Results for dishwasher
On this page:
 
Dictionary:

dishwasher

  (dĭsh'wŏsh'ər, -wô'shər) pronunciation
n.
  1. A person who washes dishes, especially one hired to wash dishes in a restaurant.
  2. A machine for washing dishes.

 
 
How Products are Made: How is a dishwasher made?

Background

Washing dishes is not the most rewarding task. Cooking can be creative, but cleaning up afterward seems like a waste of time and leaves the person washing complaining about "dishpan hands." The development of the dishwasher has helped relieve some of the monotony, as well as the grease and grime. It operates on a simple principle of washing dishes that have been placed on racks inside the machine with multiple jets of water. The modern dishwasher has features that cater to fine glassware or the toughest pots and pans; multiple cycles that clean, sanitize, and dry; and under-the-counter or stand-alone models for every size, use, and price range. It is far from perfect; tough foods may need personal attention before and after dishes and pans are cleaned in the dishwasher, and few owners of crystal glassware and fine china are willing to trust them to a machine. But the dishwasher, like other kitchen appliances invented and improved in the twentieth century, is a fixture in many kitchens of the twenty-first century.

History

The major obstacle to washing dishes has always been the availability of water. Early civilizations used limited numbers and types of dishes, utensils, and cookware and carried them to streams, ponds, or troughs of water for cleaning. The second choice was to carry the water to the dishes. Women carried water in buckets from communal water sources or from private pumps behind their homes or apartment buildings into the early twentieth century, when indoor plumbing finally brought water indoors, not only for bathing but for kitchen use as well.

The first dishwashers were patented in about 1850, but, like machines for washing clothes, they were large contraptions that used steam power and supplies of heated water to soak many dishes at a time. In some models, the dishes were held on cradles that rocked through the water; others had paddles that sloshed water around the dishes or circular racks that held the dishes and rotated to circulate them through the water. An assortment of propellers, plunging casings bearing the dishes, and plungers that drove water over the dishes were incorporated in other machines. In 1875, C. E. Hope-Vere created a machine that directed sprays of water toward racked dishes; the idea of the water jets was adopted by other inventors including A. W. Bodell, whose model was introduced in 1906. Another, the Blick machine, used a propeller that sprayed jets of water over racks filled with dishes. This basic idea is the one used today.

The first publicly displayed models were introduced in about 1915, but the dishwasher was not widely manufactured and sold to private families until about 1930. The dishwasher was not an immediate hit. The refrigerator was introduced at about the same time and swept America; but this is logical because food preservation is far more important than dishwashing. The machines were also too inefficient to completely eliminate hand work; to be fair, this was not entirely the fault of the dishwashers—soaps of the day were not suited to the task. By the 1950s, special dish-washing soaps that clean without sudsing and rinse away began to be developed especially for dishwashers, and the public began to demonstrate more interest. The automatic dishwasher is still not an absolute in every kitchen, but, by the 1970s when more women began working outside the home, the built-in dishwasher was seen as an asset.

Raw Materials

The major components of a dishwasher are made of steel and plastic. The basic structure consists of a steel frame assembly and a steel door panel. Sheets of stainless steel are purchased and fabricated in the required pieces and shapes in the factory; both the door and the wrap-around cabinet for standalone models are purchased as coiled sheet steel that has been prefinished in several standard colors. Other small steel parts are designed in house but made by suppliers to the manufacturer's specifications.

The racks that hold the dishes are also made of steel, but it is delivered to the factory as coiled wire. To coat the rack tines to prevent them from scratching dishes, the racks are dipped in plastic in the form of powder polyvinyl chloride (PVC) or nylon.

The inner box that holds the racks and the washer arms is called the tub. It is a single piece (not counting the piece lining the inside of the door) that is injection-molded in the plant. The injection molding is done with pellets of calcium-reinforced poly-propylene plastic. This plastic is respected for its strength and for the fact that it is inert; that is, it won't react with chemicals like those in detergents and is resistant to water and heat. Many other parts including the basket for cutlery, containers for detergent, and the wash tower and spray arms are also injection molded.

Motors, pumps, and electrical controls and components are made by subcontractors in accordance with designs by the dishwasher manufacturer.

