Square-valve-mouth offset-printed putty woven packaging bag

I. Product Introduction (Woven Bags)

This product is Square-bottom valve bag (glue-sealed bag) , specially for Putty specifically for true stone paint For exterior wall dry-mix mortar design. The bag body is made of a composite material consisting of PP woven fabric and PE film, with single-color printing and clearly marked product name. This packaging bag features… Automatic filling at the valve port, leak-proof and dust-proof, stable palletizing. This performance‑oriented, cost‑effective packaging solution is designed for manufacturers of putties used in conjunction with true stone paint.

II. Applicable to (Applicable Scenarios)

Packaging Putty specifically for true stone paint (For leveling the substrate of true stone paint finishes)

Fully automatic valve‑mouth filling for dry mortar production lines

Warehouse stacking, long-distance transportation, and retail sales at building materials markets

Exterior wall coating works and packaging of supporting materials for true stone paint application.

III. Applicable Materials

Specialized putty for textured paint (cement-based or gypsum-based)

Exterior flexible putty, crack-resistant putty

Exterior wall leveling putty, smooth finish putty

Other dry-powder-based architectural coating auxiliary materials

IV. Core Advantages (at the Packaging Bag Level)

Automatic filling with a square-bottom valve opening : Compatible with automated filling lines, offering high efficiency and labor savings.

Leak-proof and dustproof : Valve-sealed closure + pinhole-free adhesive bottom + PE inner liner composite, eliminating powder leakage and dust.

Economy monochrome printing : 1–2 color printing, low plate fees, and affordable unit price

Stable stacking with square bases : After filling, it takes on a brick-shaped cubic form, stacking neatly without toppling.

High-strength, shatter-resistant : PP woven fabric has high tensile strength and can safely support a load of 25 kg.

Moisture-proof and fresh-keeping : The PE film layer prevents moisture ingress, protecting the putty powder from caking.

V. Automatic Filling with Square Bottom and Valve Opening

Valve port structure : One side of the bag body is equipped with a filling valve port (typically an upper valve port).

Filling equipment : Compatible with screw‑type valve‑mouth packaging machines or pneumatic filling machines

Filling efficiency : Single machine 300 ~ 600 bags/hour, 800 on the fully automatic line ~ 1,200 bags/hour

Automatic closure Filling pressure seals the inner side of the valve opening, eliminating the need for bag sealing.

VI. Leak-Proof and Dust-Proof Design Details

Self-sealing valve port : After filling, the material pressure presses the inner side of the valve seat tightly, creating a natural seal.

PE inner membrane composite : The intermediate-layer PE film covers the woven gaps, preventing fine powder from leaking out.

Hot-melt adhesive bottom coating : Bottom with no needle holes, offering far superior sealing compared to sewn-bottom bags.

Laminated sealing : The outer coating further seals the pores of the woven fabric.

Optional microporous venting For aerated powder materials, micro-porous perforation can be performed to reduce dust emission.

VII. Monochrome Printing – Economy Model

Number of printing colors : 1–2 colors (typically the product name, brand logo, and net content)

Publication fee cost : Monochrome versions cost approximately 200–500 yuan; bulk orders may qualify for a discount.

Unit price advantage Compared to full-color customization, the unit price of monochrome models can be reduced by 30% to 50%.

Customized content : Can print company name, product name, net content, usage instructions, recycling symbol, etc.

8. Stability of Stacking with Square Bottoms

Post-filling form : The powdered material naturally forms a rectangular prism (brick-shaped) inside the bag, with a flat bottom.

Independence : Can stand independently without leaning against a wall

Stacking performance : Square and well‑shaped, stackable up to 8–10 layers without toppling.

Warehousing and Transportation : Space-saving, suitable for container and pallet transport

9. Comparison between Square-Bottom Valve Bags and Flat Bags (Open-Top Bags/Sewn-Bottom Bags)

Bottom shape : Square-bottom valve bags are square and flat, sealed with hot-melt adhesive; flat bags are sealed with stitched seams, with visible thread ends protruding.

Dustproof sealing performance : Square-bottom valve bags are superior (no pinholes); flat bags are inferior (many seam pinholes, prone to powder leakage).

