Plastics Basics: What types of plastics are there and which ones can be recycled?

by | Nov 10, 2020 | Blog, Circular economy, Optical Sorting | 0 comments

Although plastic materials were created earlier, the year 1907 is considered the beginning of modern plastic history. That was when Leo Baekeland invented Bakelite, the first thermosetting plastic. It was insulating, resistant to moderate heat, acids and water. A couple of decades later, in the 1930s, the polymers that now dominate the industry were already proliferating.

Nowadays, plastic is one of the materials that we use most in daily lives. Its use is so diverse that it is one of the ones that produces the greatest amount of waste. Something that has become a major problem and concern at a global level.

We use it and talk about the rethinking of its use, but do we really know it well? In this new article of PICVISA’s blog, we cover some basic aspects of plastics.

 

What types of plastic are there?

Plastic materials are manufactured from resin polymers mixed with substances that come from petroleum. This mixture is subjected to molding – by means of pressure and heat – which, depending on how it is done, will end up obtaining one type of plastic or another, each with its particular physical and mechanical properties (flexibility, hardness, insulation capacity, etc.).

At first glance, all plastics can be the same; but, these same properties mark the use to which they are destined. For this reason, in 1988, the Society for the Plastic Industry of the United States implemented the RIC (acronym for Resin Identification Code) as a classification standard. Currently, this code is valid in practically the whole world and determines 7 types of plastics.

Through an identification number from 1 to 7, the RIC basically serves to facilitate their separation. This number appears within a triangle with rounded corners and, below this, are the initials of the type of polymer with which the plastic in question has been manufactured.

These are the types of plastic that exist:

1. PET (Polyethylene Terephthalate). Transparent plastic that shows good resistance to steam and gases. It is one of the most used, mainly to manufacture water or soft drink bottles, food containers, some shampoo bottles and mouthwashes and even clothing and carpet fibers. It is also one of the most recycled.

In Spain, this type can only be used to manufacture water and soft drink bottles, provided that the container contains a minimum of 50% non-recycled plastic.

2. HDPE (High Density Polyethylene). This plastic, very hard and resistant to humidity, is used in different types of food packaging, drinks such as juices and milk, shampoo bottles, perfumes, toys, storage boxes or detergent bottles.

3. PVC (Polyvinyl chloride). Thirdly, we find PVC, a type of rigid, hard and versatile plastic that is used for building elements – door and window frames, gutters, pipes, etc. -, cable coating, credit cards and synthetic leather.

4. LDPE (Low Density Polyethylene). It is a very flexible and vapor-impermeable plastic. Given this characteristic, it is mainly used for food or garbage bags, squeeze bottles, flexible caps and film paper.

5. PP (Polypropylene). This is a plastic used mainly in the manufacture of kitchen utensils (plastic microwave plates, drinking straws, disposable cutlery, lunch boxes, etc.). It is also used to make bottle caps, fabric and carpet fibers, tarpaulins or diapers.

6. PS (Polystyrene). Very easy to mold, polystyrene is used for the manufacture of electronic material and packaging foam. Other items such as thermal cups, egg cartons, food trays, hangers and insulation are also made of PS.

7. The seventh type of plastic is classified as “Others”. This group includes plastics made from the mixture of various resins, such as polycarbonate and ABS (Acrylonitrile Butadiene Styrene).

They are nylon fibers, compact discs, containers for medical use, jugs from water sources…

 

What types of plastics can be recycled?

In the same way that a code was implemented to differentiate between plastics due to their differences in composition and, consequently, in purposes, there are differences in the possibility of recycling the material.

In fact, there is one type, number 7, that cannot be recycled. In addition, those that are made with materials that are difficult to separate, highly pigmented or degraded by atmospheric conditions are not suitable for recycling either.

There is a classification of the ease of recycling by type that establishes four “labels” in this regard: “easy”, “feasible”, “difficult” and “very difficult”.

The types of plastic would be distributed as follows:

Easy: PET, HDPE

Feasible: LDPE, PP

Difficult: PS

Very difficult: PVC

 

ECOPICK, the “intelligent” sorting robot from PICVISA

Whether it is to be sorted domestically or treated in recycling plants, the sorting of different types of plastic is vital to completing the circle efficiently.

At PICVISA, we know this and we have spent years investing in innovation and working to bring progress to the sector in this regard. An example of this is the ECOPICK robot with artificial intelligence (AI), which automates the classification and triage of recoverable material in recycling plants.

With the most advanced robotics and through Artificial Vision, ECOPICK adapts to the needs of the plant to recognize, classify and separate any material. The machine can be configured to meet the needs of different production or quality control processes in the recycling industry. For example, it can focus on the separation of PET bottles, briks and film or the recovery of valuable materials; among many other functions.

Discover how ECOPICK is transforming the recycling industry, here, and check the expertise of PICVISA, present in more than 15 countries with more than 250 units installed around the world.

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