Uniform classes by size and thickness
The secret of an even planter lies in the screen room.
Advanced optical sorting and screening machines remove foreign matter and kernels that differ in colour or shape: the optical sorter also catches kernels that pass the screens but are visibly defective.
The air-screen combination does three jobs at once: the airflow blows off light foreign matter, the screens catch oversize and undersize debris, and the remaining seed is sorted into classes by size and thickness. Screen selection varies by crop and batch.
Grading shows up in the field as planting uniformity: a pneumatic planter singulates properly only when kernel size is uniform. Some of what growers call "the planter isn't sowing well" was lost not in the field but in grading.
Loss is transparent here: the screened-out quantity is weighed and appears as its own line in the batch report. Leaving weak kernels in the batch just hides the problem inside the bag — we don't do that.
Measured at inlet
- Kernel size distribution — basis for selecting the screen set
- Type of foreign matter — determines the air/screen/indent cylinder combination
Delivered at outlet
- Purity — measured on the outlet sample, stated in the report
- Grade classes — size/thickness ranges printed on the label
- Loss record — screened-out quantity is weighed; a separate line in the report
