E-Plastic Separation

I’ve been meaning to do a piece on plastic e-waste for some time now. This is because I did a good amount of plastic e-waste trading last year. I purchase baled computer and television cases from the United States and import them into China for sales and distribution.

Plastic e-waste, sometimes called “e-plastic,” is composed of plastic stripped from electronic equipment such as computers, monitors, telephones, etc. Why not just grind and melt the e-plastic together and turn them back into electronic equipment チェアマット

Here lies the problem, before e-plastics can be melted and turned into recycled plastic resin, it must first be separated into its plastic type. Plastic e-waste is usually composed of the following types: ABS, ABS (flame-retardant), ABS-PC, PC, PS, HIPS, PVC, PP, PE, and more. Each type of plastic has it’s own melting point and properties and cannot be combined for product manufacturing.

So the question now is, how do we separate everything?

While things are done quite differently in the United States (probably more automated due to higher wages), I’ve been lucky enough to visit an e-plastic separation plant here in Shanghai, China where most things are done manually.

According to the owner of the facility, a majority of the e-plastics the plant processes are imported from European countries and the United States. The quality of plastic from these countries, as a whole, is better.

When I say manual, I really mean it! The first step in plastic e-waste separation is to sort the larger pieces by hand by experts that can differentiate between 7-10 plastic types just by looking, feeling, and burning it. At the same time, the workers must remove any metal (ie., screws), circuit boards, and wires found. The experts are extremely fast and can usually sort through 500KG or more a day.

I questioned the owner about accuracy of all this. He arrogantly replied, “the accuracy is up to 98%, if this was not the case, I would not have any customers buying my stuff…”

Once the larger pieces are separated, they are put through the shredding and rinsing apparatus. The resulting plastic flakes are sun dried and ready to be packaged.

For the smaller e-plastic pieces that cannot be hand separated, they are put through several tubs of chemical baths with varying salinity. From what I understand, one of the containers contains only water. Due to the densities, PP and PE plastics will naturally float to the top. These are scraped off and set aside.

The plastic at the bottom are then scooped and placed in another tub with varying amounts of salt, cleaning agents, and other chemicals. This process is repeated until the rest of the plastics are sorted.