The rpsexdoll Thermoplastic Elastomer material characteristics allow it to air-dry, but the conditions must be tightly controlled. American Society for Testing and Materials (ASTM) statistics show that TPE fully dries out in 4 to 6 hours under 25°C and 50% humidity (with a thickness of 10mm). As the humidity level rises to 80%, the drying time will take longer, up to 8 hours, and the surface may be exposed to fungal growth (the likelihood of colony count being outside the normal increases by 37%). A German user questionnaire indicates that while 68% of rpsexdoll customers prefer to be dried naturally, 23% of them exhibit a change of material hardness (Shore A value variation ±5) due to the lack of temperature and humidity control, and the touching rating is lower to 3.9/5 (4.7 upon usual treatment).
The manufacturer’s instructions clearly state that rpsexdoll should be avoided from sunlight during natural drying (ultraviolet intensity > 5mW/cm² will speed up TPE aging 8 times). Experiments by Japan Institute of Materials Research show that under cool and ventilated conditions (wind speed 0.5m/s), the moisture diffusion coefficient of microporous structure (pore size 50-200μm) is 1.2×10⁻⁹m²/s, 3.6 times greater than silicone material. However, long-term air-drying for more than 3 days will increase the oxidation hazard of internal skeleton metal components (e.g., aluminum alloy joints). The salt spray test (ASTM B117) shows the corrosion rate increases from 0.002mm/year to 0.015mm/year.
User practice experience shows there is potential hazard. In a 2023 Statista survey, 12% of rpsexdoll users had seam cracking (tensile strength reduced from 4.5MPa to 2.8MPa) due to over-air-drying, and repair costs were $89 every time. When there is a quick air-drying (e.g., direct blowing with an electric fan), a surface temperature difference of over 15°C (e.g., 30°C→15°C) will cause TPE shrinkage stress (0.8MPa), which is 167% higher than the safety limit (0.3MPa), and there is a higher risk of permanent deformation.
The comparison between alternative solutions indicates the differences. The silicone material of RealDoll (thermal conductivity 0.2W/m·K) takes 9 to 12 hours to dry, but it exhibits better antifungal efficacy than TPE (with a 72% decrease in colony count). The antibacterial treatment of rpsexdoll (with 0.3% nano-silver content) maintains lower efficacy in a humid environment. At humidity levels > 70%, the rate of sterilization reduces from 99.9% to 85% (tested under ISO 22196 standard). As per EU EN 71-3 certification standards, migrating elements (like lead) concentration in the air-dried sample should be below 13mg/kg. The measured concentration of rpsexdoll is 2.7mg/kg, and the margin of safety is 381%.
Maintenance cost analysis shows that the natural air-drying energy cost is 0 (compared to the 0.8kWh per time used by the dryer), but the time cost is tripled. If the recommended diatomite adsorption drying process (2 hours) is chosen, the cost of each care will increase by 0.5 US dollars, yet the lifespan of TPE can be extended from 3 years to 5 years (ROI is 240%). In certain extreme cases, Canadian customers underwent partial brittleness of rpsexdoll due to drying in winter (-10°C), while the repair cost was as high as 45% of the original product price.
Regulatory compliance requirements impact operational norms. Based on California Bill 65, the volatile organic compounds (VOCs) released by TPE products upon drying must be less than 50μg/m³, and the measured value of rpsexdoll is 28μg/m³ (analyzed using GC-MS). For future material upgrading directions, hydrophobic modified TPE (contact Angle > 110°) can compress drying time to 2 hours, but mass production cost will likely increase by 19%.