Shoelaces are quieter to use, but sneakers that are kept closed with Velcro are here to stay--a sign of the transformation of what was once a little-known specialty product into a mass-market, consumer item.

Velcro, a trademark for the original product known more broadly as "hook and loop," is the sticky stuff that holds blood-pressure cuffs tight, that anchors the cloth squares on the back of airliner seats and that has turned up in the last few years in a variety of new uses, including on sneakers.

The trigger for the recent growth was the expiration nearly six years ago of Velcro's proprietary patent. The patent loss and the emergence of new competitors in the field, including 3M Corp. and YKK, the Japanese firm whose zippers displaced Talon zippers, has prompted a more aggressive, market-oriented approach by the company.

"If you have a protected position, you don't run quite as hard as if someone is chasing you," conceded Velcro USA Chairman William A. Krivsky, who joined the firm about a year ago. "We're trying to get out of low gear."

Moving into higher gear means running after two major mass markets--footwear and the auto industry, both of which have begun using the product, as well as aggressively developing other new markets.

Besides replacing shoelaces in sneakers, Velcro and similar products have begun showing up as closures for high-fashion boots and in other items.

Automobile manufacturers have begun using Velcro in place of screws or glue to install headliners, door panel liners and carpeting in cars, and Velcro hopes that market will grow as automakers search for labor-cost savings. A durable fastener that outlasts most products in which it is used, Velcro works well in cars, where constant motion drives more and more of the hooks into more and more of the loops, according to the company's technical services director, George Provost.

Walter Morris, an industry analyst with Robert W. Baird & Co., estimates that "the shoe and automotive market may be three times as large as the company's total business." In 1982, the holding company of which Velcro USA is a part posted $46.7 million in revenue.

It is a new era for a firm that developed a "gee-whiz" product from a relatively simple prototype--the cocklebur. The inventor, George de Mestral, went hunting with his dog in the Swiss mountains one day in 1948. When he and the dog returned, covered with burrs, de Mestral began to wonder what made the burrs stick.

The burrs were covered with tiny hooks that held fast to loops of dog hair and fabric, he discovered. Although the discovery itself was fairly simple, turning the discovery into a practical product was not. It was years before a loom was developed that would produce hook-and-loop material.

The first manufacturing operations for Velcro USA began in Manchester, N.Y., in 1958. (Velcro USA is one of a handful of quasi-independent operating subsidiaries of Velcro Industries N.V., a holding company. Other manufacturing operations are in Canada, New Zealand, Holland and India.) Initially viewed as a potential replacement for zippers, the original product had initial quality problems, said Velcro USA's president and chief operating officer, Jack K. Mates.

"We had petticoats falling off of gals and brassieres popping open," he said.

In 1960, the company virtually halted production to deal with those problems, eventually overcoming them, Mates said. One of the early technical problems was how to cut the single-filament nylon loops to form hooks to catch on an opposing tape of nappy, multiple-filament loops.

The company ultimately came up with a process in which tiny shearing knives move back and forth, cutting one row of loops at a 3 o'clock angle and the next row at 9 o'clock.

With the improved product, Velcro moved into some substantial markets. "At the same time, we were able to put adhesives on the back of the tapes so they wouldn't always have to be attached by sewing," Mates said. "That really broadened the whole outlook for the product."

One early customer was the military, which liked the product because it was lightweight, didn't come apart in the field and did not rust. An offshoot of that involvement was early involvement in the National Aeronautics and Space Administration's program, producing Astro-Velcro, a heat-resistant product that helps keep items in place when there is no gravity to do the job.

Still another early customer was the aircraft industry, where Velcro was used to install seat covers and other furnishings. "We used to claim we had five miles of Velcro in a 747," said Mates. While the market for new aircraft was hot, business was good for Velcro.

Medical markets also have been good and still are the largest market for Velcro. In addition to being used on blood pressure cuffs, Velcros hold cervical collars and other braces together and is being used (in a cheaper, less long-lasting form) on disposable products such as hospital gowns.

In 1978, the company's patent expired, but even before then Velcro felt the hot breath of competition on its neck, Mates said. "You start to feel people coming after you, they don't wait for that day," he said. "About two years before that, we started to see infringement."

"When you have a patent, you can approach the market from one vantage point," said L. Donald LaTorre, executive vice president. LaTorre was hired nearly a year and a half ago to establish a marketing management department. "We taught people how to use it, and once we taught a customer how to use it, we sort of supplied it on our own terms."

Now the company has become more market-oriented, he said. One facet of that change has been to break the operation into eight major marketing divisions. "As the business has grown, it has gotten so big no one person can get his arms around it," said LaTorre.

The divisions cover apparel and items such as billfolds, medical, transportation, government business, furnishings, consumer products, footwear, and specialty and new applications. The company's marketing operations were moved from New York City to New Hampshire, the heart of its operations and the site of both its mills and its research and development activities.

One problem that the company confronts now is keeping its trademark intact rather than allowing it to be used as a generic term for hook-and-loop fastening. If a manufacturer uses an inferior type of fastener and the consumer identifies it as Velcro, the company is damaged, company officials asserted.

Krivsy said he also would like to see Velcro marketed more directly to consumers. "If you wanted to buy a piece of Velcro, where would you buy it?" he asked. "It ought to be available in supermarkets, corner drug stores and hardware stores.

"Of what we think are the potential uses, we're at the beginning and not at the end," LaTorre said.