Yes, methyl silicone oil emulsion can be used as a die-casting release agent, and its performance has been verified in practical applications. The following is a detailed analysis:
The application of methyl silicone oil emulsion in die-casting release has been confirmed by multiple studies and industrial practices. For example, a research developed a high-efficiency water-based release agent by emulsifying dimethyl silicone oil and polyethylene wax; its performance is close to that of imported products, while costing only 40%-50% of the latter. In aluminum alloy die-casting, methyl silicone oil emulsion can form a uniform lubricating film, significantly reducing release resistance, and the castings have good surface quality without dark spots or dullness. In addition, products from many manufacturers (such as LX0601, ML0601) are clearly labeled as suitable for die-casting release, and perform excellently especially in materials like rubber, EVA foam, and resin.
The thermal stability of methyl silicone oil emulsion covers the common temperature range of die-casting. For instance, the vapor pressure of Elkem BLUESIL™ FLD 47V series products is only 1.33 Pa at 200°C, with no volatile loss; the thermal decomposition temperature of ML0601 methyl silicone oil emulsion is >300°C, and it forms a stable film at 65-250°C, making it suitable for aluminum alloy die-casting (mold temperature around 200°C) and high-temperature plastic extrusion processes. Its molecular structure (Si-O-Si bonds) endows it with high bond energy similar to inorganic materials, ensuring no carbonization or peeling at high temperatures.
The low surface tension of methyl silicone oil (about 20-21 mN/m) allows it to form a uniform lubricating layer on the mold surface, significantly reducing the coefficient of friction. For example, LX0601 methyl silicone oil emulsion greatly reduces resistance during the release of rubber and EVA foam, and the mold remains clean with little fouling after 5-8 consecutive production cycles; ML0601 reduces the release force of EVA products by 40% and improves surface gloss by 30%. Its high adhesion also reduces mold sticking in deep cavities of complex molds, ensuring neat edges of castings without flash.
Water-based methyl silicone oil emulsion has no pungent odor, contains no VOCs (Volatile Organic Compounds), and meets environmental certifications (such as Chinese environmental standards and food contact requirements). For example, LX0601 has passed environmental certification and is suitable for sensitive scenarios like children's toys; water-soluble release agents cause no corrosion to aluminum alloys, with a corrosion rate of only 2.5×10⁻³ g/(m²·h), complying with industrial safety standards.
Methyl silicone oil emulsion can be compounded with wax emulsions, fluorine emulsions, etc., to achieve composite functions. For example, after compounding, it can simultaneously improve water resistance and stain resistance without stratification or precipitation. Its high concentration (e.g., diluted with water at a ratio of 1:20-30) reduces usage costs and adapts to different process requirements (e.g., the dilution ratio can be reduced for complex molds).
Methyl silicone oil emulsion is suitable for common die-casting materials such as aluminum alloys and zinc alloys, as well as non-ferrous metals and polymer materials like rubber, EVA, and resin. For castings that require post-processing (such as bonding and coating), it is recommended to select long-chain alkyl-modified silicone oil to avoid affecting surface adhesion.
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Dilution Ratio: For scenarios with mild adhesion, a water dilution ratio of 1:30 is recommended; for complex molds or severe adhesion, it can be adjusted to 1:20.
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Spraying Method: Use atomized spraying to ensure a uniform film layer, with focus on covering the mold parting surface and deep cavity areas.
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Mold Pretreatment: Before use, clean oil stains on the mold surface; spraying after drying will yield better results.
Methyl silicone oil emulsion can reduce the frequency of mold cleaning during continuous production (e.g., from 3 times a day to once a week). However, it is recommended to regularly check the surface condition of the mold to prevent trace residues accumulated over time from affecting the release effect.
Although the thermal decomposition temperature of methyl silicone oil emulsion is usually >300°C, in ultra-high-temperature die-casting scenarios exceeding 300°C (such as for certain special alloys), it is necessary to select materials with higher temperature resistance, such as phenyl silicone oil or fluorosilicone oil.
If castings require post-treatment such as electroplating or printing, it is necessary to test in advance the impact of release agent residues on subsequent processes. Some formulas may need to adjust the type of silicone oil (e.g., using reactive silicone oil) to improve compatibility.
With its high-temperature resistance, efficient lubricity, environmental friendliness, and flexible formula design, methyl silicone oil emulsion is an ideal choice for die-casting release agents. In practical applications, it is recommended to select the appropriate model based on specific process parameters (such as temperature and material type), and optimize the dilution ratio and spraying method through small-scale tests to achieve the best release effect and cost-effectiveness.
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