring devices, and electronics 40% Domestic appliances pot and pan handles and tableware 33%... 

Styrene (vinyl benzene) QH5CH=CH2 Polymers (CgHaln for audio and video cassettes, carpet backing, domestic appliances, packaging, food containers, furniture, toys, vehicle parts... 

Polycarbonate, polypropylene and modified PPO are popular materials for structural foam moulding. One of the main application areas is housings for business equipment and domestic appliances because the number of component parts can be kept to the absolute minimum due to integral moulding of wall panels, support brackets, etc. Other components include vehicle body panels and furniture. 

The key properties here are hardness and wear resistance, ability to. stand minor knocks and dents without cracking and resistance to various domestic chemicals. These vary with type of appliance, e.g. detergent solutions are important for washing machines, while a fridge will be required to withstand fruit juices, ketchup and polishes. Good colour and appearance in white and mainly pastel shades will be expected. Corrosion resistance is required, especially for washing machines, and domestic appliances frequently have to withstand humid conditions in kitchens. 

Yet another option for domestic appliances is to make the appliance from precoated coil. The appliance has to be designed to minimise the problem of unprotected cut edges. Electroplated zinc-coated steel, pretreated, primed and finished with special polyester-melamine, is used. The finish is designed to be hard at room temperature, yet accept bending and forming, probably, but not necessarily, at somewhat higher temperatures (ca. 60°C). 

The hardness of an enamel surface is an important property for such items as enamelled sink units, domestic appliances, washing machine tubs which have to withstand the abrasive action of buttons, etc. On Moh s scale most enamels have a hardness of up to 6 (orthoclase). There are two types of hardness of importance to users of enamel, viz. surface and subsurface. The former is more important for domestic uses when one considers the scratching action of cutlery, pans, etc. whereas subsurface hardness is the prime factor in prolonging the life of enamelled scoops, buckets, etc. in such applications as elevators or conveyors of coal and other minerals. 

The acid resistance called for on domestic appliances varies with the particular component, e.g. the oven interior of a gas cooker necessitates a higher resistance than the outside sides —the former being at least Class A using 2% sulphuric acid while the latter can have a lower grading based on the less aggressive citric acid tests. These tests are detailed in BS 1344 Part 3 (ISO 8290) and BS 1344 Part 2 (ISO 2722), respectively. 

The small condensing surface required by a domestic appliance such as a deep-freeze may allow the use of the outside metal skin of the appliance itself as a surface condenser. In such a construction, the condenser tube is held in close mechanical contact with the skin, so that heat is conducted through to the outside air, where it is lost by natural convection. This system is restricted to a few hundred watts. 

Recently, there has been considerable interest in soft-touch materials composed of thermoplastic and mbber blends. These materials when over-molded on hard or stiff stmctures such as hand tools, domestic appliances, writing gadgets, cellular phones, photographic equipments, etc. provide soft and comfortable feeling to the hand. 

An unknown area is the possibility of new domestic appliances equivalent to the breadmaker. Perhaps an appliance manufacturer is considering a home puff pastry maker. 

For a successful integration, the domestic appliances and all the other functions must be able to communicate with each other, which requires compatible software as well as hardware. Such digitalization may occur not only at appliance level, but also at the sensor level, as described in Chapter 6.2. 

As the domestic appliance industry caters for a mass market - the production volume of a single company may well be around a million units - interesting opportunities are opening up for sensors and microsystems producers, particularly, because silicon microsystems show their true potential especially when mass-produced. But there is also room for many other technologies in this interesting market, provided technology and cost are viable. 

A. Lahrmann Smart domestic appliances through innovations, 6th International Conference on Microsystems 98, Potsdam, Ed. H. Reichl, E. Obermeier, VDE-Verlag, Berlin (1998). 

The air and gas supply of domestic appliances is usually adapted using the fraction of C02 in the flue gas. The changes in the minimum required amount of air and in the total flue gas flow rate cannot be taken into account, but are negligibly small. This also applies to the maximum C02 fraction for the combustion of common natural gas, which differs by less than 1%. Therefore the variations in equivalence ratio 0 remain within tolerable limits. 

Most probably a commercial utilization of these semiconductive sensors in domestic appliances can be expected for the short term. 

Philips Domestic Appliances and Personal Care (Philips DAP) is one of the product divisions of Royal Philips Electronics, alongside Consumer Electronics, Lighting and Medical Systems. In this article we will focus on sensors that are needed within the DAP division. Philips DAP has four Business Units, each with its own specific field of interest Shaving Grooming, Body Beauty Health, Food Beverage and Home Environment Care. 

Over the past years, the annual revenues of Philips DAP have been rising steadily, underlining the importance of this division. These last five years an overall growth of almost 28% was generated, resulting 2,130 million euros in sales. It is the combined effort of marketers, developers, designers and manufacturers that has given Philips DAP a solid market position in the field of domestic appliances. 

Given this situation, it is not surprising that, over the last few years, products based on platinum thin film technology have been finding their way into the home. With the growing use of electronic control systems in the new generation of domestic appliances, platinum temperature sensors have been more widely used in ovens where they have replaced electromechanical regulators such as capillary tubes, solid expansion thermometers and NTC thermistors. Typical sensor applications in the food preparation sector are shown in Fig. 5.3. 

In addition to developing products for the domestic appliance market, Heraeus Sensor-Nite is also active in the automotive sector, and in the fields of calorimetry, electronics and medicine. The goal that Sensor-Nite has set itself for both its present and future activities is to increase process safety whilst reducing depletion of resources. 

There is strong international competition in the area of domestic appliances, partly due to market saturation for many household appliances, as described in Chapter 2. The number of newly built houses and flats, the growing age of the population and the trend towards an increasing number of single households are major influencing factors for buying decisions of domestic appliances. Especially in Europe, it is not only the price that determines buying decisions, but also benefit to customers and their social environment need to be taken into account. Many trends in the technical improvement of household appliances were consumer-driven. In Europe in particular, customers wanted ... 

Nearly all domestic appliances are using more and more electronics. Mechanical functions are replaced by electronic devices, mainly sensors and electromechanical actuators (such as pumps or electromotors) and microelectronic control systems. 

However, the pressure to keep down the costs of all parts used in domestic appliances is omnipresent and also applies to the area of sensors and microsystems. The lifetime of sensors, sometimes under adverse conditions, is critical, and a lifespan between 8 and 15 years should be expected. Commercially viable prices for sensing modules are rather low, depending on the individual functions, but less than 5 Euro for a complete module are typical [1]. Also the financial risk involved in serial production has to be considered. Just one faulty unit would cost the producer nearly 100 Euro to repair, even if this unit costs only 2 Euro. If the factory output is 2000 units per day, the loss may amount to 20 million Euro if a flaw is detected by one of the customers after 100 days of production. 

As a consequence of recent technical developments as well as legal and policy requirements, overall energy consumption for domestic appliances in Europe is expected to fall gradually. The total energy consumption of washing machines, dryers and dishwashers is estimated to be around 60 TWh in Europe, equivalent... 

One likely trend will be the integration of several functional features in the house, such as integrated control of illumination, safety, heating and ventilation, domestic appliances and audio and video function. This will be called home automation . A whole range of manufacturing areas is targeting this market, including ... 

Application > Industrial Controls > Domestic Appliances > Automotive... 

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