Yellow onions are round. White onions are oval. They roll smoothly, predictably, and consistently. Here's why a roller grader is the natural choice for packers who process round onions — and what it delivers for your bottom line.
The Round Onion Advantage
Yellow and white onions share one thing in common: they are round or oval.
This might sound obvious. But for onion packers, this simple shape characteristic determines everything about how onions should be graded.
Round onions roll smoothly and predictably. They don't shift sideways. They don't wedge into gaps at odd angles. They travel in a straight line — which means a roller grader can sort them with exceptional accuracy.
For packers processing yellow or white onions day in and day out, the choice of grader isn't complicated. Roller grading is the natural fit.
How a Roller Grader Works
A roller grader uses a series of forward-moving rollers with gradually widening gaps.
Onions travel along the rollers. Smaller ones fall through the narrower gaps first. Medium ones fall through the next. The largest continue to the end. Each size exits through a separate outlet — clean, simple, and accurate.
What this means for your operation:
Feature | What It Delivers |
|---|---|
Gradually widening gaps | Onions fall through at the exact point that matches their diameter — no guesswork, no mis-grades |
Smooth roller surfaces | Gentle handling reduces bruising — round onions stay in premium condition |
Adjustable gap settings | One machine adapts to different size specifications — switch between markets with ease |
Continuous flow | No stops, no bottlenecks — tons of onions per hour keep moving |
The result: consistent grades, minimal waste, and a packing line that keeps up with your harvest.
Three Benefits That Impact Your Bottom Line
1. Accuracy That Protects Your Revenue
When onions are graded correctly, every onion goes to the right market channel. Premium-sized onions command premium prices. Smaller onions find their appropriate market. Nothing is mis-graded. Nothing is undervalued.
2. Gentle Handling That Preserves Quality
Round onions roll smoothly between rollers — no crushing, no bruising, no damage. The onions that leave your packing line are the same quality as the ones that came in. That means longer shelf life, fewer rejected shipments, and happier buyers.
3. Speed That Keeps Your Line Moving
Manual sorting can't keep up with commercial volumes. A roller grader processes tons of onions per hour — not buckets. When the harvest comes in, your line keeps moving. No bottlenecks. No delays. No missed market windows.
Built for Commercial Packing Houses
Fstsort's onion roller graders are designed with the realities of commercial packing in mind:
· 6–8 tons per hour — Handles high-volume production with ease
· 4 or 5 adjustable grades — Customize sizes to match your market requirements
· 20–150 mm size range — Adapts to everything from small pickling onions to large bakers
· PVC roller conveyor — Durable, food-safe, and easy to clean; workers inspect quality directly on the conveyor
· Simple bagging at each exit — Pack onions directly into net bags or cartons after grading
· Customizable layout — Available in Linear, L-shape, or U-shape configurations to fit your facility
Fstsort has already delivered customized onion grading solutions to packers in Senegal, Turkey, and the United States.
Ready to see how a roller grader can transform your onion line? Explore the full specifications on our onion sorting grading machine page →
The Right Grader for Round Onions
Yellow onions are round. White onions are oval. They roll straight, sort accurately, and grade consistently — when you use the right machine.
Roller grading is that machine. It delivers accuracy, gentle handling, and the throughput that commercial packers need.
The technology exists. The question is whether your line is using the right grader for your onions.