Design

The engineers who design dishwashers are interested in improving two key features of their products. Efficient cleaning is, of course, the biggest marketing feature, but consumers are also interested in quiet operations. Cleaning systems consist of a wash tower and sprayer arms, but the openings, the power of the water pump, and positions of racks relative to the washers are all design elements. In the late 1990s, consumers became increasingly interested in the dish-washer as a tool for sanitizing dishes, so design efforts have been aimed at adding heating methods for killing germs.

Manufacturers have taken different approaches to keeping their dishwashers as quiet as possible. Maytag, for example, uses a single, powerful motor for all operations and wraps the outside of its machines with heavy insulation. By contrast, Amana Appliances has equipped its dishwashers with two motors (one to operate the water pump and another for the drainage system). Together, the two motors have the same horse-power as single-motor units, but less insulation is needed for quiet operation.

Design of the exterior of a stand-alone model is somewhat more sophisticated because it has to have an attractive outer cabinet. Usually the top of the stand-alone dishwasher is a wooden cabinet top so the machine will function as a spare work surface.

The Manufacturing Process

  1. A dishwasher begins to take shape with the injection molding of the tub. Two molds—the cavity relief mold for the outside of the tub and the core relief mold for the inside—have previously been etched into a steel tool, that, when fitted together, contains a void or space that is the shape of the tub. The tool halves are held together in the chamber of the injection molding machine. Pellets of polypropylene are melted in the machine at high temperature and injected by pressure into the void in the tool. The high pressure and liquid state of the plastic forces the plastic into every pocket and crevice in the mold inside the tool. The tool opens to release the tub, which is still hot.
  2. The warm tub is conveyed to a cooling area and cooled to a temperature that is easy for assembly workers to handle. Other plastic parts are also made by injection molding, and these smaller pieces are stored in bins (with one kind of part only per bin) that can be moved to the assembly area as needed.
  3. In another part of the plant, the steel components of the dishwasher are made. Outer cabinets for stand-alone models and the doors for all models are cut and stamped into shape from stainless steel in the form of coils that are prefinished on one side. Flat steel bars that will be assembled into the dishwasher's frame are sheared to length. The racks are also formed with tools that trim, de-bur, and shape wire into the racks in two welding steps. The perimeter of the rack is called the "mat," and a tool welds all the wire pieces of the mat together at the same time. Similarly, the little pieces or tines that support the dishes are welded into place simultaneously. The completed rack is taken by conveyor to a cleaning station where it is cleaned and prepared to receive its PVC coating. The PVC is in the form of a fine powder that is baked onto the rack. The coated rack is then cured to finish forming the PVC coating and to allow it to cool.
  4. Dishwashers are assembled at work stations along an assembly line. The workers are responsible for sets of pieces that are taken from bins alongside the workers. The frame is assembled first, and the motor or motors are attached to special mounts on the frame. The motors are provided to the line workers as completed assemblies. The tub is fitted and fastened into the frame over the motor or motors.
  5. With the tub in place, the interior components are installed beginning with the filtering system. The washtower and arms are attached followed by sets of rack rollers to support the racks and allow them to be rolled in and out of the machine so that dishes can be loaded easily. The racks are put in place along with the cutlery basket.
  6. The door assembly is completed by installing the detergent dispenser and rinse-agent cups and the controls. The door is attached to the front of the dishwasher. The exterior is completed by finishing the electrical connections and feed lines (for clean and dirty water), and the exterior is insulated to reduce noise and the effects of heat that might warp counter tops and cabinets. Insulation is prefabricated with the insulating fibers wrapped in a foil-like covering. Called "bagged insulation," it is wrapped around the machine and packed inside the toe space. Under-counter models are now complete. Stand-alone models are finished by attaching the wrap-around cabinet and wood top. Each completed machine is loaded onto a cart to be moved to the packing area.
  7. In the packing area, styrofoam bumper sections are placed along the edges of the machine and enclosed by a carton. Packets of instructions and other materials are placed on top of the machine in the carton, and the carton is sealed and moved to a storage area for shipping.

Quality Control

Quality control is assured by three basic processes. First, the assembly line workers are trained in quality issues and can reject parts or partially assembled machines. Second, the assembly process is overseen by line supervisors; when assembly is complete, quality engineers inspect the finished machine and test selected units. The most important part of the quality control process may be a design step that Amana Appliances calls a failure mode effects and analysis (FMEA). As soon as problems are observed during assembly or are reported by customers through the warranty process, corrective steps are taken. The analysis is a highly regimented learning process that continuously cycles improvements, customer feedback, and corrective actions through the marketing and design process so new models and lines benefit from any changes to the old.

