Zipper Manufacturing Process

Today's zippers comprise key components of either metal or plastic. Beyond this one very important difference, the steps involved in producing the finished product are essentially the same.

1). Making stringers — metal zippers

A stringer consists of the tape (or cloth) and teeth that make up one side of the zipper. The oldest process for making the stringers for a metal zipper is that process invented by Otto Sundback in 1923. A round wire is sent through a rolling mill, shaping it into a Y-shape. This wire is then sliced to form a tooth whose width is appropriate for the type of zipper desired. The tooth is then put into a slot on a rotating turntable to be punched into the shape of a scoop by a die. The turntable is rotated 90 degrees, and another tooth is fed into the slot. After another 90 degrees turn, the first tooth is to make the stringer for a spiral plastic zipper, a round plastic wire is notched and then fed between two heated screws. These screws, one rotating clockwise, the other counterclockwise, pull the plastic wire out to form loops. A head maker at the front of each loop then forms it into a round knob. This method requires that a left spiral and right spiral be made simultaneously on two separate machines so that the chains will match up on a finished zipper clamped onto the cloth tape. The tape must be raised slightly over twice the thickness of the scoop—the cupped tooth—after clamping to allow room for the opposite tooth on the completed zipper. A slow and tedious process, its popularity has waned.

Another similar method originated in the 1940s. This entails a flattened strip of wire passing between a heading punch and a pocket punch to form scoops. A blanking punch cuts around the scoops to form a Y shape. The legs of the Y are then clamped around the cloth tape. This method proved to be faster and more effective than Sundback' s original.

Yet another method, developed in the 1930s, uses molten metal to form teeth. A mold, shaped like a chain of teeth, is clamped around the cloth tape. Molten zinc under pressure is then injected into the mold. Water cools the mold, which then releases the shaped teeth. Any residue is trimmed.

2). Making stringers — plastic zippers

Plastic zippers can be spiral, toothed, ladder, or woven directly into the fabric. Two methods are used to make the stringers for a spiral plastic zipper. The first involves notching a round plastic wire before feeding it between two heated screws. These screws, one rotating clockwise, the other counter-clockwise, pull the plastic wire out to form loops. A head maker at the front of each loop then forms it into a round knob. Next, the plastic spiral is cooled with air. This method requires that a left spiral and right spiral be made simultaneously on two separate machines so that the chains will match up on a finished zipper.

The second method for spiral plastic zippers makes both the left and right spiral simultaneously on one machine. A piece of wire is looped twice between notches on a rotating forming wheel. A pusher and head maker simultaneously press the plastic wires firmly into the notches and form the heads. This process makes two chains that are already linked together to be sewn onto two cloth tapes.

To make the stringers for a toothed plastic zipper, a molding process is used that is similar to the metal process described in step #2 above. A rotating wheel has on its edge several small molds that are shaped like flattened teeth. Two cords run through the molds to connect the finished teeth together. Semi-molten plastic is fed into the mold, where it is held until it solidifies. A folding machine bends the teeth into a U-shape that can be sewn onto a cloth tape.

The stringers for a ladder plastic zipper are made by winding a plastic wire onto alternating spools that protrude from the edge of a rotating forming wheel. Strippers on each side lift the loops off the spools while a heading and notching wheel simultaneously presses the loops into a U shape and forms heads on the teeth, which are then sewn onto the cloth tape.

Superior garment zippers can be made by weaving the plastic wire directly into the cloth, using the same method as is used in cloth weaving. This method is not common in the United States, but such zippers are frequently imported.

If you want to know more about metal zipper and zipper puller, please contact with UZIP ZIPPER.

