A resin zipper is a zipper whose teeth are individual pieces of plastic, molded one at a time directly onto the edge of the tape. It is also called a molded plastic zipper or a molded tooth zipper. The result is a bold, chunky chain that is lighter than metal, does not rust, and can be made in almost any color.
That combination is why resin is one of the most common choices for jackets, outerwear, and children's wear.
How a resin zipper is made
The teeth are formed by injection molding. A plastic resin, most often polyacetal (also called POM or acetal), is melted and injected into a mold that shapes each tooth around the edge of the tape. Every tooth is a separate piece, fixed in place as it cools.
Top and bottom stops are usually molded the same way. The long molded chain is then cut to length, the slider is added, and an open-end zipper also gets its insertion pin and box at the bottom.
Two practical consequences follow from this process:
- Color goes through the tooth. Pigment is added to the plastic before it is molded, so the color is part of the tooth rather than a coating on top. It does not chip or peel the way paint can.
- Teeth and tape can differ. Because the teeth are molded separately from the tape, they do not have to match it. A contrast tooth color on a dark tape, or a bright tooth on a neutral garment, is a normal request.
What resin does well
Light weight. Plastic teeth weigh less than metal teeth of the same size, which matters on a long jacket front or on light fabrics where a metal zipper would pull the garment out of shape.
No rust. Resin does not corrode, so it stays clean after washing, rain, and outdoor use. This is one reason it is used so widely on outerwear and sportswear.
Color. Since the color is molded in, resin is the easiest of the three materials to match to a garment or to make stand out on purpose. Bright and fluorescent shades are possible as well as everyday neutrals.
A visible, sturdy look. The teeth are bold and evenly spaced. Unlike a nylon coil, which sits low and quiet, a resin zipper is meant to be seen.
Where it is less suited
Resin is stiffer than nylon. It bends with a garment, but it does not follow tight curves as easily, so a rounded bag corner or a curved seam is usually better served by a nylon coil.
Resin also lacks the hardware look and the extra strength of metal. For jean flies, workwear, heavy bags, and boots, where the zipper takes the most load and abrasion, metal is still the more common choice.
Finally, the teeth are thermoplastic. Pressing a hot iron directly onto them can soften or deform them, so finished garments should be pressed around the zipper or through a cloth rather than straight over the teeth.
Resin, metal, and nylon side by side
| Resin | Metal | Nylon | |
|---|---|---|---|
| Teeth | Individual molded plastic | Individual metal pieces | Continuous coil |
| Weight | Light | Heaviest | Lightest |
| Look | Bold, many colors | Hardware finish | Low profile |
| Rust | No | Can tarnish over time | No |
| Curves | Moderate | Stiff | Follows curves well |
Our comparison of metal, resin, and nylon zippers goes through the choice position by position.
Common uses
- Jacket and coat fronts, usually as open-end zippers so the front can separate fully
- Outerwear and sportswear, where weight and weather both matter
- Children's wear, where light weight and bright colors are wanted
- Lighter shoes and caps, where a colored zipper is part of the design
If you are not sure whether the front of a garment needs to separate, our guide to closed-end and open-end zippers explains the difference.
Sizes and structures
Our resin zippers come in sizes 3, 5, and 8, which correspond to a closed chain width of about 3, 5, and 8 mm. Size 5 is the everyday choice for jacket fronts; size 3 suits lighter garments and pockets; size 8 suits heavier outerwear. The size guide covers the choice in more detail.
Closed-end, open-end, and two-way structures are all available, for example the size 5 resin open-end zipper and the size 5 resin closed-end zipper. Finished zippers start from 1,000 pieces, and colors can be mixed within one order.
Conclusion
A resin zipper uses individually molded plastic teeth. It is light, rust-free, and easy to color, which makes it a natural fit for jackets, outerwear, and children's wear. Choose metal where the zipper takes heavy load, and nylon where it has to follow curves.
Send us the garment, the size, and the colors you have in mind through our quote page, and we will confirm the structure and arrange a sample.