Filling efficiency : Square-bottom valve bags are very tall and can be fully automatically filled with a tube; flat-bottom bags are lower and require manual or semi-automatic filling.

Palletizing stability : Square-bottom valve pouches are superior (self-standing cubic shape); flat pouches are standard (round bottom for easy rolling).

Automated adaptation : Square-bottom valve bags are perfectly suited for fully automated packaging lines; flat bags require manual intervention.

Cost : The square-bottom valve bag is slightly taller; the flat bag is lower.

Main uses : Square-bottom valve bags are used for cement, mortar, putty, and chemical powders; flat bags are used for ores, aggregates, and low-value bulk materials.

X. Material and Craftsmanship

10.1 Structural Composition

Outer layer: Color-printed PP woven fabric (single-color printing)

Middle layer: PE film (moisture barrier, thickness 5–12 μm)

Inner layer: PP woven base fabric (basis weight ≥ 65 g/m²)

Bag Type: Square-bottom valve bag (glue-sealed bottom, top valve opening)

10.2 Production Process Flow

Drawing → Weaving → Composite Molding → Gravure Printing → Valve Mouth Forming → Glue‑Back Bag Making → Hot‑Melt Adhesive Bottom Sealing → Finished‑Product Inspection

XI. Tensile Strength

Longitudinal tensile strength : ≥450 N/50mm (in accordance with GB/T 8946)

Zonal tensile strength : ≥450 N/50mm

Elongation at break : 15%~30%

Peel strength (composite layer) : ≥3.0 N/15mm

Safe Load Capacity : 25 kg (standard)

XII. Moisture-Proof Rating

Water vapor transmission rate (WVTR) : ≤15 g/(m²·24h) (GB/T 1037)

Moisture-proof effect Under relative humidity conditions of ≤80%, the material can be guaranteed not to absorb moisture or cake within 3 months.

Upgrade Options : The PE film can be thickened to 80 μm, reducing the water vapor transmission rate to ≤5 g/(m²·24h).

13. Packaging Drop Test

Test Standard : GB/T 4857.5

Drop height : 1.2 meters

Fall order : Elevation → Plan → Side View

Criteria for Determination : The bag is undamaged, and the contents are free of spillage.

XIV. Applicable Filling Method

Filling equipment : Valve‑port‑specific packaging machines (screw‑type, pneumatic‑conveying, impeller‑type)

Filling process : Automatic bagging → Valve‑mouth docking → Automatic metered filling → Valve‑mouth self‑sealing → Conveying to the downstream line

Auxiliary equipment : Can be equipped with an automatic palletizer and a stretch wrapper.

15. Packaging Specifications

Applicable Net Content : 25 kg (standard; not indicated in the image, per industry standards)

Common size (25 kg square-bottom valve bag) : Width 40 cm × Length 50 cm × Bottom fold 13 cm (for reference)

Bag type : Square-bottom valve bag (top valve opening)

Valve port type : Flanged type / Cylindrical type / Membrane type

16. Scope of Customization

Printed content : Product name (special putty for true stone paint), brand logo, net content, instructions for use, QR code, etc.

Net Content Specification : Customizable from 15 to 50 kg

Bag body dimensions : Customized according to material density and customer requirements

Material : PP basis weight (45 ~ 80 g/m²), PE film thickness (5 ~ 80 μm)

Other features : Anti-slip embossing, one-way vent valve, easy-tear notch

Minimum order quantity Custom-printed bags typically require a minimum order of 5,000 to 10,000 units (some manufacturers may accept as few as 1,000).

XVII. Environmental Compliance

Packaging Standards : Complies with GB/T 8946-2013 “General Technical Requirements for Plastic Woven Bags”

Ink Safety : Benzene- and ketone-free, compliant with GB 9685

Recyclability : Both PP and PE are recyclable materials.

Export Compliance : Meets the requirements of EU Regulation 10/2011 and the RoHS Directive.

18. Price and Minimum Order Quantity

Negotiable

XIX. Applicable Parties (Purchaser)

Manufacturer of putty specially formulated for true stone paint

Dry-mix mortar and exterior wall coating ancillary materials enterprise

Building materials packaging traders and export enterprises

Brand owners who require OEM contract manufacturing and packaging