Washing-up liquid

Initially a molten tube of plastic called the Parison is extruded through an annular die. A mould then closes round the parison and a jet of gas inflates it to take up the shape of the mould. This is illustrated in Fig. 4.21(a). Although this process is principally used for the production of bottles (for washing-up liquid, disinfectant, soft drinks, etc.) it is not restricted to small hollow articles. Domestic cold water storage tanks, large storage drums and 2(X)... 

High density poly(ethylene) Bottles for milk and washing-up liquid ... 

We also need soaps for cleaning the crockery after a meal of chips, pizza or greasy sausages. Such cleaning can be difficult and time-consuming unless we first add to the water an effective soap or detergent such as washing-up liquid . 

The latest advice from the Standing Conference on Drug Abuse is that the use of bleach is not recommended, as it tends to harden dried blood and therefore may protect the virus. Bleach may also corrode the metal parts of the syringe, making it harder to clean away traces of blood. The current recommendation is that works should be flushed out as soon as possible after use with several changes of clean cold water to which a small amount of washing-up liquid has been added. This advice, too, may be superseded in the future. 

It can be found as a substitute for natural materials in plastic bags, sandwich boxes, washing-up bowls, wrapping film, milk-bottle crates and washing-up liquid bottles (Figure 14.15). 

Add a few drops of washing-up liquid to 20 vol hydrogen peroxide. Divide this mixture into two portions and add manganese(rv) oxide to one portion. Compare the rate of decomposition of hydrogen peroxide in the two samples. 

Amphoteric surfactants have both a positive and a negative component at the water-attracting end. Amphoteric surfactants are used in washing-up liquids, but rarely in laundry detergents because they cost too much. The best known amphoteric surfactants are the cocamides. 

Dishwasher surfactants must not generate a lot of foam because that can block the pipes within the machine, as you may have discovered when, having run out of dishwasher detergent, you have simply tried using some hand washing-up liquid instead. The surfactants in dishwash products are low-foam non-ionic ones such as fatty alcohol ethoxylates, especially those in which the hydrocarbon chain is 12-14 carbon atoms long. These produce almost no foam. 

The wide availability of relatively inexpensive dimethylaminopropylamine (DMAPA) allows surfactant producers to convert economic triglycerides, fatty acids and methyl esters into amido -functional tertiary amines that may then be quaternized with sodium chloroacetate to produce alkylamidopropyl betaines (see Figure 6.15). The most economically significant of these is cocamidopropyl betaine which can be produced from a variety of feedstocks and lauramidopropyl betaine which is generally produced from lauric acid. These are widely used secondary surfactants in consumer products such as shampoos, bath products, washing up liquids and other cleaners. 

Essential oils can easily become absorbed by the skin and present a hazard if not removed from the fingers, which may transfer that oil to other parts of the body. It is essential that hands are thoroughly washed with warm water and a fat-dissolving cleanser such as soap or a detergent like washing up liquid. If the essential oils come into contact with the skin in delicate areas of the body, the affected areas should be washed with warm soapy water and carefully and thoroughly dried, and if necessary a gentle skin cream or medicated cream should be applied. 

Solutions A and B from the Landolt experiment (102), washing-up liquid (or similar). 

The solutions A and B from the previous Landolt experiment are used. 100 mL of the sulfite solution (B) and of the iodate solution (A) are each diluted with 100 mL of distilled water. 2 mL of the washing-up liquid arc placed in the beer glass prior to the experiment. 

Both solutions are now poured simultaneously into the beer glass. Because of the presence of the washing-up liquid a clear frothy solution is formed, which turns yellowish-brown after about 10 seconds, so that beer now appears to have been formed (colored figure 30). 

Another complication is that most of our descriptions are of complex mixtures and individual chemical signals are not always additive in a simple predictable arithmetic way. For example, it is known that the odours of the enantiomers of carvone are different. 1-Carvone (13.2) smells of spearmint whilst d-carvone (13.3) smells of caraway. Less well known is the fact that addition of nonanol (13.4), an alcohol with an oily smell reminiscent of unperfumed washing up liquid, to 1-carvone, will create an odour impression very similar to that of d-carvone. This... 

