| Screening and size separation | Differences in particle size | Vibrating or rotating screens divide material into size fractions before sensor sorting. | Prepares a more consistent feed and helps protect downstream equipment. | Screen openings should suit the incoming cullet size and the process layout. |
| Optical color sorting | Visible color differences, such as clear, green, and amber glass | Cameras or optical sensors inspect pieces as they pass through the machine. The control system identifies selected material, and timed air jets direct it into a chosen outlet. | Separates glass by color to meet the requirements of a recycling or remanufacturing process. | Performance depends on feed presentation, particle size, lighting, and the condition of the glass. |
| Optical contaminant sorting | Visible non-glass materials, including ceramics, stones, and porcelain | Sensor signals are analyzed against configured sorting criteria; compressed-air ejectors remove targeted pieces from the material stream. | Reduces contaminants that can cause quality problems in recycled glass. | Sensor configuration and sorting settings should be matched to the contaminants present in the feed. |
| X-ray sorting | Differences in X-ray absorption or density between materials | An X-ray system measures how material attenuates radiation. The sorter uses those measurements to identify selected objects and trigger separation. | Can help identify certain dense or compositionally different contaminants, depending on the system and application. | Confirm the target materials and detection limits with application-specific testing. |
| Metal separation | Ferrous and, with suitable equipment, non-ferrous metal pieces | Magnetic separators or metal-detection systems identify or remove metal from the stream. | Often used as an upstream or complementary step to protect equipment and improve material cleanliness. | The separation method depends on metal type, particle size, and where the equipment is installed. |
| Air-jet ejection and collection | Previously identified target pieces | Precisely timed compressed-air pulses divert selected pieces into a reject or product chute. | Provides the physical separation after a sensor identifies material. | Air quality, nozzle condition, timing, and consistent material spacing affect operation. |
| System evaluation | Feed suitability, separation results, and operating requirements | Performance is assessed using representative feed samples and agreed product-quality criteria. | Helps determine whether a machine configuration is suitable for a specific recycling line. | Compare test results, service support, spare parts, controls, and integration needs rather than relying on a general ranking. |