Sample assessment
The feed consists of green-tea flakes, and the two samples began with different D60 and D90 values after their first milling checkpoints. The trial explicitly used air cooling. Selection therefore needs to consider both the requested D60 endpoint and the recorded thermal conditions, while retaining the two sample histories separately.
Recorded objective
A D60 objective of 18 µm; both samples are marked as meeting the requirement.
Equipment and selection
The source identifies XQM family. The related TENCAN product association is Vertical Planetary Ball Mill, Air-Cooled Planetary Ball Mill. This identifies the recorded equipment family, rather than an independently verified serial-number configuration. Jar contact materials and charge details below are test observations; an unspecified steel grade or ball-percentage basis is not supplied by the association.
Test setup
| Recorded setup | XQM family with an external air-cooling arrangement; stainless steel jar and zirconia balls, standard charge; nominal 20 g leaf flakes; run/pause cycle recorded as 5:1; interval units unspecified. |
|---|---|
| Speed notation | Values are retained as recorded speed settings. The source does not identify the revolution/rotation reference; no separate jar speed is inferred. |
Recorded procedure and results
The first tea sample was dry milled at setting 350 for 30 minutes. Its recorded temperature was 30 °C and its distribution was D50 = 34.4 µm, D60 = 44.3 µm and D90 = 90 µm. After increasing to 400, the 90-minute checkpoint gave D50 = 7.3 µm, D60 = 8.9 µm and D90 = 17.1 µm. The second tea sample initially gave D50 = 38.9 µm, D60 = 55.3 µm and D90 = 124.6 µm at 350 and 30 minutes, again at 30 °C. Its 120-minute checkpoint at 400 gave D50 = 8.6 µm, D60 = 11.3 µm and D90 = 24.5 µm.
Interpretation
D60 is the specified acceptance measure, and both later values are below 18 µm. Their different D90 values show why substituting a median or claiming all-particle fineness would obscure the result. Air cooling was part of both recorded procedures, but the 30 °C observations belong to the initial checkpoints; the record does not establish constant temperature throughout either final stage. Flavor, color and composition were not measured.
Practical precautions
Repeat the sampling checkpoints and log temperature throughout the run. Keep leaf preparation and the particle-analysis method consistent. Sensory or chemical quality needs separate assessment if it is an application requirement.
TENCAN alternatives to evaluate
TENCAN Liquid-Nitrogen-Cooled Planetary Ball Mill: Evaluate liquid-nitrogen cooling only if a defined tea-quality or temperature requirement cannot be maintained by the recorded air-cooled arrangement. Compare D60 and actual temperature histories; neither flavor retention nor a benefit from lower temperature was demonstrated here. This is a recommendation for a new comparison, not an observed result of this trial.
Endpoint context: Sample 1: D60 = 8.9 µm; sample 2: D60 = 11.3 µm at their recorded later checkpoints.
Tested equipment association only: XQM family; exact machine variant not inferred. External air cooling explicitly recorded; air-cooled family added as an association, not a replacement machine identity.
About this trial
TENCAN laboratory trial, 2021. Observations above come from this experimental record; selection considerations and proposed comparisons are engineering interpretation. Results apply to this sample and recorded conditions.