Opening And Closing Durability
Opening and closing durability is the performance of maintaining the interlocking of the teeth, the operation of the slider, and the function of the stops and open box when a zipper is repeatedly opened and closed.
Contents6 sections
Definition and Overview
Opening and closing durability refers to the degree to which the zipper maintains its function after repeated back-and-forth movement. This involves checking that the teeth mesh properly after opening and closing, that the slider moves smoothly, and that the top and bottom stops and the opening mechanism are not damaged.
Unlike tensile strength, which indicates overall strength, this quality item assesses resistance to repetitive actions similar to those experienced in everyday use. The practical evaluation varies depending not only on the number of opening and closing cycles, but also on the product's applications, operating environment, and installation conditions.
Relationship between structure and components
A zipper consists of a slider that interlocks the teeth on both sides, upper and lower stops that secure the ends of the tooth row, a tape, and an opening mechanism used in open-type zippers. Deformation or wear of any of these components can lead to difficulty opening and closing, teeth coming loose, or the slider falling off.
Larger teeth don't necessarily mean greater durability. You need to consider the type of zipper, the strength of the tape, the combination with the slider, and the load applied to the product. Thinner teeth may be suitable for lightweight clothing, while thicker teeth are used for outerwear and bags.
- A coil zipper is a type that uses spiral-shaped teeth.
- Vislon Zipper use resin teeth.
- Metal zipper are a type that uses metal teeth.
Points to note depending on the type and specifications
Closed zipper have a design where the bottom end does not open and are used for pockets and side openings. Open zipper have a design where the bottom end can be opened and are used for front-opening jackets, etc. With two way separator and double-slider zippers, the operation of multiple sliders and opening mechanisms also affects the durability of opening and closing.
The length is generally determined from the top stop to the bottom stop, or, in the case of open zipper, from the top stop to the end of the teeth on the opening side. Since this differs from the total length including the tape end, it is important to align the length standards in the specifications, patterns, and when ordering.
How to choose and sewing tips
When selecting a product, we consider factors such as the frequency of opening and closing, the contents and the force applied during wear, the thickness and stiffness of the fabric, and whether or not it is washable or pre-washed. For products with high loads and frequent opening and closing, such as bags, workwear, and outdoor applications, we test prototypes to check the actual feel of operation and the condition after opening and closing.
In sewing, if the tape is pulled too tightly or the difference in stretch between the fabric and the fabric is ignored, the zipper will ripple, leading to resistance when opening and closing, and poor meshing of the teeth. Also, check the sewing position and presser foot operation to ensure that thick seam allowances or lining do not get caught in the slider.
Before washing, drying, pressing, garment dyeing, or garment washing, check in advance for any effects of chemicals, heat, shrinkage, or discoloration of metal parts on the garment's functionality. Closing the zipper before washing helps prevent the teeth or sliders from snagging on other garments.
Differences from similar terms
Opening and closing durability refers to the persistence of the function after repeated opening and closing. The tooth size is a specification that indicates the size of the zipper and does not guarantee opening and closing durability on its own. The length of the zipper is also a specification related to dimensions and is separate from the durability test items.
Jagging occurs when fabric, lining, yarn, etc., get caught in the slider, causing problems during use or sewing. Even if the opening and closing durability is good, jagging can still occur depending on the sewing design and usage method, so countermeasures will be taken from a different perspective.
FAQ
Does the opening and closing durability increase with larger tooth size?
While zipper tooth size is one factor affecting durability, it cannot be judged by size alone. We comprehensively check the type of zipper, the combination of slider and teeth, tape strength, presence or absence of an opening mechanism, stitching condition, and the load applied to the product, depending on the intended applications.
How do you verify the durability of the zipper on the product?
Before mass production, prototypes are made using the actual fabric, interlining, lining, and sewing specifications, and the product is opened and closed the same number of times and in the expected directions. This checks for issues such as teeth coming loose, slider movement, damage to stoppers and opening mechanisms, tape waviness, and fabric getting caught.
Does a wavy zipper affect its durability when opening and closing?
When the tape or teeth of the slider become distorted due to waviness, the slider's movement becomes uneven, which can lead to increased opening and closing resistance and poor meshing. Avoid pulling the fabric and tape, align the sewing positions on both sides, and consider appropriate sewing conditions for stretchy fabric.
