Soap has been around for 5000 years. Both the Egyptians and Babylonians used soap for personal cleaning. Soap then was a mixture of rendered animals fats and ashes. Although its basic principles remain the same, it is now made using a sophisticated chemical and manufacturing process.
During the middle ages the use of soap was considered unnatural. Some historians suggest the rejection of soap, and the associated lack of hygiene, may have contributed to the Black Death that ravaged Europe.
Even intolerance of people who continued using cleaners may have been exacerbated. Their religious laws demanded cleanliness so they continued using soap. The Europeans though, revised soap at this time because it was considered a devilish product.
To some people it is a mystery product that they imagine full of numerous secret ingredients boiled up in a caldron. While not a magical product it is definitely a substance that has helped transform society. It is something we use every day to make our busy lives easier and safer.
Detergent is not soap
Prior to World War II laundry was cleaned with soap or soap flakes. After the war detergent became the predominant laundry cleaning choice. It was less expensive, more convenient, and worked better with the new-fangled washing machines.
How clothes are cleaned
Most people do not realize that it is the water in the washing machine that does most of the cleaning, not the detergent. Primarily, it is the water that mixes with the dirt on the clothes that lifts off the soiling matter and holds it in suspension. Then when washing machine drains the water finishes the job by carrying the dirt away with it.
Question: So, if the water does the work, why do we need the detergent? Answer: Because the detergent makes it all happen more efficiently.
Although water appears to be one large body of fluid actually it's not. In fact it is made up of minuscule balls of water because of a phenomenon called surface tension. The job of detergent is to break down this surface tension. Once the surface tension is broken the water will mix better with other water molecules.
By lowering its surface tension the water can be made to penetrate the clothing fabric rather than slide off its surface. So in effect the detergent makes the water more efficient. Some people describe it as making the water "slippery". The result is that the water can attack the dirt more aggressively, loosen it, and then hold it until it can be washed away.
Also, the detergent helps keep the dirt suspended within the water. This is necessary to prevent the dirt from reattaching itself to the clothing fabric.
Detergent and hard water
When detergent is used in hard water it produces soap scum. Yes, the same stuff that makes that ring inside your bathtub. The harder the water the more soap scum.
Water hardness is a measure of its mineral content. So, the more minerals, the more soap scum. The more scum, the less concentrated the detergent. Therefore, if your water is hard you need to compensate by using more detergent. Conversely, the softer the water the less detergent is required to clean the clothes. If you read the detergent box it will usually indicate how much detergent is needed for different water hardness.
Unsure of your water hardness? Telephone your municipality or water provider and ask for the water hardness level. It is quoted in grains. That is, 2-4 grains is soft, 4-6 grains is medium, and above 6-8 grains is hard water. If you do not know your water hardness, then experiment. Cut back on your detergent. If the clothes still come out clean, cut back further.
Once the perfect amount of detergent required is determined continue to use this same amount for every load. Always use a measuring cup to dispense your detergent. The plastic one that usually comes in the detergent box is sufficient. Use a marking pen to draw a line on the measure so your proper quantity will be consistent. Simply dumping out a quantity from the box is wasteful and will contribute to poor cleaning results.
In recent years the front-loading washer has become common. They have attracted much attention because they use substantially less water and electricity. A front loader uses about 40% less water and 50% less electricity.
The clothes no longer are suspended in a large tub of water. Instead they roll inside a horizontal tub and only pass through water when at the bottom of the tub. The clothes are constantly being picked up and then dropped into the water. This tumbling action takes the place of the agitator used in a top load machine.
Along with the introduction of the front-loader has come a new generation of laundry detergent. It is called high-energy, or high-efficiency detergent. Usually referred to as HE detergent. This type of detergent produces very little suds.
A low sudsing detergent is necessary for a front loader washer. If suds were present they would form a cushion at the bottom of the tub, between the clothes and the water. This would drastically reduce the cleaning action of the water.
Also, the front-loader machines generally require less detergent per load of laundry.
Some sources indicate this is because less water needs less detergent to obtain the same water to detergent ratio. Other sources suggest it is because the HE detergent is more concentrated, and so less is needed to produce the same cleaning action.
What will the future bring to the field of laundry detergent and cleaning?
Manufacturers have been hinting at a type of washing machine that requires no detergent. Some think it will take the form of a microwave washer. The dirt is radiated to the point where it is actually vaporized. Sounds like something out of Star Trek.
Others suggest washers may use electrically charged particles to do the cleaning. The dirt would have given an electrical charge different from the clothing. In this way the dirt can then be drawn away from the fabric and then disposed of into a filter.
These things seem rather far-fetched and theoretical.
But then the same is always said until someone learns how to turn a crazy theory into a practical device.