Frequently Asked Questions
zipper. The slider interlocks these elements when moved in one direction and disengages
them when moved in the opposite direction. The curved channels inside the slider keep
the teeth spread apart and gradually bring them together thus ensuring proper meshing.
Sliders are usually made from metals such as zinc alloy (by die-casting) or brass/
aluminium strips (by press forming).
The various types of sliders are:
- Pinlock: The puller of the slider has to be manually pressed down to lock the slider
in place and prevent movement. This type of slider is used in low cost zippers.
- Autolock: This slider is always locked in place and a slight tug on the puller while
operating the slider releases the lock only during its operation. This is used in
garments such as dresses and trousers.
- Snaplock: This slider allows operation of the zipper only when the puller is at a
right angle to the zipper. This is also called springlock, flatlock or semi-automatic
lock and is typically used in metal zippers for jeans.
- Nonlock: This slider allows unrestricted movement of the slider. Typical uses
include pockets and luggage where the slider need not be locked in one position.
- Notchlock: This slider is locked when the zipper stringers are pulled apart. This
ensures that any transverse load on the zipper locks the slider in place, which can
be released only by moving the slider. This is used in sleeping bags and similar
- Reversible slider: This slider can be operated from both sides of the zipper and
may be used for applications such as tents, which require operation from both
- Slider with special pullers: This slider is attached with special pullers. The
difference is in the shape of the puller ie. Thumb, ring, stick, wire cast, ball stick
etc. The puller varies depending on the type of application.
- Slider with links: This slider is provided with links only. The customer can attach
customised pulls made of leather, rubber or tape. The different links available are
C link, Q link and link with cramper.
aesthetic point of view but also for application and functionality. A mismatch between
the zipper and the garment can cause huge financial and material loss to all involved
parties. The manufacturer needs to consider the following aspects when selecting a
Type of garment- A skirt or an evening dress usually requires an invisible zipper. Jeans
use metal zippers while jackets usually fashion plastic zips (moulded or coiled). The type
of slider varies from application to application. For example, snow jackets used in
extremely cold conditions use rubber pullers on plastic sliders so that the zipper doesn’t
feel cold when being pulled. Scuba diving suits, on the other hand, use plastic zippers
with plastic sliders, rather than metal zippers, since plastic is more durable under those
Type of fabric- The fabric of the garment is directly related to its application. Fabrics can
be broadly divided into light and heavy depending upon their weight. Light fabrics like
silk, chiffon and polyester require light zippers. Heavy fabrics like denim, jute, cotton
corduroys, lycra blends use heavier zippers capable of withstanding greater stress and
strain. Light zippers such as the invisible zipper blend with the contours of the garment,
making it aesthetically pleasing.
Special processing- Garments go through a series of processes before they are packed
for marketing. These processes may include a series of washing cycles, initially to set
the shrinkage and later to get a particular finish (stone wash, acid wash, wrinkle-free
etc). The manufacturer specifies the test that the zipper needs to pass, which in turn
reveals its suitability for use in such a garment.
Strength & performance requirements- Often, the use to which a garment is put and the
wear & tear it will undergo are deciding factors in the choice of zipper. For example, a
size 3 coil zipper used in a trouser fly will undergo less stress and strain than a size 7
zipper in a factory uniform or outerwear. The classification of zippers by end-use is
defined in British Standards BS3084, section 7, table 3.
Fashion requirements- While the above factors are important, fashion usually commands
the the zipper type for a garment. The design team chooses the type of the zipper based
on its color, finish, performance parameters and appearance on the garment.
made at this stage will have an impact on the entire garment production process.
Today, we will highlight the precautions to be taken while ordering the zipper. Typically,
the garment manufacturers specify their requirements when ordering zippers i.e. the
size, length, colour, and quantity. However, it is important to understand exactly what
these specifications mean.
