Inner Valve Square Bottom Color Printed Woven Bag | For Interior Water-Resistant Wall Putty | Auto-Fill Ready Dust-Proof & Leak-Proof

Product Overview: 
This product is a color-printed woven bag with an internal valve and a square bottom, specifically designed for the automated filling of water-resistant interior wall putties and other powdered construction materials. The internal valve conceals the filling opening within the bag body; once filled, the valve automatically seals, eliminating the need for additional sealing. The square-bottom design ensures stable upright positioning and neat stacking. A color-printed laminated finish provides clear brand visibility and basic moisture protection. It is ideal for large‑scale, automated packaging needs in putty powder manufacturing operations.

Applicable materials: 
Interior water-resistant putty, exterior wall putty, gypsum-based putty, cement-based putty, joint filler plaster, skim coat plaster, tile adhesive, self-leveling mortar, and other powdered construction materials.

Core Advantages: 
Internal valve port dust-proof and leak-proof 
The valve port is concealed on the inner side of the bag; during filling, the filling machine’s discharge nozzle is inserted into the internal valve port, allowing the product to flow into the bag. Throughout the filling process, the material moves within a sealed channel, minimizing dust spillage. The self-sealing valve eliminates the need for manual stitching or heat sealing, thereby reducing one processing step.

Stable stacking with square bottoms 
The bottom features a square, three-dimensional structure; once filled, the bag maintains a crisp, straight shape, offering greater stability than conventional flat‑bottom bags. It can be stacked 2 to 3 layers higher than flat‑bottom bags, resulting in more efficient use of warehouse space.

Difference between the inner valve port and the outer valve port: 
The internal valve port positions the valve on the inner side of the bag, so that once filling is complete, the valve is naturally concealed within the bag, resulting in a clean appearance and reducing the risk of accidental opening during handling. In contrast, the external valve port is located on the outer surface of the bag, leaving the valve exposed. For powdered construction materials such as interior wall‑ready putty, an internal valve design offers superior dust‑proofing and a more aesthetically pleasing look.

Dust-proof and leak-proof performance: 
During valve‑port filling, the material flows within a sealed channel between the filling machine’s discharge nozzle and the internal valve port, reducing dust emissions by more than 80% compared with manual bag‑filling, thereby improving the working environment in the filling workshop and minimizing material loss.

Moisture resistance: 
The color-printed laminated layer provides basic moisture protection, with a water vapor barrier rate of 85% or higher. Interior wall‑ready putty is relatively sensitive to moisture, and the standard lamination configuration can meet typical storage requirements.

For enhanced moisture resistance, an optional thickened PE liner is available, boosting the vapor barrier performance to over 95%. This solution is ideal for storage in humid environments, long-distance transportation, or long-term storage exceeding 12 months.

Material and Craftsmanship: 
The outer layer is made of PP polypropylene woven fabric, providing excellent tensile strength and puncture resistance. The surface features full-color printing with a protective PE film coating. The valve opening adopts an internal‑valve design, concealed on the inner side of the bag; its length ranges from 80 to 120 mm, with the diameter customized to match the discharge nozzle of the filling machine. The bag type is a square‑bottom valve pouch, with a three‑dimensional, square-shaped base. The bottom is sealed using heat sealing, resulting in a needle‑free, fully airtight seal.

Tensile strength: 
Testing has confirmed a tensile strength of at least 700 newtons per 50 millimeters, capable of supporting 20 to 25 kilograms of putty powder.

Packaging drop test: 
Under a 25-kg load condition, following a 1.2-meter free-fall test, the product remained intact and showed no leakage after being dropped from all six sides.

Applicable filling method: 
Compatible with impeller‑type, screw‑type, and pneumatic valve‑mouth filling machines. Customers must provide the specifications of the filling machine’s discharge nozzle; the manufacturer will then customize the valve‑mouth size accordingly.

Packaging specifications: 
The bag‑filling weight can be customized to 20 kg or 25 kg. The valve‑mouth length ranges from 80 to 120 mm, with the diameter tailored to match the discharge nozzle of the filling machine. The bag style is a square‑bottom valve bag.

Customization Scope: 
Dimensions can be customized to suit the weight of the material being loaded, with adjustable length, width, and base dimensions. Valve‑port specifications can be tailored to match the discharge nozzle of your filling machine, with customizable length and diameter. Color printing can be customized to reflect your brand’s visual identity, including patterns, colors, and text. Moisture‑proofing options include standard laminated coating or an enhanced PE inner liner.

Environmental Compliance: 
The product is manufactured using virgin PP material and is recyclable. We can provide UN‑certified hazardous‑goods export packaging, ensuring compliance with international maritime regulations for the transport of dangerous goods.

Applicable to: 
This product is suitable for manufacturers of interior water-resistant putties, exterior wall putty producers, gypsum-based putty companies, cement-based putty manufacturers, powder‑based building material brands, and building material exporters.

Price and MOQ: 
Specific pricing and MOQ are negotiable.