Plastic recycling: How to recycle & what to recycle?

Plastic is a type of material that is usually derived from crude oil. This serves as the primary raw material for most plastics. To produce plastics, various chemical processes are set into action to transform the raw materials into so-called polymers. These polymers – large molecules made up of the repeating of long chain units known as called monomers – form the basis of the diverse range of plastic materials we use today. The term polymer is often used interchangeably with plastic, as all plastics are chemically speaking polymers. However, bear in mind that not all polymers are plastics.

Bio-based plastics, on the other hand, are made from cellulose or starch. Many plastic types start with the prefix 'poly,' such as polypropylene, polyethylene, or polyamide. Coincidence? Not at all, as all plastics are composed of polymers. Interestingly, there are entirely natural polymers too, like hair or silk.

Now that we’ve unpacked what plastic is and how it's made, it’s time to look at what happens once it’s served its purpose.

Plastic recycling is the process of collecting, sorting, and reprocessing plastic waste into new, usable materials. Compared to most other materials, instead of ending up in landfill or incineration, plastic can be recycled. Thus, plastic materials can be giving a second life.

Thanks to its recyclability, the demand for so called ‘virgin plastic‘ (plastics that are made from new raw materials and haven’t been used or processed before) can be reduced efficiently.

We use virgin plastic material for our Packiro packaging to ensure that it is 100% safe for packing food items. What is more, due to legal restrictions, there are currently essentially no recycled materials with a food safety rating.

Diving a bit deeper into the topic, we will now take a look at the different types of recycling, such as mechanical and chemical recycling.

Mechanical recycling is the most common method of plastic recycling in the UK. It involves physically processing plastic waste—sorting, shredding, washing, and melting it—into new raw materials without changing the chemical structure of the plastic. This method is widely used for packaging waste like bottles and containers.

Mechanical plastic recycling can be broken down into the following 4 steps:

Step 1: Collection

Plastic waste is collected from homes, recycling sites, and businesses.

Step 2: Sorting

Before processing, plastics must be sorted according to their polymer type, which determines their melting temperature and potential end uses.

Step 3: Reprocessing

The sorted plastics are washed, ground into flakes, heated, and extruded into new pellets ready for manufacturing.

Step 4: Manufacturing New Products

The recycled pellets can be used to create new products, reducing the need for virgin plastic.

As you can see, recycling has come a long way since its early days, both politically and technologically. The bad news: despite efforts, a significant portion of plastic packaging still doesn't get recycled. Why is that?

1. Collection/Disposal by Consumers: You've likely heard that separating the aluminium lid from a plastic yoghurt pot before disposal aids recycling. This widespread belief applies broadly—few plastic containers are made entirely of one material. Pre-disposal separation, when feasible, enhances sorting efficiency. However, this often doesn't happen.

2. Sorting Multi-layered Materials & Carbon Black Pigments: Most plastic packages consist of multiple material layers bonded together to protect products cost-effectively. These layers are so tightly fused that they can't be separated in sorting facilities, rendering them non-recyclable and destined for incineration. Additionally, high carbon black content in pigments can prevent plastics from being identified by infrared scanners in sorting facilities, leading to their exclusion from the recycling stream and subsequent incineration.

3. Reprocessing: Contaminants, Printing Inks, and Adhesives: Additives are often introduced to polymers to make plastics as flexible, stretchable, and stable as needed. While practical, these additives become contaminants during recycling, hindering effective material recovery. Printing inks can also pose challenges. They can discolour the recycled material, limiting its reuse to products where colour is less critical. Anyone who's mixed too many paint colours knows the result: a greyish hue that's hard to repurpose.

4. When Is Something Considered Recycled, and When Is It Truly Recycled? In the UK, plastics collected for recycling are typically considered recycled once they've been sorted and processed into new materials. However, the effectiveness of recycling depends on the quality of the collected material and the efficiency of the recycling process. A genuine circular economy is achieved only when recycled materials are used to manufacture new products, reducing the need for virgin resources.

As noted earlier, several factors can hinder high-quality mechanical plastic recycling. Chemical recycling aims to address these challenges by breaking down plastics into their original chemical components, allowing for the separation of additives and different plastic layers. The goal is to recycle a broader range of plastics.

Often, plastics that are not suited for the process of mechanical recycling will be instead used for chemical recycling. This includes mixed (‘composed’) or heavily contaminated plastic materials.

However, the drawbacks include the high energy consumption required for these processes, making large-scale industrial application currently impractical. Additionally, concerns remain about the environmental impact of disposing of solvents and catalysts used in chemical treatments.

• Closed-Loop Recycling: Plastic waste—like PET bottles—is processed and transformed back into new products of the same quality, such as fresh PET bottles.

• Open-Loop Recycling (Downcycling): Plastic is recycled into products of lower quality or different use, like turning a plastic bottle into textile fibres or packaging materials. It extends the life of plastic but eventually leads to waste that can’t be recycled further.

• Dissolution Recycling: A more advanced technique where specific polymers are selectively dissolved using a solvent. This process helps separate valuable plastic from mixed waste streams without changing its chemical structure, allowing it to be reused in high-quality applications.

In short: unfortunately, it is not. With each recycling loop—each melting and reprocessing—the polymer chains shorten, degrading the material's quality. Currently, plastics can undergo only a limited number of recycling cycles. This leads to some sort of 'downcycling,' where, for example, a recycled yoghurt pot doesn't become another yoghurt pot but perhaps a lower-grade product. Nonetheless, using recycled materials is far more resource-efficient than producing new plastics.

An exception to this downcycling trend is PET bottles within deposit return schemes. These bottles can be recycled up to ten times, with the recycled material used to produce new PET bottles. This closed-loop system is effective because the material remains within its dedicated cycle. Once the plastic reaches the end of its recyclability, it can be repurposed into textile fibres for clothing or films. Therefore, it's crucial that PET bottles stay within their own recycling loop for as long as possible. Diverting the recycled material to other uses prematurely ends its potential for further recycling.

While recent legislation, such as the UK's Plastic Packaging Tax, has accelerated recycling efforts, the concept itself is far from new. In fact, it's ancient.

Archaeological evidence shows that even in ancient times, people collected, melted and reworked metal and glass to produce new products. Such ‘mechanical recycling processes’ still outweigh other processes today and are implemented on a large industrial scale. While official figures speak of 70 per cent recycled packaging waste, according to waste management experts, in the end only about 20 per cent of our packaging is actually processed into recyclate. In the plastics sector, this figure is (at least unofficially) even significantly lower. We will look at the reasons for this later.

To boost recycling rates of our plastic waste and advance the circular economy, the UK government introduced the Plastic Packaging Tax in April 2022. This tax applies to plastic packaging produced in or imported into the UK that does not contain at least 30% recycled plastic.

You’re running a business that is selling products to EU countries? The European Parliament and the EU Council have also agreed on a so-called ‘Green Deal’ the aim is that by 2030, all packaging placed on the market in the EU should be reusable or recyclable.

So it's about time we took a closer look at how plastic recycling actually works.

Recycling is an indispensable foundation for a functioning circular economy. That’s why at Packiro, we've developed our fully recyclable plastic packaging solutions 'Metallised Martha' and 'Transparent Toni’. Both materials consist of a single type of plastic, making them highly suitable for mechanical recycling.

Because we value transparency and accurate communication, we've had our plastic packaging tested for recyclability by Interzero, one of the leading environmental and recycling service providers.

We're proud to say that both materials have passed the practical tests with flying colours and have been awarded the 'Made for Recycling' seal. Our customers can print this seal directly on their packaging to inform the end user of the correct disposal method.