## 2 Related Works  
### Type of Plastic and Recycling Methods  
Plastic is a polymeric material that can be molded or shaped, typically through the application of heat and pressure. This property, known as plasticity, is often combined with low density, low electrical conductivity, transparency, and toughness, which enables plastics to be transformed into a wide range of products. Plastics can be classified into different categories based on their structure and usage, such as rigid and lightweight PET bottles, flexible polyvinyl chloride (PVC) garden hoses, foamed polystyrene food containers, and shatterproof polymethyl methacrylate windows [6]. Currently, there are over 200,000 types of plastic [7], but approximately 80% belong to the following seven categories [6; 8]:  
* Polyethylene terephthalate (PET or PETE) is commonly used for the creation of beverage bottles and food containers;
* High-density polyethylene (HDPE) is found in detergent bottles, milk jugs, and some plastic bags;
* PVC is used in pipes, vinyl siding, and flooring;
* Low-density polyethylene (LDPE) is employed in the production of grocery bags, bread bags, and some food wraps;
* Polypropylene (PP) is used in yogurt containers, straws, and food containers;
* Polystyrene (PS) is found in disposable cutlery, foam packaging, and insulation materials;
* Other (various plastics). This category encompasses a variety of other plastics, including acrylic, nylon, and polycarbonate. These different types of plastic are important for recycling and waste management, as they have distinct properties and, therefore, require distinct recycling processes. Numerous methods exist for recycling plastic, and researchers have consistently dedicated their time to improving this process. Their ongoing efforts have centered on automating recycling and developing innovative techniques to promote the widespread adoption of sustainable practices. The recycling method categories are as follows [9; 10; 11; 12]:  
* Physical Recycling, including:
* Mechanical Recycling, which involves processing plastics without dismantling the compounds, retaining the bond between polymers and additives, resulting in the production of flakes or granules for the development of new products;
Solvent-based Recycling uses chemicals (e.g., organic solvents) to dissolve compounded plastics, while preserving the polymer chain, enabling its reuse in new products;
* Chemical Recycling:
* Depolymerization breaks down plastics into building blocks through thermal depolymerization, hemolysis, and solvolysis, producing oligomers and monomers;
* Thermolysis decomposes polymers via thermal methods (e.g., pyrolysis, gasification), creating fragments (monomers, hydrocarbons, CO) that serve as feedstock for synthesizing new substances;
* Energy Recovery (Thermal Recycling). This process utilizes the energy content of plastics, typically through incineration (waste-to-energy) or in cement and power plants that burn solid-recovered fuels (SRFs). Plastic-sorting plants specialize in separating different types of plastics, including PET, PP, and PVC. Several researchers [13; 14] have evaluated several technologies in this context, including infrared spectroscopy, flotation, and fluorescent marking. Each method helps identify plastic types based on their density, color, or conductivity characteristics. Cleaning and granulating processes must meet environmental standards, and while the technologies are promising, their practical implementation in terms of current equipment available still requires further investigation. One proposed method, fluorescent marking, requires plastic to be labeled uniformly for automated sorting. However, implementation challenges include the global standardization of plastic markings. The study by [PERSON] et al. [15] focuses on sorting plastics for recycling, utilizing new technologies such as AI and robots. Plastic-to-fuel recycling presents a promising solution to plastic pollution. [PERSON] and [PERSON] [16] examine the economic, environmental, and technological aspects of this method.