In high-volume powdery industries in 2026—including Portland cement, micronized mineral carbonates, polymer-modified dry plasters, tile adhesives, and fine chemical compounds—bagging bottleneck delays and manual stitching overhead drastically impair productivity. SherkatTrade's Self-Closing Valve Bags (Block Bottom PP Spout Sacks) eliminate the need for manual or mechanized bag-top sewing. Engineered with precision self-closing internal valve sleeves, these sacks close automatically under internal product pressure upon detachment from filling spouts, accelerating bagging throughput by over 300%.
Manufactured at our advanced industrial complex in Isfahan utilizing hot-air welding technology and precision micro-perforation, these sacks are extruded from heavy-duty laminated polypropylene fabric. When filled via high-speed rotary or inline filling spouts, internal material weight seals the inner flap firmly against the sack wall, ensuring a dust-free production floor and immaculate pallet presentation.
Every production lot undergoes rigorous pneumatic blow-fill burst tests and dynamic drop resistance evaluations:
| Industry Sector | Fill Commodity | Strategic Advantage of SherkatTrade Valve Bags |
|---|---|---|
| Cement & Building Materials | Portland cement, white cement, dry mortars | 100% compatibility with high-speed rotary impellers without dust leakage |
| Plaster & Construction Chemicals | Polymer gypsum, joint compounds, tile adhesives | Instant valve closure maintaining clean outer sack surfaces and clean pallets |
| Micronized Mineral Powders | Calcium carbonate (400-2500 mesh), barite, talc | Felt-lined internal valve preventing fine micron powder seepage |
| Polymers & Chemical Resins | Masterbatch pellets, PVC resin, specialty chemicals | Hermetic isolation preventing external contamination and ambient moisture ingress |
Removing bag-top sewing machinery eliminates maintenance costs, thread break stoppages, and needle replacement overhead entirely.
Packing operators or automated bag applicators simply slide the valve over the filling spout, filling up to 1,500 bags per hour per rotary packer.
The brick-like block bottom geometry prevents bag bulging, ensuring rigid pallet stacks that maximize shipping container space utilization by 15%.
Laminated seamless construction makes it virtually impossible for counterfeiters to open and refill sacks without causing obvious structural destruction.
| Performance Criterion | SherkatTrade PP Valve Sack | Standard Open-Mouth PP Bag | Traditional Kraft Paper Sack |
|---|---|---|---|
| Closure Method | Self-closing hermetic valve | Requires manual/machine sewing | Glued valve / sewing |
| Packaging Line Speed | Up to 1,500 bags/hour | Max 300 bags/hour | Moderate (burst-prone at speed) |
| Workplace Dust Emission | Zero dust with micro-perforation | Heavy dust at sewing station | Moderate to high at valve area |
| Moisture & Rain Barrier | 100% Laminated waterproof | Water enters through needle holes | Paper absorbs water, degrades quickly |
| Total Packaging Overhead | Highly economical & durable | Continuous thread/needle cost | Expensive with high breakage loss |
No, the internal valve sleeve is engineered so that increasing internal product weight forces the flap tighter against the wall, reinforcing the seal.
Yes, our valve sacks are manufactured strictly according to international dimensional and aerodynamic standards for Haver & Boecker, Ventomatic, and Claudius Peters packers.
Custom production with client-specified dimensions, valve type, and up to 6-color flexographic printing starts from 5,000 bags.
Contact the SherkatTrade valve packaging export department for engineering datasheets, trial sample packs, and volume pricing:
| Dimensions | 50x90 cm (Customizable) |
| Weight per Bag | 80g - 120g |
| Material | Standard Woven Polypropylene |
| Color | Pure White |
| Printing Type | Flexographic Printing |
| Load Capacity | 25kg - 50kg |
| Closure Type | Valve / Spout |
| UV Treatment | Yes |
| Food Grade | Yes |
| Custom Size Available | Yes |
