production of needles

Sewing needle

Needles used for hand sewing

A sewing needle is a long slender tool with a pointed tip. The first needles were made of bone or wood; modern ones are manufactured from high carbon steel wire, nickel- or gold plated for corrosion resistance. The highest quality embroidery needles are plated with two-thirds platinumand one-thirds titanium alloy. Traditionally, needles have been kept in needle books or needle cases which have become an object of adornment.

A needle for hand sewing has a hole, called the eye, at the non-pointed end to carry thread or cord through the fabric after the pointed end pierces it. Hand sewing needles have different names depending on their purpose.

Needle size is denoted by a number on the packet. The convention for sizing is that the length and thickness of a needle increases as the size number decreases. For example, a size 1 needle will be thicker and longer, while a size 10 will be shorter and finer.

Contents  [hide] ·         1 Types of hand sewing needles ·         2 Special purpose needles ·         3 Needles in archaeology ·         4 How sewing needles are made ·         5 Notes ·         6 See also

[edit]Types of hand sewing needles

Eye of a No.5 sharp

These come in 10 sizes, ranging from No.1: very heavy to No.12: very fine.

§  Sharps are needles used for general sewing. They have a sharp point, a round eye and are of medium length. The difference between sharps and other sewing needles can mainly be seen in their length.

§  Embroidery needles, also known as Crewel needles, are identical to sharps but have a longer eye to enable easier threading of multiple embroidery threads and thicker yarns.

§  Betweens or Quilting needles are shorter, with a small rounded eye and are usually used for making fine stitches on heavy fabrics such as in tailoring, quilt making and other detailed handwork.

§  Milliners' needles are longer than sharps, are useful for basting and pleating, and are used inmillinery work.

§  Easy- or Self-threading needles, also called Calyx-eyed Sharps, have a slot for the thread, rather than an eye.

§  Side threading needles, also called Spiral Eye needles, have a slot in the side of the eye to make threading easier and still stay threaded when using them.

[edit]Special purpose needles

These needles come in various sizes so numbering will differ from the needles described above.

§  Ballpoints have a rounded point and are used for knitted fabrics. Sizes 5-10.

§  Beading needles are very fine, with a narrow eye to enable it to fit through the centre of beads and sequins. They are usually long so that a number of beads can be threaded at a time. Sizes 10-15.

§  Bodkin. This is a long, thick needle with a ballpoint end and a large, elongated eye. They can be flat or round and are generally used for threading elastic, ribbon or tape through casings and lace openings.

§  Chenille needles are similar to tapestry needles, but with large, long eyes and a very sharp point to penetrate close weave fabrics. Useful for ribbon embroidery. Sizes 13-26.

§  Darning needles have a blunt tip and large eye, similar to tapestry needles, but are longer, with yarn darners being the heaviest with very large eyes to thread yarn. Various types, with sizes ranging from 1-18.

§  Doll needles are long and thin and are used for soft sculpturing on dolls, particularly facial details. Size 2.5"-7" long.

§  Leather needles, also known as Glovers needles, have a triangular point for piercing the leather without tearing it. Used on leather, suede, vinyl and plastic. Also known as wedge needle, this may also describe the shape. Sizes 3/0-10.

§  Sailmaker needles are similar to leather needles, but the triangular point extends further up the shaft. Used for sewing thick canvas or heavy leather.

§  Spiral Eye Side Threading needles come in a variety of sizes and types. The precision cut and the geometry of the eye allows for most material to slide over the opening on the side. Good for those with low vision or dexterity issues.^[1]

§  Tapestry needles have a large eye and a blunt tip. They are used for working on embroidery canvas, even-weave material and other loosely woven fabrics. The blunt tip allow the needle to pass through the fabric without damaging it. Double ended tapestry needles, with the eye in the middle, are also available for the convenience of embroiderers who work with fabric mounted in a frame. Sizes from 13 (heaviest) to 28 (finest).

§  Tatting needles are long and are the same thickness for their entire length, including at the eye, to enable thread to be pulled through the double stitches used in tatting.

§  Upholstery needles are heavy, long needles that can be straight or curved. Used for sewing heavy fabrics, upholstery work, tufting and for tying quilts. Curved needles are used for difficult situations where a straight needle is not practical and are also used in fabric box-making. Heavy duty 12" needles are used for repairing mattresses. Straight sizes: 3"-12" long, curved: 1.5"-6" long.

[edit]Needles in archaeology

Magdalenian, Gourdan-Polignan France - Muséum of Toulouse

A variety of archaeological finds illustrate sewing has been present for thousands of years. The Romans left elaborate traces of their sewing technology, especially thimbles and needles. Even earlier Stone Age finds, such as the excavations on the island of Öland at Alby, Sweden, reveal objects such as bone needle cases dating to 6000 BC. Ivory needles were also found dated to 30,000 years ago at the Kostenki site in Russia.^[2] Native Americanswere known to use sewing needles from natural sources. One such source, theagave plant, provided both the needle and the "thread." The agave leaf would be soaked for an extended period of time, leaving a pulp, long, stringy fibers and a sharp tip connecting the ends of the fibers. The "needle" is essentially what was the tip end of the leaf. Once the fibers dried, the fibers and "needle" could then be used to sew together skins and other items used in a cloth-like manner.

