As an example, I was in a craft shop some years ago and passed a shelf where there were some sequins on sale. These particular ones caught my eye because they were made from a multilayer co-extrusion with more than 100 layers of the polymers and because of the slight mismatch in refractive index there was a tiny reflection from each interface that built up an produced an iridescence to the sequin. The sequins were just discs that had been stamped out of a sheet of film. Further down in the same shop I saw the sheet of film the sequins had been stamped out of also for sale as a table decoration. Assuming that sales of each item were equal then there was zero waste from this product. My thought then was whoever thought up the use for the off-cuts to not only eliminate the waste but also be able to charge a fee for the waste certainly earned their salary that day.
This then set me thinking as to what we can do with the waste from the various vacuum-coating processes. Unfortunately, I do not appear to be earning my salary today.
The waste that we can produce is the edge trim from the metallizing or sputtering process. This can be ground up and be reprocessed as polymer in some cases as the amount of metal is small and, when oxidized, it disappears as it becomes transparent. However, in other cases it is just sent to landfill as partially metallized, and because of the grading of the metal from dense to zero, it is difficult to think of a use for it other than for it to be ground up and down cycled into a low-grade polymer.
The material from sputtering processing can be equally as difficult as the coating thickness may well be more significant and in some cases needs controlled disposal because of the coating composition.
In some processes before the polymer web is coated it is cleaned using tacky rolls which remove the particles from the web and transfer them onto a high tack roll which accumulates the debris. This contaminated film that has collected all the particles is discarded. I am reminded that in the UK it is possible to purchase a bottle of British Standard Dust. There is a British Standard that defines what it means by Dust and you can purchase a reference dust that you can use to compare your own dust to. Now to do this the Standards team has defined the composition, size, shape and quantity of whatever makes up this bottle of British Standard Dust. This is not all. To be able to sell this Standard Dust they need to be able to make the dust and one University in the UK had a contract to make this as a product.
So I am left pondering as to what use I can make use of the discarded sheets of high-tack film that had become ineffective because of being clogged up with particles.
If any of you can think of a use for this material, then not only will you make a fortune but also I suspect you will have a large number of companies wanting to supply you with material along with gratitude that they will no longer have to pay to dispose of the material.
So everyone get their thinking caps on. Let's be creative about changing our waste into our next new product.