Cable Ties are made from virgin nylon 66. What is meant by virgin nylon 66 is that it is brand new nylon 66 polymers; in the blend there is normally a UV stabilizing agent to prolong the life expectancy of the cable ties. The very best cable ties are made this way and these are the most expensive that’s why brands like Panduit and Thomas & Betts charge the prices they do and why they are specified in a lot of manufacturing industries where there is no room for error.
But what of the every day cable ties that you buy from people like us? Well, what happens here is the cable ties are manufactured in the same way but a small percentage of the nylon 66 is reground from the waste material you get from the injection molding process. This is perfectly ok and the cable ties are tested to the highest standards. Good quality cable ties should adhere to or be approved by UL (Underwriters Laboratories) and CE (European Conformity) and have the flammability standard of UL 94V2.
A lot of cable ties are manufactured to these standards and I underline the TO in that they are manufactured to the standard but they may not be certified. Certification costs money and these costs are passed on in the product price so this is another reason that some cable ties can cost more than others, it does not mean that the quality is necessarily poorer.
The main reasons that some cable ties are of a very poor quality is they have too much reground nylon added or nylon that has been reground too many times. Nylon 66 is hydroscopic and absorbs moisture, part of the manufacturing process is to add moisture to the cable ties as this gives the cable tie it’s flexibility. If the cable ties get too little water added or they are not left to cure for long enough then this can cause brittleness. Cable ties should be stored at a temperature between -40º and +85º Celsius, storing at temperatures outside of this range can also cause a problem.