Slide Fasteners

7/27/2019 Slide Fasteners

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Slide fasteners or zip-fastenersA zipperor slide fasteneris a device for temporarily joining

two edges of fabric together by means of a sliding tab. It is widely used in

clothing, bags and suitcases, pursed, tents, sleeping bags and other textiles.

Alternatives that are also frequently used are Buttons,

Velcro, laces, buckles, and Safety pins. The bulk of a zip consists of two strips of

fabric tape, one permanently fixed to each of the two flaps to be joined, and each

carrying tens or hundreds of specially shaped metal or plastic teeth. Another part,

the slider, which is operated by hand, rides up and down the two sets of teeth.

Inside the slider is a Y-shaped channel that pushes the opposing sets of teeth

together or apart, depending on the slider's direction of travel. The friction of the

slider against the teeth causes a characteristic buzzing noise, which is probably

the origin of the name zip. Some zips have slides on both sides, allowing one to

vary not only the size, but also the position of the opening.

All zippers are categorized on the basis of the rawmaterial and technology used to manufacture the zipper teeth. The main tape (or

the fabric stringer) is generally made out of polyester yarn (POY), Earlier Cotton

or Cotton-blended with viscose/polyester was used, but now the pure polyester

variety which is mostly in use.

Zips Fastener Sliders used in all types of Zippers are

mainly made of Zinc Alloy, however few sliders are made of Brass of Plastic also,

but most sliders are of zinc alloy only.


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Anatomy of a Zipper

Terminology

CHAIN: The continuous piece that is formed when both

halves of a zipper are meshed together.

CHAIN SIZE: Refers to the specific gauge of the chain, i.e., size of

the teeth.

TEETH: The individual elements that make up the chain.

SLIDER: The device that moves up and down the chain toopen or close the zipper.

PULL TAB: The part of the slider that you hold to move the sliderup or down.

MATERIAL: Refers to the type of chain that is used in theconstruction of the zipper, such as, metal chain,

molded plastic chain or coil (nylon) chain.

TAPE: The fabric part of the zipper.TAPE WIDTH: Refers to the width of the fabric on one side only, of

the zipper chain.

TAPE ENDS: The fabric part of the zipper, that extends beyond theteeth, at the top and /or bottom of the chain.


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STYLE: Refers to the manner in which the zipper isassembled for a particular application.

TOP STOP: Two devices affixed to the bottom end of a zipper, toprevent the slider from coming off the chain.

BOTTOM STOP A device affixed to the bottom end of a zipper, to

prevent further movement of the half of the zipper

from separating.

BRIDGE STOP: A device similar to a bottom stop, used at the top andof a zipper to prevent each half of the zipper from

separating.

PIN: A device used on a separating (jacket type) zipperwhose function is to allow the joining of the two

zipper halves.

BOX: A device used on a separating (jacket type) zipperwhose function is to correctly align the pin, to begin

the joining of the zipper halves.

HEAT SEAL PATCH: The cotton and nylon laminated material fused to thebottom end of a separating zipper, used to reinforce

the type.

HEAT-SEALABLE

ZIPPERS (WELDABLE

LAMINATED ZIPPERS):

Any zipper that has a strip of plastic fused to each

half of the zipper tape to allow a manufacturer to

electronically "weld" the zipper onto the garment or

item that is being manufactured, without the need of

sewing or stitching.

CONTINUOUS CHAIN: Any material or size of zipper chain that iscontinuously spooled without sliders or any other

components. Typically used by fabricators on a cut-

as-need basis.

CUT-TO-LENGTHZIPPERS:

(Finished Zippers) Any zipper that is finished to a

specific length, with all necessary components

attached.


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Materials for zipper.Zippers may be manufactured from 3 different types of materials as shown below

MetalChain

MoldedPlasticChain

Coil(Nylon)Chain

1.Polyester zippers. CFC, CH, LFC).Coil zippers are often referred to as nylon zippers. These

zippers are very flexible and are available in a variety of sizes (gauges). Coil

zippers have many applications from fashion-wear to all types of tents and

canvas goods.

