Umbrella - How is it Made
Wednesday, October 29, 2008
A modern umbrella is made by a hand-assembly process that, except for a few critical areas, can be done by semi-skilled workers. Choices of materials and quality control occur throughout the manufacturing process. Although a well-made umbrella need not be expensive, almost every purchasing decision impacts directly upon the quality of the final product.
Collapsible rain umbrella that telescope into a length of about a foot is the most recent innovations in umbrellas. Though mechanically more complicated than stick umbrellas, they share the same basic technology. Among the differences between a stick umbrella and a collapsible umbrella is that the collapsible uses a two piece shaft that telescopes into itself, and an extra set of runners along the top of the umbrella. This section will focus on the manufacture of a stick umbrella.
The stick umbrella will usually begin its life as a shaft of either wood, steel, or aluminum, approximately 3/8 inch (.95 centimeter) thick. Fiberglass and other plastics are occasionally used, and in fact they are common in the larger golf umbrella. Wood from various types of ash trees, including Rowan wood from Asia, is among the popular choices for a sturdy wood shaft. While wood shafts are made using standard wood-shaping machines such as turning machines and lathes, metal and plastic shafts can be drawn or extruded to the proper shape.
The ribs and stretchers are assembled first, usually from "U" shaped or channeled steel or other metal. Ribs run underneath the top or canopy of the umbrella; stretchers connect the ribs with the shaft of the umbrella. The ribs are attached to the shaft of the umbrella by fitting into a top notch—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.
Next, the ribs and stretchers are connected to each other with a joiner, which is usually a small jointed metal hinge; as the umbrella is opened or closed, the joiner opens or closes through an angle of more than 90 degrees.
There are two catch springs in the shaft of each umbrella; these are small pieces of metal that need to be pressed when the umbrella is slid up the shaft to open, and again when the umbrella is slid down the shaft for closing. Metal shafts are usually hollow, and the catch spring can be inserted, while a wood shaft requires that a space for the catch spring be hollowed out. 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 cover or canopy of the umbrella is hand sewn in individual panels to the ribs. Because each panel has to be shaped to the curve of the canopy, the cover cannot be cut in one piece. Panels are sewn at the outer edges of the ribs, and there are also connections between the ribs and the panels about one-third of the way down from the outer edge of the canopy. Each panel is cut separately from piles of materials called gores; machine cutting of several layers at once is possible, although hand-cutting is more typical. The typical rain umbrella has eight panels, although some umbrellas with six panels (children's umbrellas and parasols usually have six panels) and as many as twelve can occasionally be found. At one point, the number of panels in an umbrella may have been an indication of quality (or at least of the amount of attention the umbrella maker paid to his product). Today, because of the quality of the material available to the umbrella maker, the number of panels is usually a matter of style and taste rather than quality.
The fabric used in a good-quality umbrella canopy is usually a nylon taffeta rated at 190T (190 threads per inch), with an acrylic coating on the underside and a scotch-guard type finish on the top. The coating and finish are usually applied by the fabric supplier. Fabric patterns and designs can be chosen by the manufacturer, or the manufacturer might add his own patterns and designs using a rotary or silk screening process, especially for a special order of a limited number of umbrellas. Similarly, other fabrics besides nylon might be used according to need or taste; a patio umbrella attached to an outdoor table does not have to be lightweight and waterproof as much as a customer might want it to be large, durable, and attractive.
The tip of the umbrella that passes through the canopy can be covered with metal (a ferrule) that has been forced over and perhaps glued to the tip, or left bare, depending on the desire of the manufacturer. The handle is connected to the shaft at the end of the process, and can be wood, plastic, metal, or any combination of desired ingredients. Though handles can be screwed on, better-quality umbrellas use glue to secure the handle more tightly.
The end tips of the umbrella, where the ribs reach past the canopy, can be left bare or 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.
Finally, the umbrella is packaged accordingly and sent to customers
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Posted byParvez Ahmed at 7:55 AM
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what up i love this information on the umbrellas it is very helpful because i have a hard science project on them tahnks a million o du yhu kno lil wayne