The recycling of plastic
|Release time:2013-02-28 Source:admin Reads:|
Plastics can be pyrolyzed into hydrocarbon fuels, since plastics have hydrogen and carbon. One kilogram of waste plastic produces roughly a liter of hydrocarbon.
Thermoplastics can be remelted and reused, and thermoset plastics can be ground up and used as filler, although the purity of the material tends to degrade with each reuse cycle, belt hangers makers commonly use purity plastic material. There are methods by which plastics can be broken back down to a feedstock state.
The greatest challenge to the recycling of plastics is the difficulty of automating the sorting of plastic wastes, making it labor intensive. Typically, workers sort the plastic by looking at the resin identification code, although common containers like soda bottles can be sorted from memory. Typically, the caps for PETE bottles are made from a different kind of plastic which is not recyclable, which presents additional problems to the automated sorting process. Other recyclable materials such as metals are easier to process mechanically. However, new processes of mechanical sorting are being developed to increase capacity and efficiency of plastic recycling. In fact, many plastic products such as food bags, belt hangers, drinking bottles are ban to use recycled plastic.
While containers are usually made from a single type and color of plastic, making them relatively easy to be sorted, a consumer product like a cellular phones may have many small parts consisting of over a dozen different types and colors of plastics. In such cases, the resources it would take to separate the plastics far exceed their value and the item is discarded. However, developments are taking place in the field of active disassembly, which may result in more consumer product components being re-used or recycled. Recycling certain types of plastics can be unprofitable, as well. For example, polystyrene that usually used to make belt hangers is rarely recycled because it is usually not cost effective. These unrecycled wastes are typically disposed of in landfills, incinerated or used to produce electricity at waste-to-energy plants.