DOWSIL™ 7091 Adhesive Sealant

Harmonization Code : 3910.00.00.90 |   Silicones in Primary Forms; Others
Main features
  • Non-sag rheology
  • One-part moisture cure
  • Stable and flexible from -40 to 180℃

Product Description

DOWSIL™ 7091 Adhesive Sealant is a high-performance, one-part neutral cure silicone adhesive/sealant designed for applications that demand a strong but flexible bond. It cures at room temperature when exposed to moisture in the air to form a tough, flexible rubber. With a non-sag, paste consistency and an alkoxy cure system, it maintains stability and flexibility across a wide temperature range from -40°C (-40°F) to 180°C (356°F). It is ideal for bonding materials with differing thermal expansion rates, such as glass to metal or glass to plastic.

Product Key Features

  • One-Part Moisture Cure - cures at room temperature upon exposure to atmospheric moisture, simplifying the dispensing and assembly process.
  • Working Time - offers a skin-over time of 15 minutes and becomes tack-free in approximately 28 minutes.
  • Non-Sag Rheology - maintains a non-slump paste consistency, making it easy to apply on vertical or uneven surfaces.
  • Mechanical Profile - cures to a flexible rubber with a Shore A hardness of 32, a tensile strength of 2.5 MPa, and an exceptional elongation at break of 680%.
  • Thermal Stability & Compliance - remains stable and flexible from -40°C to 180°C and is approved for railway standard EN 45545-2 (HL1, HL2, HL3).

Applications

This adhesive is suitable for assemblies that require strong, flexible bonds to accommodate differing thermal expansion rates, as well as applications needing reliable unprimed adhesion to common industrial substrates.

  • Dissimilar Material Bonding: Excellent for bonding materials with differing thermal expansion rates, such as glass to metal or glass to plastic.
  • Unprimed Industrial Assembly: Provides strong, unprimed adhesion to commonly used materials including enameled and painted steel, aluminum, ceramic, glass, and certain engineering plastics.
  • Gasketing: Effectively used as a Formed-in-Place Gasket (FIPG) material for durable sealing applications.
Product Family
DS-7091  
310Ml Cartridge 250Kg Drum 25.5Kg Pail
White Gray Black

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Packaging
TDS, SDS & Technical documents

Technical Specifications

General Properties
Color
Color
The color
 Black, white, gray
Specific Gravity
Specific Gravity
Specific gravity (SG) is the ratio of the density of a substance to the density of a reference substance; equivalently, it is the ratio of the mass of a substance to the mass of a reference substance for the same given volume.

For liquids, the reference substance is almost always water (1), while for gases, it is air (1.18) at room temperature. Specific gravity is unitless.
 1.4
Physical Properties
Viscosity
Viscosity
Viscosity is a measurement of a fluid’s resistance to flow.

Viscosity is commonly measured in centiPoise (cP). One cP is defined as
the viscosity of water and all other viscosities are derived from this base. MPa is another common unit with a 1:1 conversion to cP.

A product like honey would have a much higher viscosity -around 10,000 cPs-
compared to water. As a result, honey would flow much slower out of a tipped glass than
water would.

The viscosity of a material can be decreased with an increase in temperature in
order to better suit an application
 609,000 mPa.s
Mechanical Properties
Hardness
Durometer (Shore A) 32
Tensile Strength
Tensile Strength
Tensile Strength
Tensile strength determines the resistance of a material to break under tension and it measures how much elongating load (or tensile stress) it can handle before fracture.

To make it simple, it measures how much force we have to apply when pulling apart a material before it breaks.
 >2.5 MPa
Elongation
Elongation
Elongation is the process of lengthening something.

It is a percentage that measures the initial, unstressed, length compared to the length of the material right before it breaks.

