The kraft paper valve bag is a specialized high-end packaging product designed for industrial powders and granular materials. Constructed from multiple layers of fully wood-pulp kraft paper composite, it features a flat-bottom valve structure compatible with fully automated filling production lines.
These bags offer automatic sealing, prevention of powder leakage, high strength, excellent stacking durability, and superior moisture and dust resistance. They serve as the standard 25kg packaging solution across industries including chemicals, construction materials, starch, and powder materials.
Self-sealing valve structure automatically locks after filling without stitching or tying, preventing dust emission and powder leakage for cleaner workshop environments.
Built with 2 to 4 layers of high-strength kraft paper composite providing uniform tensile strength, impact resistance, and tear resistance for reliable transportation.
Optional internal PE liner or coated moisture-proof layer blocks water vapor and humidity, preventing content clumping and ideal for maritime export.
Square bottom and three-dimensional shaping ensures upright positioning and stable, orderly stacking without tilting or collapsing.
Made from pure wood pulp kraft paper that is recyclable, biodegradable, odorless, and pollution-free, meeting food contact packaging safety standards.
High-definition multicolor printing displays logos, specifications, and bilingual instructions without fading, enhancing brand image and export qualifications.
| Parameter | Specification |
|---|---|
| Material | 100% virgin wood pulp stretch kraft paper (80-100 gsm) |
| Layer Options | 2, 3, or 4 layers (typically three paper layers + one membrane) |
| Loading Capacity | Customizable: 10kg, 20kg, 25kg, 40kg, 50kg |
| Bag Structure | Square bottom valve bags, external valve, internal valve types |
| Moisture Protection | No membrane, single PE membrane, or double-layer moisture-resistant coating |
| Printing | 1 to 6 colors, double-sided printing, Chinese/English customization |
| Size Tolerance | Width: ±2mm, Length: ±3mm |
| Paper Quality | Pure virgin wood pulp without recycled content, smooth surface with strong toughness |
| Adhesion Process | Fully automated high-temperature adhesion, secure bonding without glue failure |
| Sealing Requirements | Neat valve openings for smooth filling and automatic self-sealing |
| Physical Performance | Passes drop and stacking tests, no damage during normal storage/transportation |
| Appearance Standards | Clear printing, accurate color matching, no stains/wrinkles/damage |
Potato starch, sweet potato starch, corn starch, flour, food additives, protein powder, glucose powder. Suitable for domestic sales and export inspection.
Resin powders, rubber/plastic additives, dry powder coatings, chemical powders, fillers, pigment powders, desulfurization agents.
Putty powder, gypsum powder, cement mortar, tile adhesives, bonding agents, waterproof powders, refractory materials, insulation powders.
Feed additives, organic fertilizer powders, compound fertilizer powders, pesticide powders. Supports automated production line packaging.
Moisture resistance, compression resistance, impact protection for sea/land transportation. Custom English/bilingual printing with customer logos.