A common error made while ordering zippers is to measure the length of the teeth or
the length of the opening between the top stop and the bottom stop. A faulty order of
this sort may result in the buyer ending up with a zipper 6 to 12mm short (1/4” to
1/2”). Another error is to measure and order a zipper by taking into account the tape
extension, which will give a much larger zipper than intended. Close-ended zipper:
length should be measured from top of the top stop to the bottom of the bottom stop
Open-ended zipper: length should be measured from top of the top stop to the bottom
of the box & pin
Colours & DTM
Colours that are selected from the standard range are usually delivered faster. Every
zipper manufacturer has a standard shade card with a large number of colour options
(for example, the TEX shade card offers over 300 shades). Colours can also be
DTM(Dyed-To-Match). DTM involves developing 3 colour options for the type of zipper
required, based on fabric swatches provided by the garment manufacturer. The buyer
can select the closest match or request further options. The process of developing DTM
shades sometimes leads to extension of delivery period by 5-7 days. At times, the
matching is extremely difficult, especially if it involves multi-colour fabrics/mixed
yarn/velvets or pile fabrics/fabrics with sheen e.g. silks. In some cases, computer
matching is used to confirm the match between the zipper sample and the swatch.
concerned. Because we custom make each order, once it is impossible to alter the
requirements once it is in production.
Given below is a checklist of technical and commercial requirements that should be kept
in mind before ordering zippers. Go ahead – print it!
Type of Zipper
Specify whether the zipper is metallic, plastic, LFC or CFC, #3 or #5, closed end or open
end, woven or knitted (in case of invisible zippers).
Type of Slider
Specify whether autolock, pinlock or no-lock sliders are required. If you need custom
pullers, be sure to tell us that!
Specify whether the color is from the standard shade card or from some other reference.
Is color approval required before production?
Assess the correct requirement from the garment. Make sure the length corresponds to
the type of zipper measurement. For instance, in the case of a close-ended zipper,
length should be measured from top of the top stop to the bottom of the bottom stop.
For an open-ended zipper, length should be measured from top of the top stop to the
bottom of the box & pin
Specify quantity required by type, color and size.
This specification is particularly important for metal zippers, where several finishes to
the zipper slider are possible.
Make sure both supplier and buyer are clear about the delivery date.
AZO free, nickle free, heavy metal free and other such requirements must be specified in
• Industrial washing, particularly harsh washes, are designed to give the garment or fabric a rugged or ‘worn down’ look. As a result, a zipper, which is typically sown on to the garment before washing, also gets affected.
• DO: close the zipper fully, and tack the top before industrial washing. Failure to do this will result in damage to the slider or the teeth of the zipper
• DO: immediately move washed garments from one sub-process to the next. Leaving garments in wet condition with chemicals on them can result in unforeseen tarnishing of the chain or the slider
• DO: Always test samples for washing before washing bulk, particularly for fluorescent colors,
as fluorescent dye-stuff can sometimes react with brass to cause stains. To avoid stains on
body of garment, keep zipper closed and covered.
• Potential Problems
• Black / green / blue tarnishing seen on Brass parts of zipper: These are copper oxides and chlorides formed due to reaction with washing chemicals.
• White powder seen on zinc parts: These are zinc oxides, and harmless to humans. Can be easily brushed off the zipper with a moist brush. To avoid white powder, don’t leave garments in wet condition after bleaching / scouring
• Broken Puller: Long pullers should be tacked down or tied before washing. Consider using a snap-lock zipper instead of autolock zippers
• Broken Teeth: This is a problem seen if the top of the garment is not tacked, and there are forces pulling the zipper apart. Always tack on the top of the garment before washing
• Green deposit on slider seen after sulfur dyeing: Sulfur dyeing is a very harsh process, and there is no way to avoid these deposits on brass and zinc parts. Extent of deposits can be reduced by ensuring garments are swiftly neutralized and dried after each step.
Use a light fabric fly covering the coil of the
zipper from inside to prevent direct contact of the
coil with the skin
Consider using fusing for light / stretch fabrics to
stabilize the seam
For lined garments, lining should be provided up
to 5 mm short of seam. Lining should stop short of
the fold area
When used with lightweight fabrics, pay special
attention to ensure that the fabric does not
interfere with the slider movement
Use a hook and eye or snap on the inside of the
dress at the top stop end while attaching invisible
zipper in a garment
Take special care when stitching over seams or
on garments with embroidery or embellishments
to make sure slider has free track to move.
Provide a V-notch at the seam to reduce seam
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