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19 October 2015

Velcro



The invention: 

A material comprising millions of tiny hooks and
loops that work together to create powerful and easy-to-use fasteners
for a wide range of applications.

The person behind the invention:

Georges de Mestral (1904-1990), a Swiss engineer and inventor




From Cockleburs to Fasteners

Since prehistoric times, people have walked through weedy fields
and arrived at home with cockleburs all over their clothing. In 1948, a
Swiss engineer and inventor, Georges de Mestral, found his clothing
full of cockleburs after walking in the Swiss Alps near Geneva.Wondering
why cockleburs stuck to clothing, he began to examine them
under a microscope. De Mestral’s initial examination showed that
each of the thousands of fibrous ends of the cockleburs was tipped
with a tiny hook; it was the hooks that made the cockleburs stick to
fabric. This observation, combined with much subsequent work, led
de Mestral to invent velcro, which was patented in 1957 in the form of
two strips of nylon material. One of the strips contained millions of
tiny hooks, while the other contained a similar number of tiny loops.
When the two strips were pushed together, the hooks were inserted
into the loops, joining the two strips of nylon very firmly. This design
makes velcro extremely useful as a material for fasteners that is used
in applications ranging from sneaker fasteners to fasteners used to
join heart valves during surgery.

Making Velcro Practical

Velcro is not the only invention credited to de Mestral, who also
invented such items as a toy airplane and an asparagus peeler, but it
was his greatest achievement. It is said that his idea for the material
was partly the result of a problem his wife had with a jammed dress
zipper just before an important social engagement. De Mestral’s
idea was to design a sort of locking tape that used the hook-andloop
principle that he had observed under the microscope. Such a
tape, he believed, would never jam. He also believed that the tape
would do away with such annoyances as buttons that popped open
unexpectedly and knots in shoelaces that refused to be untied.
The design of the material envisioned by de Mestral took seven
years of painstaking effort. When it was finished, de Mestral named
it “velcro” (a contraction of the French phrase velvet crochet, meaning
velvet hook), patented it, and opened a factory to manufacture
it. Velcro’s design required that de Mestral identify the optimal
number of hooks and loops to be used. He eventually found that using
approximately three hundred per square inch worked best. In
addition, his studies showed that nylon was an excellent material
for his purposes, although it had to be stiffened somewhat to work
well. Much additional experimentation showed that the most effective
way of producing the necessary stiffening was to subject the
velcro to infrared light after manufacturing it.
Other researchers have demonstrated that velcrolike materials
need not be made of nylon. For example, a new micromechanical
velcrolike material (microvelcro) that medical researchers believe
will soon be used to hold together blood vessels after surgery is
made of minute silicon loops and hooks. This material is thought to
be superior to other materials for such applications because it will
not be redissolved prematurely by the body. Other uses for microvelcro
may be to hold together tiny electronic components in miniaturized
computers without the use of glue or other adhesives.Amajor
advantage of the use of microvelcro in such situations is that it is
resistant to changes of temperature as well as to most chemicals that
destroy glue and other adhesives.

Impact

In 1957, when velcro was patented, there were four main ways to
hold things together. These involved the use of buttons, laces, snaps,
and zippers (which had been invented by Chicagoan Whitcomb L.
Judson in 1892). All these devices had drawbacks; zippers can jam,
buttons can come open at embarrassing times, and shoelaces can
form knots that are difficult to unfasten. Almost immediately after
velcro was introduced, its use became widespread; velcro fasteners
can be found on or in clothing, shoes, watchbands, wallets, back-
packs, bookbags, motor vehicles, space suits, blood-pressure cuffs,
and in many other places. There is even a “wall jumping” game incorporating
velcro in which a wall is covered with a well-supported
piece of velcro. People who want to play put on jackets made of
velcro and jump as high as they can. Wherever they land on the wall,
the velcro will join together, making them stick.
Wall jumping, silly though it may be, demonstrates the tremendous
holding power of velcro; a velcro jacket can keep a twohundred-
pound person suspended froma wall. This great strength is
used in a more serious way in the design of the items used to anchor
astronauts to space shuttles and to buckle on parachutes. In addition,
velcro is washable, comes in many colors, and will not jam. No
doubt many more uses for this innovative product will be found.



Georges de Mestral



Georges de Mestral got his idea for Velcro in part during a
hunting trip on his estates and in part before an important formal
social function. These contexts are evidence of the high
standing in Swiss society held by de Mestral, an engineer and
manufacturer. In fact, de Mestral, who was born in 1904, came
from a illustrious line of noble landowners. Their prize possession
was one of Switzerland’s famous residences, the castle of
Saint Saphorin on Morges.
Built on the site of yet older fortifications, the castle was
completed by François-Louis de Pesme in 1710. An enemy of
King Louis XIV, de Pesme served in the military forces of Austria,
Holland, and England, rising to the rank of lieutenant general,
but he is best known for driving off a Turkish invasion fleet
on the Danube in 1695. Other forebears include the diplomat
Armand- François Louis de Mestral (1738-1805) and his father,
Albert-Georges-Constantin de Mestral (1878-1966), an agricultural
engineer.
The castle passed to the father’s four sons and eventually
into the care of the inventor. It in turn was inherited by Georges
de Mestral’s sons Henri and François when he died in 1990 in
Genolier, Switzerland.


See also : Artificial heart