Startup Presents Patented Plastic Deinking Technology

The Spanish start-up Cadel Deinking has recently been working on a new deinking technology. The technology removes inks from various plastic materials before getting a recycled material. Since printed ink spoils a product both visually and in its mechanical properties, this method gives the product a high added value. The technology has been patented in more than 20 countries and was presented by an executive from Cadel Deinking at the Association of Plastic Recyclers (APR) Technical Forum, which was held in early March together with the Plastics Recycling 2017 conference in New Orleans.

Cadel Deinking originates from Olax 22, which owns a 50 percent stake in Cadel. Cadel Deinking started its business in 2014 with the aim to commercialise the technology. The company has a pilot plant in Alicante, Spain, where they demonstrate the process and conduct tests with materials from their customers. The facility was built in 2015 – the year the company launched the technology to the market.

Innovative Water-Based Deinking Method

At the APR Technical Forum, Adriana Pineda, who works in the business development department for Cadel, explained that inks impart colour and odor and thus affect the mechanical properties as well as the look of recycled plastics. As a result, they cause processing problems and add extra costs. Therefore, simplifying the process and restricting the costs have been two important issues Cadel’s researchers focused on. However, according to the Olax 22 website,

 “The innovative character of this project lies in the formulation of water-based products, which differs from conventional de-inking solutions formulated with a solvent base”.

This characteristic constitutes a significant advantage from the economic and environmental point of view compared to processes that use solvents.

Aside from being water-based and free of environmentally hazardous chemicals, the technology should also reduce residues as much as possible. Cadel Deinking was able to achieve this by developing the following method: In a first step, the plastic products are grinded. Afterwards, the plastics are inserted in a water-treatment system, where they enter a deinking reactor. In this reactor, they are first exposed to the reagent and then rinsed with water to remove traces of pigments. Finally, the plastics are dried, melted, extruded and pelletized. This way, retailers need to use only one degassing step instead of two and the life of melt filters can be extended. Furthermore, the deinking solution and the rinsing water are continually reused in the system.

Ongoing Research on Delamination

The technology can be applied to many different inks, regardless of whether the inks were included in masterbatches or printed onto plastics. For laminated packaging, however, the process is slightly more complex. Laminates are plastic products composed of various kinds of plastics joined by glues and adhesives. In this case, the layers have to be separated first, allowing the deinking solution to reach the dye in the inner layers. Accordingly, the company states on its website:

“The results obtained at a laboratory level indicate that it is possible to separate the plastic layers and remove the ink that was between them, and so allowing them to be recycled.”

Cadel Deinking is doing a lot of research to improve the technology for laminates. Moreover, they try to drive the commercialisation of the technology forward by licensing it to third parties so they can build and develop plastic recycling plants. Adriana Pineda said that Cadel will either offer turn-key plants or provide instructions for assembling a deinking plant