Dow Introduces DOWSIL™ 7091 High-Performance Neutral Silicone Adhesive Sealant, Meeting Railway Standard EN 45545-2

Dow the full market availability of its DOWSIL™ 7091 one-part, neutral cure silicone adhesive sealant. This high-performance, alkoxy-cured elastomeric sealant is designed for applications demanding a strong yet flexible bond, particularly when bonding materials with differing coefficients of thermal expansion. It achieves excellent 100% cohesive failure on common engineering substrates. Its certification to the railway fire safety standard EN 45545-2 (HL1-R22, HL2-R23, HL3-R24) makes it an ideal choice for rail vehicles, electric vehicle battery assembly, and other high-standard industrial applications.

In modern manufacturing, with the diversification of materials, designers and engineers often face the challenge of bonding glass, metal, ceramic, and various plastics. The neutral cure characteristic of DOWSIL™ 7091 means it does not release corrosive by-products during curing, making it friendly to most substrates, including sensitive metals and certain engineering plastics, significantly reducing the risk of substrate corrosion or stress cracking. Its non-sag, paste-like consistency allows for application on vertical or overhead surfaces without dripping, ensuring a neat and reliable bead.

Typical Properties

DOWSIL™ 7091 cures at room temperature upon exposure to atmospheric moisture to form a tough, flexible rubber. Its typical properties include:

• Excellent Application Properties: A skin-over time of approximately 15 minutes and a tack-free time of about 30 minutes provide a sufficient time window for adjustment and tooling.
• Outstanding Mechanical Properties: A cured Shore A hardness of 32, tensile strength of 2.5 MPa, and an elongation at break of 680% endow the bond with excellent flexibility and stress-relief capability, effectively withstanding vibration and thermal cycling.
• Broad Substrate Adhesion: It provides good adhesion to enameled steel, painted steel, aluminum, ceramic, glass, and engineering plastics like ABS and polycarbonate (with appropriate surface treatment such as corona treatment), achieving 100% cohesive failure, indicating that the bond strength exceeds the strength of the sealant itself.

"The introduction of DOWSIL™ 7091 reflects Dow's commitment to meeting our customers' dual needs for material performance and safety standards in demanding applications," said a relevant manager at Dow. "Whether for rail interior assemblies pursuing lightweight and safety, or for electric vehicle battery packs requiring long-term reliable sealing, DOWSIL™ 7091 provides a proven solution."

Typical Applications

• Railway Transportation: Bonding and sealing of interior panels, ventilation systems, and electrical cabinets in rail vehicles.
• Automotive Industry: Headlamp assembly, EV battery pack sealing and thermal interface management (as a Formed-in-Place Gasket, FIPG), structural bonding of metal and plastic components.
• Industrial Assembly: Bonding glass to metal/plastic in control cabinets, sensors, and appliances (e.g., oven viewing windows), as well as FIPG applications.

The DOWSIL™ 7091 sealant has a shelf life of 12 months from the date of production when stored in unopened containers at or below 30°C. For more technical information, safe handling guidelines, or sample requests, please visit the official Dow website or contact your local sales representative.