There are many products that use textile in a good measure.
One of such textile products
is the umbrella. An umbrella can be simply defined as a canopy for protection against rain, snow or sunlight.
The term umbrella has been derived from the Latin word umbra which means "shade".
Umbrellas are generally hand-held portable devices rendering fashion statement in some societies
and used as an accessory in some other societies. However, some of these can be big enough
that can be fixed to patio tables or other outdoor furniture. They are the 'Parasols', the term
which is synonymously used for umbrellas as well. Parasols can be bigger as well as smaller
but they are primarily meant for protection only against sun.
Fabric Selection for Umbrellas
Historically speaking, a variety of fabrics had been used for making umbrellas that included linen, cotton, leather, taffeta variety of silk, lace and the special fabric that was first made for umbrellas only- the Gloria. Gloria which means ' bright', is a plain weave of silk and wool, and silk and cotton. After that, rayon and acetate were widely used for making umbrellas. Nowadays, the fabric generally used is nylon taffeta with an acrylic coating on the underside and a scotch-guard type finish on the top. Most recently,
with new water repellent finishes are also being used by the umbrella manufacturers
When using nylon taffeta, the fabric's coating and finish are generally done by the fabric suppliers. It's the prerogative of the
to select the fabric patterns and designs. These umbrella manufacturers can even add their own patterns and designs with the help of rotary or silk screening processes which is cost effective only for a special order of a limited number of umbrellas.
The Making of Umbrella
Umbrella manufacturing is basically a hand-assembly process where various parts are joined to each other in a methodical manner. Apart from the canopy made of fabric, the other parts of umbrella are Shaft, Ribs, Stretchers, Runner, and Handle. They can be made of wood, metal, plastic or any other such material.
It is usually made from wood, steel, or aluminum. Sometimes Fiberglass and other plastics are used, which can commonly be seen in the larger golf umbrellas. When consisting of wood, shafts are made with the help of wood-shaping machines such as turning machines and lathes. Metal and plastic shafts are drawn or extruded for giving them the required shape.
Ribs and Stretchers
Ribs run underneath the canopy of the umbrella and stretchers join the ribs with the shaft of the umbrella. They are assembled methodically to give "U" shape to the ribs and are usually made of steel or some other such metal. The ribs are attached to the shaft by fitting it into a top notc--a thin, round nylon or plastic piece with teeth around the edges, and then held with thin wire. The stretchers are connected to the shaft of the umbrella with a plastic or metal runner, the piece that moves along the shaft of the umbrella when it is opened or closed.
The ribs and stretchers are interconnected with a joiner, which is usually a small jointed metal hinge. When the umbrella is opened or closed, the joiner opens or closes simultaneously through an angle of more than 90 degrees. Then there are two catch springs in the shaft of each umbrella. They are small pieces of metal that has to be pressed whenever the umbrella is slid up the shaft to open, and again when the umbrella is slid down the shaft for closing. Metal shafts are generally hollow so that the catch spring can be inserted in it without much efforts. A wooden shaft requires to be hollowed out to make space for the catch spring. A pin or other blocking device is usually placed into the shaft a few inches above the upper catch spring to prevent the canopy from sliding past the top of umbrella, when the runner goes beyond the upper catch spring
The canopy of the umbrella is hand sewn to the ribs in form of individual panels. The canopy cannot be cut from one piece of cloth because each panel has to be shaped according to the curve of the canopy by making the panels follow the thread pattern of the weave, otherwise the material will pull on the bias and create puckers. Each panel is cut separately from piles of materials called gores. Machine cutting of several layers at once is also possible which is less cumbersome. The standard rain umbrella has eight panels. However, there can be six panels in smaller umbrellas such as parasols and children's umbrellas. The larger umbrellas can have as many as twelve panels too.
A metal ferrule may or may not be forced over and glued to the tip of the umbrella that passes through the canopy. The handle made of wood, plastic, metal, or any other material is fixed at the end of the shaft with the help of screw or glue. The end tips of the cover where the ribs reach past the canopy, may be left without any covering or may be covered with small plastic or wood end caps that are either pushed or screwed on, or glued, and then sewn to the ends of the ribs through small holes in the end caps. This completes the process of making an umbrella.
Variations of Umbrella
The above described process is typically followed for making a stick umbrella.
There are collapsible rain umbrellas too, which are mechanically more complicated than stick umbrellas,
although they are made through the same basic technology. The difference between the two is that while making
a collapsible umbrella a two piece shaft that telescopes into itself is used. Apart from this, an extra set of
runners along the top of the umbrella is also provided.
A good quality umbrella is always comfortable to use and truly serves the purpose for which it is made. At one point of time, an umbrella having a number of panels was considered to be of good quality but with the improvement in quality of fabrics and other materials, it no longer stands as a criterion for a good quality umbrella. When buying an umbrella one should look for the comfort of the handle, the ease with which the umbrella is opened and closed, and the closeness with which the canopy segments are connected to the ribs.