Plastics have become an integral part of our daily lives, but their disposal is a significant environmental challenge.
This article introduces the various types of plastics and explores the techniques used to recycle them, contributing to a more sustainable future.
Plastics are a broad range of materials with many different applications in various industries. They can be classified according to their chemical composition and properties. The recyclability of plastics varies depending on factors such as the specific type of plastic, the applications for which it is used, the presence of impurities and contaminants, colorants, additives and fillers, the availability in terms of volume, and the existing recycling facilities.
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Polymers and plastics products: Matching
From Plastic Europe FY2024: The Circular Economy for Plastics - a European analysis | 2024
The most common types of plastics include polyethylene terephthalate (PET), polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), polystyrene (PS), and polyurethane (PUR).
Plastics are categorized through Resin Identification Codes (RIC), created in 1988, where they are identified by their acronyms below a triangle made of three arrows surrounding a number from 1 to 7 (Plastic Packaging Resin Identification Codes)
The objective of this codification is to help consumers and recyclers to identify and consequently to sort each type of plastic.
Each plastic is known for its properties and characteristics:
Two main plastics families depend on their behavior when heated: thermoplastics and thermosets. Thermoplastics can be reheated and remolded many times until the plastic chemically degrades, while thermosets cannot be remolded. This property makes thermoplastics more suitable for being mechanically recycled, while thermoplastics can be recycled, thermosets are not easily recyclable using conventional methods.
PET, PE and PP belong to the thermoplastics family. Thermosets are comprised of polyurethane (PUR), unsaturated polyesters, and epoxy ethers.
Over the past few decades, the world has shifted towards a Circular Economy, particularly for plastics, emphasizing the importance of reusing materials rather than discarding them. Plastics are collected, sorted and recycled, giving a value to our waste and avoiding a negative impact on our planet and our health.
There are different techniques for plastic recycling, they could be divided into two main groups: Mechanical Recycling and Chemical Recycling.
Mechanical Recycling is the most commonly available method , this process involves sorting the waste plastic into different types and subjecting it to decontamination treatments. The plastic waste is transformed into flakes or granules, which can be then used as raw material.
The process has low energy intensity. However mechanical recycling is limited when having mixed waste streams, multi-layer films, multicolor, and/or low-quality waste feedstock (contamination, impurities, etc.). Additionally, repeated mechanical plastic recycling results in a progressive loss of quality.
Chemical Recycling involves breaking down plastics into its molecular components, which can then be used to create new plastic products. Its main advantage is the ability to produce high-quality, high purity polymers even from low-quality feedstocks suitable in health and food applications. Although Chemical Recycling has a higher energy intensity than mechanical recycling and requires higher investment, , it can process plastics that are not suitable for mechanical recycling, which would otherwise be destinated for landfill or incineration.
Plastic recycling starts at home with each of us. Understanding the different types of plastics and their recycling potential and challenges allows us to make informed choices and contribute to a more sustainable future.
Plastic recycling plays a critical role in reducing the environmental impact of plastic waste. Each in its own category, mechanical and chemical recycling is dedicated to giving a new life to discarded plastics and minimizing the need for virgin plastic production. Mechanical and Chemical recycling are complementary, and both are necessary to achieve a circular plastics economy.
Such feedstocks should not anymore go to landfill / incineration or downcycling.
