Velcro is a brand name of fabric hook-and-loop
fasteners used for connecting objects.
Velcro was invented
in 1948 by George de Mestral, a Swiss engineer. The idea
came to him after he took a close look at the seed pod burrs
which kept sticking to his dog on their daily walk in the
Alps. De Mestral named his invention after the French words
velours, meaning 'velvet', and crochet,
Velcro consists of two layers: a "hook" side,
which is a piece of fabric covered with tiny plastic hooks,
and a "loop" side, which is covered in equally
tiny plastic loops. When the two sides are pressed together,
the hooks catch in the loops and hold the pieces together.
When the layers are separated, the Velcro strips makes a
telltale ripping sound. Since the name Velcro is
a registered trademark, generic implementations often use
the name "hook and loop", though in common usage, "velcro"
is used generically.
The strength of the Velcro bond depends on how well the
hooks are embedded in the loops and the nature of the force
pulling it apart. If Velcro is used to bond two rigid surfaces,
e.g. auto body panels and frame, the bond is particularly
strong because any force pulling the pieces apart is spread
evenly across all hooks. Also, any force pushing the pieces
together is disproportionally applied to engaging more hooks
and loops. Vibration can cause rigid pieces to improve their
When one or both of the pieces is flexible, e.g. a pocket
flap, the pieces can be pulled apart with a peeling action
which applies the force to relatively few hooks at a time.
If a flexible piece is pulled parallel to the plane of the
velcro surface the force is spread evenly like with rigid
There are three ways to maximise the strength of a Velcro
bond with one or more flexible pieces:
- ensure that the force is applied parallel to the
plane of the Velcro surface, e.g. bending around a corner
- increase the area of the Velcro bond, e.g. long
- use a pulley system, e.g. shoe closures.
Shoe closures can resist a large force with little bonding
area by wrapping a strap through a slot which reduces the
force on the Velcro by ensuring the force is parallel to
the plane of the Velcro and by halving the force on the
Velcro bond by acting as a pulley system.
Velcro has several deficiencies: it tends to accumulate
hair, dust, and fur in its hooks after a few months of regular
use and the loops can become elongated or broken. It often
becomes attached to articles of clothing, especially loosely-woven
items like sweaters. Additionally, the clothing may be damaged
when one attempts to remove the Velcro, even if they are
separated slowly. The tearing noise made by unfastening
Velcro makes it inappropriate for some applications, but
is useful against pickpocketing.
The strength of a Velcro bond depends on how much surface
area is in contact with the Velcro hooks: full-body Velcro
suits have been made that can hold a person to a Velcro-covered
The US Army has the Velcro
company investigating a
silent version of Velcro
for use with Army soldier