It is commonly referred to as Ultimate Elongation or Tensile Elongation at break.
 680 %

Additional Information

High Performance Neutral Cure Silicone Adhesive/Sealant

DOWSIL™ 7091 Adhesive Sealant

DOWSIL™ 7091 Adhesive Sealant is a high-performance, one-part neutral silicone system designed for applications demanding a strong yet highly flexible structural bond. Utilizing an alkoxy cure mechanism, this material cures at room temperature when exposed to atmospheric moisture, transforming into a tough, durable rubber. It provides exceptional unprimed adhesion to common industrial materials with differing thermal expansion rates, making it highly effective for critical glass-to-metal and glass-to-plastic assemblies.

One-part moisture cure 15 min skin-over time Alkoxy neutral cure system EN 45545-2 railway approved
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Typical values only. Performance profiles are measured after full moisture activation at room temperature settings.

DOWSIL 7091 Adhesive Sealant product package
DOWSIL™ 7091 Adhesive Sealant

Key Features

  • One-part neutral alkoxy formulation avoids standard multi-component meter-mix complexities.
  • Thixotropic non-sag paste consistency ensures dependable bead tracking without slumping.
  • Cures smoothly to form a highly resilient, flexible rubber providing extensive stretch recovery.
  • Excellent unprimed adhesion profiles over glass, ceramics, aluminum, and painted or enameled steels.
  • Maintains flexibility across a wide temperature spectrum from -40°C to 180°C.
  • Fully approved for European railway flame safety standards under EN 45545-2 benchmarks.

Processing Summary

Ease of Application: Ready-to-use industrial paste structure requires no material pre-heating or manual component agitation. Extrusion rate performance tracks at a steady 185 g/minute.
Skin & Tack Windows: Develops a protective surface layer skin-over in 15 minutes at room temperature and 50% RH. Material transitions to a tack-free state in approximately 28 minutes.
Inward Cure Progress: Once surface skin formation completes, moisture cure advances inward from the exterior environment at a predictable depth rate of roughly 2 mm per 24 hours.
Tooling Recommendation: Complete any joint alignment or surface tooling adjustments before the 10-15 minute skin window elapses. The non-slump paste can be shaped using a spatula.
Handling and Application Guidance

Process Notes 

Storage and Shelf Life
  • Usable shelf life extends up to 12 months from the initial production date.
  • Store materials unopened inside original containers at or below 30°C (86°F).
  • Keep packages sealed tightly when not in active use to prevent environmental moisture exposure.
Surface Preparation
  • All target joint faces must be thoroughly dry and free from dust or contaminants.
  • Degrease surfaces using cleaning solvent lines like isopropyl alcohol, acetone, or MEK.
  • Low-energy plastics like polyethylene, polypropylene, and PTFE require pre-testing.
  • For maximum structural adhesion, use DOWSIL™ 1200 OS Primer after solvent cleaning. Allow the specialized primer layer to dry for 15 to 90 minutes.
Cure Environmental Factors
  • Moisture activation requires adequate access to ambient open air.
  • Extremely deep joints or highly confined cross-sections will prolong the complete cure time.
  • Low surrounding humidity environments will extend the overall deep-section cure tracking.
  • Allow assemblies sufficient cure time before packaging to ensure line joint integrity.
Typical Properties

Engineering Data for DOWSIL™ 7091

Physical Properties (As Supplied)

Property Typical Value Standard / Test Condition
Appearance Non-slump paste Thixotropic consistency
Available Colors Black, white, gray Standard production assortment
Extrusion Rate 185 g/minute ASTM D2452 (3.18 mm nozzle at 0.62 MPa) / CTM 0364
Low Shear Viscosity (1/s) 609 Pa.s CTM 1377
High Shear Viscosity (10/s) 125 Pa.s CTM 1377

Mechanical Properties (Cured 7 Days in Air at 23°C and 50% RH)

