Manufacturer · Fashion & Home Accessories
A moulded tooth zip (moulded zip, plastic zip, also known as a Vislon-type zipper) is a zip in which each tooth is moulded individually from plastic directly onto the edge of the textile tape. The teeth are most often made of polyacetal (POM). A moulded zip is as strong as a metal one but lighter, does not rust and works reliably in cold and wet conditions.
What a moulded tooth zip is
Look closely and a moulded zip resembles a metal one: separate, clearly distinguishable teeth arranged in two rows. The difference is that the teeth are plastic and are not clamped on but moulded. The edge of the tape is reinforced (with a woven-in cord or a denser weave), and the plastic is injected around it in a mould, enclosing the edge. This way each tooth is firmly “locked” onto the tape.
The name “Vislon” is a trademark of one of the major zip manufacturers and is often used in the industry as a general name for this type of construction. In Bulgarian the terms “tractor zip” and “chunky plastic zip” are also used.
How a moulded zip is produced
- Weaving the tape – a polyester tape with a reinforced edge on which the teeth will be moulded.
- Moulding the teeth – in an injection mould, molten polymer is injected around the edge of the tape; the teeth cool and harden in fractions of a second.
- Colouring – the tape is dyed and the teeth are moulded from coloured polymer. That is why the colour of the teeth can differ from the tape.
- Assembly – stops, a slider and, on open-end zips, a pin and box are fitted.
The material: polyacetal (POM)
Polyacetal is an engineering thermoplastic used in gears, clips and mechanisms. It is suitable for zip teeth because it:
- is hard and wear-resistant;
- has low friction – the slider moves easily;
- does not absorb moisture and does not swell;
- keeps its properties at low temperatures;
- does not corrode – unlike metal zips.
Moulded, coil or metal zip – how it differs
| Characteristic | Moulded zip | Coil zip | Metal zip |
|---|---|---|---|
| Teeth | Separate, moulded plastic | Continuous coil | Separate, metal |
| Weight | Light | Lightest | Heaviest |
| Flexibility | Medium | High | Low |
| Corrosion | No | No | Possible with moisture and salt |
| Shortening | By removing teeth | Easy | By removing teeth |
| Look | Sporty, chunky | Discreet | Classic |
A coil zip is more flexible and suits curves, while a metal zip is the classic for jeans and leather. A moulded zip sits in the middle: chunky like metal, light and resistant like plastic.
Where moulded zips are used
- winter and ski jackets, parkas, gilets;
- hoodies and sports tops;
- workwear and protective clothing;
- children’s jackets and snowsuits;
- backpacks, holdalls, sports bags;
- tents, awnings, equipment covers;
- sailing and beachwear, where salt damages metal zips.
Types and sizes
Moulded zips are produced as closed-end (pockets, bags), open-end (jackets, hoodies) and two-way (long jackets, holdalls). The most common sizes are No. 5 for hoodies and light jackets, and No. 8 and No. 10 for winter, work and outdoor clothing. The smaller No. 3 is used in children’s products and accessories.
Colours
One of the big advantages is freedom of colour. The teeth can be in the colour of the tape, in a contrasting, neon, transparent or metallic-effect colour. This makes the moulded zip a favourite detail in sports collections.
Sliders and pulls
Sliders for moulded zips are made specifically for the profile of the moulded teeth – a slider for a coil or metal zip of the same size will not work properly. The body is made of zinc alloy or plastic, and the pulls can be metal, rubberised, cord or with a logo. On ski and work jackets, larger pulls that are easy to grip with gloves are preferred.
Tape
The tape is usually polyester and is dyed in a wide range of colours. For technical products there are also versions with a denser or coated tape, and for children’s clothing with reflective elements.
Disadvantages and limitations
- Less flexible than a coil zip – not suitable for tight curves.
- A single tooth can break off under a hard impact; the zip then starts to split.
- Not suitable for high temperatures – ironing directly on the teeth can deform them.
- Shortening requires cutting off teeth and fitting new stops.
Caring for a moulded zip
A moulded zip needs no special maintenance, but a few habits extend its life. Close it before washing so that it does not snag other garments. Do not iron directly on the teeth. After the beach or snow, rinse the chain with clean water to remove salt and sand. If the slider is stiff, lubricate the teeth with a dry lubricant – paraffin wax or graphite.
How to recognise a moulded zip
Look at the chain from the side: on a moulded zip the teeth are separate “blocks” of the same shape, clearly separated from each other, and feel like plastic. On a coil zip the chain is a continuous winding, and on a metal zip the teeth are cold to the touch and clink. There is often a stamped number on the back of the slider that indicates the size.
See the full range in the moulded plastic zips category and, for comparison, nylon coil zips and metal zips. A general overview is in zips.
Polkom – moulded zips for manufacturers
Polkom is a Bulgarian manufacturer of accessories for fashion, furniture, footwear and bags from Sofia with over 30 years of experience. We offer moulded zips in various sizes, tape and tooth colours and with logo sliders, with fast sampling and delivery within the EU. Send an inquiry with a description of the product.
