Chemical Engineering in Daily Life – Question 49: Why do towels become hard after being used for a while? But clothes won’t? How to make it softer?

1. Towels become hard because free calcium and magnesium ions in water combine with soap, forming calcium and magnesium soaps that adhere to the surface of the towels. 2. Pour the water used for washing rice (from the first and second washes) into a pot, put the towels in and boil them; after they come to a boil, continue boiling them for a while longer. After doing this, the towel will turn white, become softer, thicker than before, and have a mild rice fragrance. 2. Place the towel in hot water with detergent, boil or scald it for 5 minutes, and then wash it clean while it’s still hot. 3. Washing towels frequently, and boiling them in soap, laundry detergent, or lye for a few minutes from time to time, can prevent them from becoming hard. When boiling, the towel should be completely submerged in water to prevent oxidation due to contact with air, which could reduce its softness. When washing the towel, place it in water containing a concentrated solution of soap, vinegar, or alkali and boil it for a while; the soap solution should cover the towel entirely during boiling. Then rinse several times with clean water and warm water in turn, and let it dry in a well-ventilated area while still wet. After drying, the towel will return to its softness. It should be noted that towels should not be exposed to the sun for long periods of time; it is better to let them dry naturally in a well-ventilated area. 5. Scientific method for disinfecting towels: First, boil the towels in boiling water for about 10 minutes, then wash them with soap, rinse thoroughly with clean water, and finally fold the towels and place them in the microwave for 5 minutes. 6. The best method is to use vinegar essence; dissolve it in a solution with a ratio of 1:4. Use not too much water – just enough to cover the towel. After soaking for 5 minutes, scrub the area and then rinse it thoroughly with clean water.

Cloth fabrics are softened before leaving the factory, but after just one wash, most of the softening agents are lost, and the clothes become stiff

The original poster raised so many questions at once; I don’t know the answers to many of them:

This post was last edited by Dawn Bellows on 2015-8-22 at 10:17. The original poster has an excellent knowledge of chemistry; in fact, every aspect of daily life is closely related to chemistry! I only know that soaking it in some edible white vinegar for a few minutes, then taking it out, washing it, and letting it dry will make it softer; if washed with soap and hard water, it becomes harder (that is, sodium stearate adheres to the surface of the towel or clothes), making it difficult to clean thoroughly.