Recycling of fishingnets

Collecting

Strong partnerships between recycling companies and consumers (fishermen) are crucial prerequisites for obtaining nets that are still recyclable.

Sorting

Currently, there are many different types of plastics, and even materials from the same plastic can significantly differ due to their additives and/or manufacturing processes. To produce high-quality materials through recycling, attention should be paid to the purity of the materials. Therefore, the ‘sorting’ step plays an important role: Here, the material is identified and differentiated according to the respective types. Various analytical methods are required for this, as fishing gear is rarely marked with a plastic code that would allow for easy identification.

Shredding & Cleaning

Nets are difficult to shred. Due to their geometry, the nets often wrap around the cutting tools during shredding, blocking them, which is why special emphasis must be placed on suitable machines. Another important aspect here is the degree of contamination. Nets that have been in the sea or on the beach for a long time are often contaminated with sand, algae, or even fish scales, which must be removed before recycling.

Extrusion

In the recycling process of fishing nets, after shredding, the shredded material is processed through extrusion. Extrusion is a crucial step where the shredded plastic material is melted and forced through a die to create a continuous shape, typically in the form of pellets or rods. This process allows for the transformation of the shredded plastic into a molten state, facilitating its further processing into usable forms. Extrusion homogenizes the plastic material and prepares it for subsequent processing stages.

Granulation

After the plastic is melted, the extruded strand is granulated. This step occurs at the end of the extrusion process. The granulate that is produced is typically in the form of small grains or pellets. Granulation allows for better handling and storage of the plastic material and prepares it optimally for the next processing step.

Injection Molding

Following extrusion, the molten plastic material is processed using injection molding. Injection molding is a manufacturing process wherein the molten plastic is injected into a mold cavity under high pressure. The material then cools and solidifies, taking on the shape of the mold. This method allows for the efficient production of complex and precise plastic components. In the context of recycling fishing nets, injection molding enables the creation of new plastic parts or test specimens with desired shapes and dimensions. It offers versatility and scalability in producing a wide range of plastic products while minimizing material waste.

Testing Procedures

Once the test specimens are produced through extrusion and injection molding, they undergo various mechanical tests to evaluate their quality and performance. Tensile testing measures the material’s strength under tension and provides insights into its mechanical properties such as elasticity and tensile strength. Impact testing evaluates the material’s ability to withstand sudden forces or shocks, simulating real-world scenarios. The melt flow index test evaluates the flow properties of the molten plastic, crucial for understanding its processability. These testing procedures ensure that the recycled plastic meets the required standards and specifications, validating its suitability for diverse applications in industries ranging from construction to automotive. Through rigorous testing, the performance and reliability of recycled plastic materials are verified, reinforcing their role in sustainable manufacturing processes.

Marketing

The marketing and economic viability of recyclates pose a challenge, as primary raw materials are often much cheaper! The premium over new goods becomes lower, but so far, companies have often not found it worthwhile to switch to recycled goods. Despite political action already taken, further measures need to be taken to make the purchase of recyclates more attractive.