Two-Month Water Immersion Test Observation of Filler Sodium Sulfate Particles in Production

On January 13, 2025, we conducted a special presentation on whether adding sodium sulfate filler to PE films and composite films could optimize costs. On January 9, sodium sulfate particles were immersed in water for testing, and the experiment has continued until now. Today, on March 10, let’s observe the changes.

Compared to polyethylene, which shows no significant changes after water immersion, the liquid with sodium sulfate has turned red, with precipitated powder adhering to the cup walls, and the sodium sulfate particles have reduced in size.

This phenomenon confirms sodium sulfate’s high water solubility. It demonstrates that in PE films containing sodium sulfate filler, the sodium sulfate migrates and precipitates to the surface under high humidity or prolonged storage.

For circuit board packaging, these precipitates can adhere to precision components, potentially causing functional risks. In food and pharmaceutical packaging, the residues may contaminate contents, posing potential health hazards.

This experiment reveals non-negligible risks of sodium sulfate in packaging, particularly for circuit boards, food, and pharmaceuticals. We urge the industry to carefully evaluate filler choices and avoid sodium sulfate and similar additives.

We recommend clients avoid sodium sulfate and barium sulfate fillers and instead opt for higher quality, 100% polyethylene-based PE and composite films, ensuring both cost efficiency and guaranteed performance.