1. Measurement and Length Tolerance

Before measuring the length of a zipper, close the zipper by pulling the slider to the right position, as shown in the diagram below.


For one-way open-end zippers, the correct length is the figure measured from the bottom of the chain to the top head of the slider.


For one-way closed-end zippers, the correct length is the figure measured from the bottom stopper to the top head of the slider.


For two-way closed-end zippers, the correct length is the figure measured from the top stopper to the bottom stopper.


The measurements for two-way closed-end zippers and two-way open-end zippers are the same. The correct length is the figure measured from the head of the bottom slider to the head of the top slider.


The letter “L “shows in the following picture is the right length measured.

2. Factors to Samples’ Color Difference

1) Different fabrics of the same colour including floss, reflective fabric, blended fabric and ultra-thin fabric have a different hue reflection on the inspector. Therefore, the colour of lap dips/samples made according to the hue reflection of different fabrics, display significant colour difference.


2) On a general basis, the bigger the size, the more accurate the colour hue reflecting on the inspector is. due to this, the fabric samples acquired by YCC from customers, should not be smaller than 2cm*2cm.


3) Different fabrics display different absorbing abilities when introduced to dye. this is the reason why colours of some lad dips/samples cannot reach the same brightness as that of fabric samples offered.


4) Colour hue reflection will be different if the tape is inspected under a different kind of light, in an alternative environment, or by another person. Contrary to this, YCC implement an independant colour inspection, conducted by professional QC staff under light D65.


5) Water repellent membrane has an impact of the tape colour when exposed. Despite this, it is professional practice to only take the colour of tape without posting membrane as standard.

3. Zippers for Children’s Apparel

Children’s apparel means clothes for persons range from newborn infants to juveniles in 14 years old, classified into ,generally, toddlers and pupils (0-7 years old), and juveniles (7-14 years old), who are immature and of great interest in everything that they have no or relatively weak ability to discern potential risks which could cause mechanical injures to them. What’s more, being at their growing-up stage, they are vulnerable to invasions and damages from outside world. Therefore, zippers, as one type of garment trims, should be pretty safe enough in its design and functions to ensure children’s safety.


Following classifications of zippers are inadvisable for children’s apparel.

1)No.3 water repellent nylon zippers; 2)Invisible zippers; 3)No.3 open-end and two-way open-end nylon zippers; 4)No.4 open-end nylon zippers; 5)No.5 two-way open-end nylon zippers; 6)water repellent plastic zippers; 7)No.3 open-end plastic zipper, two-way open-end and 40cm-plus closed-end zippers; 8)No.3 open-end metal zippers; 9)zipper with metal stoppers; 10)closed-end zippers without stoppers; 11)fabric, plastic, rubber, elastic and indirect pullers;12)wadded/filled, looped, pull ring zippers and other pullers with open design.


Besides, all zippers used on children apparel should be nickel-free and KENSIN qualified. Stoppers should be secured and harmless to children.

4. Needle Detection for Zippers

Needle Detection, also called KENSIN in Japan, is a kind of regulation on garments and garment accessories such as buttons, drafted by KENSIN Functioning Products Development Group in 1989. It aims to find out stuffs excess in ferromagnetic materials such as needles that could hurt users.


Therefore, before being sewn on garments, trims like zippers and buttons should go through Needle Detector. However, considering that there may be several zippers and buttons on a garment, another needle detecting standard was formulated.


For different target objectives to be inspected, a multitude of standards were made, as displayed below in the chart:


In YCC, both Needle Detection-qualified and Non-Needle-Detection products are available. The Needle Detection-qualified zippers are up to standards of NC-A and ND-B. Basically, zippers of size 3 and size 5 meets NC-A standard, while zippers of size 8 and size 10(relatively large pullers) meet ND-B standard.


However,different pullers on a zipper may also impact on the inspection result. Zippers with large pullers or circle-type ones may fail the Needle Detection inspection. Another factor that impacts is plating coat on pullers which contains chemical elements unavailable for Needle Detection inspection. Currently, Black Nickel, Antique Nickel and Dull Dark Antique Nickel plating pullers in YCC may contain magnetic elements that could cause the failure of Needle Detection inspection.

