2009년 12월 2일 수요일

Upholstery


Upholstery is the work of providing furniture, especially seats, with padding, springs, webbing, and fabric or leather covers. The word upholstery comes from the Middle English words up and holden, meaning to hold up. The term is applied to domestic furniture and also to in automobiles and boats. A person who works with upholstery is called an upholsterer; an apprentice upholsterer is sometimes called an outsider or trimmer.

Upholstery of domestic furniture
The materials which are important to the quality of an upholstered product, such as a bed, sofa, chair or ottoman, may be considered in four categories: the frame (usually wooden) on which the upholstery is to be constructed; the spring system; the cushioning or padding; and the final fabric or leather covering.

Frames
Main article: Upholstery frame
The life of a piece of upholstered furniture begins with its frame: although the underlying wooden framework cannot all be seen in the finished product, the type of wood used to create it will have a bearing on the quality of the final product. Where parts of the frame, such as chair legs, may be seen outside the upholstery these are termed "show-wood".

Some furniture employs softwoods, but may suffer from its difficulty in supporting the joinery that is required for the best quality furniture. The tight graining of hardwoods allows for pegs, screws and tacks to be set securely, reducing the likelihood of their becoming loose over time. Hardwoods used in upholstered furniture include oak, alder and other woods with tight graining. Hardwood laminates are often used for blocks and braces because laminates are actually stronger than solid wood in these applications.

The wood for a piece of upholstered furniture must be assembled into a sturdy frame. Generally, the more rigid the frame the better, because a loose frame can crack or fail, and several craftsman processes can be used to create a good, strong frame. A variety of woods and laminates are used for joining, blocking and dowelling and sometimes several techniques are used.

Joints are the places where one piece of frame wood intersects to another part of the frame at an angle. Joints must be reinforced with blocks or dowels for extra support or the frame will be susceptible to loosening over time.

Blocking refers to the process of placing additional blocks of wood behind or diagonal to joints and corners for support in areas where the furniture craftsman believes there may be greater stress. Blocks provide lateral support and a larger area for screws and fasteners to set wood elements securely. This extra bracing at stress points contributes to the lasting integrity of the frame. An alternative to blocking is dowelling.

Dowelling refers to the process whereby one or two dowels are drilled, hammered and glued into the wood at stress-points to provide extra strength and support to the frame. Nails, screws, fasteners and glue may also support many parts of a frame.

Spring systems
Once the frame is constructed, a spring system is installed to support the seating area. Furniture manufacturers employ two main types of spring support systems: standard springs and eight-way hand tied springs. When the spring system is finished with a top layer of padding, it is commonly called the "seat deck".

Standard Springs provide good support at a lower price than the alternative. Most manufacturers offer either sinuous springs or drop-in-springs as their standard, depending on how they make their furniture. Both types affix to the frame to support the seat deck. Standard springs have a formal, very firm "sit" and only move in the up/down direction. In contrast, eight-way hand-tied springs can move in many more directions.

Sinuous springs are heavy-gauge steel springs that have been heat formed into continuous "S" shapes. They are cut into lengths and affixed to the frame. Drop-in Springs are mass-manufactured welded units that are more cheaply manufactured and considered to be of lower quality than sinuous springs.

Eight-way hand-tied springs have a wide range of movement providing a very even and individual "sit", because they move up and down and side to side. In the construction of these systems, the craftsman individually ties heavy gauge coils from front to back, side to side and diagonally (eight ways) to provide the highest level of quality, comfort and durability. This process costs more because it is time consuming and can only be done by hand.

[edit] Cushions, pillows, padding and fills
Once a piece of upholstered furniture has its frame and springs, the next components are the cushions and padding. Seat cushions sit on top of the spring system and seat deck. Back pillows, if present, rest against the back and arms of the piece.

Most cushions are made of a high-density foam core that is then wrapped with either soft polyester, feather and down, or a hypoallergenic down substitute. Dacron adds resilience so that pillows and seats keep their shape, while the wraps form a soft envelope. Cushions and pillows are usually sewn into cotton cases to ensure smooth upholstering.

Feather and down offers the maximum comfort and softness in cushions and pillows that most people desire and designers prefer. Feather and down back pillows and wrapped seat cushions can always be "fluffed-up" to maintain an attractive look. Feather and down fills and wraps require a little more maintenance than polyester and high density-foam but they have greater comfort, durability and resilience.

Buckwheat hulls are also used as filling for a variety of upholstered goods, including pillows and zafu. The hulls are durable and do not conduct or reflect heat as much as synthetic fills. They are sometimes marketed as an alternative natural fill to feathers for those with allergies.

Horsehair and hay have also been used in upholstery as cushioning/padding, however this practice is not as common today as using foam.

[edit] Fabrics and leathers
Textiles, a term used in the furniture industry, encompass both fabrics and leathers and the choice of textiles can account for up to 80% of furniture price.

Tightly woven fabrics and blends tend to wear longer than light or loose-weave natural fibers.

Leather is a durable and easy-care natural material that softens and improves with time. To create quality leather, top-grain hides are tanned, processed and dyed to give a certain color or look. Tanning refers to the process in which salts are used to cure the hide and to stabilize its shape. Dyeing refers to infusing the hide with different color dyes.

Aniline dyeing is a high quality process that imparts color but does not disguise the natural character of the hide. Some leathers are further treated with a pattern, texture, or polish.


Automobile upholstery

A typical leather-upholstered car seat.An Automotive upholsterer is also known as a Trimmer, Coachtrimmer or Motor Trimmer. The trade shares many of the skills required in upholstery, in addition to being able to work with carpet.

The term Coachtrimmer derives from the days when car bodies were produced by manufactures and delivered to Coachbuilders to add a car body and interior trimmings. Trimmers would produce soft furnishings, carpets, soft tops and roof linings often to order to customer specifications. Later Trim shops were often an in-house part of the production line as the production process was broken down into smaller parts manageable by semi-skilled labor.

Many automotive trimmers now work either in automotive design or with aftermarket trim shops carrying out repairs, restorations or conversions for customers directly. A few high quality motor car manufacturers still employ trimmers, for example Aston Martin. The way the market is changing and manufacturers are cutting corners, it is a better idea to use a trim shop to use aftermarket materials. Adding your own touch can be a way to show originality while retaining the retail value of the vehicle. In some cases actually raising the retail value. Trim shops are now equipped with a higher quality, longer lasting and better color fastness, than many manufacturers.

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