Sorting Plastic for Industrial Recycling

In May we did an article about Industrial Plastic Recycling, identifying common recyclable plastics and best practices for recycling. This week, we want to take the topic of industrial plastic recycling a step further and focus on the process of sorting plastics.

While sorting any kind of recyclable can help increase its value, it is especially important for companies to be extra vigilant in sorting plastics for industrial recycling. Unlike recycling at home, plastic recycled at the industrial level usually isn’t sorted after it reaches a recycler.  This means that recycling companies rely on their suppliers to correctly sort the plastic prior to recycling it.

Why Sorting Matters
As we mentioned in our May article, there are 7 universally recognized resin grades for plastic. However, there are thousands of types of plastic that span these grades. Each type of plastic has a unique combination of dyes and additives which affect its color, shape, texture, strength, flexibility, and melting point – and for manufacturers looking to use recycled plastic resin to make new products, it is vital for them to have the correct type of plastic. There is also a safety reason for sorting plastic. Some kinds of plastic cause deadly chemical reactions when mixed together. For instance, adding one PVC bottle to a 900 lbs. load of PET bottles can cause the entire load to be contaminated. This is because PVC and PET when mixed together form hazardous acids, or a dioxin emission, that is toxic to humans. If the contaminated load of PET went undetected, the toxic emissions created could pose a serious safety concern for employees at the processing facility.

Best Practices for Sorting Plastic
The safest and most efficient way to recycle industrial quantities of plastic at your manufacturing or distribution facility would be to provide your recycling company with data sheets containing technical specifications for the plastic resins of each plastic item you are trying to recycle. Such technical specifications would tell a recycler things like the Melt Flow, Resin Number, Extrusion or Injection Grade, Izod, and Durometer for that particular type of plastic. Your recycling company may also ask questions like the following:

  1. What is the form of your item?
    For example, a plastic item might be in the form of a part, purge, regrind, film, resin, or repo resin.
  2. How is it packaged for recycling?
    For example, you might choose to bale this material or it may come on rolls, skids, in gaylords, or in a compactor.
  3. Is there any cross contamination?
    For example, are there different types of plastic extruded together to form the part or type of film? This is especially common with food wrappers.  Another way to ask this question is to consider if there are any laminations, coatings, foils, etc. as these will affect how the plastic item can be recycled.

Below we’ve also included a rough guide for identifying plastics by resin type (especially for instances where no resin number is included on the item).

Infographic - Sorting Plastic