5. Inadequacy of Physical Tests on Zippers

Normally, YCC adopted BS3084 as the major physical test standard, but tests such as durability for invisible zippers, zippers damaged with hook cramp and iron flat pullers are judged according to a lower-level standard than that of regular ones. Due to this, it is more beneficial to negotiate with our sales when places orders of this kind.

6. Matching of Zippers and Fabrics

1)Light-color and PU fabrics, orders of contrast colours

We recommend not to use dark coloured zippers with light colour PU fabrics and during packing process place a separator between the garment and zipper to avoid contact during transportation. When ordering contrast zippers the customer must inform the sales team to allow a 18 migration test to be completed.


2)Coating fabrics

It is better not to sew PU or PVC coating fabrics directly with zippers of dark colour as the coating on fabrics would aggravate the colour migration. It is necessary to place a separator between them.


3)Leather fabrics

In tanning dye process, chemical reaction could happen when metal parts contact with the remained acid and chromium and sulfur compounds on fabrics. On this point, direct contact between zippers and leather fabrics is not recommended unless chemical ingredients on leathers are cleaned out and leathers are dried up after tanning.

7. Zipper Selection for Garment Levels
8. Garment Dyeing’s Effect

Dye and auxiliaries used in garment dyeing process vary according to the different natures of fabrics. For example, Sulfur Dye, Reactive Dye or Direct Dye is for cotton fabrics, while Acid Dye is for nylon products. In addition, some chemicals like reducing and oxidizing agents, acids and alkalis may be also added in this process. Garment process takes a long time which will probably be 7 to 8 hours, during which unavoidable and undesirable changes would happen to zippers, if they were dyed together with garments.

Here are some possible damages should be noted:


1) Corrosion of sliders, metal box/pin and top/bottom stops by dye agents and chemical solutions;


2) The shrinkage of zipper size, the hunch-up or waving of zippers due to a long-time heat;


3) Color migration caused by the reaction between metal zippers and acid dyestuffs;


4) The peel-off of reinforced tape on open-end zippers due to a long-time soaking of high temperature;


5) Poor color fastness of zipper.

9. Garment Washing’s Effect

Laundry has a big difference with Garment/Industrial Washing. Zippers are only available for laundry. Following damages could happen if Garment/Industrial Washing applied.


1)Damages on Zipper

Sliders or teeth may scratch with inner washing machine leading to the peel-off of paint or plating; slider may insert the holes of the tumble to cause the broken-off and torsion of pullers and covers; if washed without being zipped, zippers’ boxes, pins and teeth would be damaged. (If washing is indeed necessary, zippers should be wrapped with chain zipped and pullers fastened.)


2)Chemical Reaction

The remained dye stuffs and chemicals on zippers may react with metal parts on zippers to cause the color change on zippers if not cleaned and dried up timely after garment washing,



Slightly shrinkage could happen to tapes.

10. Garment Ironing’s Effect

The Possible Major Effects:

1) Wax protection on metal zipper teeth would dissolve under heat, thus staining the fabrics.


2) High temperature from the iron would make zippers curved and soften the teeth to a different type.


3) Metal parts would react with moisture or steams in ironing process which produces blue rust stains(Cu2+)on fabrics.


4) When ironing, high temperature would bring about the shrinkage of tapes or even serious shrinkage to make zipper pucker, as well as the melting of water repellent membrane or bulge on zippers.


We suggest that garment ironing should be done under temperature of 130℃ within five minutes, meanwhile there should be cloth gone between zippers and the iron to avoid direct contact. They shouldn’t be packed unless they are desiccant enough.

11. Package, Storage and Transportation of Zippers


Packages should be ventilated and damp-proof. Light-colour zippers will change colour if packed in PVC bags for a long time.



Store them in a ventilate atmosphere and avoid from direct exposure in air and sunshine. Avoid high concentration of gases H2 S and Cl2 in storage, otherwise they will turn black.



Please inform our technical staff of your shipping preferences as the high temperature, high moisture and high salinity content in marine transportation will easily corrode metal parts on zippers or metal teeth. A salt-spray test is required for zippers in marine transportation.