But after that, things get a lot less clear.
And for companies making packaging decisions, that unclear middle matters. A material can be recyclable in theory and still have a hard time making it through the recycling system. Whether a package is recyclable is only part of the question. For recyclable plastics, what happens after collection matters just as much.
How is that package handled once it leaves the bin? Can it be recognized and sorted into the right material stream? Is there a processor that can take it? Is there a real market for the recycled material on the other side?
These questions matter for brands, converters, and manufacturers, but they also matter for consumers. Recycling systems depend on people taking part, but when the process feels unclear, it can be harder to trust that the effort is worth it.
So let’s follow a plastic package — in this case, a typical yogurt cup — after collection and look at where recycling works well, where it can break down, and why infrastructure plays such a large role in the final outcome.
Once our yogurt cup is placed in the recycling bin, it gets collected along with paper, cardboard, metals, glass, and other plastics.
From there, it’s sent to a Material Recovery Facility, often called a MRF.
A MRF is where mixed recyclables are sorted into separate material streams. At this point, the yogurt cup isn’t being recycled yet. It’s just one item in a large, mixed stream of materials.
MRFs don’t turn used plastic into new plastic. Their job is to sort materials so they can be sold and sent to the next processor.
Inside the MRF, the yogurt cup moves through a series of sorting systems. Depending on the facility, those systems may include:
Mechanical screens
Optical sorters that use near-infrared technology
Magnets
Air classifiers
Manual sorting lines
The goal is to separate materials into streams that can be processed and sold.
Plastics are identified and separated into resin streams such as:
If our yogurt cup is made from polypropylene, the best outcome is for it to be recognized and sorted into a PP stream — but that’s not a given.
Separation isn’t perfect, and a lot can affect whether the cup is sorted correctly:
Shape: rigid vs. flexible
Size: items that are too small may fall through screens
Color: dark or opaque materials are harder to detect
Contamination: food residue, labels, multi-material structures
This is one of the first places where recycling can break down.
The cup may be made from a recyclable resin, but if the facility can’t recognize it, separate it, or send it into the right stream, it may never make it to a reprocessor.
The good news is that sorting technology is improving
AI-powered sortation, including systems from companies like AMP, is helping facilities identify and recover more materials. These systems use computer vision and machine learning to recognize different types of packaging at high speed.
For our yogurt cup, better sorting could make a real difference.
If the system can identify the cup more accurately, it has a better chance of landing in the right bale instead of being missed or sent to a lower-value mixed stream.
That helps every part of the system. It can reduce material loss at the MRF, create cleaner bales for reclaimers, and help build stronger recycling streams for materials that are still gaining ground.
Still, better sorting isn’t a complete fix on its own.
The package still has to be designed for the system it’s entering. The recycling stream still needs enough volume. And there still needs to be demand for the recycled material after it’s processed.
If the yogurt cup is successfully sorted into the PP stream, it’s grouped with other polypropylene items, which are then compressed into large bales.
At this point, the cup still hasn’t become anything new; it has only made it through sorting. Now the bale needs to be sold to a reclaimer or reprocessor that can handle PP.
This is the difference between “recyclable” and “actually recycled.”
Some plastic streams have strong, mature recycling systems. Others are still building the collection, sorting, and processing base they need.
The difference isn’t just chemistry — it’s infrastructure, standardization, and demand.
PET and HDPE are widely considered practically recyclable.
A clear PET water bottle, for example, is widely collected, widely sorted, and supported by strong end markets.
HDPE has a similar advantage. It’s commonly used in products like milk jugs, detergent bottles, crates, pipe, and decking.
These materials aren’t just recyclable in theory — they are consistently captured, processed, and reused at scale, supported by decades of infrastructure investment, standardized formats, and strong end markets. That’s what turns recyclability from theory into reality.
Polypropylene (PP, including XPP) is increasingly recyclable, but infrastructure is still catching up.
PP products like our yogurt cup can be recycled. Sorted PP bales can be sent to reclaimers, where the material may be washed, ground, reprocessed, pelletized, and used in new products.
But the bigger question is whether enough PP is being collected, sorted, and sent to the right processors in practice.
Companies like PureCycle Technologies are using dissolution-based processes to purify polypropylene waste, removing color, odor, and contaminants to produce near-virgin quality recycled PP. This creates new potential for higher-value applications, including food-grade packaging, which has historically been difficult to achieve with mechanically recycled PP.
