The Recovery of Mixed Waste of PE and Aluminium, Challenges and New Opportunities: The Bausano Method

The ability to efficiently recover and reprocess post-consumer plastic waste of unconventional composition plays a crucial role for the packaging industry, which is being called upon to become a key player in the green transition.

Specifically, several challenges characterise the recycling of multi-layer packaging, such as aseptic beverage packaging. Composed mainly of cardboard (75%), these containers have thin polyethylene (20%) and aluminium (5%) foils inside, which preserve the food from contact with external agents. At the end of its use, the cellulose from the packaging is extracted and fed back into the recycled paper chain, while the solid residues of PE and aluminium create a compound, also called polyAl, compatible with numerous applications, attracting increasing interest from plastics converters.

Bausano is a pioneer in polyAl recycling with the E-GO R extruder line. In response to this need, Bausano – a leading international player in the design and production of customised extrusion lines for plastics processing – has developed an innovative solution to transform LDPE- and aluminium-based post-consumer waste into core tubes, in harmony with the principles of the Circular Economy. A result made possible by Bausano’s ability to carry out feasibility analyses aimed at developing specially designed solutions for recycling contaminated plastic waste.

In detail, the polyAl recovery plant consists of a single-screw extruder for E-GO R 60/37 tubes with double degassing and forced loading system, ideal for managing the density of the material and ensuring its smooth flow within the machinery. Before extrusion, the material undergoes a densification process, which is essential to increase its firmness and transform it into a manageable compound suitable for further processing.

The final output is a robust tube with a smooth surface feel, both internally and externally, ideal for winding reels of cloth, film, paper and other materials. As well as being synonymous with low environmental impact, these recycled products are a cheaper alternative to traditional cardboard or virgin polymer cores.

The Bausano Method: from feasibility analysis to testing, in the name of innovation

At the root of the success of Bausano’s solutions is its unique process, which starts with the customer’s specific formula and then works out structured analyses to make each extrusion line completely customised. To this end, Bausano involves its experts, even before the plant design phase, in carrying out a feasibility study before the project itself.

Following the preliminary evaluation, the process continues in Bausano’s laboratory, where the material is analysed using a capillary rheometer to understand its viscosity as a function of the shear rate. Starting with the rheological characterisation of the molten material, Bausano’s team engineers can optimise the design of the screw and extrusion head. A subsequent test, conducted on the Brabender plastograph, provides crucial information for predicting the behaviour of the cast material during all processing steps.

In this case, the use of the plastograph made it possible to accurately record values for the mixture’s melting speed, rotor torque and energy required for the process. Using software for fluid-dynamic analysis, the data obtained were compared with the rheological characteristics of already known materials compatible with extrusion. The comparison showed that the process parameters of the polyAl processed by the customer were in line with those of materials easily extruded using Bausano technology, ensuring optimal output levels in terms of both quantity and quality.

A further benefit, guaranteed by Bausano, is using the feedback from the analysis to verify the composition of the material, including parameters such as melt flow index and bulk density. During this last phase, the waste polyAl is tested with an MD30 twin-screw counter-rotating laboratory extruder to confirm the suitability of the solution for industrial scale-up in terms of amperage, thrust and head pressure values.

“Bausano’s distinguishing feature lies in the know-how of its experts, providing a consultative and customer-oriented approach. A rigorous process, which qualifies the company as a reference point for the development of innovative solutions capable of satisfying even the most complex production needs, linked to the recovery of non-conventional materials,” says Clemente Bausano, Vice President at Bausano, who concludes, “Cutting-edge extrusion technologies, such as those developed by Bausano, open up new horizons in the recycling of post-consumer plastic waste, in favour of an eco-friendly future.”

Read more from Bausano here.

Bausano
+44 (0) 7815 921 951
Website
Email