Byproducts/Waste

Dishwasher manufacturers produce a range of lines of dishwashers and other appliances but no true byproducts. Waste is virtually eliminated by a thorough recycling program that includes metals, plastics, and paper.

The Future

All industries struggle with the issue of how to attract more customers to their product. For dishwashers, the market is still growing because it is a more open field than for other appliances. Marketers discuss this in terms of market penetration; for example, 99.8% of American households own refrigerators, but only 56.5% have dishwashers. This seems promising for dishwasher manufacturers, but it shows that potential customers who don't have dishwashers may not see that these appliances provide benefits over hand-washing dishes. To attract customers, the latest advance in dishwasher manufacture is the sanitization option with a high heat cycle to kill bacteria. Quiet operation, energy efficiency, and clean dishes without prerinsing are existing features that are continuously being improved.

Where to Learn More

Books

Cohen, Daniel. The Last Hundred Years: Household Technology. New York: M. Evans and Company, Inc., 1982.

Weaver, Rebecca, and Rodney Dale. Machines in the Home. New York: Oxford University Press, Inc., 1992.

Other

Amana Appliances. http://www.amana.com (August 2000).

[Article by: Gillian S. Holmes]


 
Word Tutor: dishwasher
pronunciation

IN BRIEF: Someone or something that cleans plates and bowls.

pronunciation Are tectonic plates dishwasher-safe? — Herb Caen (1916-1997) U.S. popular columnist for San Francisco Chronicle, special lifetime Pulitzer Prize 1996.

 
Wikipedia: dishwasher
A Dishwasher
Enlarge
A Dishwasher
A two drawer DishDrawer dishwasher.
Enlarge
A two drawer DishDrawer dishwasher.
This article is about the appliance. For manual dishwashing, see dishwashing.

A dishwasher is a mechanical device for cleaning dishes and eating utensils. They can be found in restaurants and also in the kitchens of many private residences.

How dishwashers work

Unlike manual dishwashing, which relies largely on physical scrubbing to remove soiling, the mechanical dishwasher cleans by spraying hot (55-65 degrees Celsius or 130-150 degrees Fahrenheit) water on the dishes. First detergent-added water is used for cleaning purposes, then clean water to remove the detergent residue. Some dishwashers have multiple wash and rinse periods within the complete cycle. In some dishwashers, a rinsing aid can be added to the rinse cycle. As there is no human contact during the process, strong detergents may be used which would be too alkaline for habitual exposure to the skin. Many dishwashers also contain a heating element to achieve fast drying and sanitation of the dishes. In some models, this element can also be used to heat the hot water to the desired wash temperature.[1]

Human dishwashers

The word dishwasher may also refer to a person who washes dishes in a commercial setting. These employees rinse dishes, load them into a stainless steel dishwasher, unload them, and stack them into their respective dish holders. Pots and pans are also washed by hand by scrubbing them in a soap and water mix, dipping them in a rinse of plain water, and then dipping them in a water/sanitizer solution for 30 seconds. Silverware is washed by placing loose silverware in a tray, washing them several times like this, then sorting them into circular holders, and washing them again in the dishwasher. Being a dishwasher is very hard work and considered manual labour.

History

The first reports of a mechanical dishwashing device are of an 1850 patent by Joel Houghton of a hand-powered device.

Modern dishwashers are descended from the 1886 invention of Josephine Cochrane, also hand-powered, which she unveiled at the 1893 Chicago World's Fair. Cochrane was quite wealthy and was the granddaughter of John Fitch, the inventor of the steamboat. She never washed dishes herself and only invented the dishwasher as her servants were chipping her fine china.

Models installed with permanent plumbing arrived in the 1920s, and electric drying elements were added in 1940.

Adoption was greatest at first in commercial environments, but by the 1970s dishwashers had become commonplace in domestic residences in the developed world.

Characterization

Capacity

The international standard for the capacity of a dishwasher is expressed as standard place settings. Dishes or plates of irregular sizes may not fit properly in a dishwasher's cleaning compartment, so it is advisable to check for compatibility before buying a dishwasher.

