Square Bottom Valve PP Woven Bag for Gypsum | Basic Printing Economy Model | 25kg/40kg Powder Packaging | For Auto-Fill Lines

Product Overview: 
This product is a square-bottom valve-mouth gypsum woven bag, specifically designed for the automated filling of powdered materials such as gypsum powder. Made from PP polypropylene woven fabric, its square-bottom valve-mouth design is compatible with high-speed valve-mouth filling machines, delivering high filling efficiency and minimizing dust spillage. Standard printing processes meet basic labeling requirements while effectively controlling packaging costs. It is suitable for packaging 25 kg and 40 kg specifications of gypsum powder and other powdered materials.

Applicable materials: 
Building gypsum powder, high-strength gypsum powder, modeling gypsum powder, joint-filling gypsum, bonding gypsum, plastering gypsum, putty powder, cement, dry-mix mortar, talc powder, calcium carbonate powder, and other powdered construction materials.

Core Advantages: 
The square-bottom valve-mouth design is compatible with automated filling, delivering high filling efficiency with minimal dust generation; standard printing ensures cost-effectiveness; suitable for packaging 25 kg or 40 kg of powder; the reinforced woven material offers excellent puncture resistance; and the valve mouth features self-sealing, eliminating the need for additional sealing.

Compatible with automatic filling: 
This product is specifically designed for high-speed valve-mouth filling machines and is compatible with various valve-mouth filling equipment, including impeller-type, screw-type, and pneumatic systems. During filling, the machine’s discharge nozzle is inserted into the valve mouth, allowing the powdered material to flow into the bag through the valve. Once filling is complete, the nozzle retracts, and the valve mouth automatically seals itself due to the internal material pressure and its own structural design, eliminating the need for additional sealing.

Standard economical printing: 
This product is manufactured using standard gravure printing, available in single- or two-color options, with simple yet crisp graphics and low plate costs, significantly reducing upfront investment. It is ideal for gypsum powder manufacturers that require large-volume procurement, have modest packaging appearance requirements, and prioritize cost control. Compared with full-color laminated bags, this product can cut packaging costs by 30% to 50%.

Thickened, woven, puncture-resistant: 
Made from high-density, heavy-weight PP polypropylene woven fabric, this bag offers exceptional tensile strength and puncture resistance. Although gypsum powder particles are fine, they have sharp edges; ordinary woven bags are prone to tearing during filling and handling. The thickened woven structure of this product effectively resists penetration by powder particles, ensuring package integrity and preventing leaks.

Moisture resistance: 
This product features an economical design without laminated coating or inner lining, resulting in only moderate moisture resistance. Gypsum powder is highly sensitive to moisture and will clump, harden, and lose its effectiveness when exposed to damp conditions. For long-term storage or use in high-humidity environments, we recommend selecting a version with a PE laminated coating or a PE inner liner. Laminated products reduce water vapor transmission by more than 90%, effectively preventing gypsum powder from absorbing moisture and forming lumps.

Valve port specifications: 
The valve port length typically ranges from 80 to 120 millimeters, with the diameter customized to match the discharge nozzle of the filling machine. The valve port can be configured as either a center-mounted or an eccentric design. The valve port is made from the same material as the bag body, formed in one piece to eliminate the risk of delamination or detachment.

Material and Craftsmanship: 
The outer layer is made of PP polypropylene woven fabric, with basis weight customized to meet load-bearing requirements of 25 kg or 40 kg. The bag style is a square-bottom valve bag, featuring a three-dimensional, square-shaped bottom. The valve opening is either cuff-style or flap-style, integrally molded. Printing is carried out using conventional gravure printing, in one or two colors.

Packaging drop test: 
Under a 40 kg load condition, the product passed a 1.2-meter free-fall test with no breakage and no leakage on any of its six sides.

Packaging specifications: 
The standard bag weights are 25 kg or 40 kg. Bag dimensions are customized according to the fill weight: for 25 kg, the recommended size is 500 × 400 × 120 mm (length × width × bottom width); for 40 kg, the recommended size is 600 × 450 × 130 mm. The valve opening length ranges from 80 to 120 mm, with the diameter tailored to the discharge nozzle of the filling machine.

Customization Scope: 
Dimensions can be customized to 25 kg or 40 kg specifications for length, width, and bottom width. Valve port specifications can be tailored to match the discharge nozzle of the filling machine in terms of length and diameter. Printing supports single-color or two-color standard printing. Fabric weight can be adjusted according to requirements. Optional features include a PE laminating layer or a PE inner liner to provide moisture resistance.

Environmental Compliance: 
The product is manufactured using virgin PP material and is recyclable.

Applicable to: 
This product is suitable for manufacturers of building gypsum powder, high-strength gypsum powder, modeling gypsum powder, joint-filling and bonding gypsum, plastering gypsum, dry-mix mortar, and building-material packaging purchasers.

Price and MOQ: 
Specific pricing and MOQ are negotiable.