DOWSIL PV-804
Harmonization Code : 3919.10.80 | Other self-adhesive plastic rolls not exceeding 20 cm wide.
Main features
- One-Part Neutral Alkoxy Silicone Sealant
- 190 g/min Non-Slump Extrusion Rate
- 620% Cured Elongation
Product Description
DOWSIL PV-804 Neutral Sealant is a one-part, moisture-cure silicone adhesive/sealant for photovoltaic module assembly. It is used for junction-box bonding and frame sealing, with adhesion to typical PV substrates such as glass, aluminum and common backsheet polymers and a non-slump consistency for controlled bead application. Documented applications include junction-box bonding and module-frame sealing. The time required before handling or packaging depends on the joint geometry and application and should be determined for the specific assembly.
Key features
- Material system:: One-part neutral alkoxy moisture-cure silicone for photovoltaic frame sealing and junction-box bonding.
- Flow and dispensing: Non-slump paste with 190 g/min extrusion rate and about 30-minute tack-free time.
- Electrical performance: Cured elastomer reaches Shore A 39, 620% elongation and 16 kV/mm dielectric strength.
Applications
- Junction-box bonding
- Module-frame sealing
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Mechanical Properties
Electrical Properties
Additional Information
Sealants
One-part neutral alkoxy silicone for photovoltaic bonding and sealing
DOWSIL PV-804 Neutral Sealant is a one-part, moisture-cure silicone adhesive/sealant for photovoltaic module assembly. It is used for junction-box bonding and frame sealing, with adhesion to typical PV substrates such as glass, aluminum and common backsheet polymers and a non-slump consistency for controlled bead application.
As-Supplied Properties
Application and cure-entry properties
The product is supplied as a non-slump paste in white or black. Cure timing depends on exposure to atmospheric moisture.
| Property | Typical Value | Method / Condition |
|---|---|---|
| Color | White or black | As supplied |
| Consistency | Non-slump paste | As supplied |
| Extrusion rate | 190 g/min | ASTM D2452 / CTM 0364, 3.18 mm nozzle at 0.62 MPa |
| Tack-free time | 30 minutes | CTM 0095 |
| Skin-over time | About 10-15 minutes | Room temperature, 50% RH |
Tack-free time is distinct from through-cure and service readiness.
Processing
Surface preparation, bead application and moisture cure
Apply the sealant to clean, dry surfaces and complete tooling before the surface skin forms.
- Clean and dry all bonding surfaces and remove contaminants that could impair adhesion.
- Apply a bead to one prepared surface and quickly bring the mating substrate into position.
- Complete tooling before the material skins over, approximately 10-15 minutes at room temperature and 50% RH.
- Allow moisture cure to progress through the joint before handling or packaging the bonded assembly.
Cure-depth guidance
- Tack-free: about 30 minutes.
- Cure depth: about 2 mm in 24 hours at room temperature and 50% RH.
- Deep or confined sections take longer to cure.
- Lower humidity extends cure time.
The time required before handling or packaging depends on the joint geometry and application and should be determined for the specific assembly.
Storage and Handling
Keep the moisture-cure sealant tightly sealed
When stored at or below 30 deg C in the original unopened container, DOWSIL PV-804 has a usable life of 12 months from the date of manufacture.
- Keep opened containers tightly sealed when not in use.
- A cured plug may form in a cartridge or tube tip and can be removed before reuse.
- A surface skin may form in pails and should be removed before material is placed in dispensing equipment.
- The product is available in cartridge, pail and drum packaging.
Technical Guidance
Substrate and joint considerations
The PV application scope includes common module substrates, while surface condition and cure access remain important to adhesion and through-cure.
PV substrate preparation
Typical adhesion is identified to glass, aluminum and common backsheet polymers. Certain plastics may require specific surface treatment for optimum adhesion.
Moisture access
Cure proceeds inward from the exposed surface. Thick or confined sections with limited atmospheric moisture require more time than open, shallow beads.
Tooling window
Complete tooling before skin formation. Uncured excess can be wiped away before cure; cured material requires mechanical removal.
Final-State Properties
Cured mechanical, electrical and UL data
Physical values were measured after 7 days at 23 deg C and 50% relative humidity unless otherwise noted.
| Property | Typical Value | Method / Condition |
|---|---|---|
| Specific gravity | 1.4 | ASTM D0792 / CTM 0022, 23 deg C |
| Durometer hardness | Shore A 39 | ASTM D2240 / CTM 0099 |
| Tensile strength | 377 psi (2.6 MPa) | ASTM D412 / CTM 0137A |
| Elongation at break | 620% | ASTM D412 / CTM 0137A |
| Tear strength, Die B | 14 kN/m | ASTM D624 / CTM 0159A |
| Dielectric strength | 16 kV/mm | ASTM D149 / CTM 0114 |
| Volume resistivity | 1.0 x 1015ohm-cm | ASTM D257 / CTM 0249 |
| UL 94 flammability | HB | UL 94 |
| UL 746B RTI Elec / Imp | 140 deg C / 105 deg C | UL 746B |
| UL 746C outdoor UV/H2O | f2 | UL 746C |
These values are typical and are not intended for preparing specifications.
Applications
Photovoltaic module assembly
DOWSIL PV-804 supports two primary photovoltaic bonding and sealing tasks.
Junction-box bonding
Bond photovoltaic junction boxes to prepared module surfaces using the neutral alkoxy moisture-cure sealant.
Module-frame sealing
Seal photovoltaic module frames where the substrate, bead geometry and moisture-cure conditions are appropriate.
Review PV substrate, bead and cure requirements
Krayden can help review DOWSIL PV-804 substrate preparation, extrusion, skin-over time, cure depth, mechanical properties and electrical properties for photovoltaic junction-box bonding and frame-sealing processes. Krayden can also help review the documented processing conditions and evaluation criteria before testing.