Size

Dishwashers that are installed into standard kitchen cabinets have a standard width and depth of 60 cm (Europe) or 24 inches (US), and most dishwashers must be installed into a hole a minimum of 86 cm (Europe) or 34 inches (US) tall. Portable dishwashers exist in 45 and 60 cm (Europe) 18 and 24 inch (US) widths, with casters and attached countertops. Dishwashers may come in standard or tall tub designs; standard tub dishwashers have a service kickplate beneath the dishwasher door that allows for simpler maintenance and installation, but tall tub dishwashers have approximately 20% more capacity and better sound dampening from having a continuous front door.

Features

The inside of a dishwasher, called the tub, can be composed of plastic or stainless steel. Stainless steel tubs resist hard water, provide better sound dampening, and preserve heat to dry dishes faster. They also come at a price premium. Older models used a baked enamel on steel and are prone to chipping and erosion; chips in the baked enamel finish must be cleaned of all dirt and corrosion then patched with a special compound or even a good quality two-part epoxy.

Mid-to-higher end North American dishwashers often come with hard food disposal units, which behave like miniature garbage (waste) disposal units that eliminate large pieces of food waste from the wash water. One manufacturer that is known for omitting hard food disposals is Bosch, a German brand; however, Bosch does so in order to reduce noise. If the larger items of food waste are removed before placing in the dishwasher, pre-rinsing is not necessary even without integrated waste disposal units. Pre-rinsing under a running tap beforehand simply wastes water.

Many newer dishwashers feature microprocessor-controlled, sensor-assisted wash cycles that adjust the wash duration to the quantity of dirty dishes (sensed by changes in water temperature) or the amount of dirt in the rinse water (sensed chemically/optically). This can save water and energy if the user runs a partial load. In such dishwashers the electromechanical rotary switch often used to control the washing cycle is replaced by a microprocessor but most sensors and valves are still required to be present. However, pressure switches (some dishwashers use a pressure switch and flow meter) are not required in most microprocessor controlled dishwashers as they use the motor and sometimes a rotational position sensor to sense the resistance of water, when it senses there is no cavitation it knows it has the optimal amount of water.

Most dishwashers include a large cone or similar structure in the bottom dish rack to prevent placement of dishes in the centre of the rack. The dishwasher directs water from the bottom of the dishwasher up through this structure to the upper wash arm to spray water on the top dish rack. Some dishwashers, including many models from Whirlpool and Kitchenaid, use a tube attached to the top rack that connects to a water source at the back of the dishwasher which allows full use of the bottom rack.

Some dishwashers include a child-lockout feature to prevent accidental starting or stopping of the wash cycle by children.

Sound Damping

Modern dishwashers are quieter than ever before. Using blankets, panels, and sound-absorbing materials in various configurations, dishwashers can achieve sound damping levels down to 44 decibels or so. Undampened, low-end dishwashers generally output noise levels of anywhere from 65-70 decibels. Manufacturers generally use their own nomenclature with sound damping, i.e. QuietGuard (Kenmore), QuietPartner (Whirlpool), Whisper Package (Maytag), etc. How this nomenclature translates into decibel level is different for every manufacturer.

Detergent

Dishwashing detergent contains:

  • Phosphates
    • Dissolves calcium and magnesium ions to prevent 'hard-water' type limescale deposits.
  • Oxygen-based bleaching agents (older-style powders and liquids contain chlorine-based bleaching agents)
    • Breaks up and bleaches organic deposits.
  • Non-ionic surfactants
    • Lowers the surface tension of the water, emulsifies oil, lipid and fat food deposits, prevents droplet spotting on drying.
  • Enzymes
    • Breaks up and dissolves protein-based food deposits, and possibly oil, lipid and fat deposits. They do this by emulsifying them.
  • Anti-corrosion agents

Dishwashing detergent may also contain:

  • Anti-foaming agents
    • Used as foam decreases the effectiveness of the washing action.
  • Additives to slow down the removal of glaze & patterns from glazed ceramics
  • Perfumes
  • Anti-caking agents (in granular detergent)
  • Starches (in tablet based detergents)
  • Gelling agents (in liquid/gel based detergents)
  • Sand (inexpensive powdered detergents)

Dishwasher detergents are strongly alkaline (basic).

Intuition suggests that a powder will provide a better scrubbing action due to a soft media sandblasting effect, though liquid detergents have marketed themselves as premium products. Inexpensive powders sometimes actually contain sand, which can be verified by dissolving the powder in boiling water and then passing the solution through a coffee filter; these detergents should be avoided to prevent wear of the dishes and the dishwasher. Powdered detergents are more likely to cause fading on china patterns [2].

