I don't understand. There's tons of fancy, expensive running shorts from Nike or specific running brands that only have open pockets with no zippers. Who wants this? Who would ever want to run with something in their pocket that could potentially fall out? Imho all running shorts should have zippers on the pockets. I don't understand why there's 60 Euro running shorts from Nike with no zippers at all, while all 5 Euro Kalenji ones have them.
Anyone else annoyed??
There are three major types of zippers, and each are made using a unique process.
With all zippers the manufacturing process starts by creating a tape, which is the fabric portion of the zipper. The tape is usually a polyester woven textile product, zipper manufacturers generally seem to weave their own tape.
Once you have the tape you have to create the teeth (also called "elements"). This is done differently for each type of zipper.
Coil zips are generally formed from an extruded nylon or polyester filament that is tightly coiled like a spring. The completed coil is then sewn to the zipper tape.
Moulded zips feed the tape into a metal mould. The top closes and plastic resin (eg. Delrin) is injected into the mould and on to the tape. The plastic cools and solidifies creating teeth that are permanently affixed to the tape.
Metal zips are created with actual metal. Thin stock is stamped into shape and then crimped around the tape, securing it in place.
To make a zipper water resistant you have two problems: the tape and the teeth. On all zippers the tape is solved by coating it with clear polyurethane. Moulded zipper teeth interlock tightly enough that they are deemed water resistant. But coil zipper teeth are leaky, so they have to seal those too.
Sealing occurs by flipping the zipper around, and then adding the clear polyurethane. The tape on the back side of the coil zipper closes up almost com... keep reading on reddit ➡
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