3 Common Mistakes in Suitcase Anti-Mold Treatment and Their Standard Basis

Mistake 1: Treating Only the Leather, Ignoring Secondary Contamination from Packaging Paper

Many factories believe that the core of suitcase anti-mold lies in the leather itself, assuming that as long as the leather is treated, no additional attention is needed in the packaging process. The flaw in this approach is overlooking the possibility of packaging paper acting as a mold carrier. We tested a batch of exported suitcases where the leather was sprayed with (containing silver-zinc composite active ingredients that can penetrate mold cell walls and inhibit ergosterol synthesis) before leaving the factory. However, after simulating high-humidity shipping conditions (temperature 30°C, relative humidity 85%) for 7 days, mold spots appeared on the inner side of the suitcase. Investigation revealed the issue was with the packaging paper—its moisture content was as high as 12.5%, and it had not undergone any anti-mold treatment. According to ASTM G21 standard, a mold growth rating of 4 or above (clearly visible) on the material surface is considered a failure. The packaging paper tested at level 5, directly causing secondary contamination of the suitcase.

Mistake 2: Believing Higher Fungicide Concentration Yields Better Results

Another common misconception is arbitrarily increasing the fungicide dosage, thinking that doubling the concentration will double the effect. However, this is not the case. Taking as an example, its recommended concentration is 1.5%-2.5% (based on paper weight). Beyond 3%, the anti-mold effect does not significantly improve, but may instead affect the paper’s breathability and adhesion due to excessive residue. We conducted a comparative test of treatments at 2.5% and 4% concentrations: in ISO 846 Method C (soil burial test), the mold coverage rates for the two groups were 0% and 2%, respectively, showing minimal difference. However, the 4% group experienced a paper strength reduction of about 15% and exhibited noticeable chemical stains. The marginal benefit of increasing concentration is extremely low, while the side effects cannot be ignored.

Mistake 3: Neglecting Moisture Content Control of Packaging Paper

Many factories focus only on the uniformity of fungicide spraying but overlook the moisture content of the packaging paper itself. If packaging paper is improperly stored from the paper mill to the usage stage, its moisture content may exceed 10%. When moisture content surpasses 8%, mold can still proliferate in the water film even after anti-mold treatment. According to GB/T 2679.6 standard, the moisture content of packaging paper should be controlled between 5% and 8%. We tested a batch of packaging paper with a moisture content of 9.2%. After spraying with and placing it for 48 hours, a small amount of mold (level 2) still appeared on the surface. When the same batch of paper was dried to a moisture content of 6.8% and then treated, the mold level dropped to 0. Moisture content is a prerequisite for anti-mold treatment; without addressing it, the effectiveness of any fungicide will be compromised.

Comparison Table of Correct and Incorrect Practices

Suitcase anti-mold requires a systematic approach: leather treatment, packaging paper treatment, and moisture content control are all indispensable. Only when every step is properly executed can the mold transmission chain be truly blocked.