Biodegradable detergent

Besides chemical detergents for dishwashers, biodegradable detergents also exist for dishwashers. Manufacturers include (but are not limited to): Ecover, ...

Hand-washing detergent

Hand-washing dish detergent (washing up liquid) should not be used in a dishwasher, as it will create a large foam of bubbles which will leak from the dishwasher. If hand-washing detergent is accidentally used, the foam may be removed by spraying with salt, and the dishwasher should be forced into a drain cycle to remove the soap and water.

Rinse aid

Rinse aid (sometimes called rinse agent) contains surfactants that prevent droplet formation by reducing the surface tension of the water, so that it drains from the surfaces in thin sheets, rather than forming droplets.

The benefits of using it are that it prevent 'spotting' on glassware (caused by droplets of water drying and leaving behind dissolved limescale minerals), and can also improve drying performance as there is less water remaining to be dried.

Dishwasher salt

Dishwasher salt is used to recharge the built-in ion-exchange water softener in dishwashers. Unlike salt used for culinary purposes, it does not have added iodide salts. However, it should have minimal iron and manganese salt content, as these mineral ions tend to form precipitates that clog the ion-exchange resin.

Some dishwasher detergents are marketed as not requiring the use of dishwasher salt. These instead use increased levels of phosphates to increase the solubility of hard water ions. In very hard water areas, the amount of phosphate may be insufficient, requiring the additional use of salt in any case.[3] Some newer dishwashers have a setting for "all in one" tablets. Incorrect use of "all in one" tablets may not be covered under the warranty; it's advisable to check the instruction book when using these types of tablets.

Pouring table salt or detergent into the salt compartment is not recommended, as it will damage the water softener unit.

Hazing of glassware, prohibition on dishwashing lead crystal

Glassware washed by dishwashing machines typically develops a white haze on the surface over time. This may be caused by any or all of the below processes, only one of which is reversible:

  • Limescale deposit
    - If the dishwasher has run out of the salt that recharges the ion exchange resin that softens the water, and the water supply is 'hard', limescale deposits can appear on all items, but are especially visible on glassware. It can be removed by cleaning with vinegar or lemon juice, or a proprietary limescale removal agent. The dishwasher should either be recharged with salt, adjusted appropriately for the hardness of the supply water - or possibly this is a symptom of failure of the ion exchange resin in the water softener (which is one of the more expensive components). The resin may have stopped working because it has been poisoned by iron or manganese salts in the supply water.
  • Silicate filming/etching/accelerated crack corrosion
    - This film starts as an iridescence or 'oil-film' effect on glassware, and progresses into a 'milky' or 'cloudy' appearance (which is not a deposit) that cannot be polished off or removed like limescale. It is formed because the detergent is strongly alkaline (basic) and glass dissolves slowly in alkaline aqueous solution. It becomes more soluble in the presence of silicates in the water (added as anti-metal-corrosion agents in the dishwasher detergent). In certain cases, the etching will primarily be seen in areas that have microscopic surface cracks as a result of the items' manufacturing.[4] Limitation of this undesirable reaction is possible by controlling water hardness, detergent load and temperature (see Maytag Web site). The type of glass is an important factor in determining if this effect is a problem.
  • Physical abrasion
    - Glassware placed such that it is physically touching can abrade and produce a milky surface.
  • Devitrification
    -Components found in dishwasher detergents can chemically scour the glass, causing tiny crystals, which can precipitate further crystal growth that can turn entire glasses cloudy[5]

Lead crystal should not be cleaned in a dishwasher as the corrosive effect of dishwasher detergent is high on such types of glass - that is, it will quickly go 'cloudy'. In addition, the lead in the crystal glass can be converted into a soluble form, which is not good for the health of subsequent users.[6]

Items that should not be put in a dishwasher

Some items can be damaged if washed in a dishwasher because of the effects of the chemicals and hot water. Lead crystal will be irreversibly damaged if put in a dishwasher, while aluminium items will discolour. Saucepan manufacturers often recommend handwashing due to the harsh effects of the chemicals on the pan coatings.[7] Valuable items - such as antiques - should be washed by hand as they may be dulled or damaged, and detergents will gradually fade the glazing and print. Sterling silver and pewter will oxidize and discolour from the heat. Furthermore, pewter has a low melting point and may warp in some dishwashers.[8] Cast iron is likely to rust in a dishwasher.

