Wacker AK 350® – Silicone Oil Plasticiser for Casting Silicones & Viscosity Reduction
Wacker AK 350® – Silicone Oil Plasticiser for Casting Silicones & Viscosity Reduction
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Variant: 5 Kg Wacker AK 350
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In stock
Ordered and paid on a working day: usually ships the same day
Delivery to Netherlands: usually within 1 working day
In stock
Ordered and paid on a working day: usually ships the same day
Delivery to Netherlands: usually within 1 working day
In stock
Ordered and paid on a working day: usually ships the same day
Delivery to Netherlands: usually within 1 working day
In stock
Ordered and paid on a working day: usually ships the same day
Delivery to Netherlands: usually within 1 working day
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Silicone oil plasticiser for casting silicones, suitable for food contact materials
Wacker AK 350 is a linear, non-reactive polydimethylsiloxane (silicone oil) with a kinematic viscosity of approximately 350 mm²/s. The oil is added to pourable addition-cure and condensation-cure silicones to make the cured rubber softer and more flexible and to thin the uncured mixture for better de-airing and detail reproduction. The colourless, odourless fluid has a density of 0.97 g/cm³, a flash point of 260 °C and a low surface tension of 0.021 N/m.
According to Wacker’s Regulatory Product Information (version 1.22, June 2026), Wacker AK 350 is suitable, provided it is processed appropriately, for the manufacture of materials and articles intended for food contact under Regulation (EC) No 1935/2004. See the Food contact section below.
Key benefits
- ✓ Viscosity 350 mm²/s: free-flowing oil that mixes easily and homogeneously into addition and condensation silicones
- ✓ Density 0.97 g/cm³: accurately dosed by weight for controlled hardness reduction
- ✓ Hardness reduction of about 3 to 5 Shore A at 8 percent: predictable softening without making the silicone unusable
- ✓ Flash point 260 °C: safe to handle and store
- ✓ Low surface tension 0.021 N/m: improves the flow of the silicone mixture into fine details and crevices
- ✓ Suitable for food contact materials: EC 1935/2004, EU 10/2011 positive list without a specific migration limit and BfR Recommendation XV Silicones
- ✓ Fully miscible with all Wacker AK silicone oils: any intermediate viscosity can be set
Typical applications
- → Softening pourable addition and condensation silicones for more flexible moulds
- → Reducing the viscosity of mould rubber for better de-airing and detail reproduction
- → Additive in the production of silicone articles and coatings intended for food contact
- → Smoothing brushed-on silicone by hand in brush-on and spatula techniques
- → Release agent and lubricant in industrial and technical applications
- → Water repellent and defoamer
- → Liquid dielectric and heat transfer oil for electrical applications
Processing
- Prepare your silicone: mix Part A and Part B in the correct ratio by weight according to the data sheet of the silicone in question and stir thoroughly first.
- Add Wacker AK 350 by weight, between 1 and 15 percent. About 8 percent gives a softening of roughly 3 to 5 Shore A points. Above 10 percent, the final strength can decrease noticeably.
- Mix until fully homogeneous, so that the oil is evenly distributed through the silicone mixture.
- Pour or process the mixture within the pot life of the silicone used.
- Allow to cure according to the cure time and temperature of the silicone used.
Food contact
According to the Regulatory Product Information of Wacker Chemie AG (version 1.22, 26 June 2026):
- → Regulation (EC) No 1935/2004: suitable, provided it is processed appropriately, for the manufacture of food contact materials and articles
- → Regulation (EU) No 10/2011: listed as an additive on the positive list under polydimethylsiloxane (ref. no. 76721), without a specific migration limit (SML)
- → BfR Recommendations: XIV Plastic Dispersions, XV Silicones, XXXVI Paper and Board and XXXVI/2 Paper and Board for baking purposes
- → Switzerland: listed in SR 817.023.21, annexes 2, 9 and 10
- → Other markets: listed in the positive lists of Japan, China (GB 4806.16-2025 and GB 9685-2016) and Mercosur
- → United States: a food contact statement is available separately on request
Polydimethylsiloxane is also approved as food additive E 900, but Wacker explicitly advises against using AK 350 as a food additive. The manufacturer of the finished article remains responsible for compliance, including migration, restrictions and the effect on the taste and odour of the food.
Other product information
According to Wacker, AK 350 contains no intentionally added allergens, latex or fragrances, is not derived from genetically modified organisms or animal sources, and substances covered by RoHS, EN 71-3, PFAS and bisphenols are not intentionally added.
Shelf life
At least 5 years when stored below 50 °C in a dry, cool and tightly closed container.
Professional support
Not sure about the right dosage for your silicone, or would you like the Regulatory Product Information or the US food contact statement? Contact us at info@siliconesandmore.com.
Product Properties
- Viscosity350mPa·sViscosity of the uncured silicone
- Density0.97g/cm³Density of the cured material
Physical Properties
- Flash point260°CMin. temperature at which the product ignites
- Surface tension0.021N/mSurface tension at 25°C
- Refractive index1.403Refractive index at 25°C
Thermal Properties
- Max. temperature50°CMaximum service temperature
Certification & Safety
- Food-gradeYesSuitable for food contact
Application
- Use casePlasticizer and viscosity reducer for casting siliconesIntended use
- Silicone type["Silicone oil","Auxiliary"]Type of silicone or polymer
Safety Information
According to the safety data sheet (section 2), Wacker AK 350 is not classified as a hazardous substance or mixture. No GHS labeling is required, and no hazard pictograms, H-phrases, or P-phrases apply. Under normal and intended use, the product is not classified as hazardous. Personal protective equipment is not prescribed. However, general industrial hygiene measures are recommended: do not eat or drink during use and wash hands after handling. Safety glasses and gloves are recommended. Spilled product is slippery and can pose a slip hazard; clean up spills immediately. For complete information, please consult the manufacturer's safety data sheet (SDS).| Safety Pictograms | Safety Data Sheets (SDS) |
|---|---|
Required protection (ISO 7010)
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Technical data sheets
Frequently asked questions
What is the delivery time for my order?
Orders placed and paid on working days are in most cases shipped the same day. Weekend orders are processed on the next working day.
Indicative delivery times: Netherlands usually within 1 working day, Belgium and Germany typically 1–2 working days, other countries depending on destination and carrier. These are guidelines, not guarantees: peak periods, public holidays or carrier delays can have an effect.
What is the return policy?
You have 30 days to return after receipt. Email info@siliconesandmore.com within 30 days of delivery with your name and order number. The full conditions are in our return policy.
How can I track my order?
As soon as your order has shipped, you'll receive a track & trace code by email. It can take up to 24 hours before the code is active.
I have a problem with my order – how do I reach you?
Contact us via our contact page or email info@siliconesandmore.com. We're happy to help you quickly.
Can I order as a business?
Yes. Apply for a business account; we review your application within 3 working days. After that you order while logged in and pay on invoice, with payment terms of 14 days after delivery.
EU businesses outside the Netherlands with a valid VAT number order with VAT reverse-charged (0%, intra-community supply). The VAT number is stored in your business account; it cannot be added to an order after it has been placed.