| Separate by particle size | Vibrating screen or sieve grader with interchangeable mesh screens | Crushed, broken, or granular teas that need consistent size fractions | Specify the desired size range and the permitted share of material outside that range for each grade. | Screen aperture options, number of decks, ease of screen changes, and whether the machine handles the tea without excessive breakage. | Run a representative batch; weigh each output fraction and compare it with the agreed size and yield targets. |
| Remove discolored material | Optical color sorter using cameras and controlled air ejection | Finished leaf or granular tea with visible color defects, foreign particles, or uneven appearance | Define the defect types to reject, acceptable defect carryover, and acceptable loss of good tea. | Camera resolution and lighting, channel configuration, adjustable rejection settings, dust control, and access for cleaning. | Test with known acceptable and defective samples; inspect both accepted and rejected streams for accuracy and good-product loss. |
| Remove stalks and light impurities | Air separator, aspiration unit, or a combined optical and air-separation system | Leaf teas containing stems, fibers, dust, or other particles with different aerodynamic or visual properties | Set limits for stalk or impurity content while preserving intact tea leaves and minimizing product loss. | Airflow adjustment, dust collection, feed uniformity, separation access, and performance with the tea’s actual moisture and leaf shape. | Measure impurity content before and after sorting, and weigh usable tea found in the reject stream. |
| Grade by shape or appearance | Machine-vision sorter configured for the product’s visual features | Whole-leaf or specialty teas where leaf shape, twist, or visible uniformity matters | Describe the acceptable appearance using reference samples and clear pass/fail defect categories. | Ability to distinguish the required features, stable product presentation, recipe adjustment, and repeatability across batches. | Have operators classify a blinded sample, then compare their results with the machine’s accepted and rejected outputs. |
| Meet throughput and production-line needs | A grader or sorter sized and configured for the complete processing line | Any tea operation with a defined hourly production requirement or multiple grades | Set the required usable output per hour, number of grades, and quality targets at the intended operating rate. | Confirm rated capacity for the specific tea, feed consistency, upstream and downstream equipment, cleaning time, and operator requirements. | Conduct a sustained trial using production material; record throughput, downtime, grade yield, and quality results. |