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PET sorting by handheld NIR spectroscopy

24 October 2022 | Product
by Ian Michael

trinamiX now supports the flexible differentiation between PET-A and PET-G with its mobile NIR spectroscopy solution. The handheld solution for on-the-spot identification of more than 30 different plastics is supplemented by a new application, which provides information about the type of a PET sample.

Amorphous polyethylene terephthalate (PET-A) is one of the most important thermoplastics. PET-A is a popular material for recyclable packaging of food, cosmetics or hygiene products. PET-G is modified PET that has been combined with glycol. As a result, PET-G features a higher transparency than PET-A, which remains stable even after heating. In addition, molten PET-G has a lower viscosity. These properties favour specific applications in the areas of packaging, 3D printing and visible parts, for example.

The clean separation of PET-G and PET-A is important for several reasons. First, only pure materials can be completely recycled. Due to different melting ranges, recycling a combination of PET-A and PET-G is difficult. In addition, mixtures have a negative effect on the desired properties, such as temperature stability. Ultimately, there is also an economic component: pure PET-G usually achieves higher prices on the market than PET-A.