Key Factors Influencing Sulfur-Free Paper Shelf Life

The shelf life of sulfur-free paper is not constant but influenced by multiple environmental factors. In-depth understanding of these key factors and their mechanisms is essential for scientifically managing sulfur-free paper inventory and extending its service life. Studies show that temperature fluctuations, humidity changes, and light conditions are the three core elements affecting sulfur-free paper shelf life, accelerating physical performance degradation and chemical property changes through different pathways.
Temperature control is the primary condition for ensuring sulfur-free paper stability. According to research data from multiple authoritative paper companies, the optimal storage temperature range for sulfur-free paper is 18°C to 25°C. Excessive temperatures accelerate the aging of internal paper fibers, causing expansion, fading, or even brittleness. Extremely low temperatures may affect the paper’s flexibility and processing performance. Equally critical is temperature stability—frequent temperature fluctuations cause the paper to repeatedly expand and contract, damaging fiber structures and leading to curling or deformation. In extreme cases, high-temperature environments exceeding 30°C can shorten the shelf life of sulfur-free paper by 30%-50%, explaining why electronics manufacturers prioritize summer warehouse temperature management.

Humidity management is equally critical for sulfur-free paper shelf life. The relative humidity of the storage environment should be controlled between 40% and 60%. Excessive humidity (>60%) causes the paper to absorb moisture, potentially leading to sulfidation, mold, deformation, and reduced tensile strength. Insufficient humidity (<40%) causes the paper to lose water and become brittle, decreasing tear resistance. Notably, humidity and temperature have a synergistic effect—high-temperature and high-humidity environments damage sulfur-free paper far more than single factors. Experimental data shows that sulfur-free paper stored at 25°C with 70% humidity deteriorates 2-3 times faster than under standard conditions.
Light conditions, particularly ultraviolet (UV) radiation, are the third major factor affecting sulfur-free paper shelf life. Long-term exposure to sunlight or strong artificial light accelerates the photo-oxidative degradation of paper fibers, causing color fading and strength reduction. UV damage is cumulative, and even short-term exposure may cause irreversible damage. Therefore, sulfur-free paper should be stored in dark environments or packaged with UV-resistant materials. Industry best practices show that sulfur-free paper packaged in sealed, light-proof materials can extend its service life by over 20% compared to ordinary packaging.