Sorting materials and removing contaminants in the plastics recycling industry

More and more plastics processors are turning towards recycling. Not only does this save energy, but used plastics are often cheaper than their new counterparts as well. However, recycling used plastics is only a profitable venture if the material has previously been separated into homogeneous fractions by color and type in order to meet high quality standards. Our sorting systems are there to handle this job – with precision, reliability and efficiency.

Sesotec is one of the leading specialists in industrial plastics-sorting machines and systems. Our systems reliably differentiate between materials using various types of sensor technology and efficiently separate material flows into homogeneous fractions by color and type.

Product examples of our customers
Sesotec's strengths

over 40 years of experience and reliability

Personal support in the after-sales area


Long-term reliability for spare part supply


Why is plastic recycled?

Plastic is produced mainly from petroleum, which is a finite resource. Plastics that are not recycled end up in landfills or in the environment, where they serve as long-term sources of pollution, since they do not decompose or do so only very slowly. It is therefore necessary to recycle plastic waste in an eco-friendly way or to at least recover thermal energy through incineration.

Recycling saves energy, is good for the environment and is economical too, as recycled materials are frequently cheaper than new ones. What is more, it helps businesses that process plastics become more independent of fossil feedstock and cushion the rising costs of raw materials. Recycled plastics can serve as an equivalent substitute for new, crude-oil-based materials in many applications. In addition, they can be recycled in many ways. For example, PET bottles can be turned into PET bottles (bottle-to-bottle principle) and textile fibers, polystyrene can be turned into pens, and CDs can be transformed into computer cases.


What are the challenges?

Plastics collected for recycling must have a high degree of purity. Only then can they be economically recycled and introduced back into the production cycle as high-quality materials. However, sorting certain plastics can place complex demands on the sorting system. Our separation and sorting systems remove contaminants, such as metals, wood and extraneous plastics, from the material and separate mixed material flows into homogeneous fractions by color and type. To ensure safe detection, the systems are equipped with features such as near-infrared sensors and high-resolution CCD cameras.

Sesotec also offers complete small-scale plants for plastic flake sorting with screening, air classification, optical sorting and material handling

What are the advantages of our systems?

Sesotec has been one of the market leaders in the field of contaminant removal and sorting technology for more than 40 years. We develop standard solutions as well as complete custom solutions for plastic recycling companies in particular and cover the entire range of contaminant removal and sorting. This extends from a sorting system designed to handle larger objects, such as PET bottles, to the intricate sorting of plastic regrind and PET flakes.

Our sorting systems work with precision, speed and efficiency. Better material quality, greater throughput levels and less loss of material increase added value. As a result, the purchase of equipment amortizes rapidly. The machines can also reliably handle complex sorting tasks. They are used to pre-sort materials, perform quality checks, as well as sort or separate the following:

  • Colors
  • Metals
  • Plastics, such as PET, HDPE, PVS and many more
  • Contaminants, such as wood, paper and bioplastics

All Sesotec systems have a modular design. Depending on the application, the components that are necessary for a specific sorting task can be combined in one machine.


What products or materials are sorted?

Sesotec systems select plastic bottles and cups, as well as plastic films, granulate, plastic regrind and “flakes” − plastic pieces that are created during the process of recycling PET bottles. A granulator shreds the bottles at the recycling plant. After this step, the sorting system separates the pieces by color and removes contaminants. This results in homogeneous granulate based on color and type, which can be turned into new, high-quality products. Recycling rates of up to 100 per cent are possible with the use of Sesotec systems for recycling plastic.


Optical sorting is the core of the recycling cycle
Green Mind relies on Sesotec sorting systems for PET Flakes in highest quality
Sesotec sorting technology replaces manual sorting of PET flakes
Waste reduction with Sesotec sorting systems
Taiwanese company automates plastic bottle sorting
MultiPet improves PET flake quality with Sesotec sorting systems
Reliable sesotec sorting systems convince RecyPET
MB-Sort – Recycling of metal waste and plastics with Sesotec VARISORT COMPACT sorting system
Sesotec sorting systems secure supply of recycled PET material
All about PET
Sesotec live! - Our upcoming exhibitions
Circular Economy
Case Studies
Latest news and blog articles
Circular Economy
Profitable recycling – how recyclers can work efficiently
Click here to read the story
Circular Economy
Circular economy – it needs to be profitable
Click here to read the story
Circular Economy
Sesotec under the Banner of "Circular Plastics Economy"
Click here to read the story
Circular Economy
Sesotec makes the circular economy efficient when it comes to plastics
Click here to read the story
Circular Economy
Plastic: part of the problem…part of the solution - Part 2: the European Union’s solution
Click here to read the story
Case Studies
Sesotec sorting systems at New Zealand’s first PET recycling plant
Click here to read the story