Benefits
Excellent Heat and Light Reflection
The aluminum foil backing provides a reflective surface for both heat and light, making 3M 439 suitable for selected heat-reflection and shielding applications.
Moisture Barrier and Sealing Performance
3M specifies a low water vapor transmission rate of 0.77 g/m²/24 h, supporting sealing and patching applications where a foil barrier is beneficial.
Flexible Conformability
The dead-soft aluminum foil backing can conform to curved and irregular surfaces, making it useful for applications where a rigid foil construction would be difficult to apply.
Easy Handling and Die-Cutting
Unlike self-wound aluminum foil tape constructions, 3M 439 includes a kraft paper liner with silicone release, making the material suitable for easier handling and die-cutting.
Long-Term Aging Performance
3M describes 439 as having good aging performance both indoors and outdoors, supporting selected applications exposed to moisture, weathering and UV conditions.
Flame Resistance
The product is described by 3M as meeting UL 723, Class L low-flammability requirements and FAR 25.853(a) requirements.
Technical Specifications
| Property | 3M™ Aluminum Foil Tape 439 |
|---|---|
| Product type | General Purpose Aluminum Foil Tape |
| Backing material | Dead-soft aluminum foil |
| Adhesive type | Transparent acrylic |
| Color | Shiny silver |
| Backing thickness | 0.05 mm (1.9 mil) |
| Total tape thickness | 0.08 mm (3.1 mil) |
| Liner material | Tan kraft paper with silicone release |
| Liner thickness | 0.14 mm (5.6 mil) |
| 180° peel adhesion to steel | 4.5 N/cm (41 oz/in) at 23°C |
| Tensile strength | 31.5 N/cm (18 lb/in) |
| Elongation at break | 3% |
| Water vapor transmission | 0.77 g/m²/24 h |
| Minimum long-term temperature resistance | -54°C (-65°F) |
| Maximum long-term temperature resistance | 149°C (300°F) |
| Recommended application temperature | Above 0°C (32°F) |
| Flame classification | UL 723, Class L |
| Aerospace flammability | FAR 25.853(a), applicable requirements |
The values above are typical or representative values and should not be treated as contractual specifications. Always use the latest 3M technical data sheet for final qualification and purchasing.
Applications
Sealing and Patching
3M 439 can be used for permanent sealing and patching where aluminum foil provides a useful protective and barrier layer.
Heat Reflection
The aluminum foil surface reflects radiant heat and can be considered for selected thermal-management and heat-reflection applications.
Light Reflection
The shiny foil surface can provide light-reflection functionality in suitable industrial applications.
Splicing
The tape can be evaluated for holding and splicing applications involving foil and other compatible materials.
Chemical Masking
3M identifies 439 for selected masking applications, including processes such as aluminum electroplating and chemical operations requiring foil-backed masking.
Die-Cutting and Converted Parts
The linered construction is suitable for die-cut adhesive components, making 439 a practical candidate for custom-shaped foil adhesive parts.
Equipment and Appliance Applications
3M technical documentation for the 431/439 family identifies use in applications involving appliances and thermal or protective functions.
Compatible Materials
3M™ Aluminum Foil Tape 439 may be evaluated for use with:
- Aluminum
- Steel
- Other metal surfaces
- Foil substrates
- Selected plastic surfaces
- Appliance components
- Selected insulation and barrier materials
Adhesion performance depends on the substrate condition, surface energy, coating and application environment. Painted, coated or chemically treated surfaces should be tested before production use.
Industries
3M™ Aluminum Foil Tape 439 may be relevant to:
- Aerospace
- Automotive
- Appliance Manufacturing
- HVAC and Refrigeration
- Metal Processing
- Chemical Processing
- Electronics
- Industrial Manufacturing
- Construction
- Maintenance and Repair
Its aerospace relevance is supported by the product’s published FAR 25.853(a) requirement compliance, while the product documentation also identifies permanent sealing, masking, splicing and protection applications.
Why Choose 3M™ Aluminum Foil Tape 439?
3M™ Aluminum Foil Tape 439 combines a thin dead-soft aluminum foil backing, transparent acrylic adhesive and a silicone-release kraft paper liner in a 0.08 mm total-thickness construction.
A major feature of 439 is its linered design: 3M identifies it as the linered version of 431 and specifically notes its suitability for die-cutting applications.