Jessica Kung

Skype: tdysho

Wechat: jessicakung1017

Whats: 8613631458295

Zipper Types

Coil zippers now form the bulk of sales of zippers worldwide. The slider runs on two coils on each side; the teeth are formed by the windings of the coils. Two basic types of coils are used: one with coils in spiral form, usually with a cord running inside the coils; the other with coils in ladder form, also called the Ruhrmann type. Coil zippers are made of polyester coil and are thus also termed polyester zippers. Nylon was formerly used and though only polyester is used now, the type is still also termed a nylon zipper.

Invisible zippers have the teeth hidden behind a tape, so that the zipper is invisible. The tape's color matches the garments, as does the slider's. This kind of a zipper is common in skirts and dresses. Invisible zippers are usually coil zippers. They are also seeing increased use by the military and emergency services because the appearance of a button down shirt can be maintained, while providing a quick and easy fastening system.

Reverse coil zippers are a variation of the coil zipper. A reverse coil zipper is exactly that - the coil is on the reverse (back) side of the zipper and the slider is engineered to work on the flat side of the zipper (normally the back, now the front). Unlike an invisible zipper where the coil is also on the back, the reverse coil shows stitching on the front side and the slider will accommodate a variety of pulls (the invisible zipper requires a small, tear-drop pull due to the small slider attachment). Water resistant zippers are generally configured as reverse coil so that the pvc coating can cover the stitching.

Metal zipper is the classic zipper type, found mostly in jeans today. The teeth are not a coil, but are individual pieces of metal molded into shape and set on the zipper tape at regular intervals. Metal zippers are made in brass, aluminum and nickel, according to the metal used for teeth making. All these zippers are basically made from flat wire. A special type of metal zipper two way is made from pre-formed wire, usually brass but sometimes other metals too. Only a few companies in the world have the technology. This type of pre-formed shiny silver zipper is mainly used in high grade jeans-wear, work-wear, etc., where high strength is required and zippers need to withstand tough washing.

Plastic-molded zippers are identical to metallic zippers, except that the teeth are plastic instead of metal. Metal zippers can be painted to match the surrounding fabric; plastic zippers can be made in any color of plastic. Plastic zippers mostly use polyacetal resin, though other thermoplastic polymers are used as well, such as polyethylene.

Open-ended zippers use a box and pin mechanism to lock the two sides of the zipper into place, often in jackets. Open-ended zippers can be of any of the above described types.

Closed-ended zippers are closed at both ends; they are often used in luggage.

Magnetic zippers allow for one-handed closure and are used in sportswear. 

If you want to know more about metal zipper, please contact with UZIP ZIPPER.

Jessica Kung

Skype: tdysho

Wechat: jessicakung1017

Whats: +8613631458295

How to Get a Zipper to Work Smoother

You've just pulled on your favorite jacket and you're running out the door into the cold night air -- when the gold metal zipper gets stuck. Instead of having this or any other zipper professionally repaired, save a bundle of cash and fix the stuck zipper you. Zippers typically get stuck if they're blocked by an obstruction, but they may also stop gliding smoothly as a garment ages. Fix your corn teeth zipper by using one of several common household items to lubricate the zipper teeth.

Step 1

Check your highly polished metal zipper for obstructions as small pieces of lint or a thread can stop the zipper from sliding properly. If the zipper lining is caught in the zipper, pull the fabric back and forth a few times to get it out. If you see an obstruction that you can't pull out with your fingers, try using a small pair of scissors to remove it. Take care not to damage the garment with the scissors.

Step 2

Open the zipper all the way. Rub over the zipper teeth with a bar of unscented soap, a pencil graphite, a crayon or some candle wax.

Step 3

Zip up the zipper and rub the soap, crayon, candle wax or pencil over the teeth again.

Step 4

Pull the zipper up and down a few times until it glides smoothly. If the zipper continues to stick, apply another coat of wax, soap, crayon or graphite.

Step 5

Rub the zipper with a dry cloth to get rid of any excess residue.

If you want to know more about smooth zipper, please contact with UZIP ZIPPER.

Jessica Kung

Skype: tdysho

Wechat: jessicakung1017

Whats: 8613631458295