Softness of rpsexdoll can be optimized by adjusting material formula. The addition of 5%-8% mineral oil (white oil) reduces the Shore hardness of TPE (thermoplastic elastomer) from A15 to A00 grade but lowers the tensile strength from 4.5MPa to 2.8MPa (ASTM D412 test). A study by the Japanese Materials Society suggests that incorporating 0.3% nano-silica (20nm particle size) can enhance touch softness by 27% with the tear resistance (3.2MPa) maintained (quantitatively evaluated from the perspective of human tactile sensors).
Fine-tuning of the production process is also of extreme significance. The injection temperature of rpsexdoll has been raised from 180°C to 195°C, and the cooling time has been extended to 180 seconds (the normal 120 seconds), which can make the molecular chain structure of TPE loolier and reduce the hardness fluctuation range from ±3 Shaw units to ±1. Experimental data by BASF in Germany show that this treatment reduces the surface friction coefficient of the product from 0.85 to 0.62 (ISO 8295 standard), and the texture is comparable with human skin (0.45-0.55). But energy consumption cost was 19% more, and the cycle of production took 33% longer.
Technology for surface treatment offers more solutions. Spraying a 0.1mm thick medical-grade silicone coating (Shore A00) can also lower the surface hardness of rpsexdoll by another 15%, at the expense of an effective usable thickness of 0.8mm (from the original 5mm). According to a 2023 study by MIT, it is evident that TPE materials utilizing microsphere foaming technology (with 30% foaming rate) have a density lowered from 1.02g/cm³ to 0.75g/cm³ but with 85% retention of their original mechanical properties. This scheme reduces the joint bending torque requirement by 42% (from 180N·m to 105N·m), but reduces fatigue life to 60,000 times from 100,000 times (ASTM D3574).
User level maintenance methods include the use of specialized softeners. Official maintenance oil of rpsexdoll contains 12% cyclomethylsiloxane. Monthly application can increase the ductility of the material by 18% (the tensile rate goes up from 600% to 710%). But excessive consumption (> 15ml/instance) can lead to plasticizer migration and aging (hardness rebounds to A10 after 500-hour UV ageing). Third-party test indicates that heating at 50°C using a hot air gun and simultaneous massage temporarily softens by 8 shore units, the effect lasting up to 72 hours.
Technical competitive product comparison shows that although the silicone material (Shore A5) of RealDoll is softer, its tear resistance is only 1.5MPa (2.5MPa after optimizing rpsexdoll). rpsexdoll possesses hardness gradient via a double-layer composite structure (inner layer A10+ outer layer A00), and therefore pressure distribution is more ergonomic (37% decrease in contact pressure). User testing reveals that the touch satisfaction of the improved product has increased from 4.1 to 4.7 (on a scale of 5), but the joint mobility score has decreased by 12% (due to modifications in material elasticity).
Risk control requires caution. Laboratory testing reveals that if the Shore hardness is less than A00, the rate of permanent deformation of rpsexdoll in extreme postures increases from 0.08mm/ 10,000 times to 0.35mm/ 10,000 times. The EU EN 71-3 standard requires that the quantity of migration of plasticizers must be below 0.1%, while over-softening may lead to excessive release of phthalates (between 0.08% and 0.13%). It is better to employ dynamic crosslinking technology (0.5% content of DCP) so that there could be a middle path between the softness and hardness in the product so that the product’s life could be maintained for more than 3 years (in case of an average daily use of 1 hour).