Items soiled by wax, cigarette ash or anything which might contaminate the rest of the wash load (such as poisons or mineral oils) should not be put in a dishwasher. Objects contaminated by solvents may explode in a dishwasher. Glued items, such as some cutlery handles, may be melted or softened if dishwashed, especially on a hot wash cycle when temperatures can reach 75 °C; these high temperatures can also damage plastic items which are labelled as not being dishwasher safe, however some plastic items can be distorted or melted if placed in the bottom rack too close to an exposed heating element, hence many dishwasher-safe plastic items advise placing in the top rack only (many newer dishwashers have a concealed heating element away from the bottom rack entirely). Squeezing plastic items into small spaces may cause the plastic to distort in shape.

Dishwashers should only be used to wash normal household items, like plates, cutlery, cups, mugs, kitchenware etc. Items such as paintbrushes, tools, furnace filters etc. should not be put into a dishwasher as this will cause the subsequent washes to become contaminated and may cause damage to the appliance.

Drying

The heat inside the dishwasher dries the contents after the final hot rinse. Rinse aid is used in the final rinse cycle to allow water to run-off items and prevent water droplets forming. Plastic and non-stick items may not dry properly compared to china and glass, which hold the heat better. Some dishwashers incorporate a fan to improve drying.

Chemical drying agents such as JET-DRY are also available.[citation needed]

Level of sanitising

Dishwashers do not sterilise the utensils, as proper sterilisation requires autoclaving at 121 °C with pressurised wet steam for at least 15 minutes. Commercial dishwashers can use one of two types of sanitisation methods: hot water sanitising (using final rinse water at a temperature of at least 83 °C (180 °F)), or chemical sanitising (by injecting chlorine in the final rinse water). Not all dishwashers are capable of reaching the high temperature required for hot water sanitising. Medical grade dishwashers and sanitizers are starting to use ultrasonic cleaners[citation needed], which use a liquid bath treated with sonics to remove particles and sterilize instruments.

Most consumer dishwashers use a 75°C thermostat in the sanitising process. During the final rinse cycle, the heating element and wash pump are turned on, and the cycle timer (electronic or electromechanical) is stopped until the thermostat is tripped. At this point, the cycle timer resumes and will generally trigger a drain cycle within a few timer increments.

Most consumer dishwashers use 75°C rather than 83°C for reasons of burn risk, energy consumption, total cycle time, and possible damage to plastic items placed inside the dishwasher. With new advances in detergents, lower water temperatures (50-55°C) are needed to prevent premature decay of the enzymes used to eat the grease and other build-ups on the dishes. This also saves energy and can allow the washer to be hooked directly to the hot water supply for the house.

In the US, residential dishwashers can be certified to a NSF International testing protocol which verifies the cleaning and sanitation performance of the unit.[9]

Commercial dishwashers

Large heavy-duty dishwashers are available for use in commercial establishments (e.g. hotels, restaurants) where a large number of dishes must be cleaned. Commercial machines can wash a rack of dishes in just a few minutes. In the UK, the British Standards Institute set standards for dishwashers. In the US, the NSF International (an independent not-for-profit organization) sets the standards for wash and rinse time along with minimum water temperature for chemical or hot water sanitizing methods.[10] There are many types of commercial dishwashers including under counter, single tank, conveyor, flight type, and carousel machines.

Dishwashers and the environment

Dishwashers versus washing dishes by hand

Comparing the efficiency of automatic dishwashers and hand-washing of dishes is difficult because hand-washing techniques vary drastically by individual. At least one privately funded, non-peer-reviewed study concludes that automatic dishwashers when fully loaded use less water than even the most efficient hand-washers, while relative energy use depends on hand-washing technique and number of place settings washed per load (a smaller load still favours hand washing)[11] The study does not address costs associated with the manufacture and disposal of dishwashers or the cost of possible accelerated wear of dishes from the chemical harshness of dishwasher detergent.

Many people are skeptical of these claims, and one private individual has shown that dishwashers are comparable to efficient hand-washing in water usage;[12] however this small-scale study did not include any measurements of other environmental impact.

