Hay muchos tipos de envases multicapa para alimentos frescos, cocinados, productos farmacéuticos o cosméticos.
It is estimated that only 14% of all plastics worldwide are recycled. In Europe, the figure is higher: the average recycling rate for plastic packaging in 2020 reached 46%, according to figures from Cicloplast, a Spanish entity representing the plastics sector.
Even so, more than half of plastics are still not recycled. One of the reasons for this, but not the only one, is the difficulty of separating the different types of plastic in packaging.
Scientists at the Instituto de Ciencia y Tecnología de Polímeros of the CSIC have developed a new adhesives for packaging that can help to improve recycling rates. It is mainly based on polyurethane systems and incorporates components that allow the adhesion and separation properties to be reversible at will. Loss of adhesion is achieved by raising the temperature and can be activated using an infrared light source.
Applied to multilayer packaging, these new adhesives will facilitate the recovery of the various components and their reuse. This is, in fact, a common problem in the recycling of multi-material packaging. Multilayer packaging combines sheets of different polymers to preserve products (rigid trays for stability, absorbent materials to trap moisture, flexible covers to ensure vacuum sealing, etc.). But the subsequent mechanical separation of their different components for recycling is laborious and not always possible.
The adhesive developed by the CSIC scientists maintains the adhesion of the different layers during their use and offers the possibility of reversing the adhesion by applying heat, between 90 and 160 degrees C, which makes possible to separate and recover the different polymers.
Separation process of the polymer films can be triggered remotely by irradiating the material with infrared light. The time required to reverse adhesion properties ranges from 30 minutes when using conventional heating to less than 2 minutes when external radiation is applied. The adhesive is reversible for more than 20 heating cycles.
The scientific team is looking for companies in the adhesive or multilayer packaging sector interested in licensing the patent for development and commercialisation.
Contact:
Álvaro González Gómez
Instituto de Ciencia y Tecnología de
Polímero - CSIC
Tel.: 915622900