Compression Tester for Packaging Bags & Pouches

Pouch & Bag Compression Testing Mechanics

When testing flexible packaging (such as food sachets, liquid infusion bags, retort pouches, and chemical bags), compression theory centers on how internal fluids and gases redistribute applied downward force onto heat-sealed edges. Using dedicated pneumatic instruments like the Qualitest Q200G and Q200A, parallel platens compress the package to measure pressure resistance, seal integrity, and burst thresholds without risking product leaks during shipping.

Test Methods for the Q200G & Q200A Series

Core Testing Procedures & Equipment Specs

• Pneumatic Platen Loading: The Qualitest Q200G applies controlled pneumatic force across a 50 to 700 kPa pressure range (supported by a 0–0.7 MPa air supply) with a high precision readout of ±0.8%.
• Platen Clearance & Working Area: The upper 280 × 180 mm compression platen moves down across a 0 to 100 mm test clearance distance, delivering uniform pressure distribution across liquid bags, sachets, or vacuum-sealed pouches.
• Hydrostatic Pressure Redistribution: Compressing a gas- or liquid-filled pouch causes internal contents to exert equal outward pressure in all directions. This hydrostatic force acts against the interior film walls, hunting down the weakest point along the heat-seal seam.
• Real-Time Digital Tracking: Technicians input target force values directly on the clear LCD screen. The benchtop unit maintains steady compression or adjusts load levels throughout the test cycle to detect slow seam creep or pinhole air leaks.

Parameters Influencing Pouch Compression Results

Key material and process variables directly dictate how a flexible bag performs during 50 to 700 kPa pressure testing:

• Heat-Seal Quality (Temperature, Pressure, Dwell Time): Under-sealed seams peel apart easily under pneumatic load, whereas over-sealed seams cause localized film thinning along the seal edge, creating a weak tear line.
• Trapped Headspace Volume: Gas-filled bags act like pressurized cushions, resisting compression immediately and transferring high tensile stress onto the heat seals. Packages with minimal headspace flex further across the 0 to 100 mm platen distance before pressure builds up.
• Laminate Layer Bonding: Delamination between inner barrier films (like Aluminum foil or EVOH) and outer protective layers reduces total tensile strength, triggering early seal failure under load.
• Compression Loading Speed: Rapid compression causes polymer films to react rigidly, whereas slower loading speeds allow the plastic film time to stretch and dissipate stress across the 280 × 180 mm platen area.

Applicable Testing Standards

The Qualitest Q200G and Q200A compression testing units follow established international standards to ensure repeatable quality control data across production batches:

• ASTM D4169: Standard practice for performance testing of shipping containers, bags, and distribution systems.
• ASTM D642: Standard test method for determining compressive resistance in packaging containers and bags using flat platens.
• ISO 12048: International standard for evaluating compression and stacking resistance in filled transport packages.
• ISO 2872: International standard method for compression testing on complete, filled transport packages.
• JIS Z0212: Japanese industrial standard method for container and packaging compression testing.
• TAPPI T804: Standardized compression test method for packaging materials and containers.