Waterless dishwasher concept

A team of students from the University of New South Wales in Sydney won top honors in the 2004 Electrolux Design Laboratory competition for their Rockpool waterless dishwasher design. Its primary feature was the use of supercritical carbon dioxide in place of water in closed-loop operation. Pressurized carbon dioxide behaves like a nonpolar solvent, which can effectively remove grease. It also demonstrates the physical properties of a liquid, hence the solvent effectiveness, and a gas, which fills its container and thus does not require as much mechanical agitation. The grease is filtered from the carbon dioxide and removed from the system. Supercritical carbon dioxide has previously been used in dry cleaning. The primary benefit of this concept is the fact that it uses no water directly.[13]

Dishwasher detergents and rinse aids

Most dishwasher detergent contains complex phosphates, as they have several properties that aid in effective cleaning. However, the same chemicals have been removed from laundry detergents in many countries as a result of concerns raised about the increase in algal blooms in waterways caused by increasing phosphate levels (see eutrophication). The State of Maryland is considering a bill to limit phosphates in dish detergent to help clean up the Chesapeake Bay.[14]

In addition, rinse aids have contained nonylphenol and nonylphenol ethoxylates. These have been banned in the European Union by EU Directive 76/769/EEC.

References

  1. ^ How dishwashers work
  2. ^ http://www.hotpointservice.co.uk/hs/pages/content.do?keys=FAQ:PRODUCT_INFO_DISHWASHING
  3. ^ Dishwashing in hard water areas
  4. ^ http://www.scienceblog.com/community/older/2003/F/20033788.html Dishwashers and microscopic scratches}
  5. ^ Ancient glass and vitrification
  6. ^ "Lead Contamination In Our Environment"
  7. ^ Cooking equipment and dishwashers
  8. ^ Dishwashers and silver
  9. ^ NSF Consumer Information: Residential Appliances and Other Products for the Home
  10. ^ NSF aticle on dishwashers
  11. ^ Dishwashers versus handwashing (PDF)
  12. ^ Diswashers versus handwashing, II
  13. ^ Waterless dishwasher
  14. ^ Md. Dish Soap Bill Might Help Clean Bay

See also

External links

Commons-logo.svg
Wikimedia Commons has media related to:

This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)

 
Translations: Dishwasher

Dansk (Danish)
n. - opvaskemaskine, opvasker, tallerkenvasker

Nederlands (Dutch)
afwasmachine

Français (French)
n. - lave-vaisselle, machine à laver la vaisselle, laveur de vaisselle, plongeur

Deutsch (German)
n. - Geschirrspülmaschine, Geschirrspüler

Ελληνική (Greek)
n. - πλυντήριο πιάτων, πλύντης πιάτων (κν. λαντζιέρης)

Italiano (Italian)
lavastoviglie

Português (Portuguese)
n. - máquina (f) de lavar louça

Русский (Russian)
посудомоечная машина

Español (Spanish)
n. - lavavajillas, lavaplatos

Svenska (Swedish)
n. - diskmaskin, diskare

中文（简体） (Chinese (Simplified))
洗碗机, 洗碗的人

中文（繁體） (Chinese (Traditional))
n. - 洗碗機, 洗碗的人

한국어 (Korean)
n. - 접시 세척기, 할미새

日本語 (Japanese)
n. - 皿洗い, 自動皿洗い機, 食器洗い機, ハクセキレイ, セグロヒタキ

العربيه (Arabic)
‏(الاسم) آله غسل الصحون, الشخص الذي يغسل الصحون‏

עברית (Hebrew)
n. - ‮מדיח כלים‬

If you are unable to view some languages clearly, click here.

To select your translation preferences click here.


 
 

Join the WikiAnswers Q&A community. Post a question or answer questions about "dishwasher" at WikiAnswers.

 

Copyrights:

Dictionary. The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2007. Published by Houghton Mifflin Company. All rights reserved.  Read more
How Products are Made. How Products are Made. Copyright © 2002 by The Gale Group, Inc. All rights reserved.  Read more
Word Tutor. Copyright © 2004-present by eSpindle Learning, a 501(c) nonprofit organization. All rights reserved.
eSpindle provides personalized spelling and vocabulary tutoring online; free trial.  Read more
Wikipedia. This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Dishwasher".  Read more
Translations. Copyright © 2007, WizCom Technologies Ltd. All rights reserved.  Read more

On this page:   E-mail   print Print  Link  

 

Keep Reading

Mentioned In:

 |  More >More >
 

Do you have the answers?