RTV-1 silicone adhesive for food contact and addition cure silicones
Wacker ELASTOSIL® E43 N Transparent is a one component, condensation curing silicone adhesive based on acetoxy chemistry. It cures at room temperature under the influence of air moisture to form a permanently flexible silicone rubber with very good mechanical properties. The consistency ranges from non slump to self levelling.
The key difference from the standard E43 is that E43 N does not inhibit the cure of platinum cured addition silicones, and that once fully cured it is suitable for applications involving food contact. Available in 90 ml and 310 ml cartridges.
Key benefits
- Suitable for food contact: once fully cured and provided appropriate processing, see the conditions below
- No inhibition of addition cure silicones: does not interfere with platinum cured silicones, essential in silicone workshops
- Non slump to self levelling: thixotropic, stays in place on vertical surfaces and flows out smoothly on horizontal ones
- High mechanical strength: tensile strength 7.8 N/mm² and tear strength 12.5 N/mm
- UV and weathering resistant: retains elasticity and transparency under prolonged UV exposure and changing climatic conditions
- Electrically insulating: suitable for electronics applications, potting and sealing of components
Typical applications
- Assembly and repair of culinary silicone moulds and kitchen utensils
- Silicone workshops: bonding and sealing alongside platinum cured silicones without inhibition risk
- Electronics and potting: sealing of components, sensors and housings
- Household appliances, machine building, heating and cooling
- Formed in place gaskets
- Laboratory and workshop: general purpose silicone adhesive for repair and assembly
Food contact
Provided appropriate processing, fully cured ELASTOSIL® E43 N Transparent is suitable for the manufacture of food contact materials and articles according to Regulation (EC) No 1935/2004. The ingredients comply with BfR Recommendation XV Silicones, limited to a maximum of 0.5 percent volatiles and 0.5 percent extractable substances. The product is suitable for use under FDA 21 CFR 175.105, 175.300, 177.1210 and 177.2600, within the extraction limits stated there.
Conditions for food contact use: the product must be fully cured, acetic acid must no longer be released when the product contacts food, and the residual solvents present must be completely removed from the finished article. Responsibility for compliance of the finished article, including migration, extraction and volatile limits, rests with the manufacturer of that article.
Please note: the product does not comply with the Chinese standards GB 9685-2016 and GB 4806.11-2016.
Technical characteristics
Comparison with E43: E43 N has a higher tensile strength than the standard E43, 7.8 against 6.5 N/mm², and a lower elongation at break, 450 against 500 percent. Its distinctive advantage is that it does not inhibit the cure of addition silicones. Choose E43 N when working alongside platinum cured silicones or when food contact is involved.
Processing instructions:
- Abrade the substrate and remove dust and contamination
- Degrease with white spirit or alcohol and allow to evaporate completely
- Apply E43 N and spread evenly
- Skin formation after 5 to 10 minutes at 23 °C and 50 percent relative humidity
- Through cure approximately 1.6 mm per day. The cure rate is limited by moisture diffusion into the rubber, so free access of air moisture is essential
- Heat curing only for layer thicknesses below 0.5 mm, otherwise blistering occurs due to the rapid release of acetic acid
- Always run preliminary tests on the actual substrate
Safety information: during curing a total of approximately 3.5 percent by weight of acetic acid is released. Work only in well ventilated areas. Avoid contact of the uncured product with eyes and mucous membranes. In case of eye contact, rinse immediately with plenty of water. The product is not classified as a hazardous substance or mixture under Regulation (EC) No 1272/2008. Refer to the safety data sheet for full information.
Wacker Chemie has more than a hundred years of experience in silicone technology for industrial sealing, electronics and food contact applications.
Technical support
Our technical specialists advise on substrate preparation, adhesion properties, the difference between E43 and E43 N, and optimal results for your specific sealing or bonding application. Contact us for the technical data sheet or the safety data sheet.