Mechanical Property Typical Value Standard Test Method
Durometer Hardness 32 Shore A ASTM D2240 / CTM 0099
Tensile Strength 2.5 MPa ASTM D412 / CTM 0137A
Elongation at Break 680 % ASTM D412 / CTM 0137A
Tear Strength (Die B) 15 kN/m ASTM D624 / CTM 0159A
Specific Gravity 1.4 Measured at 22°C (72°F) / ASTM D0792 / CTM 0022
Adhesion Qualification Performance Note: Peel testing achieves a 100% cohesive failure result across metals, glass, ABS, polycarbonate, corona-treated talc-filled polypropylene, and anti-scratch coated plastics.
Applications

Where DOWSIL™ 7091 Fits

Dissimilar Material Interfaces
Specifically configured for structural attachment steps joining materials that present widely differing linear thermal expansion rates.
  • Durable structural glass-to-metal bonding.
  • Reliable glass-to-plastic attachment joints.
  • Absorbs expansion movement without losing line hold.
Railway Vehicle Manufacturing
Fully tested and approved to meet rigid international mass transit fire safety requirements for structural vehicle assembly.
  • Certified to fire safety standard EN 45545-2.
  • Meets safety designations HL1(R22) and HL2(R23).
  • Complies with highest danger rating criteria under HL3(R24).
Formed-in-Place Gasketing (FIPG)
Serves as an engineered liquid gasket profile alternative to traditional pre-molded rubber seal options for industrial equipment housings.
  • Conforms seamlessly to irregular mating flange patterns.
  • Forms a highly resilient fluid-tight compression seal.
  • Non-sag thixotropic profile stays placed on overhead runs.
Product Demo

See One-Part Moisture-Curing Industrial Silicone Application Methods

Observe the processing of one-part non-sag industrial silicone adhesive sealants via manual cartridge pneumatic gun setups. This presentation highlights best practices for balancing surface extrusion speeds, performing tooling adjustments before early skin layer formation, and controlling standard bead geometry.

Package & Support

Standard Packaging & Technical Help

Standard Container Sizes
  • Available in an array of standard industrial protective container sizes.
  • Detailed package and container metrics can be obtained from the closest Dow Sales Offices.
  • Tightly sealed logistics safeguards components against premature ambient air moisture activation.
Technical Help Capabilities
  • Evaluating custom substrate configurations to address varying thermal expansion differentials.
  • Troubleshooting surface prep parameters to maximize unprimed dính bám on engineering plastics.
  • Configuring automated manufacturing line pump metrics to align with specified extrusion rates.
  • Guidance regarding regulatory safety and formal mass transit fire compliance tracking (EN 45545-2).
Technical Guidance

Tips and Troubleshooting

Issue Recommended Action
Surface tearing or poor aesthetics during bead finishing steps
  • The finishing tooling actions are likely occurring after the surface skin has begun to form.
  • Ensure any smoothing adjustments using a spatula are fully completed within 10 minutes of extrusion.
  • Maintain surrounding application areas close to normal room temperature and 50% relative humidity.
Incomplete or extended cure timeline tracking down through joint centers
  • Deep material configurations rely strictly on atmospheric moisture access to advance completely inward.
  • Expect an extended cure process profile if moisture access inside the joint cross-section is constrained.
  • Cure processing speeds will also automatically slow down if factory relative humidity scales fall low.
Adhesion failure over low surface energy plastic variations
  • Unprimed configurations will not normally establish ideal bonds onto PTFE, polyethylene, or polypropylene.
  • Ensure joint surfaces are washed clean of process fluids using alcohol, acetone, or MEK solvents.
  • Apply a thin uniform coat of DOWSIL™ 1200 OS Primer following solvent washing step.
  • Allow the specialized primer layer to dry for 15 to 90 minutes before tracking the silicone bead.
Next Steps

Ready to Qualify DOWSIL™ 7091?

Share your material performance, joint profile designs, and manufacturing assembly constraints with us. Tell us about your quality control parameters, ambient shop environment limits, and volume expectations. Our application engineers are prepared to assist your team with processing tests to confirm reliable mechanical results on your line.