Teeth of polyester zippers like CFC, CH, and CFC are all

made of 100% polyester monofilament. Polyester zippers.

Polyester zippers are mainly of 4 types.

CFC Coil Filler Cord type,

CH Coil without cord type.

LFC Ladder type coil.


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2.Metal zippers Brass, Aluminium, Bronze or Nickel silver).Metal zippers have been around quite a while. Metal zippers

are available in four different finishes:

Aluminium Chain that is constructed principally from aluminum.

Brass Chain that is constructed of brass, typically a combinationof copper and zinc.

Antique Brass Chain made from brass that is chemically treated to give the

Appearance of worn or tarnished brass.

Black Oxidized Chain made from brass that is chemically treated to a

black matte finish.

3.Plastic Injection moulded zippers

Zipper stylesThere are many styles available in zippers.

In Open-end zippers, both the ends get separated from

each other. A box &pin mechanism is provided on the lower end of the zipper to

join with each other and close it using a slider. These zippers are normally used

on jackets.

Closed-end zippers are non-separating and are normally

opened and closed with a slider. These zippers used on Jeans, shirt pockets etc.

Finishes on sliders.

Many finishes both metallic and non-metallic to suit all

kinds of requirements.

Epoxy painted shades.

Spl painted shade as per swatch

Oxisidized epoxy painted

Cleaned zinc

Nickel and Brass.


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Open and closed types

Multiple slider types.

Manufacturing of zippers
http://www.lenzip.com/styles/bridgetop.htm


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Metal zippersMetal zippers teeth are stamped out of metal strips like

Brass, Aluminium, bronze or even nickel silver alloys .All these have different

fashion appeal as well as varying strengths.

Plastic zippersThese plastic zippers have individually injected molded

teeth, fused directly onto the tape of the zipper. The resins to used to

manufacture the molded plastic chain are incredibly strong. These zippers are

ideal for many medium and heavy weight garments or any outdoor application.

Polyester or Nylon zippers

The teeth of these zippers are extruded plastic, sewn ontothe zipper tape.

Zipper failureFailures in brass slide fasteners occur due to a

phenomenon known as season cracking. More faults arise with slide fasteners

owing to incorrect insertion than because of mechanical defects.

Test Method for zipfastenerThe fastener is clamped at one end, while the other end is

tensioned by means of a 5 lb weight. Crosswise loads of 4 lb are applied to the

two stringers (i.e. tapes) midway between the top and bottom stops so as to

separate them when the fastener is opened. The slide is reciprocated

mechanically so that in the test the fasteners is repeatedly opened and closed

whilst subjected to both lengthwise and crosswise loads.

Based on the width across the chain the slide fasteners

are basically are of 5 types.


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The types with the upper limits of width given in brackets.

Ultra light (3.5mm)

Light (4.5mm)

Medium (6.5mm)

Medium-heavy (6.5mm)

Heavy (9mm)

These measurements are subjected to a 5% upward

tolerance. It will be noticed than there is no diff in width between medium and

medium-heavy, both being over 4.5mm but not exceeding 6.5mm, but the latter

are designed for more arduous applications. The strings may be stronger and

the members (teeth) may also be superior in quality and shape.

For footwear the important types are medium and

medium-heavy.

Result of Endurance test (cycles).

500 cycles -Poor.

500-1000 cycles -Doubtful.

1000-2000 cycles -Satisfactory.

Over 2000 cycles -Good.

Failures in wear are known to have occurred on fasteners,

which gave results of 800 cycles or fewer in the test.

In the endurance test most frequent are that the members

fail to lock and hold together when the slider traverses transversely loaded

position, and that the stringers break or tear, partly or wholly due to abrasion by

slider.


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Slide Fasteners

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