Usage of zipper in today's world has smoothened the work of tailors as they can be sewn directly on the garment than clamping the teeth on the cloth.

The main elements of zipper are:

  • stringer, the assembly of tape and teeth that makes one side of the zipper

  • Slider, used for opening and closing the zipper

  • Tab, for moving the slider

  • Stops, for preventing the slider from leaving the chain

There are some zippers that are characterized with better strength, anti-friction, anti-high temperature ironing properties, anti-washing properties, etc. They are used for common applications such as manufacturing of raincoats, tents, outdoor equipment and various others. These zippers are called heavy duty zippers made with sophisticated technologies.

Heavy duty zippers can be classified based on their applications.

1.      Two-way zippers can be opened from both the ends of the zipper tape and thus are applied more in luggage, bags, and tents. 

2.      Separating zippers are majorly used in jackets and coats as the teeth get completely separated when unzipped along the way. Heavy-duty version of the separating zippers is used in firefighter suits, astronaut suits and many more.

3.      Extra long zippers are basically the ones with long length. They are used in sleeping bags and tents.

4.      Water-resistant zippers are made with special material and technology with the finish to avoid the water leakage. Such kind of zippers are commonly found in waterproof bags and raincoats.

5.      Marine zippers are very much similar to "water-resistant zippers" with extra protection against salt water corrosion and are commonly applied in seat cover of a boat.

6.      Self-mending/Self-Repairing zippers will re-align their teeth even if misaligned or stuck just by opening/closing them as far as the zipper teeth have not got broken.

Despite the fact that they vary from each other due to their difference in designs and materials, there are some significant characteristics that can be found in almost all heavy duty zippers:

  •           Teeth size zippers are equipped with better individual teeth in comparison to the standard one, due to which generally a heavy duty zipper will need approximately 30 per cent more force for operating.

  •       Zipper tapes used in both the heavy duty and standard zippers are generally the same except a few. While the stiffness and the rigidity found in the heavy duty zippers limit their usage in wearable items. They are widely used in jeans, pants and jackets as they are significantly stronger when you pull them from the side.

  •       If one of the teeth of the heavy duty zipper is broken, it can't be replaced individually. It has to be replaced just like the standard zippers.

Heavy duty zippers are usually meant for safety usage. Despite appearing to be costly on the initial level, they can be helpful in the long run and avoid replacement cost.

Reference:

1. SBS zipper

2. Enclyclopedia.com