If We Recycle Plastic Bottle Caps, Will They Be Used?

Continuing with our theme of preventing plastics from going to the landfill, what about the caps for all these bottles now being processed by recyclers? We are in a much better position to capture these pieces for recycling and with the increase in volume/processing, it has created a growing market. In the past, there was no significant market for these caps, because of any of the following reasons:

  1. Caps were usually not coded or used very small symbols
  2. The recycling centers couldn’t bale them properly
  3. The plastics processor couldn’t separate them from #1 or #2 plastic bottles effectively

 Increased demand for recycled plastics in some lower end applications means that we need to recover more of the caps, just to produce the tonnage required.  This is possible because of their many uses in products not requiring the same quality levels as #1 PET and #2 HDPE primary plastic packaging. Let’s look at these separately for the process improvements made:

Caps were not coded or were coded with very small symbols

A few reasons for this:

–      Not required by law. Coding was only required for the packaging themselves like the bottles. People were choosing to code to look eco-friendly, but may have been inaccurate about it.

–      American Society for Testing & Materials (ASTM) has a strict method for testing for the codes and adding new codes. If you don’t have a code identified or established, you are a #7, which is a catch-all other category and tends to be put in the trash to the landfill

–      Cap was so small, producer wouldn’t bother to identify the resin or

–      Coding was so small, the recycling center couldn’t take the time to look for it and therefore would toss the cap into the bins for trash to be sent to the landfill

The Association of Postconsumer Plastic Recyclers (APR) has addressed this issue by documenting Design for Recyclability Guidelines to help producers of bottles using resins that can be recycled. Key point here is that producers of #1 resins, use #1 caps and producers of #2 resins, use #2 caps. Also, the waste management service provider should encourage consumers to leave the caps on the bottles to aid in the sorting and baling.

Even if the caps do not match the bottle resins, these caps can still be collected for low end markets, if the volume collected can be sufficiently high to be utilized by the recycling centers.

Recycling Centers Baling Techniques Needed Improvement

As the bottles get baled, the caps were getting lost in the process and therefore not being included in the bale or an even worse problem was getting the bales mixed up with different resins. Not every recycling center that takes bottles can take bottles with caps. Centers with horizontal balers can take them by puncturing the bottles to push off the caps. Most centers use horizontal balers. As more recycling centers become standardized in their process, this issue should go away. For more information on baling specifications, please look at the documentation provided by APR on Model Bale Specifications.

Recycling Processors Are Improving Their Techniques to Separate the Resins

With the baling issues identified in the previous issue, the recycling processors have developed better technologies to separate the bales into their usable components. Even with up to ~20% of contamination in the bales, the processors are able to quickly sort the other resins out, including caps. With demand increasing for all resins and caps, the resins not usable at the particular processing center are being sent to other recycling processors and less is going to the landfill.

Caps are no longer a throw-away resin, but a vital component in the process for recycling all plastic resins.

“The APR encourages this practice because we are committed to increasing the available supply and the actual amount of plastics being recycled while at the same time reducing the instances of litter and waste in local communities in North America,” explains APR’s Executive Director Steve Alexander. 

We welcome any other topics you wish to see or your comments on our posts.

Need more information? Envision Plastics Vice President, Tamsin Ettefagh will be happy to discuss your comments or concerns in greater depth. Contact her at 336/342-4749 Ext 225.

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2 thoughts on “If We Recycle Plastic Bottle Caps, Will They Be Used?

  1. Interesting point on matching the bottle cap resin to the container resin. In theory, this would solve a lot of problems in the recycling process. However, I learned from experience that using the same material forclosures and bottles can create a real problem in maitaining the target torque values when applying the closures. This is caused by having the same coefficient of friction for both materials. Some closures will be so loose the container leaks and some will be so tight they are impossible to remove by the consumer.
    Now that closures are being recycled for other uses, it seems imperative that this information get out to the public. In Massachusetts, many of us have to take our waste to transfer centers, having it sorted for recycling. If consumers knew to take caps off (and rinse the containers for that matter) it wouls ease the burden on recyclers and the recycling process.

  2. Bob,

    Thanks for commenting. We appreciate that someone with your high level of expertise comments on real world applications in packaging. Please check in with our blog regularly and critique our commentary.

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