[edit]How sewing needles are made

1.    The raw material is a high quality steel coil which is drawn down to the required size.

2.    From the coils the wire is straightened and cut to the length of two needles.

3.    Each length of wire is pointed at both ends.

4.    Pairs of matching dies stamp the eye impression in the centre of the wire

5.    A hole is punched through the two eyes at the centre.

6.    The wires are broken into two separate needles.

7.    The waste metal around the sides of the eye is clipped or ground off.

8.    The waste metal from the top of the eye is clipped or ground off.

9.    So far the wire has been soft, but it is now hardened

10.  It is tempered to ensure the correct amount of spring in each needle.

11.  The needle is scoured which both cleans it, makes it completely smooth and highly polished.

12.  The needles are usually nickel plated unless a special coating such as gold or platinum is required.^[3]

Finally, every needle is inspected by eye before being packaged for sale

production of zips

A zipper (British English: zip or (rarely) zip fastener) is a commonly used device for temporarily joining two edges of fabric. It is used in clothing (e.g., jackets and jeans), luggageand other bags, sporting goods, camping gear (e.g., tents and sleeping bags), and other daily use items.

Description

The bulk of a zipper consists of two strips of fabric tape, each affixed to one of the two pieces to be joined, carrying from tens to hundreds of specially shaped metal or plastic teeth. These teeth can be either individual or shaped from a continuous coil, and are also referred to aselements.^[1] The slider, operated by hand, moves along the rows of teeth. Inside the slider is a Y-shaped channel that meshes together or separates the opposing rows of teeth, depending on the direction of the slider's movement.

Some zippers have two sliders, allowing variation in the opening's size and position. In most jackets and similar garments, the opening is closed entirely when one slider is at each end. In most baggage, the opening is closed entirely when the two sliders are next to each other at any point along the zipper.

Zippers may:

§  increase or decrease the size of an opening to allow or restrict the passage of objects, as in the fly of trousers or in a pocket.

§  join or separate two ends or sides of a single garment, as in the front of a jacket, dress or skirt.

§  attach or detach a separable part of the garment to or from another, as in the conversion between trousers and shorts or the connection / disconnection of a hood and a coat.

§  decorate an item.

These variations are achieved by sewing one end of the zipper together, sewing both ends together, or allowing both ends of the zipper to fall completely apart.

A zipper costs relatively little, but if it fails, the garment may be unusable until the zipper is repaired or replaced—which can be quite difficult and expensive. Problems often lie with the zipper slider; when it becomes worn it does not properly align and join the alternating teeth. If a zipper fails, it can either jam (i.e. get stuck) or partially break off.

History

Elias Howe, who invented the sewing machine, received a patent in 1851 for an "Automatic, Continuous Clothing Closure". Perhaps because of the success of his sewing machine, he did not try to seriously market it, and missed out on any recognition he might otherwise have received. Forty-two years later, Whitcomb Judson, who invented the pneumatic street railway, marketed a "Clasp Locker". The device was similar to Howe's patent, but actually served as a (more complicated) hook-and-eye shoe fastener. With the support of businessman Colonel Lewis Walker, Whitcomb launched the Universal Fastener Company to manufacture the new device. The clasp locker had its public debut at the 1893 Chicago World's Fair and met with little commercial success.

Gideon Sundbäck, a Swedish-American electrical engineer, was hired to work for the Universal Fastener Company in Hoboken, New Jerseyin 1906. Good technical skills and a marriage to the plant-manager's daughter Elvira Aronson led Sundbäck to the position of head designer. After his wife's death in 1911, he devoted himself to the worktable, and by December 1913 had designed the modern zipper.

Sundbäck increased the number of fastening elements from four per inch to ten or eleven, introduced two facing rows of teeth that pulled into a single piece by the slider, and increased the opening for the teeth guided by the slider. The patent for the "Separable Fastener" was issued in 1917. Sundbäck also created the manufacturing machine for the new device. The "S-L" or "scrapless" machine took a special Y-shaped wire and cut scoops from it, then punched the scoop dimple and nib, and clamped each scoop on a cloth tape to produce a continuous zipper chain. Within the first year of operation, Sundbäck's machinery was producing a few hundred feet of fastener per day.

Zipper slider brings together the two sides

The popular "zipper" name came from the B. F. Goodrich Company; they opted to use Sundbäck's fastener on a new type of rubber boots (or galoshes) and referred to it as the zipper, and the name stuck. The two chief uses of the zipper in its early years were for closing boots and tobaccopouches. However, it was almost twenty years before the fashion industry began seriously promoting the novel closure on garments.

