Main types of plastics by use and recycling tolerance

Although it may seem that plastic has always been present in the economy, its origin dates back to the end of the 19th century, although it was not until the first decade of the 20th century that Leo Baekeland invented Bakelite, the first thermosetting plastic. Two decades later, the first polymers were developed, which today are the ones that are massively worldwide. 

Currently, around 300 million tons of plastic waste of different types are produced annually, although, according to the United Nations, only 14% is collected for recycling. Throughout history, it is estimated that only 9% of the plastic waste produced has been recycled. This reality represents a great business opportunity for many companies and industries, in a context of growing global concern for the sustainability of the planet and for the implementation of Circular Economy initiatives to protect it.

Most outstanding classes

Depending on their internal structure, plastics can be classified as thermoplastics, thermosets or elastomers, although, more generally, the main types of plastics according to their use, each with a different degree of recyclability, are as follows:

• Polyethylene terephthalate (better known as PET). It is probably the easiest to recyclemost. It is used in the commercialization of countless products in sectors such as food, automotive, textile or pharmaceutical. Usually, for recycling, this plastic is crushed and ground into small pieces that are then reprocessed, although work is continually being done on innovative techniques to improve this process. RepetCo, for example, offers its own patented, environmentally friendly system for post-consumer PET/PE multilayer food packaging. Through a unique process, rPET pellets and rPE are generated that can be reused in the food industry with multilayer PET/PE trays and sheet packaging; in bottles for soft drinks or detergents; and in fibers for the textile and automotive industry.
• High density polyethylene (or HDPE). It is usually more resistant than PET, but also more polluting (it contains antimony) and has a similar level of transparency. It is also easy to recycle.
• Low density polyethylene (or LDPE). It is somewhat more difficult to recycle than PET or HDPE but contains some toxic substances, such as aldehydes, ketones or carboxylics. It is one of the most widely used materials in different industries today.
• Polyvinyl chloride (or PVC). It contains a toxic substance called nonylphenol, which does not prevent it from being used in a wide range of products, from door frames to credit cards to various construction materials. It is one of the most difficult plastics to recycle.
• Polystyrene (PS). It is somewhat easier to recycle than PVC but a far cry from PET. It also contains toxic substances such as styrene, benzene, antimony or bromine. It is currently used, for example, in certain yogurt containers, packaging fillers and even toys.
• Polypropylene (PP). It can be recycled fairly easily but has the disadvantage that it includes many toxic substances, such as phenol, aldehydes, ketones, carboxylics or phthalates. It is used in many products, such as straws and bottle caps, in some sanitary materials such as syringes, or in various fabrics, such as tarpaulins or carpets.

rPET, a very sustainable material

According to the study ‘rPET: the best solution to ensure the circularity of packaging’, prepared by the Innovation and Development Center for the Circular Economy (Cidec), rPET is the plastic material that causes less environmental impact because it is the one that emits the least greenhouse gases into the atmosphere.

Its main advantages include:

• It is completely recycable
• Reduces fossil fuel consumption because it is lightweight and therefore requires less energy to transport and distribute
• It is transparent, making it easy for consumers
• It’s flexible
• It’s strong, which is ideal for marketing various products.

Other articles of interest: What real benefits does PET plastic recycling have for the economy