Production and Recycling
This is our last information page on Kevlar, we hope you've learned a lot so far and continue to learn from this last page.
Let's start off with how Kevlar is produced.
Kevlar is synthesized from two monomers, 1,4-phenylene-diamine (para-phenylenediamine) and terephthaloyl chloride, in a condensation reaction (also known as dehydration synthesis, basically where two molecules combine and form a larger molecule through the loss of smaller molecules, in this case 2HCL for each monomer produced).
The result of this reaction produces a crystal forming, opaque liquid, which as we learned from the last page can be spun to essentially form Kevlar, with hydrochloric acid as a byproduct (that HCL I mentioned above).
There are a couple other substances involved in the production of Kevlar nowadays as well. N-methyl-pyrrolidone and calcium chloride are used in the process of polymerization (in short, when you get monomers to react tpgether to form polymers) as solvents.
Another substance involved is sulfiric acid, which is actually where the bulk of the expense involved in synthesizing Kevlar comes from. It's used to keep the Kevlar in solution while it spins in the spineret. It's been historically very difficult to use concentrated sulfiric acid but it's a necessary process, which is why it is one of the most expensive parts of production.
Finally, once this product has been spun it can be woven together, which gives it more strength than it would have if it were left as a sheet
Here's an image of what the final product, spun and woven Kevlar, may look like:
Finally, let's talk about recycling.
You may be asking "how will this material affect the environment?".
We're happy to tell you that Kevlar is 100% recyclable!
Generally what happens when you recycle Kevlar is they remove any outer padding (like what you see on bulletproof vests), recycle of that as normal, and then chop down the Kevlar fibres into what they call "staple fibre", which is generally around 30-60mm long pieces of Kevlar fibre.
Then, this staple fibre can be used in a multitude of ways. It can be respun into new yarn, it can be used in padding for things, it can be pulped, in general Kevlar is very much recyclable so there's no need to feel bad about buying products that contain Kevlar.
Then you might be asking, "but how and where do I dispose of it?".
Well, this answer varies depending on where you live and what programs you have access to.
If you're in the military you can generally recycle your Kevlar items through their programs, if you live in a large city with a recycling centre make sure to call them and ask them if they accept Kevlar.
If neither of the above apply to you, you can always google for "where to recycle Kevlar" and you should find some relevant places to dispose of it that are close to your area.
We hope we've helped you learn about Kevlar and helped to alleviate any concerns you may have had about using it. Feel free to take a look through the portfolio and get in touch with us through the contact page.