A simple emulsion can be prepared by shaking a solution of household liquid detergent (washing-up liquid) diluted 1 10 with an equal volume of white spirit (turpentine substitute) or a few drops of cooking oil. The resulting emulsion is stable for several hours. 

Put approximately 100 ml oil and 200 ml water in the container jar. Notice that the oil and water form separate layers, with the oil on top. Shake the container vigorously for a few seconds to form an emulsion, and then leave it to stand. The oil and water separate as soon as you stop shaking, and rapidly form two layers. Now add a few drops of washing up liquid and repeat. The washing up liquid contains surface active molecules that stabilize the emulsion so that it does not separate out. 

To demonstrate the same effect for a foam, repeat this experiment without the oil (if you use the same container you must rinse it thoroughly first to remove any traces of the washing up liquid). Put approximately 200 ml of water in the container and shake vigorously. Bubbles form but burst very quickly when you stop shaking. When you add the washing up liquid, the surface active molecules stabilize the bubbles and a much longer lasting foam is formed. 

Lather cannot form until all the calcium or magnesium ions have been precipitated. Note that soapless detergents, which are an ingredient of many washing-up liquids and detergents, do not form a scum with hard water. 

A PE-HD/HDPE high density polyethylene, e.g. bottles for washing-up liquids... 

We should not forget ecological applications. A duck s feathers are not wet-table by water, but if we spill surface active molecules, such as are found in washing-up liquid, into our rivers, the surface tension of the water is reduced. Young s equation shows that cos e is increased and may attain the value unity. At this point, capillary imbibition occurs and water will penetrate duck feathers. Ducks catch cold and die. 

Washing-up liquids, cleaning agents and soaps are usually water based and, when used in recommended concentrations, there are only mild effects on the skin however, used in too high a concentration, they can cause skin injuries. Sometimes organic solvents, such as white spirit or isopropanol, are added. 

Solubilization of toxic substances may result in their enhanced absorption and, thus, the presence of surfactants in river and tap water could increase the absorption of the carcinogenic polycyclic compounds, which are generally insoluble in body fluids, as a result of their solubilization. The hazards of exposure to household surfactants, in washing-up liquids, in toothpaste and in water supplies should not be underestimated. In addition, the irritant effects of surfactants (cutaneous toxicity) present in many cosmetic products should be addressed, and this led to the introduction of surfactants that are milder to the skin. For more detail on surfactant toxicity, the reader should refer to the text by Attwood and Florence. 

To recap, in extensional flow the elements of a fluid are stretched out or squeezed down rather than sheared. A good example of this is found in the flow in and out of a short tube, see figure 1, which is fhe kind of flow experienced when liquids such as ketchup, washing-up liquid and skin lotion are squeezed from plastic bottles, or when toothpastes, meatpastes and processed cheese are squeezed from tubes. 

Some are used to make washing-up liquids, washing powders, paints, drugs and cosmetics. 

These different characteristic films can often be produced with impure surfactants washing-up liquids. The impure rigid film can often be prepared with the addition of a quantity of glycerine. 

No special soap solution is required for these demonstrations. A bowl of cold water plus a couple of squirts of any washing-up liquid is adequate providing the solution is stirred and bubbles are removed from the surface of the liquid. The films between a set of plates will last for about 60 seconds. For longer lasting soap films one should prepare one of the special solutions mentioned in section 1.7. 

The normal modes of a soap film membrane with a rectangular boundary, circular boundary, or a boundary of any shape, can be easily demonstrated experimentally.29.96-114 It is an advantage to use one of the long lasting recipes, section 1.7, for the soap film. However, solutions made from washing-up liquid can be used but will not have as long a lifetime. 

Yes. SLS is an excellent foaming agent, and this is one of the reasons it s included in many personal care products, such as toothpaste and washing-up liquid. However, its ability to foam has a very little effect on the functional performance of the product. Foaming properties are actually added due to consumer demand. The amount and quality of foam produced is associated by consumers as an indicator as to whether the product is working. This myth is propagated by advertising... 

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