Closed-end Zipper
A closed-end zipper is a zipper with the lower end secured by a bottom stop, so the left and right tapes cannot be completely separated.
Definition and Overview
A closed-end zipper is a zipper in which the left and right zipper tapes are joined by the bottom stop at the lower end, so even when the slider is lowered, they do not open all the way apart. It is used for areas that do not need to be separated, such as garment openings and pockets.
It differs from an open-end zipper, which can be opened at the lower end to separate the left and right sides, in the presence or absence of the bottom stop and in the structure of the retaining box. A closed-end zipper is generally designed to open and close from one direction, but depending on the application, multiple sliders may also be attached.
Structure and Components
The main components are the elements that interlock to form the opening and closing section, the slider that engages and disengages the elements, the top stop that prevents the slider from coming off at the upper end, the bottom stop that fixes the left and right sides at the lower end, and the zipper tape that supports the elements.
An open-end zipper has a retaining box at the lower end, but a closed-end zipper does not. The retaining box is a component for separating and joining the left and right sides, and its function differs from that of the bottom stop. The pull tab is the operating component attached to the slider.
- Elements: the parts that interlock on the left and right.
- Slider: the moving part that opens and closes the elements.
- Top stop and bottom stop: components that restrict the slider's range of movement.
- Zipper tape: the fabric-like part sewn to the textile.
Types and Specifications
Elements may use coiled plastic, molded plastic elements, or metal elements. Selection is based on appearance, flexibility, thickness, strength, and suitability for washing and the usage environment.
Element size is a specification that indicates the size of the elements. Larger is not necessarily more suitable; it is determined by the balance of textile thickness, opening and closing frequency, opening length, and the product's design. Zipper length usually refers to the continuous length of the elements from the top stop to the bottom stop, and is different from the total tape length.
Even in closed-end specifications, you can choose the number of sliders, whether or not to include a locking mechanism, the shape of the pull tab, and the tape color. When using two sliders, clearly specify the slider direction and range of movement in the specification sheet.
Main Applications
Used for front and side openings of pants and skirts, back openings of dresses and gowns, pocket openings, and the openings of pouches and bags. It is a suitable specification for openings that do not need the lower end to separate.
For lightweight garments, check whether the thickness of the elements and tape, and the seam impression, do not show on the surface. For heavy garments and bags, it is important that the textile does not get caught in the elements during opening and closing, and that the required opening size can be secured.
Selection and Handling Notes
When selecting, in addition to the finished opening size, check the seam allowance, how the upper and lower ends are finished, and the position through which the slider passes. The required opening size and zipper length may not match, so determine them according to the pattern and sewing specifications.
When sewing, do not stitch too close to the elements so as not to interfere with the slider's movement. Also, if the left and right tape positions are misaligned, it can cause poor opening and closing or appearance defects, so align the starting point of stitching and the bottom-stop position.
For washing, close the zipper and tuck the pull tab inside to help reduce snagging on other garments and deformation of the elements. If product washing, dyeing, or chemical processing is performed, check in advance the resistance of the elements, slider, and tape.
Frequently Asked Questions
What is the difference between a closed-end zipper and an open-end zipper?
A closed-end zipper is joined at the lower end by a bottom stop, so the left and right tapes cannot be separated. An open-end zipper has a retaining box at the lower end, so the left and right sides can be detached. Open-end specifications are used for areas such as front-opening outerwear, where the item needs to open fully for putting on and taking off.
Where do you measure the length of a closed-end zipper?
Generally, measure the continuous length of the elements from the inside of the top stop to the inside of the bottom stop. Since the zipper tape has extra length at the top and bottom, check the specification sheet and the notation used when ordering so that the total tape length is not treated as the zipper length.
How can I prevent a zipper from being damaged in washing?
Before washing, raise the slider to close the zipper and tuck the pull tab toward the textile side. This helps reduce snagging on other garments and stress on the elements. For metal elements and similar types, also check compatibility with detergents, bleach, and product processing.
