Wacker AK 100® – Silicone Oil Plasticizer for Casting Silicones & Viscosity Reduction

Premium Silicone Oil Plasticizer for Professional Mold Making and Viscosity Applications

Wacker AK 100 is a linear, non-reactive polydimethylsiloxane (silicone oil) with a kinematic viscosity of approximately 100 mm²/s. The oil is added to pourable addition and condensation silicones to make the cured rubber softer and more flexible, and to thin the uncured mixture for better de-airing and detail reproduction. Due to its lower viscosity compared to AK 350, this oil mixes even more easily and flows faster into fine details. The colorless, odorless liquid has a density of 0.96 g/cm³, a high flash point of 253 °C, and a low surface tension of 0.021 N/m. Dosing is by weight, typically between 1 and 15 percent relative to the silicone mixture, with more oil resulting in a softer end product and less oil maintaining the original hardness. The core application is to custom adjust the hardness and fluidity of molding rubbers.

Key Benefits

• Viscosity 100 mm²/s – very low viscosity oil that mixes quickly and homogeneously with addition and condensation silicones
• Density 0.96 g/cm³ – accurately dosable by weight between 1 and 15 percent for controlled hardness reduction
• Hardness reduction approximately 3 to 5 Shore A at 8 percent – predictable softening without rendering the silicone unusable
• Flash point 253 °C – high thermal safety margin during processing and storage
• Low surface tension 0.021 N/m – improves the flow of the silicone mixture, allowing it to penetrate better into fine details and crevices
• Infinitely miscible with all Wacker AK silicone oils – any desired intermediate viscosity can be set

Typical Applications

• Softening of pourable addition and condensation silicones for more flexible molds
• Viscosity reduction of molding rubber for better de-airing and detail reproduction
• Manual smoothing of spreadable silicones using spreading and spatulating techniques
• Release agent and lubricant in industrial and technical applications
• Water repellent and defoaming agent
• Liquid dielectric and heat transfer oil for electrical applications

Processing

1. Prepare your silicone: mix the A and B components in the correct weight ratio according to the silicone's datasheet and stir thoroughly first.
2. Add the Wacker AK 100 oil by weight. Dosage between 1 and 15 percent; approximately 8 percent gives a noticeable softening of about 3 to 5 Shore A points. More oil softens further, but above 10 percent, the final strength may decrease unacceptably.
3. Mix until completely homogeneous, ensuring the oil is evenly distributed throughout the silicone mixture.
4. Pour or process the mixture within the pot life of the silicone used.
5. Allow to cure according to the curing time and temperature of the silicone used.

Wacker Chemie AG is a global market leader in the development and production of silicones for industrial and technical applications.

Special Notes

Adding silicone oil is a form of customizing your silicone. Please note that the final values in certain areas will differ from the values on the silicone's datasheets. The oil does not cross-link in the silicone, causing it to slowly sweat out over the years and under stress, leaving a greasy layer and causing the mold to shrink slightly.

Food Contact

Wacker AK 100 formally complies with Regulation EU 10/2011 and is listed as polydimethylsiloxane (E 900) on the positive list. In addition, the product is listed by the German Umweltbundesamt as a base oil for lubricants in contact with drinking water. However, Wacker explicitly advises against its use as a food additive; the substance has no technological effect in food. Suitability for a specific food or drinking water contact material must always be determined by the manufacturer of the end product.

Shelf Life

At least 5 years when stored below 50 °C in a dry, cool, and well-sealed container.

Professional Support

Are you unsure about the correct dosage for your specific silicone or application? Feel free to contact us; we are happy to help you find the optimal adjustment of hardness and fluidity.