In the 1930s, a sales campaign began for children's clothing featuring zippers. The campaign praised zippers for promoting self-reliance in young children by making it possible for them to dress in self-help clothing. The zipper beat the button in 1937 in the "Battle of the Fly", afterFrench fashion designers raved over zippers in men's trousers. Esquire declared the zipper the "Newest Tailoring Idea for Men" and among the zippered fly's many virtues was that it would exclude "The Possibility of Unintentional and Embarrassing Disarray."

The most recent innovation in the zipper's design was the introduction of models that could open on both ends, as on jackets. Today the zipper is by far the most widespread fastener, and is found on clothing, luggage, leather goods, and various other objects.^[2]

Types

A coil zipper with its slider removed.

§  Coil zippers now form the bulk of sales of zippers worldwide. The slider runs on two coils on each side; the "teeth" are the coils. Two basic types of coils are used: one with coils in spiral form, usually with a cord running inside the coils; the other with coils in ladder form, also called the Ruhrmann type. This second type is now used only in a few parts of the world, mainly in South Asia. Coil zippers are made of polyester coil and are thus also known as polyester zippers. Nylon was formerly used and though only polyester is used now, the type is still known as a nylon zipper.

§  Invisible zippers' teeth are behind the tape. The tape's color matches the garment's, as does the slider, so that, except the slider, the zipper is "invisible". This kind of a zipper is common in skirts and dresses. Invisible zippers are usually coil zippers. They are also seeing increased use by the military and emergency services because the appearance of a button down shirt can be maintained, while providing a quick and easy fastening system.

§  Metallic zippers are the classic zipper type, found mostly in jeans today. The teeth are not a coil, but are individual pieces of metal moulded into shape and set on the zipper tape at regular intervals. Metal zippers are made in brass, aluminum and nickel, according to the metal used for teeth making. All these zippers are basically made from flat wire. A special type of metal zipper is made from pre-formed wire, usually brass but sometimes other metals too. Only a few companies in the world have the technology. This type of pre-formed metal zippers is mainly used in high grade jeanswear, workwear, etc., where high strength is required and zippers need to withstand tough washing.

§  Plastic-molded zippers are identical to metallic zippers, except that the teeth are plastic instead of metal. Metal zippers can be painted to match the surrounding fabric; plastic zippers can be made in any color of plastic. Plastic zippers mostly use polyacetal resin though other resins are used as well, such as polyethylene.

§  Open-ended zippers use a "box and pin" mechanism to lock the two sides of the zipper into place, often in jackets. Open-ended zippers can be of any of the above specified types.

§  Closed-ended zippers are closed at both ends; they are often used in baggage.

[edit]Airtight / Watertight zippers

Waterproof zipper on a diving dry suit. The exterior metal segments clamp the waterproof sheeting over the individual zipper teeth. The zipper teeth are not visible in this image.

Airtight zippers were first developed by NASA for making high-altitude pressure suitsand later space suits, capable of retaining air pressure inside the suit in the vacuumof space.

The airtight zipper is built like a standard toothed zipper, but with the zipper teeth wrapped in a fabric-reinforced polyethylene sheeting. The sheeting is then crimped around each zipper tooth using a C-shaped metal clip. As the zipper is closed, the facing edges of the plastic sheeting are pressed together between the C-shaped clips, both above and below the zipper teeth.

This double-mated surface is good at retaining both vacuum and pressure, but the fit must be very tight to press the surfaces together firmly. Consequently these zippers are typically very stiff when zipped shut and have very minimal flex or stretch. They are hard to open and close because the zipper anvil must bend apart teeth that are being held together by the tough plastic sheeting. They can also be derailed and damage the sealing surfaces if the teeth are misaligned while straining to pull the zipper shut.

These zippers are very common where airtight or watertight seals are needed, such as on scuba diving dry suits, ocean survival suits andhazmat suits.

A second, less common water-resistant zipper is similar in construction to a standard toothed zipper, but includes a molded plastic ridge seal similar to the mating surfaces on a ziploc bag. Such a zipper is much easier to open and close than a clipped version, and the slider has a gap above the zipper teeth for separating the ridge seal. However, this ridge seal is structurally weak against internal pressure, and can be separated by pressure within the sealed container pushing outward on the ridges, which will simply flex and spread apart, potentially allowing air or liquid entry through the spread-open ridges. Ridge-sealed zippers are sometimes seen on lower cost surface dry suits.

[edit]Components

Components of a zipper

The components of a zipper are:

§  1 - top tape extension

§  2 - top stop

§  3 - slider

§  4 - pull tab

§  5 - tape

§  6 - chain width

§  7 - bottom stop

§  8 - bottom tape extension

§  9 - single tape width

§  10 - insertion pin

§  11 - retainer box

§  12 - reinforcement film

[edit]Manufacturing

Japan makes 90% of the world's zippers^{[citation needed]}.^[3]

One large manufacturer is YKK, which has production facilities in 68 countries and the world’s largest zipper manufacturing center in Macon, Georgia, USA, with 900 employees^{[citation needed]}. Almost all of the rest are made in South Asia and East Asia^{[citation needed]}. Major zipper manufacturing countries in South Asia are now Bangladesh, India and Pakistan