A horizontal flow wrapper can pack one fresh green onion or a bunch in a sealed film bag. Support the bulb and leaves lengthwise to keep roots and tips out of the end seals. Dry bulb onions sold in a net need a separate weighing and net-closing setup.
Budget US$5,000–25,000 for a compatible base wrapper for one agreed green-onion pack, before product-specific feeding. A new basic one-format dry-onion weighing and tubular-net clipping cell is US$20,000–60,000. Quote heavier bag handling separately.
Film packs for green onions and net bags for dry bulbs
| What you pack | Route to assess | Purchase check |
|---|---|---|
| One green onion or a bunch in a sealed retail film bag | Orient the single onion or bunch lengthwise and assess a horizontal flow wrapper. | Run the longest onion or bunch. Keep roots and leaves out of both end seals. |
| Dry bulbs in small retail mesh bags | Weigh a portion, feed continuous tubular netting around the filling tube, then gather, clip and separate the filled net. | Check giveaway at the lightest pack size and retention of the smallest bulb. |
| Whole onions or potatoes in a heavier net bag | Present the specified premade mesh sack, weigh and fill it on load support, then close its mouth by the method agreed for that sack. | Confirm whether the supplied sack needs stitching, tying or another specified closure. Define who presents the sack and moves it to the closer; do not assume a small-net clipper suits it. |
Dry bulbs: weigh → support filled net → clip
Green onion bunch: orient leaves → wrap → check end seals
How a small tubular-net pack is made
Tubular-net cycle — process diagram, not a machine layout
- 1 → Weigher outlet → filling tube.The prepared portion is released through the tube; the tube carries a supply of continuous tubular netting around its outside.
- 2 → Net feed → supported fill.A closed lower end retains the onions while net is drawn off the tube. Support carries the filled portion rather than leaving its weight on the gathering point.
- 3 → Clear neck → gather and clip.Keep bulbs, skins and tails out of the neck. The specified clip closes the gathered net; the cutting sequence separates the pack and prepares the next net end.
- 4 → Discharge → check and replenish.Move the closed bag onto supported outfeed. The operator replenishes onions, net and clips and checks finished-pack weight and closure.
A premade heavy sack starts from a different bag supply. An operator may put its mouth onto a filling spout while a platform supports the load. Its closure station and transfer are selected for that actual sack. Comwin can separate these tasks in the quotation, so a weighing-only station is not mistaken for complete sack filling and closing.
Measure weight variation and closure rejects together
Take representative bulbs from each intended size band. Test whether a portion can be brought close to the target without adding an entire oversized bulb at the last step. Log actual net weight as well as accepted count. If the system overfills consistently, compare changes to size input, weighing setup and target combinations. A good average can conceal costly giveaway on the lightest bags.
Run the dry skins and tails that arrive on a normal shift. Inspect where they collect and whether they interfere with net gathering, clipping or label placement. Use the real net and clips. Lift and handle finished bags at the agreed test load, and watch the bag change when the net supply is replenished.
Flow wrap a green onion or a bunch
For one leafy onion, support the bulb as it enters the forming box and keep the leaves from folding back into the seam. A bunch also needs room for the thickest normal group. Hand loading can handle variable presentation. For automatic feeding, trial overlap detection and the spacing after a restart.
If the brief calls for dry bulbs in film, test the counted or weighed portion with the actual bulb grades and the approved material and ventilation. Flexible green stalks and round dry bulbs need different supports.
Decide where automation saves handling
For a premade sack, an operator can present the bag while the weighing system supplies the portion; bag removal and closure remain defined jobs. For the small tubular-net route, coordinate weighing, net feed, clipping and supported discharge. In a two-crop station, trial a full switch between onions and potatoes and record the parts, settings and cleaning involved. Compare accepted bags per hour over a run that includes refills and changeovers.
Onion packing machine price depends on what closes the bag
For early budgeting, allow US$20,000–60,000 for a new, basic one-format dry-onion weighing and automatic tubular-net clipping cell supplied from China. This conditional reference assumes stable incoming bulbs, continuous net fed from a filling tube, supported filling and basic discharge. It excludes grading, inspection, special labels, freight, duties and site installation. It is not a price for filling and closing heavy premade mesh sacks; quote that bag presentation, load support and actual closure separately.
A compatible green-onion film wrapper falls under a separate US$5,000–25,000 base wrapper reference, before a product-specific infeed. Film sealing and tubular-net clipping are priced as separate equipment.
Does an onion weighing machine also close the bag?
The weigher prepares the portion. Ask whether the quoted equipment merely discharges it, presents and fills a bag, or also closes the bag. Request a video that follows one portion from the weigher to a closed pack.
Show us your closed onion pack
Send photos of the onions and closed bag, target weight, bulb size range and required good bags per hour. Comwin can define the weighing, bag supply, closure and operator tasks in a proposed configuration. We then review bag material, clips or other closure samples, available height and any potato changeover. Request an onion packing scope and trial plan.
