Color-printed, canned, square-bottom, valve-mouth exterior wall putty in woven bags

I. Product Introduction

This product is a square-bottom valve bag (glue-sealed bottom bag), specifically designed for dry powder mortar products such as exterior wall putty. The bag surface features monochrome or two-color gravure printing, clearly displaying product information:

Product Name: Exterior Wall Putty

Optional types: Standard, Flexible, Water-resistant, Regular, Pliable, Elastic (multiple-choice checkbox)

Key selling points: environmentally friendly, easy to apply and scrape, highly disease-resistant, and quick for labor-saving application.

This woven bag features automatic filling compatibility, leak‑proof and dust‑proof design, and stable palletizing, making it an economical and practical packaging solution for putty powder manufacturers.

II. Applicable to (Applicable Scenarios)

Exterior wall putty powder for packaging (including various formulations such as standard, flexible, water-resistant, pliable, and elastic types)

Fully automatic valve‑mouth filling on the building materials production line

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

Powder packaging applications requiring moisture protection, leak prevention, and neat palletizing.

III. Applicable Materials (Types of Materials That Can Be Packaged in Bags)

Exterior wall putty powder (cement-based/gypsum-based)

Interior wall putty powder, leveling putty

Tile adhesive, grout

Crack-resistant mortar, thermal insulation mortar

Other dry powdered building materials

IV. Core Advantages (of the woven bag itself)

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

Leak-proof and dust‑proof: self‑sealing valve opening + needle‑free sealed bottom + PE inner liner composite, effectively preventing powder leakage and dust generation.

Monochrome printing – economy option: 1–2 colors, low plate fees, and an affordable unit price, ideal for bulk orders.

Square‑bottom palletizing stability: After filling, the product forms a brick‑shaped cubic form that can stand upright, allowing for neat stacking without toppling.

High Strength and Tear Resistance: The PP woven fabric boasts high tensile strength and can safely support a load of 20–25 kg.

Moisture-proof and freshness-preserving: The PE film layer blocks moisture, preventing the putty powder from caking.

V. Automatic Filling with Square Bottom and Valve Opening

Valve port configuration: One side of the bag is equipped with a filling valve port (either an upper or lower valve port).

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

Filling efficiency: up to 300 per machine ~ 600 bags/hour, fully automatic line 1200 ~ 1,400 bags/hour

Automatic sealing: Filling pressure causes the valve to seal itself, eliminating the need for bag stitching.

VI. Leak-Proof and Dust-Proof Design Details

Valve‑port self‑sealing: After filling, the material pressure presses the inner side of the valve port tightly, creating a natural seal.

PE inner‑membrane composite: A PE film in the intermediate layer covers the woven gaps, effectively preventing fine powder leakage.

Hot-melt adhesive bottom sealing: The bottom is free of pinholes and seams, offering significantly superior sealing performance compared to sewn-bottom bags.

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

VII. Monochrome Printing – Economy Model

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

Plate‑making costs: A single‑color plate costs approximately RMB 50–200; bulk orders may qualify for a discount.

Price advantage: Compared with full-color customizations, monochrome models can reduce the unit price by 30% to 50%.

Customizable content: Includes options to print the company name, product name, type checkboxes, environmental certification marks, and more.

8. Stability of Stacking with Square Bottoms

Post-filling morphology: The powder forms a rectangular prism within the bag, with a flat bottom.

Independence: Can stand independently without leaning against a wall.

Stacking performance: The corners are neatly aligned, and the stack can reach a height of 8 to 10 layers without toppling.

Warehousing and Transportation: Space-saving, suitable for container and palletized shipping.

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

Bottom shape: The square-bottom valve pouch has a flat, square base (thermally sealed with hot-melt adhesive); the flat pouch features a sewn seam closure with visible thread ends.

Filling method: Square-bottom valve bags are filled with automatic tube insertion at the valve opening; flat bags are filled manually through the open mouth and require bag-sewing.

Sealed and dustproof: Square-bottom valve bags are superior (no pinholes); flat bags are inferior (seam pinholes can easily leak powder).

Palletizing stability: Square-bottom valve bags are superior (they stand upright as cubes); flat-bottom bags are average (the round bottom makes them prone to rolling).

Automated adaptation: The square-bottom valve bag fully automatic line is perfectly compatible; flat bags require manual intervention.

Cost: Square-bottom valve bags are slightly more expensive; flat bags are less costly.

X. Material and Craftsmanship

10.1 Structural Composition

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

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

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

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

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/50 mm (GB/T 1040.3)

Weft tensile strength: ≥450 N/50mm

Elongation at break: 15%–30%

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

Safe load capacity: 20–25 kg (stacking test)

XII. Moisture-Proof Rating

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

Moisture‑proof performance: Under relative humidity conditions of ≤80%, the putty powder is guaranteed not to absorb moisture or cake up within 3 months.

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

13. Packaging Drop Test

Test standard: GB/T 4857.5

Drop height: 1.2 meters

Fall sequence: Elevation → Plan → Elevation

Acceptance criteria: The bag shall be free of tears, and the contents shall not have spilled or leaked.

XIV. Applicable Filling Method

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

Filling process: automatic bag feeding → valve‑mouth docking → automatic metered filling → valve‑mouth self‑sealing → conveyor discharge

Auxiliary equipment: Optional automatic palletizer

15. Packaging Specifications

Applicable net content: 20 kg / 25 kg / 30 kg (common)

Common size (25 kg): Width 40 cm × Length 50 cm × Bottom fold 13 cm

Bag Type: Square-bottom valve bag (with top or bottom valve)

Valve port type: Flanged / Cylindrical

16. Scope of Customization

Printed information: product name, brand logo, type options (standard, flexible, water-resistant, etc.), environmental certification mark, QR code.

Net content specification: customizable from 15 to 50 kg.

Bag dimensions: Customized according to material density.

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, minimum 10,000 to 30,000 pieces.

XVII. Environmental Compliance

Domestic Standard: 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)

Exterior wall putty powder manufacturer

Dry-mix mortar enterprise

Building materials packaging trader

Brand owners requiring OEM manufacturing services