Dry cleaning means not using water but using some solution to clean the fabric. Water can damage some fabrics, such as wool, leather and silk; Sometimes washing in a normal washing machine will damage buttons, lace, sequins and other delicate decorations. Therefore, these items need to be dry cleaned.
There are many types of dry cleaning solvents for each type of fabric. In the past, people used gasoline, kerosene, benzene, and turpentine, which are flammable and dangerous solutions. During the 1930s, a number of synthetic, non-flammable solvents, such as perchlorethylene (PCE) and decamethylcyclopentasiloxane (liquid silicon) were discovered and used to this day.
Detergents are also often added to these solvents to remove soil contamination. Detergent can be added to the solvent before washing or during washing as the case may be, and has the following effects: Provides moisture to help clean water-soluble soil; Prevent soil from clinging back to the fabric; As a conductor so that the solvents can make the fabric cleaner.
Dry cleaning means not using water but using some solution to clean the fabric.
Dry cleaning machine consists of 4 parts: A solvent compartment; A pump to feed the solvent into the machine; The filter bags retain dirt; A cylinder or a rotating cage to hold the fabric to be washed.
During washing, the pump sucks solvent from the storage compartment through the filter bags to filter out any dirt, and then pours it into the rotating drum. Here the solvent comes into contact with the fabric and removes the dirt. The solvent then returns to the original reservoir and repeats the process.
After the fabric has been washed, the machine will operate the spin mode to remove the remaining solvent in the fabric. The drum rotates at high speed to knock solvent droplets off the fabric, just like a typical household washing machine.
After spinning is complete, the cylinder (washing tub) stops, fabrics can be dried in the same drum if it is a self-contained system or transferred to a separate dryer. The solvent is retained, filtered, and returned to the original reservoir.
Dry cleaning has been around since ancient times. Records of methods of washing perishable items have been found in the ruins of the city of Pompeii, which was buried by the volcano Vesuvius in 79 AD. Back then, a lot of cloth clothes were made of wool and would shrink if soaked in water. Washers used solvents such as ammonia (taken from urine) and lye, and a special clay to remove dirt, sweat and grease stains from fabrics.
The first so-called dry cleaning in modern times may have been the story of a clumsy maid who dropped some kerosene on a greasy tablecloth. The kerosene quickly evaporated, and she found that the spot where the kerosene was spilled was cleaner than the others. After that “accident” , a lot of experimentation was done to determine which solvent was best for removing grease stains. These include turpentine, kerosene, petroleum-based liquids, gasoline, and camphor oil.
Dry cleaning was first offered in 1825 by the Jolly-Belin company in Paris. In Paris, of course, because there fashion is an important part of everyone’s life. Clothes are soaked in tubs filled with pine oil, then put in a washing machine , and then left to dry for the pine oil to evaporate.
The first dry cleaning service in the US appeared around the same time. Thomas Jennings, an American tailor and inventor, used the “dry cleaning” method to clean fabrics that could not be washed in the usual way. His method was patented in 1821, and Jennings ran a very successful garment and laundry business in New York.
The biggest disadvantage of petroleum-based solvents is that they are highly flammable, so efforts have been made to find substitutes. And in 1821, an English physicist and chemist named Michael Faraday synthesized PCE for the first time. However, it was not until the early 1930s that this solvent was used for dry cleaning, after an American dry cleaner named William Joseph Stoddard found a way to improve PCE as a dry cleaning solvent. This substance was used a lot in the late 30s, early 40s due to the scarcity of oil during World War II.
PCE is a hazardous substance for both the environment and health, especially for workers in the laundry.
Although PCE is the most common choice for dry cleaning, it is hazardous to both the environment and to health, especially to laundry workers. In addition, people who regularly wear dry cleaning clothes can also be affected. If they inhale PCE vapor for a long time, they may experience dizziness, lightheadedness, blurred vision, loss of coordination and mild memory loss, skin rashes.
People who work in the dry cleaning industry are also at increased risk for certain cancers. Long-term exposure to these chemicals can lead to cancers of the esophagus, bladder, cervix, blood, and non-Hodgkin’s lymphoma. In addition, they are also at risk of other diseases of the nervous system, liver, kidneys, and lungs.
There have been many studies on the relationship between PEC and cancer, especially PEC used in the dry cleaning industry. After a careful review of previous studies, as well as testing the harmful effects of PEC in mice, in 2014 researchers concluded that exposure to PEC is strongly associated with a number of diseases. cancer. Similar to the EPA’s classification in 2012, a 2014 study by scientists also found that PEC is a human carcinogen regardless of the form of exposure to this chemical, especially Dry cleaning workers are at particularly high risk of bladder cancer.
Although definitive conclusions cannot be drawn, the US Environmental Protection Agency (EPA) has also provided some evidence that PEC affects the reproductive systems of both men and women, altering the structure of the sperm. infection and reduced fertility. There have also been some studies on birth defects due to PEC, but there are still few and insufficient evidence to conclude.
PEC can evaporate into the air, dissolve in water and soil in areas where it is produced or used and in the vicinity. Most of the PEC in the atmosphere is emitted by the dry cleaning industry, according to the United States Agency for Toxic Substance Diseases and Diseases. This compound decomposes very slowly in the atmosphere, so it can spread over great distances. PEC can dissolve in water and leach into the soil through wastewater contaminated with this solvent. Much of this PEC quickly evaporates from water and soil, but the rest also decomposes very slowly and is therefore very long-lived and can spread over a large area around the source of the emission.
According to IBISWorld, a market research company, there are currently about 36,000 dry cleaning workers in the US alone. However, some data sources show that this number of workers is decreasing, partly because of the current trend of many people preferring to use clothes of ordinary materials, more durable fabrics, and cheaper clothes. so many places in the US the number of dry cleaning shops is less and less.
Another reason is that there are many private dry cleaning shops, operating on a family scale, and when the old generation is out of working age, the younger generation does not inherit but moves to another profession. Environmental concerns are also changing the industry. For example, the state of California is phasing out the use of PEC in dry cleaning and replacing it with less toxic substances, such as laundry that combines water and carbon dioxide ( CO2 ).