Sole molding mostly relies on thermosetting or thermoplastic materials such as polyurethane (PU), EVA, and rubber. It is easy to stick to the mold after high temperature and high pressure injection, and high-efficiency mold release agents must be used.With extremely low surface tension, excellent lubricity, chemical inertness and wide temperature stability, silicone oil has become the core additive for sole release.


1. Mechanism of action  
The main chain of the silicone oil molecule is a soft Si-O-Si, with the methyl side chain facing outwards, which can quickly spread out into a single molecular film on the surface of the mold, physically isolating the sole material of different polarities from the metal mold cavity; at the same time, the high thermal stability of the silicone oil (-50~200℃) can resist PU foaming and exothermic, avoid film rupture or carbonization, and ensure that the sole texture is complete and there is no migration pollution.


2. Product form  
1. Pure oil type: low-viscosity dimethyl silicone oil can be sprayed directly or diluted with 10-200 times water. It is low-cost and easy to operate. It is suitable for EVA and PVC soles.  
2. Emulsion type: Silicone oil-wax-emulsifier, high shear emulsification, particle size ≤1 µm, can be diluted with water, and the mold can form a film at about 60℃. It is commonly used in PU shoe materials.  
3. Solvent/semi-permanent type: Add 5-15% MQ silicone resin or alkyl modified silicone oil to the silicone oil, and one coating can be continuously demoulded dozens to hundreds of times, significantly improving the beat and reducing labor.  
4. Water-based and environmentally friendly: it is emulsified at low temperature with special silicone oil, wax liquid, and non-ionic surface activity, and does not contain benzene-based solvents to meet export environmental protection requirements.






4. Summary of advantages  
①the release of the mold is completely free of residues, the surface of the sole is smooth, and it can be glued or painted immediately; ②The mold life is extended, carbon deposits and corrosive cleaning are reduced;高The dilution ratio is high, the consumption is low, and the overall cost is reduced;④The water-based system has low VOC, which is in line with the trend of green manufacturing.


With the upgrading of the demand for fine texture and high yield of high-end sports shoes, silicone oil release agents are iterating in the direction of high solid content, low coating content, semi-permanent, and re-coating, providing more efficient and environmentally friendly technical support for the sole industry.