Differences between New Plastics and Recycled Plastics

I am interested in using recycled plastics for one of my designs. It’s relatively straightforward to get information and samples on raw plastics, but it is proving difficult to get info on their recycled counterparts. I have heard from some people that once a plastic has been recycled, it’s properties change completely and must be used for something else.

Does anyone have any good books or websites I can use to get technical info on recycled plastics?
Do the same processes that work on new plastics work with recycled plastics?
Finally, what are some good suppliers of recycled plastics? For now I am looking at material recovery facilities but there must be another outlet for these plastics.

Thanks in Advance!

No response? I’m sure someone has some experience using recycled plastics that they can share?

Hi koca,

please be more specific.

Do a research first, what type of plastic suits the needs of the product you haven in mind and determine what kind of manufacturing process will be involved. On the journey exermining these questions you might also find the answers on your first question for yourself.

“plastics” is a much to global term, to be able to give a realistic answer here.


yours mo-i

The fact that there is so little information should tell you one thing - not a lot is available yet.
Try the big dogs websites first - Sabic, Dow, Eastman. They are slowly coming out with PCR resins for select processes.
Then go to www.ides.com and search PCR and look for contacts to talk to.

Thanks to those who replied. I found a book called “ecoDesign” which lists projects, the type of recycled materials they used, and the manufacturers for those materials. There are also a few magazines out recently that have good articles on Sustainable Design. I will start from here.

-koca

One big difference is recycled plastic is the plastic varies in consistency with each batch. Often made up of regrind plastic instead of virgin pebble (of course right it’s recycled plastic) and a wide multitude of varying brands of specific plastics. This causes problems for a mechanical engineer interested in drop testing a polycarbonate cellular product for example. First let me describe the drop test procedure many manufactures conduct before releasing a product.

1 you freeze the cellphone to -30f and heat it to 150f where each hour the chamber heats… then the next hour it cools. 12 cycles and you have the 24 hour period.
2 then the engineer straps electrodes to the product and watches the shock as the product is dropped at 4 feet onto concrete. This explains why there is often a square patch of carpet cut out of a typical Motorola/NCR/Garmin engineer’s cubical. (before all this occurs the engineer will try to fist guess where the shock will be so the design can be modified. That guess work maybe done with Pro/MECHANICA or COSMOS)
3 Looking at stress and fractures the parametric model will be updated/revised for later production.

Now the equation is much more complicated if the plastic consistency is uneven like that of regrind or recycled plastics. Typically the melt as plastic is referred to when it’s injected can be different with each batch making it difficult to guess calculate and design the structural integrity of a product. When you can’t guess what strength the plastic will be in your mold how could you design with confidence a product that can withstand the pressures of falling out of your pocket and onto the street …into the toilet… or off the top of the car.

I drop my phone almost every day and it holds up for about six months. A cellular product that uses a recycled plastic may not last one drop.

I could go on for 4 hrs on recycled and bio plastics. I teach a two day or five day plastics class that covers this topic in one of the many lectures BTW.

The most common type of recycled plastic High Density Poly Etheline is often down cycled into large durable goods like plastic panels, plastic benches. Styrene peanuts tend not to get recycled because the weight of the expanded styrene (stirophome) and large size vs weight makes it not cost effective to recycle.

Another problem with recycled plastics is getting that perfect color match. Industrial designers might have to make color match sacrifices for the trade off of using a recycled plastic. Imagine someone sorting blue jugs, red jugs and white jugs into separate bins for the grind precess… What die to you use to blue to get white? bleach? See the problems. Smart designers will turn those problems into opportunities and brand differentiation.