Bottom Stop
A bottom stop is a component on the lower end of a closed-end zipper that prevents the left and right teeth and slider from coming off, and forms the endpoint of the opening and closing range.
Contents6 sections
Definition and Overview
The bottom stop is a fastening part attached to the lower end of a zipper. It catches the slider’s movement when the slider is pulled down and prevents the slider from coming off the left and right tapes. It is the counterpart to the top stop, which prevents the slider from coming off at the upper end.
In general, a zipper with a bottom stop is a closed zipper whose lower end does not separate. The bottom stop itself is not the teeth, but it is an important part that fixes the end of the teeth row and establishes the opening and closing range as a zipper.
Structure and Relationship to Zipper Specifications
A zipper is mainly made up of teeth that interlock to create the opening and closing section, a slider that engages and disengages the teeth, zipper tapes that support both sides, and top and bottom stops. The shape and attachment method of the bottom stop differ depending on the type of teeth, such as coil, resin, or metal.
In a closed zipper with a bottom stop, the slider cannot move past the bottom stop. By contrast, an open zipper is a specification in which the lower end can be separated, and it uses a separator instead of a bottom stop. A separator consists of a box and pin, and its function differs from that of a bottom stop.
- The larger the zipper teeth size, the more thickness and firmness are likely to appear around the bottom stop as well.
- When a chain zipper is finished for use in a product, a bottom stop is attached at the specified position to make it a closed specification.
- Even in a two way separator zipper, a bottom stop may be used when the lower end does not open.
Main Applications
Closed zippers with bottom stops are used in places that do not need the lower end to open, such as front openings and side openings in pants and skirts, back openings in dresses, pockets, and pouches. Depending on the application, the type of teeth, teeth size, slider shape, and tape color are selected.
For apparel, concealed zippers are chosen for thin fabrics or openings that should not be visible, while coil, resin, or metal zippers are selected for areas that require strength or design appeal. However, if the zipper specification does not allow the lower end to separate, the bottom stop becomes the endpoint of opening and closing.
Selection and Sewing Precautions
When selecting one, check the intended use of the opening, the required opening length, the thickness and firmness of the textile, whether washing or garment washing will be done, and the teeth size. The area around the bottom stop tends to become thick, so in thin fabrics it is important to confirm in a prototype whether it shows through to the surface, and in thick fabrics whether step differences make sewing difficult.
Zipper length is often indicated based on the openable section from the top stop to the bottom stop. However, the notation method and the overall length including the tape ends differ depending on the specification, so when ordering, confirm by matching the required opening dimensions with the measurement standard in the product specification sheet.
During sewing, avoid sewing directly through the bottom stop with the needle, and make sure the seam does not get too close to the teeth row near the bottom stop. For products that are washed or garment washed, evaluate in advance the rippling caused by fabric shrinkage, the load around the bottom stop, and the operation of the slider.
Differences from Similar Terms
The top stop is a part that prevents the slider from coming off at the upper end of the zipper, and its attachment position differs from the bottom stop attached to the lower end. The teeth are continuous parts that interlock on both sides, and the slider is the moving part that opens and closes the teeth; both have roles different from the bottom stop.
A separator is a part that makes the lower end of an open zipper detachable. A bottom stop is a part that fixes the lower end and stops the slider’s movement, so for uses such as the front opening of a blouson that need to separate all the way to the hem, a separator is normally used instead of a bottom stop.
Frequently Asked Questions
Can a zipper with a bottom stop open all the way to the hem?
A closed zipper with a bottom stop cannot separate the left and right sides at the lower end because the slider stops at the bottom stop. For front openings that need to open completely from the hem, choose an open zipper with a separator rather than a bottom stop.
Where is zipper length measured from, including the bottom stop?
In general, zipper length is treated as the length of the openable section from the top stop to the bottom stop. However, the overall length including the tape ends and the measuring position differ depending on the specification, so please confirm the same measurement standard in planning, ordering, and sewing.
Is it okay to sew near the bottom stop?
If the needle hits the bottom stop, it can cause needle breakage or sewing defects. Set the seam line at a position that avoids the bottom stop and the teeth row, and in thick fabrics or materials with large steps, it is important to confirm with a test sew, including the presser foot and sewing sequence.
