As a product, the characteristics of silicon free release agents are as follows:
1. The surface tension is low and easy to disperse, forming a thin oil film on all surfaces of the mold. It can also be used in molds with complex structures.
2. Poor affinity with organic polymer materials, non adhesive, and excellent effect of multiple continuous demolding. It will not cause expansion or contraction of the demolded plastic and rubber parts, ensuring the design size requirements of the product.
3. Excellent thermal oxidation stability, no chemical activity, and minimal residue of decomposition products on the mold. It does not react chemically with the molding material, does not contaminate the molded parts, and gives the surface gloss.
4. No physiological activity, in fact non-toxic.
According to the form of silicone oil release agent products, silicone free release agent products can be divided into the following six types:
1. Aerosol silicone oil release agent
This is a silicone oil release agent filled with gas. A typical product in China is the Jinxiang brand silicone oil release agent developed by the Institute of Synthetic Materials Aging of the Ministry of Chemical Industry. It does not contain organic solvents, is odorless and non-toxic, resistant to high temperatures, and is simple and convenient to use. At a distance of 25-35 centimeters from the mold, gently press the valve, and the release agent will be sprayed and dispersed on the mold as mist like liquid particles, with a uniform oil film. For molds with complex or micro structures, using this type of release agent is particularly convenient to operate. Therefore, Shenzhen, Zhuhai and the Pearl River Delta counties and cities (especially export-oriented enterprises using engineering plastics) all use this release agent, and they are exported to Hainan, Guangxi, Guizhou, Sichuan and other provinces.
2. Oil based silicone oil release agent
Use silicone oil alone and apply it to the surface of the mold with a soft cloth. Usually, silicone oil with a viscosity of 100~1000 centipoise is used. When the mold temperature is below 100 ℃, low boiling point solvents such as toluene and mixed xylene are used as diluents. When precision molds are coated at high temperatures, high boiling point mineral oil is used as a diluent.
3. Solution type silicone oil release agent
This is a low viscosity (1-5 centipoise) release agent made by dissolving silicone oil in toluene and industrial gasoline. After coating with a brush and solvent evaporation, the remaining silicone oil shows demolding effect. The solvent contained in this release agent is flammable, and the hygiene management and fire safety work of solvent gas emissions during use should be taken seriously.
4. Lotion type silicone oil free release agent
This release agent emulsifies silicone oil with non-ionic surfactants. Dilute with 100 times water and remain stable for a long time. Dilute with water, low cost, fire prevention, hygiene, but less volatile than solvents, not suitable for use when the mold temperature is low. When diluting, it is better to use low hardness water.
5. Paste type silicone oil release agent
Adding silica powder to silicone oil becomes a white semi transparent paste type release agent. Due to its excellent thermal oxidation stability, it is suitable for release at high temperatures and pressures. For example, synthetic fibers such as nylon have a nozzle temperature of nearly 300 ℃ during melt spinning. Applying a release agent to the nozzle can prevent fiber breakage and adhesion of fibers and aging products to the nozzle.
6. Sintered silicone oil release agent
This is mainly composed of silicone resin, coated on the mold with a brush, and then heated at 150 ℃~200 ℃ for 30 minutes to form a hard film, which can be used for repeated demolding in food processing and rubber product molding processing.
