Valve bag manufacturer · Wenzhou, China

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Valve Bag Supplier Kunpeng Packaging
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Valve bag manufacturer · Wenzhou, China

Valve bags built around what's inside.

Powders, granules and pellets all behave differently in a bag. We make PE, PP woven, paper-plastic and multi-layer paper valve bags around your material, your filling line and your pallet pattern.

Request a quote Explore bag types
  • 15–50 kgfill range
  • Up to 6print colours
  • 2–5 plypaper builds
Finished valve bags stacked in the production hall
Finished valve bags · production hall
Self-closing valve 15–50 kg

Typical custom build

Material
PE / PP / paper
Valve
Corner or internal
Print
Up to 6 colours
01 PEMoisture barrier 02 PP wovenHigh strength 03 Paper-plasticBalanced performance 04 Multiwall paperPremium print & strength

The range

Four material systems. One specification process.

The right bag is not simply the cheapest material. It is the structure that fills cleanly, protects the product and survives the pallet. Start with the material — then let us match the build to your line.

Compare all valve bags
White PE valve bag on a brown work surface 01 Moisture barrier

Polyethylene film

PE Valve Bags

Moisture-proof film bags with a self-closing valve.

  • LDPE / HDPE / LLDPE
  • 60–180 μm
  • 15–50 kg
View specifications
Close-up of an external valve on an industrial bag 02 High strength

Polypropylene woven fabric

PP Woven Valve Bags

High-strength woven bags for granular products.

  • 70–120 g/m²
  • Laminated or breathable
  • 15–50 kg
View specifications
Stack of paper-plastic composite bags 03 Balanced performance

Kraft paper + plastic

Paper-Plastic Composite Valve Bags

The stiffness of paper, the toughness of plastic.

  • Kraft + PE / PP
  • 15–50 kg
  • Print-ready surface
View specifications
Brown multi-layer paper valve bag 04 Premium print & strength

2–5 ply kraft paper

Multi-Layer Paper Valve Bags

2–5 ply kraft sacks for cement, mortar and powders.

  • 2–5 plies
  • 70–90 g/m² per ply
  • 15–50 kg
View specifications

Not sure where to start? Send us the product and fill weight. We will recommend a structure before you commit to a sample.

Ask for a recommendation
VALVE CROSS-SECTION / SCHEMATIC NOT TO SCALE BAG WALL INTERNAL SLEEVE SELF-CLOSING FILLING SPOUT PRODUCT IN PRODUCT PRESSURE CLOSES THE VALVE

The internal sleeve opens around the spout, then closes under product pressure.

Valve engineering

The valve is the difference.

A valve bag is only as good as its valve. It has to open cleanly around the filling spout, fill at speed without dust, and close itself before the bag leaves the line.

  1. 01
    Clean filling

    Internal sleeve and corner-valve options contain dust and reduce product loss around the spout.

  2. 02
    Self-closing

    The pressure of the filled bag seals the valve. No sewing, heat sealing or separate closure after filling.

  3. 03
    Line-matched

    Valve dimensions are set against your spout, fill rate and bag weight — not guessed from a catalogue.

Internal sleeveCorner valvePasted valve
Talk to us about your filling line

How we work

From brief to pallet, in five controlled steps.

A valve bag is a fitted component, not a commodity. We keep the specification, sample and production approval in one clear sequence so there are no surprises at the filling line.

  1. 01

    Specification

    Share the product, fill weight, filling line and print requirements. We recommend the structure, dimensions and valve.

  2. 02

    Sample & fill trial

    Pre-production samples for your line. We adjust the valve, film or paper build before you commit to volume.

  3. 03

    Artwork & proof

    We check artwork for the substrate, confirm the dieline and provide a colour proof before plates are cut.

  4. 04

    Production & QC

    Extrusion, weaving, lamination, printing and conversion are checked against the approved specification.

  5. 05

    Packing & export

    Baled or cartoned, palletised and container-loaded with the packing list, batch identification and export documents.

Applications

Built for the products that fill your line.

Different products put different demands on a bag. These are the applications we specify most often — each one starts with the product, not the bag.

Explore applications

Cement & dry mortar

Stack strength, dust control and a premium printed face for bagged building materials.

