How Nylon Yarn is Made
NYLON, silk’s young but overwhelming rival, is spun out of air, water and coal. The drawings at the right take the raw materials through the process that chemists worked out in the 1930s to produce the tough, lustrous thread.
About 90 percent of this yarn is used today in the manufacture of women’s stockings. The first nylon hosiery appeared in the stores on May 15, 1940; to date, the supply has never equaled the demand. During the war all nylon yarn was allocated to the armed services, largely for use in the manufacture of parachutes. Du Pont now plans to deliver up to 23,000,000 pounds of the thread annually, enough to make 450,000,000 pairs of women’s stockings.
As many as 32 pairs of nylon stockings are knit simultaneously on machines 40 feet long. Gauge, or sheerness, is determined by the number of needles per inch and a half on the knitting needle barâ€”51 needles make a 51-gauge stocking.
How Mechanical SPIDERS SPIN Bay Bridge Cables
by C. W. GEIGER
This article describes in simple language how a wire long enough to encircle the world three times is carried back and forth across San Francisco Bay by traveling wheels to spin the suspension cables of the world’s longest structure, the mammoth San Francisco-Oakland Bay Bridge.
BY FAR the most spectacular operation in the construction of a suspension bridge is the spinning of the mighty cables which loop gracefully from tower to tower, supporting a roadway hung far below. How are these mile-long cables, each weighing 9,500 tons and containing 17,464 strands of steel, being stretched from tower to tower for the San Francisco-Oakland Bay suspension bridge?
Machine Speeds Pretzel Bending
THERE are more crunchy pretzels to munch when you sip long, cold drinks this summer, thanks to a new automatic pretzel-twisting machine that rolls and ties them at the rate of 50 a minuteâ€”more than twice as fast as skilled hand twisters can make them. Developed by the American Machine & Foundry Co., of New York City, the pretzel . bender is helping to meet the increased demand of pretzel lovers, who eat millions of pounds each year. On this and the following page is the story of how pretzels march from raw dough to baked twist.