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Onion Bag Making Machine

PP/HDPE woven mesh bags (commonly known as onion bags, or leno bags) are lightweight, breathable, and high-strength packaging solutions designed for onions, potatoes, citrus fruits, garlic, and other fresh agricultural products. Manufactured from polypropylene (PP) or high-density polyethylene (HDPE) flat yarn using a leno weave circular loom, these mesh bags allow air circulation that prevents moisture buildup spoiled the foods and extends shelf life — critical for fresh produce supply chains.

At Hao Yu Precision Machinery Industry Co., Ltd., we have supplied complete onion mesh bag production lines since 1980. Our turnkey solutions cover every stage — from flat yarn extrusion through leno circular loom weaving, high-speed automatic cutting and sewing — engineered for high-output, consistent mesh structure, and reliable bag dimensional control for fresh produce packaging applications worldwide.

Detailed Onion Bag Manufacturing Process

01

Raw Materials Mixer (HY7-400)

This mixer uniformly blends PP/HDPE resin with additives (CaCo3, UV stabilizers, recycled polymer & colorants) before extrusion. With a capacity of 400 kg per full tank and a 2.25 kW gear reduction motor (dimension: 2,000 mm x 1,150 mm x 1,200 mm), it ensures homogeneous material composition critical for consistent flat yarn color & quality.

02

PP/HDPE High Speed Flat Yarn Extrusion Line (HE Series)

PP/HDPE granules are melted and extruded into flat yarn (raffia). Max. PP melting output reaches 100/ 160/ 240/ 320/ 420/ 520/ 600 kg/hr.; Max. HDPE melting output reaches 80/ 120/ 190/ 250/ 320/ 400/ 480 kg/hr. Equipped with a plastics melt pump, belt-type screen filter changer, pro-back up long-life filter and rotary blade slitting system, the take-off unit is controlled by a pneumatic system, electronically tension control winder and synchronized central electronic control box — ensuring consistent yarn width, tensile strength and a flat & even winding edge.

03

4 Shuttles Circular Leno Loom (HY7-m4SCLL)

The four-shuttle circular leno loom weaves flat yarn into an open-mesh tubular fabric using the leno weave pattern — the defining characteristic of onion mesh bags. Unlike standard plain weave, the leno weave locks each weft yarn in a twisted warp yarn pair, preventing mesh aperture distortion under load and maintaining breathability throughout the supply chain. Hao Yu's mini four-shuttle circular leno loom (HY7-m4SCL) achieves up to 100 m/hour with auto-stop systems for warp and weft yarn breakage and auto compensation for uninterrupted production.

04

High Speed Auto Cutting & Sewing Machine (HY7/SP-150H)

A fully automatic conversion line driven by servo motor that produces finished bottom fold-sewn mesh bags directly from tubular leno fabric rolls. The line integrates cutting to precise bag length, bottom sewing, and count-stacking in a single high-speed pass. Its minimal moving parts design reduces labor consumption and maintenance requirements while maintaining consistent bag dimensions — critical for reliable automated filling and net weight accuracy on produce packing lines.

05

Finished Onion Mesh Bag

The completed onion mesh bags feature an open leno weave structure that provides maximum ventilation, reducing moisture accumulation and extending fresh produce shelf life. Standard applications include packaging for onions, potatoes, garlic, citrus fruits, carrots, and other root vegetables. Bags are available in a range of mesh aperture sizes, bag dimensions, and yarn colors to meet retailer, distributor, and export market specifications.

Why Choose Hao Yu for Your Leno Bag Production Line?

1

46+ Years of Machinery Expertise

Established in 1980, Hao Yu has delivered PP/HDPE woven bag production lines to more than 100 countries manufacturers across Asia, the Middle East, Eastern Europe, and Latin America.

2

Turnkey Solutions

We supply the complete production line, which includes: mixer, flat yarn extrusion line, circular loom, lamination machine, printing machine, cutting & sewing machine and auxiliary equipment including hydraulic baling presses, laboratories equipment.

3

Custom Engineering

Our machines are configurable to your desire bags sizes, required output capacity (bags/hour), yarn denier specifications, and printing requirements.

4

Global After-Sales Support

Our engineering team provides installation, commissioning, and on-site training wherever you are, ensure your production line runs smooth production from day one.

FAQ — PP/HDPE Woven Leno Bag Production Line

Q:
What raw materials are used to make PP/HDPE woven leno bags?
A:

It is recommended to use the polymers under Raffia Tape Extrusion Grade and the melt flow index recommended (PP - 2 ~ 5 g/10 min / HDPE - 1~5 g/10 min).

Onion mesh bags are produced from polypropylene (PP) or high-density polyethylene (HDPE) resin granules, blended with UV stabilizers, lubricants, and colorants as required. PP is most commonly used for produce packaging due to its light weight, flexibility, and cost efficiency. HDPE is selected when higher stiffness or chemical resistance is required.

Q:
What machines are required for a complete onion bag production line?
A:

The list of required equipment mainly as follows:

  1. Raw materials mixer
  2. High speed flat yarn extrusion line
  3. Four shuttles circular leno loom
  4. Auto cutting & sewing machine
  5. Hydraulic baling press
  6. Downstream auxiliary
  7. Quality control equipment

A complete line requires: (1) Mixer Machine, (2) Flat Yarn Extrusion Line, (3) 4 Shuttles Circular Leno Loom, and (4) High Speed Auto Cutting & Sewing Machine. The leno loom is the critical differentiating machine compared to standard woven bag lines — the leno weave pattern produces the open-mesh structure required for ventilated produce packaging.

Q:
What is the difference between a leno loom and a standard circular loom?
A:

Leno loom is designed for making breathable mesh fabric and standard circular loom is designed for making close-weave woven fabric.

A standard circular loom produces a plain weave (over-under) tubular fabric with no open mesh. A circular leno loom produces a leno weave where each weft yarn is locked between a twisted pair of warp yarns — creating a stable open-mesh structure with defined aperture sizes. The leno weave prevents mesh distortion under load, maintaining ventilation throughout filling, transport, and retail display.

Q:
What products can be packaged in PP/HDPE leno mesh bags?
A:

Ideal packaging solutions designed for onions, potatoes, citrus fruits, garlic, and other fresh agricultural products.

Leno mesh bags are suitable for onions, potatoes, garlic, citrus fruits (oranges, lemons, grapefruits), carrots, beets, and other root vegetables or hard produce. Their breathable open-mesh structure is also used for firewood, shellfish (oysters, clams), and sporting goods packaging applications requiring ventilation and visibility of contents.

Q:
How do I get a quote for an onion bag production line?
A:

You can reach us via:

  1. Our company e-mails: [email protected] / [email protected]
  2. Our company telephone: +886-4-26303998
  3. Our company WhatsApp: +886-919042429

Contact Hao Yu Precision Machinery Industry Co., Ltd. with your target bag dimensions, required mesh aperture size, output capacity (bags/hour), yarn color specifications, and end-use produce application. Our engineering team will recommend the appropriate production line configuration and provide a detailed quotation.

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