Multiwall paper / paper-plastic

Fertilizers

Moisture protection and UV stability for blended, granular and water-soluble fertilizers.

PE / PP woven

Chemicals & minerals

Clean filling and puncture resistance for fine powders, crystals and abrasive minerals.

PE / paper-plastic

Resins & pellets

A clean, moisture-resistant pack for polymer pellets, compounds and masterbatch.

PE

Flour & food ingredients

Food-contact materials, reliable seals and print that meets retail and export expectations.

Multiwall paper / PE

Feed & agriculture

Tough, breathable or barrier bags for feed, seeds and agricultural inputs.

PP woven / paper-plastic
Printed valve bags moving through the bag-making machine Artwork approved
before plates

Print & brand

Your brand has to survive the pallet.

A sharp print run starts with artwork that suits the substrate. We review colour, line weight, barcode contrast and print position before production — so the bag that arrives looks like the one you approved.

  • Up to 6 colours on film and BOPP; up to 4 on paper
  • Water-based inks and food-grade options
  • Barcode, QR and batch-coding areas built into the layout
  • Colour proof and dieline confirmation before plates are cut
Read the print guide

Quality control

Tested for the way bags actually fail.

Drop, stack, seal, valve and print adhesion. Our QC plan targets the failure modes that matter on a filling line and in a container — not just the ones that are easy to measure.

01Batch traceability from material to pallet
02Dimensional and valve-fit checks
03Pre-shipment sample retention
See our quality process

Typical QC checks

  • 01Dimensional check
  • 02Valve fit & function
  • 03Seal / weld strength
  • 04Drop test
  • 05Stack test
  • 06Print adhesion
  • 07Moisture barrier when specified
  • 08Food-contact documentation on request

Where we work

WENZHOU

28.0° N · 120.6° EPingyang County, Zhejiang, China

Xiaojiang Town — part of Wenzhou's packaging manufacturing cluster.

The company

A valve-bag specialist, not a catalogue of everything.

Wenzhou Kunpeng Packaging Co., Ltd. manufactures PE, PP woven, paper-plastic composite and multi-layer paper valve bags from our base in Pingyang County. Under the ValveBagSupplier brand, we work with converters, distributors and industrial end users who need a specification-led source rather than a commodity quote.

Our range lets us recommend the right structure for the product — and our team stays close enough to the line to adjust the valve, dimensions and print before a bag is approved.

3,500 m²production base
60+team members
25Mvalve bags / year
About Kunpeng Packaging

Questions buyers ask

Before you request a quote.

The short answers to the questions we hear most often. If your specification is unusual, send it over — we would rather review the detail than give a generic price.

Ask a different question
What is a valve bag?
A valve bag is a sealed sack with a small filling opening — the valve — built into the top or corner. The filling machine inserts a spout into the valve, fills the bag, and the valve closes itself under the pressure of the product. No sewing or sealing is needed after filling.
Which material should I choose: PE, PP, paper-plastic or paper?
PE gives the best moisture barrier for hygroscopic powders and pellets. PP woven gives high strength for granular products and heavy loads. Paper-plastic composites balance stiffness, print and moisture protection. Multiwall paper gives the best stack strength and premium print for cement, mortar and flour. We recommend a structure after reviewing your product and filling line.
Can you make custom sizes, valves and print?
Yes. Bags are made to your dimensions, gusset, valve type and print artwork. Send a sample or drawing if you are matching an existing bag. Print is available in up to 6 colours depending on the substrate.
What is your minimum order quantity?
Typically from 5,000 bags per size and print design, depending on structure. We can discuss smaller trial quantities for a first order, but the unit price will reflect the shorter run.
Can you match my existing bag?
Send a physical sample or a dimensioned drawing, plus artwork if available. We measure the bag, valve, gusset and print layout, then confirm a matched specification before making a sample.
Do you provide samples before production?
Yes. We provide stock or plain samples for structure review, and custom printed samples for approved artwork. Sample cost and lead time depend on the specification and are confirmed before we start.

Start a specification

Send us your product. We'll engineer the bag.

Share your fill weight, product type, filling line and print requirements. We will come back with a recommended structure, sample plan and quotation.

Request a quote Chat on WhatsApp
01

Send your specification or a sample bag

02

Receive a structure recommendation and quote

03

Approve a sample, then move to production