Because cable ties are everywhere, and their current global production is estimated to be about a billion units per day. In use, it's common for less than half of a tie to be actually used, with the rest simply being cut off and thrown away. That adds up to a lot of waste, and an alternative was needed.
The original cable tie was designed in Paris in 1956 by Kurt Wröbel.
The Origins of the Cable Tie
Made from tough nylon 66, cable ties were developed in the mid 1950s after injection moulding equipment made it possible to cheaply mass-produce complex plastic items. Thomas & Betts were the early market leader, their ties comprising a plain tail portion wth a metal spike embedded in the head. (T&B are now part of the ABB Group.) The inventor of this version (Maurus Logan) is said to have got the idea after vising an aircraft factory and seeing hand-laced cabling. (As mentioned in US3022557, filed June 1958).
However, this is not the cable tie that came to dominate. The all-plastic design we're more familiar with was actually developed two years earlier by Kurt Wröbel in France (GB0811973, filed Sep 1956).
Wröbel's version is instantly recognisable, and uses the familiar ratcheting approach, with a toothed-tail engaging with pawls moulded into the head.more
Early attempts at waste-free cable ties were not very sophisticated. However, they were cheap and easy to make, and variants of these designs are still used today.
Beyond Single-Use
It was immediately recognised that the original cable tie is a wasteful single-use item, and it wasn't long before a more efficient alternative was being sought.
Franz Grzemba soon invented a continuous, waste-free plastic tying strip for bags (DE1079537, filed Dec 1958), and Frederick Lige had a similar idea for cables (US3224054, filed Feb 1963).
Both used a 90° twist to fit and lock the ties, an approach necessitated by their longitudinal apertures. (This is because horizontal slots are inherently too narrow to accomodate the full width of the strip. And as William Evans showed in 1967 (US3438095), trying to thread the ties horizontally would require a lot of brute force. His design actually shows a metal hook being used to fit them!)
This cellular design was the forerunner to the Classic rapstrap. It pioneered the concept of using deformable geometry but took many years to perfect.
Despite environmental awareness increasing throughout the 1970s and 80s, the cable tie waste problem remained unsolved. (Though not forgotten, and there were indeed several other attempts during this period.)
Then, in the mid 1990s, Andy Harsley had the idea of using deformable apertures to make the ties easier to use (US5799376). These apertures would need to be just-right, expanding to allow threading and then closing back up to securely prevent withdrawal. The approach took many years perfect, but the result was the rapstrap Classic.
The original rapstrap Classic could not be made from nylon, so Andy Harsley spent another decade developing a version that could.
Closing the Loop
In order to work at all, the Classic rapstrap design needed to be soft, flexible and elasticated. This made it popular in many industries where nylon ties were deemed too 'industrial', but it also made the design unsuitable for rigid applications.
A nylon counterpart was clearly needed, but this required a totally different approach that took several more years to prefect.
The result was the rapstrap i-Tie, and derivatives of this design have been successfully made in nylons 6, 66 and 11.
On the face of it, the use of these super-strong polymers seems to be the ultimate goal. However it turns out that the polyamides are not necessarily the best materials to be using: Nylons are expensive, difficult to work with, and are not particularly good for the environment.
A waste-free and biodegradable cable tie had been considered during the late 1990s. However, the early rapstrap designs were not sophisticated enough to work with the materials then available.
Fortunately, once a rapstrap design existed that worked in these demanding materials, it was relatively easy to adapt it to work with others. This opened up many new possibilities, and led to the creation of recycled and biodegradable rapstraps.
These include a cold water soluble version that's essentially made from glue, and a version made with up to 30% potato starch. Following-on from this, we have also experimented with other renewably-resourced polymers; Today, we can produce rapstraps from bio-polyurethane and bio-polyester, and these contain up to 43% renewable biocarbon content.
Research & development in this area is ongoing, but the ultimate aim remains the same: to produce a more sustainable alternative to the traditional cable tie that doesn't create so much waste.