Two Critical Areas in Powder Packaging

During nickel sulfate filling, the material first passes through the top filling spout. During unloading, it is concentrated through the bottom discharge spout. These top and bottom areas connect multiple fabric sections and are directly exposed to material flow, dust movement, and localized deformation.

The top and bottom panels of this FIBC use 190 g/m² externally coated material. The bag has a Ø45 × 60 cm filling spout and a Ø45 × 45 cm discharge spout. Its circular body uses 180 g/m² externally coated woven fabric, while an approximately 90 μm PE liner provides an additional material-isolation layer.

Why Coat the Top and Bottom?

Coated Top for Filling-Dust Control

When powder enters the bag, continuous material flow and displaced air affect the area around the filling spout. Fine dust may escape through woven openings or connection areas if the top fabric has an open woven surface.

The 190 g/m² coated top panel is intended to:

• Cover openings in the PP woven surface;
• Reduce dust escape directly through the top fabric;
• Help keep the filling area cleaner;
• Reduce entry of fine material into the woven layer;
• Provide a coated surface around the filling-spout connection.

Actual dust control also depends on equipment connection, spout fastening, liner installation, and seam condition. The coated panel does not replace enclosed filling or dust-collection equipment.

Coated Bottom for Discharge-Area Control

During discharge, the material moves toward the bag bottom and exits through the discharge spout. This area also connects the body, outlet structure, and cross-bottom lifting belts.

The 190 g/m² coated bottom panel helps:

• Reduce fine-powder escape through the woven bottom surface;
• Limit entry of material into the bottom woven layer;
• Keep the discharge area relatively clean;
• Work with the PE liner and closure structure during unloading;
• Reduce material loss through woven openings under normal handling conditions.

A coated bottom should not be described as completely leakproof. Spout closure, liner connection, seam construction, and particle size still affect containment performance.

Panel Body and Structural Stability

The 190 g/m² value applies to the top and bottom panels, not to the entire bag body. The circular body uses 180 g/m² externally coated woven material with specified warp and weft fabric strengths of at least 1760 N.

Within the filled-bag structure:

• The top panel connects the filling spout to the upper body;
• The 180 g/m² circular body forms the main material-containing section;
• The bottom panel connects the discharge spout to the body;
• Four 7 cm wide lifting belts extend along the corners and beneath the bag;
• The PE liner separates the nickel sulfate from the woven outer bag.

The purpose of the 190 g/m² panels is not limited to higher local fabric weight. They also provide transition sections around the filling spout, discharge spout, and woven body. Filled-bag shape still depends on bulk density, flowability, filling distribution, actual filling weight, and pallet support.

Bag Area | Main Risk | Structural Response

Main Specifications

Where This Configuration Is More Useful

Filling

When nickel sulfate enters through a pipeline, screw conveyor, or gravity filling system, the 190 g/m² coated top covers the woven surface around the inlet. The filling spout must match the equipment connection, and the PE liner must be correctly extended and secured.

Short-Term Storage

After filling, the coated top and bottom panels work with the PE liner to limit direct exposure of the material to the woven layer and storage environment. The filling spout and liner still need to be properly closed, and the bag should not be placed directly on a damp floor.

A defined moisture-barrier requirement or extended storage period requires confirmation of the liner closure and barrier performance.

Internal Transfer

During internal movement, the bag bottom remains in contact with the pallet or supporting surface. The 190 g/m² coated bottom works with the cross-bottom lifting structure, but the pallet must provide complete support and remain free from burrs that could damage the coating or liner.

Discharge

During unloading, material is concentrated through the Ø45 × 45 cm discharge spout. The coated bottom reduces powder escape through the bottom woven surface, while actual discharge control depends on the spout closure, liner connection, and material flowability.

For material that tends to bridge or agglomerate, confirm whether the outlet diameter and downstream equipment can support the required discharge process.

What to Confirm for Top and Bottom Coating

1. Filling-Spout Structure

Confirm the filling-equipment outlet diameter, connection method, filling speed, and whether enclosed filling is used. The Ø45 × 60 cm spout should be checked against the equipment interface.

2. Discharge-Spout Structure

Confirm whether the material will be discharged by gravity, vacuum transfer, or manual assistance. Verify that the Ø45 × 45 cm outlet matches the required flow rate and downstream equipment.

3. Powder Particle Size and Flowability

Fine powder places greater demands on woven openings, seams, and spout closure. Poorly flowing material may accumulate around the bag bottom. Particle-size range, bulk density, and flow behaviour should be provided before production.

4. Higher Moisture-Barrier Requirements

External coating covers the woven surface but does not prove a specified moisture-barrier level. Extended storage, sea freight, or high-humidity conditions may require a different liner thickness, closure method, or barrier specification.

5. Inner-Liner Requirement

The current configuration includes a 200 × 340 cm PE liner with an approximate thickness of 90 μm. If the liner is removed, the dust-containment and environmental-isolation conditions change, requiring the coating, seams, and spout closures to be reassessed.