Monday, October 11, 2010

Nylon for Jewelry... Bonded or Waxed?

And more about bond than you probably want to know...

Nylon #18, a cord made originally for upholstery, used to be available waxed or bonded in the U.S., but sometimes in the late 70's the waxed variety became discontinued most likely due to the demand. The bonded kind must have surpassed the waxed one.

Nylon was originally invented in 1935 by Wallace Hume Carothers at DuPont as an alternative to silk for stockings. Nylon is a continuous fiber like filament silk making nylon thread and cord very strong. Whereas polyester is a spun fiber mimicking cotton with shorter fibers spun into thread. Spun thread or cord is usually less strong, has more stetch and breaks more easily when pulled. This makes cotton or polyester good choice for sewing as they are less slippery, but not as good for jewelry as they are not as strong as filament fibers such as filament silk and nylon.

For making jewelry, waxed cord is a bit easier to knot, but bonded nylon once you get past the learning curve, is a better choice.

Bonded nylon versus waxed nylon
  • Better abrasion resistance
  • Easier to undo knots
  • Bond outlast wax
  • Wax is allergenic
Bond? What is it and all about it...

What is bond? Bond is a coating applied the cord after it has been plied. It hold all the nylon filament together and adds durability. It adds a tough, smooth protective coating. This increases its abrasion resistance. The bond is essential for working with beads and for jewelry making, but of course how much bond is desired is a real complex question... too much bond creates a thread that is stiffer... too little may be too soft... and...

Occasionally bond issue or a change in the bond quality occurs, such as the changes happening right now with the Conso Nylon #18. The newer supply has completely different bond quality than the older supply and the newer dye lots do not match previous ones.

Another problem encountered sometimes is called 'bond whitening'. This problem seems to occur when the cord has been exposed to too much temperature difference. It always seems to occur in the middle of the summer or winter... and may be due to extreme temperatures in delivery truck.  Occasionally it appears over time or when the manipulation of the thread creates a lot of abrasion. Here is the explanation and solution from one of the C-Lon factory expert. I tried it and it works.

To make bobbins stick together and hold their shape, bond and tack is applied to the thread. This coating is critical in keeping the plies together and the thread consistently wound in a finished bobbin. When the bond or tack experiences friction or abrasion, it will go from its transparent form to more of a white/grey color....think of cooled wax. When you break a colored candle, at the crack or breaking point you see white in the color. This whitening is going to happen with all colors but shows up more in the dark colors and is almost impossible to completely avoid. It can be worse when the bond level is on the heavy side.

One way to correct the whitening or dulling of the color after the thread has seen friction or abrasion is to rub a bit of alcohol across it. The alcohol activates the bond back to it's translucent form. This whitening is more noticeable in the darker colors and the heavier sizes.

Some waxed nylon is still available but mostly in just black and white. I ordered some samples a while ago, but only black was available. A waxed polyester named Linhasita is available in South America and some bead stores in Mexico but it is difficult to find in the U.S.. It is made for sewing leather and shoes. Occasionally I get a request for this thread, and I got some from the factory in Brazil, but it does not ages well over time, plus I am allergic to its wax.

I have been making jewelry with bonded nylon and silk all my professional life. Some of my pieces in my personal collection were made many years ago and have been worn extensively. Other than a slight fading and an occasional washing, they are in remarkable shapes.

In 2005 after a disruption of bonded nylon supply, I started an online supply store specializing in thread & cord for my students. It features bonded nylons & silks. - Marion

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