Do you know how the different types of plastics are identified and encoded?

Not all plastics, for example, are suitable for food use, or are plastics suitable for channeling drinking water...

There is a diversity of plastic materials, each type with its particular characteristics and recycling capacity according to various processes.

Not all plastics, for example, are suitable for food uses, or are plastics suitable for channeling drinking water. That is why the process of recycling and filtering plastics must be sustainable and above all very safe and efficient in order to keep the different materials separate. For this we have the seven plastic identification codes, depending on the material and its recycling possibilities.

These universal plastic recycling symbols are made up of a triangle formed with three contiguous arrows and an identification number inside.

The recycling symbol for plastics is based on the Möbius triangle


Depending on the material with which the product is made and its possibility of being recycled for a new use, the 7 codes are classified as:


The most widely used plastic in the creation of food packaging. Lightweight, low-cost plastic with high recyclability. The usual uses of PET are for the manufacture of bottles of water and other beverages, as well as other liquids such as oils. In its recycling, PET is usually destined for car parts, furniture, carpets and even sometimes for new food packaging.


High Density Polyethylene is characterized by exceptional resistance to temperature and chemicals. It is a rigid and hard plastic, and suitable to obtain plastic products by forming like thermoplastics. It is therefore a plastic blow molding of large parts and injection, extrusion, film and a myriad of molded plastic products.

In a first phase it is usually used for the creation of supermarket bags, personal hygiene and cleaning products, liquid containers such as milk and derivatives or juices. Once recycled, it is usually used for new products such as oil containers, tubes, detergent bottles and other plastic applications such as weather-resistant outdoor furniture.


This plastic is born from the chemical combination of carbon, hydrogen and chlorine. It comes forty-three percent from crude oil and fifty-seven percent from salt. Therefore, it is considered as the least oil-dependent plastic. This plastic can be formulated in many possible ways, which allows its use and destination for many different end products. However, it stands out for its low recycling and for its ease of expelling toxins, which makes it a plastic not suitable for use in food chain products.

The usual uses of vinyl or pvc plastics, given their high resistance to acids and hardness, are the manufacture of tubes and pipes, detergent bottles, medical equipment, footwear, construction and other various uses.


Unlike the hardness of high density, in this case we are facing a very flexible and transparent plastic. These characteristics make this thermoplastic ideal for the manufacture of all kinds of bags, freezer bags, milk carton coatings and laboratory containers. In this case, if we are facing a plastic that allows its reuse in applications such as containers and bins, pipes, panels and plastic tiles, in wire and cable applications, in protective devices (helmets, knee pads, elbow pads …), washers, spacers, caps and caps, detergents, and other chemical products, toys, pallets, waterproofing of land, parts for the automotive sector.


This thermoplastic polymer is often used as an engineering plastic and competes with materials such as ABS. In a translucent plastic, with high resistance to fatigue and stands out for its hardness, as a vapor barrier and its resistance to heat. With these characteristics it is used in a wide variety of applications such as packaging, textiles, plastic parts, containers of various types, laboratory equipment, speakers, automotive components. Through a specific recycling process, it is reused on a regular basis for brushes, trays, battery cables and light signals.


Polystyrene is one of the least recommended plastic for food use, due to its ease of emission of toxins. On the other hand, it is one of the most widely used thermoplastics in today’s industry. Why? Its low cost and high rigidity. As an obvious application that we can all recognize we have the manufacture of CD cases. But despite the aforementioned we can find it in many other applications such as cutlery, glasses and plates, cosmetic containers, protective packaging, insulating material, caps, bottles …

We can find this plastic material with four different finishes: crystal polystyrene, transparent, highly rigid and therefore brittle. High-coefficient, opaque, impact-resistant polystyrene. Expanded polystyrene, valued for its high lightness, and extruded polystyrene, denser and more waterproof than expanded polystyrene, but also light.

Its classification with the number six is due to the fact that it is a very difficult material to recycle.


This section would include another series of plastics of varied compositions that are created for other specific and common uses such as for the manufacture of vehicle headlights, electrical parts, technical parts in cars such as handles, screens, sunglasses, DVD …

They are plastics resulting from mixtures of PC (polycarbonate), ABS (acetal butadeino styrene), SAN, TPO, Polyamide (PA), PBT, POM, ABS / PC, ASA.

And this is not why they are little used because, for example, ABS can be found usually in our homes, consisting of toys, telephones, electrical appliances, vacuum cleaners, control panels, veneers, shower trays, furniture, luggage … The commitment to recycling within the ODS must be part of everyone, both manufacturers and end users, the latter very important agents, since if the demand for a plastic decreases, its production will decrease. And it will be replaced by other more recyclable and environmentally friendly materials. Meanwhile at EURAPROIN we will continue working on our environmental commitment, innovating and searching for the best filters and systems for the industry.


We already have a classification of plastics according to their characteristics and recycling possibilities. Now it’s time to continue researching and improving recycling technology and processes.

What types of plastic recycling processes exist?

  • Plastic mechanical recycling processes

Se basa en el troceado, corte o granulado de las piezas de plástico, facilitando su posterior tratamiento y reutilización, trabajando con macromoléculas de polímeros.

  • Plastic chemical recycling processes

It is based on the degradation of the plastic material through temperature to break it down again into simple molecules, with which to obtain other types of plastics and fuels.

  • Energy recycling processes

In this case, the process does not intend to obtain other processable materials to obtain new products for the industry, but instead the plastic is converted in a way that later involves energy use.

At EURAPROIN we are fully committed to the goal of zero waste. We put all our effort in helping producers and managers of the industry, in achieving an effective waste policy and fully comply with Law 22/2011 on waste and contaminated soils published in the BOE, which you can access through the link of the title Of the same.

We are fully committed to excellence, quality and innovation and we can advise you on the best current options for your filtering need.

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