Chain

Definition and Overview

In zipper , the chain is a long piece of zipper material with teeth continuously attached to the left and right zipper tapes. It is cut to the required length for each product, and the slider, top and bottom stops, or opening mechanism are attached afterward.

Unlike closed and open zipper, which are supplied in finished lengths, chains are characterized by their ease of individually specifying the length and end specifications. They are processed as needed for mass production and prototyping of bags and clothing.

Structure and parts

The basic structure of a chain consists of a pair of zipper tapes on the left and right, and a continuous set of teeth on the inside. These are combined with a slider that engages the teeth, upper and lower stops to prevent the slider from coming off at the end, and a mechanism that creates an openable end.

Chain teeth come in various types, including coil, resin molded, and metal, differing in appearance, flexibility, durability, and the processing methods they can be used in. Since the ends of the chain are unfinished, it is necessary to check in advance whether the ends can be secured after cutting or whether a tool can be attached.

• Teeth: These are elements that open and close by biting together on the left and right sides.
• Slider: A movable part that opens and closes the teeth of a screw.
• Upper stopper/Lower stopper: These parts limit the range of motion of the slider.
• Opening mechanism: This is a component that separates and connects the left and right sides at the lower end of the open design.

Types and specifications

When selecting a zipper, check the type and size of the teeth, the color and width of the tape, the type of slider, and how it opens after completion. The tooth size is an important specification that indicates the size of the zipper and is related to the balance between the strength required for the applications, flexibility, and appearance.

From the chain, various types can be created, including closed designs with the bottom end closed, open designs with the left and right sides separated, and two way separator and double-slider designs that open and close from both directions. However, the corresponding sliders, stops, and opening mechanisms must match the tooth specifications of the chain.

Main applications

In clothing, it is used for front openings on pants and skirts, back openings on dresses, pockets, and cuffs. Because the length can be precisely adjusted, it is also used when different zipper dimensions are required for different sizes and designs during mass production.

It is used for long openings and curved openings in bags, pouches, boxes, etc. For applications with heavy loads, the tooth size, tape strength, slider locking mechanism, and end reinforcement method are considered according to the product requirements.

How to choose and points to note

The finished length is generally determined based on the point where the teeth mesh, but the product specifications after attaching the stopper and opener are not the same as the chain dimensions before cutting. Specifying the measurement standard for the finished length, the stopper position, the slider orientation, and the type of pull tab in the specifications will prevent misunderstandings.

During sewing, if the stitching position from the edge of the tape is too close to the zipper teeth, it may obstruct the movement of the slider. After sewing, check the smoothness of opening and closing, the meshing of the zipper teeth, and the secureness of the ends. If washing or product washing is to be performed, pre-tests should be conducted to check for differences in shrinkage between the textile and the zipper, discoloration of metal parts, and color transfer of the tape.

FAQ

What is the difference between a chain zipper and a regular zipper?

A chain zipper is a long piece of material with continuous teeth, and is usually cut to the required length before the slider and stopper are attached. Finished zipper differ in that their length and end specifications are predetermined.

Can an open zipper be made from a chain?

You can create this by combining the appropriate chain, slider, and opening tool. However, not all chains can be processed to fit an opening tool. You need to check the type and size of the teeth and the compatibility with the opening tool and slider you will be using.

How do you determine the required length of the chain?

Determine the required finished length on the product and set the cutting length, including the allowance needed for end finishing and tool attachment. Since the interpretation of measurement positions varies depending on the specifications, it is safer to list the tooth length, finished length, and cutting length separately in the specifications.