Key advantages include:
- Thin aluminum foil construction
- Flexible dead-soft foil
- Acrylic pressure-sensitive adhesive
- Easy-release kraft liner
- Heat and light reflection
- Low moisture vapor transmission
- Sealing and patching capability
- Chemical masking potential
- Long-term indoor and outdoor aging performance
- Die-cutting and custom converting suitability
Installation Guide
1. Prepare the Surface
Clean the substrate thoroughly and remove dust, oil, grease and other contaminants.
2. Check the Application Temperature
For best results, 3M recommends applying the tape to a clean, dry surface above 0°C (32°F).
3. Cut the Required Length
Measure and cut the required tape length while avoiding unnecessary deformation of the thin aluminum foil.
4. Position the Tape
Align the tape with the intended seam, joint, masking area or component.
5. Apply Firm and Even Pressure
Press the tape firmly and evenly across the surface to maximize adhesive contact and minimize air entrapment.
6. Inspect the Bond
Check for wrinkles, lifting edges or gaps, especially when the tape is being used for sealing or chemical masking.
For critical applications, validate adhesion and environmental performance under the actual process conditions.
Storage
Store 3M™ Aluminum Foil Tape 439 in its original packaging in a clean, dry indoor environment.
Protect the tape from:
- Direct sunlight
- Excessive heat
- High humidity
- Dust and contamination
- Mechanical damage
One published 3M data sheet for the 431/439L family specifies a 12-month shelf life from date of dispatch when stored at 21°C (70°F) and 50% relative humidity. Because storage and shelf-life information can vary by region and product documentation, the latest applicable 3M documentation should be used for commercial purposes.
FAQ
What is 3M™ Aluminum Foil Tape 439?
3M 439 is a liner-backed aluminum foil tape featuring a 0.05 mm dead-soft aluminum foil backing, transparent acrylic adhesive and silicone-release kraft liner. It is designed for permanent sealing, holding, splicing and masking applications.
What is the difference between 3M 431 and 439?
The principal difference is the liner. 3M 439 is the linered version of 3M 431, making it more suitable for handling and die-cutting applications.
How thick is 3M 439?
The total tape thickness is approximately 0.08 mm (3.1 mil), including a 0.05 mm (1.9 mil) aluminum foil backing.
What adhesive does 3M 439 use?
It uses a transparent acrylic pressure-sensitive adhesive.
Is 3M 439 suitable for die-cutting?
Yes. 3M specifically identifies the linered 439 construction as suitable for die-cutting applications.
Is 3M 439 suitable for heat reflection?
Yes. The aluminum foil backing provides an excellent reflective surface for heat and light.
Is 3M 439 a high-temperature aluminum foil tape?
It has a published long-term temperature range of approximately -54°C to 149°C (-65°F to 300°F). It should not be confused with 3M’s dedicated High Temperature Aluminum Foil Tape 433/433L product family.
Can 3M 439 be used outdoors?
3M describes the product as having good aging performance both indoors and outdoors. Suitability for a specific outdoor application should still be validated based on exposure conditions.
Can 3M 439 be used for chemical masking?
Yes. 3M identifies chemical masking applications, including aluminum electroplating-related masking. The actual chemical, concentration, temperature and exposure time should be validated before use.
Is 3M 439 electrically conductive?
The tape contains an aluminum foil backing, but the technical documentation reviewed here does not establish a specific electrical conductivity or EMI shielding rating for 439. It should therefore not be marketed as a dedicated conductive or EMI shielding tape without additional supporting data.
Is 3M 439 suitable for aerospace applications?
The 3M technical data sheet states that 439 meets FAR 25.853(a) requirements. Final aerospace qualification should still be based on the complete application specification and applicable customer requirements.
Is 3M 439 suitable for moisture-barrier applications?
Yes. Its published water vapor transmission rate is 0.77 g/m²/24 h, and 3M identifies sealing and patching performance as a key feature.
Can 3M 439 be custom slit or converted?
The linered construction can be evaluated for slitting, laminating, die-cutting and other converting operations, subject to the required geometry and process conditions.
Downloads
Available upon request:
- 3M 439 Aluminum Foil Tape Technical Data Sheet (TDS)
- Safety Data Sheet (SDS)
- Product Brochure
- Die-Cutting Capability Guide
Please contact our sales team if you require the latest technical documentation.
