Toni Pearson, age 15, of Akron, Ohio, for his question:
HOW IS NYLON MADE?
Nylon is the name given to a number of synthetic products that are made from coal, water, air, petroleum, agricultural byproducts and natural gas. Nylon is a tough, strong and vary elastic substance and it is regarded as one of the world's most important chemical inventions.
Nylon is made by combining two chemical compounds: adipic acid and get ready for a fancy looking word hexamsthylenadiamine. After the two compounds are combined they form hexamsthylsne diammonium adipate. The common name for this compound is "nylon salt."
The nylon salt is put into a machine called an autoclave, which heats it under pressure. The molecules that make up each of the chemical substances then combine into larger molecules. The procedure of forming large molecules out of smaller ones is called polymerization.
When polymerization is complete, nylon comes out of the machine as a plastic ribbon. The ribbon is cut into chips and than blended for uniformity.
Nylon fiber is made by melting the chips over heated grids covered with inert gas to keep the oxygen of the air from getting into the melted nylon.
When the nylon reaches a liquid form, it is pumped through small holes of a unit called a "spinneret." The threads harden as soon as they meet the air. They are quickly wound onto spools that collect about a half mils of thread each minute.
From one to as many as 2,500 strands called filaments from the spinneret are combined into a textile nylon yard. The filaments are twisted a few times each inch before they are wound on bobbins.
Nylon is then cold drawn after it is made into yard. The thread is stretched or drawn so the molecules fall into parallel lines. This gives the yard strength and elasticity. The process is completed by unwinding the filament from one spool and winding it onto another, with the winding up rate being four or more times as fast as the .unwinding. This stretches the yarn.
The size of the yarn depends on the original size and the degree of stretching. If the yarn is drawn to four times its original length, its diameter is only half its original diameter.
Nylon's size is measured in "deniers." A denier is the weight in grams of 9,000 meters of yarn. Nine thousand meters of nylon yard that weighs 15 grams is called 15 denier.
A chemist by the name of Dr. Wallace Carothers, working for the Du Pout Company in Wilmington, Del., was a leader in the development of nylon back in the early 1930s. Commercial nylon became available in 1938.
The Du Pont team made nylon from coal, air and water. Petroleum, natural gas and agricultural byproducts were developed later as raw materials. Since the early days, a number of different nylons have been developed.