However, even with these advancements, one constraint remains: Advanced recycling doesn’t replace the need for collection and sorting — it depends on it.
These technologies rely on consistent, quality feedstock. Without sufficient volumes of PP being captured and separated upstream, even the most advanced systems can’t operate at scale.
Now let’s say our yogurt cup doesn’t sort cleanly into the PP stream.
Maybe the label gets in the way. Maybe the cup is too small for the local system. Maybe the facility doesn’t have a strong PP sorting program, so the cup gets grouped with mixed plastics instead.
In that case, the path gets harder. Mixed plastics and multi-material packaging often have weaker end markets. They may be harder to separate, leading to them being downcycled into lower-value uses or, in some cases, they may not be recycled at all.
This is where “recyclable” can be misleading.
A package may be recyclable under the right conditions. But if it doesn’t make it into the right stream, the real-world outcome may be very different.
Once our yogurt cup does make it to a PP reclaimer, the next step is reprocessing.
Typically, the material is:
Washed and cleaned
Ground into flakes
Melted and filtered
Converted into pellets
Those recycled pellets can then be sold and used in new products.
But not all recycled material has the same value. Buyers care about quality, consistency, performance, and cost.
If the recycled PP performs well and is available in steady supply, buyers are more likely to use it. If quality is uneven or supply is limited, demand can drop.
That matters because recycling isn’t just a technical process. It’s also a market.
For the yogurt cup to become part of a useful recycled material stream, someone has to want the material on the other side.
If everything goes well, the yogurt cup may become part of a new product.
It may go into another application, such as an automotive part, a storage bin, a crate, or another rigid plastic product. That would be an open-loop recycling outcome, where the material is recycled into a different type of product.
In some cases, recycled plastic can move through a closed-loop system, such as bottle-to-bottle recycling.
In other cases, it may be downcycled into a lower-value use.
And if the package falls out of the system at any point, it may end up in landfill or waste-to-energy.
A lot has to go right in order for the package to be correctly recycled:
The package has to be designed well
The consumer has to recycle it
The local program has to accept it
The MRF has to sort it
A reprocessor has to want it
Someone has to buy and use the recycled material
Our yogurt cup may be made from a recyclable material, but that alone doesn’t decide its outcome.
To be practically recyclable, it needs support from the system around it:
It needs to be accepted in collection programs.
It needs to be recognized and sorted correctly.
It needs to move into a clean enough bale.
It needs access to a reprocessor.
It needs a real market for the recycled material.
That’s why packaging decisions can’t stop at the resin code.
A package doesn’t get recycled just because the label says it can. It gets recycled when the system can collect it, sort it, process it, and use it again.
For brands, converters, and manufacturers, the question isn’t only: “Can this material be recycled?”
It’s also:
Will this package be accepted where it’s sold?
Will it be recognized at a MRF?
Can it sort into the right stream?
Is there enough infrastructure to process it?
Is there demand for the recycled material?
Does the package design help or hurt its chances?
Materials like PET and HDPE have strong recycling systems today. PP, including XPP, is gaining ground as infrastructure improves and demand grows.
For form fill seal applications, XPP gives brands a way to move away from polystyrene while still thinking carefully about performance, cost, and recyclability. But like any material, it has to be considered within the real recycling system.
After collection, recyclable plastics are sent to a MRF, where they are sorted into material streams before being sold to reprocessors.
Some packages are not accepted locally, are missed during sorting, are contaminated, or lack strong end markets for the recycled material.
A plastic is practically recyclable when it can be collected, sorted, processed, and sold into a reliable end market at scale.
They can design for real recycling infrastructure, choose compatible materials, reduce contamination risks, and evaluate end markets early.
By the time our yogurt cup reaches the end of the recycling process, one thing is clear: every step matters.
Collection, sorting, reprocessing, and end markets all have a massive effect on whether materials get recycled. And design decisions made long before the package reaches a consumer can affect what happens after that package is used.
That’s why recycling has to be part of the packaging conversation from the start.
At ICPG, we help packaging teams think through the full picture: how the material performs in use, how it runs on existing equipment, how it supports cost and sustainability goals, and how it fits into the recovery systems it may enter after use.
If you’re evaluating materials for a packaging application, we can help you look beyond the recyclability claim and assess how the package may perform in the real system.
Reach out to ICPG to discuss your application, performance needs, and material options.