Penicillin Comes Of Age In 'A Fierce Radiance'
It's hard to imagine that people used to die from things as small as a scratch on the knee -- but that's what life was like before penicillin. Author Lauren Belfer's new novel, A Fierce Radiance , follows the intrigue as pharmaceutical companies race to mass-produce lifesaving drugs during World War II.

Ykk India World Leading Zipper Manufacturer Company

YKK India World Leading Zipper Manufacturer Company, YKK produces a vast range of zippers, suitable for every application from high fashion to heavy industry. Whatever your needs, YKK can supply the fastening solution. Every zipper is made to the highest quality standards and with the attention to detail that has made YKK number one worldwide.

Zipper consists of two strips of fabric tape, each affixed to one of the two pieces to be joined, carrying tens or hundreds of specially shaped metal or plastic teeth. 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 its movement. The friction of the slider against the teeth causes a characteristic buzzing noise, which is probably the origin of the name zip(per). The name also may have originated in the greater speed with which the two sides of a zipper can be joined or separated, compared to the time needed for fastening or undoing laces or buttons

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

Zippers may:

(a) increase the size of an opening to allow the passage of larger objects, as in the fly of trousers or in a pocket .

(b) join or separate completely two ends or sides of a single garment, as in the front of a jacket.

(c) attach or detach completely one separable part of the garment to or from another, as in the conversion between trousers and shorts.

(d) decorate an item.

A zipper costs very little, but if it fails, the garment may be unusable until the zipper is repaired or replaced. Problems often lie with the zipper slider, which may have bent upwards due to wear. If so, it can be easily repaired by pushing the slider downwards

Types

· Coil zippers now form the bulk of sales of zippers world-wide. 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 or to be precise polyester zipper.

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, aluminium 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. These type of pre-formed metal zippers are 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 too like 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.

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