Shoelace Construction

Shoelace Braiding Process

There are many different manufacturing processes for shoelaces – let's begin with the common braiding process.

Most of us are familiar with the way that hair or string can be “braided” (or “plaited”) by hand, using as few as three strands. To create a useful shoelace requires braiding at least a dozen strands – and preferably two dozen or more. That really requires a machine, the original of which (and probably most common) is called a “Tubular braider”.

Tubular braiding process

To demonstrate the basic principle behind the process, I've created a couple of detailed animations of a tubular braiding machine. The first of these is a rather hypnotic overhead view, which I'll explain below.

TIP: I've drawn some parts semi-transparent so that you can zoom in and see how they mesh together.

Looking at the machine from above, we see twelve spools of white thread running around the perimeter of the machine, with threads from each spool drawn towards the centre. Twelve counter-rotating cogs are guiding the spools along two winding tracks.

Notice how the six spools that I've colored yellow are running clockwise, while the six that I've colored blue are running counter-clockwise. This results in the two sets of spools running in opposite directions, weaving alternately left and right as they pass by each other.

Forming the braid

Looking at the machine from the front, we see a sparse “cone” of threads converging high above the spools. The inward and outward movement of the spools causes the threads to pass inside and outside each other, gradually braiding them into an ever-tighter “tube” of material.

This continuous braided tube is steadily drawn off at the top of the machine.

Flat versus Round

For flat shoelaces, the tubular braid next passes between heated rollers (see photo), which “iron” it flat to form a double-walled flat material (like a squashed drinking straw).

For round shoelaces, the tubular braid is instead formed around an additional solid core (commonly made of a bundle of strands of rough material) and is not ironed flat. The result is a firm shoelace that holds its round shape, has greater strength and has less stretch.

On the downside, solid round shoelaces don't bend or compress into a tight knot as easily as hollow flat shoelaces, thus they don't stay as securely tied. For maximum security, I always recommend using a Secure Shoelace Knot when tying round shoelaces.

More Complex Braiding

Most of the shoelaces that I've seen in recent years are braided using a slightly different tubular braiding machine. The basic principle is the same – two sets of counter-rotating cogs guiding the spools along two winding tracks.

The difference is that each cog has four spool slots instead of two. This allows up to twice as many spools to be loaded into the same size machine.

Comparing this overhead view with the previous overhead view, we can now see 24 × spools of white thread running around the perimeter of the machine, with two sets of yellow spools (light and dark) following each other clockwise plus two sets of blue spools (also light and dark) following each other counter-clockwise.

More spools = more complex choreography. Personally, I find it hard to comprehend!

Comparison of braids

With this complex setup, a yellow spool passes to the left of two oncoming blue spools, then to the right of the next two, and so on. The finished braid will end up with each thread passing over two threads, under the next two threads, and so on. This is called a “Regular” (or “2/2”) braid.

With the previous, simpler setup, a yellow spool passes to the left of only one oncoming blue spool, then to the right of the next one blue spool, and so on. The finished braid will end up with each thread passing over one thread, under the next thread, and so on. This is called a “Diamond” (or “1/1”) braid.

One machine, multiple braids

Note that either of the above braids can be produced on the one machine:

• When loaded to its full capacity (24 × spools), it will produce a regular braid (2/2).
• When loaded to only half capacity (12 × spools), it will produce a diamond braid (1/1).

Other braids are also possible, using different numbers of spools and/or different setups. Imagine using 12 × clockwise-running spools and only 6 × counter-clockwise-running spools (or vice-versa). It makes this type of machine pretty versatile – no wonder they're so widely used.

Shoelace Machines

Tubular braiding machines

This photo (taken by Rico Gerstner) shows a tubular braiding machine running at high speed. Motion blur in the photo results in a translucent “cone” of spools and threads.

Machines for creating tubular braided shoelaces have been around since the 19th century. It's said that the inventor of the first such machine was inspired by watching a Maypole Dance. Such machines are therefore known as “Maypole braiders” (or “circular braiders”).

I've always been fascinated by complex machines. The ones that make braided shoelaces are particularly fun to watch!

Flat braiding machines

Slightly different machines for creating “flat braided” shoelaces have also been around since the 19th century.

Rather than having the spools of thread weaving past each other in continuous circles, they can instead run most of the way around the circle, then change direction and weave back. In other words, the spools follow tracks arranged like a letter “C” instead of an “O”.

This video (taken by Jan Fieggen, a Dutch relative) shows a flat braiding machine with the spools changing direction on the left side. Try following the three red spools as they weave past the front of the machine, firstly travelling from right-to-left, then back again from left-to-right.

The resulting braid is naturally flat and thus does not need ironing, but is flimsier than a tubular braid because it's single-walled instead of double-walled.

Antiques in action

A number of antique braiding machines (some around 200 years old!) are still working to this day. Two museums that I know of where you can see them in action – and even purchase custom shoelaces – are:

• The Shoelace Factory, part of the City Museum in St Louis, USA.
• Weverijmuseum (Weaving Museum), in Geldrop, The Netherlands.

The Final Step

Cutting and finishing

Having made a continuous length of braided material, the final step is to cut it into standard lengths and add the tips, which are called aglets.

Nowadays, most aglets are made of plastic, and are formed directly onto the material using a large, complex “shoelace tipping” machine (see photo).

A typical plastic aglet begins with clear acetate tape, twice the width of the required aglet, which is wrapped around a section of the uncut material. Carefully controlled heat – and often a solvent such as acetone – is applied at the same time, which just melts the tape directly onto the material as well as bonding the tape to itself.

When cooled, the acetate-wrapped section is cut through the middle, leaving half of the acetate tape on each side of the cut. This single operation creates two aglets: One attached to the end of the cutoff section of material (which completes the previous shoelace), the other attached to the start of the uncut section of material (which begins the next shoelace).

After two such operations, we finally have a finished pair of what we can truly call “shoelaces”.

Summary

So that's how shoelaces are made. What an amazing process! After discovering just how complex it is to create these humble lengths of cord, will we still take them for granted?