Sikasil® AS-785
Fast curing and structural assembly silicone adhesive
Sikasil® AS-785 is a fast curing structural 2-component industrial silicone adhesive and sealant. It is none corrosive, has a very broad adhesion range as well as an outstanding long-term durability in harsh environment conditions.
- Outstanding adhesion and mechanical performance under harsh environment conditions
- Excellent adhesion to a wide variety of substrates
- Very good mechanical properties
- Performance retention over a wide temperature range
- Long-term durability
- Low volatility
- Meets EOTA ETAG 002
- UL® certified: UL94 V-1, QOQW2 (-40 °C – 105 °C)
PRODUCT BENEFITS
- Outstanding adhesion and mechanical performance under harsh environment conditions
- Excellent adhesion to a wide variety of substrates
- Very good mechanical properties
- Performance retention over a wide temperature range
- Long-term durability
- Low volatility
- Meets EOTA ETAG 002
- UL® certified: UL94 V-1, QOQW2 (-40 °C – 105 °C)
Areas of Application
Sikasil® AS-785 is especially designed for fast and/or automated bonding of structural adhesive joints. Especially for interior or exterior applications where a high mechanical performance under harsh conditions are required, like in appliances, solar and automotive. Common substrates are metals, particularly aluminum, glass, metal primers and paint coatings (2-part systems), ceramic materials and plastics. This product is suitable for experienced professional users only. Tests with actual substrates and conditions have to be performed ensuring adhesion and material compatibility.Product Details
| Properties |
| ||||
| Chemical base | 2-component silicone | ||||
| Color (CQP001-1) |
mixed |
| |||
| Cure mechanism | Polycondensation | ||||
| Cure type | Alkoxy | ||||
| Density (uncured) | mixed |
| |||
| Mixing ratio | A:B by volume A:B by weight | 10:1 13:1 | |||
| Viscosity (CQP029-5 / ISO 3219) | at 0.89 s-1 |
| |||
| Consistency | Paste | ||||
| Application temperature | ambient | 5 ─ 40 °C | |||
| Snap time (CQP554-1) | 12 minutes A, B | ||||
| Tack free time (CQP019-3) | 40 minutes A | ||||
| Shore A hardness (CQP023-1 / ISO 48-4) | 45 | ||||
| Tensile strength (CQP036-1 / ISO 527) | 2 MPa | ||||
| 100 % modulus (CQP036-1 / ISO 527) | 1.2 MPa | ||||
| Elongation at break (CQP036-1 / ISO 527) | 250 % | ||||
| Thermal resistance (CQP 513-1) | 4 hours 1 hour | 190 °C 200 °C | |||
| Service temperature (CQP513-1) | -40 ─ 150 °C | ||||
| Shelf life |
|
| CQP = Corporate Quality Procedure | A) 23 °C / 50 % r. h. | |
| B) The snap time can increase add. 6 min. with component B at the end of shelf life |
|
CURE MECHANISM
Sikasil® AS-785 starts to cure immediately after mixing the two components.
The speed of the reaction depends mainly on the temperature, i.e. the higher the temperature the faster the curing process. Heating above 50 °C could lead to bubble formation and is therefore not allowed.
The mixer open time, i. e. the time the material can remain in the mixer without flushing or extrusion of product, is significantly shorter than the snap time indicated above.
Application
Surface preparation
Surfaces must be clean, dry and free from grease, oil and dust. Surface treatment depends on the specific nature of the substrates and is crucial for a long lasting bond.
Application
Before processing Sikasil® AS-785 both components have to be mixed homogeneously and air-bubble-free in the correct ratio as indicated with an accuracy of ± 10 %. Most commercially available metering and mixing equipment are suitable. For advice on selecting and setting up a suitable pump system, contact the System Engineering Department of Sika Industry.
Consider that the B-component is moisture-sensitive and must therefore only be exposed briefly to air.
Joints must be properly dimensioned.
Tooling and finishing
Tooling and finishing must be carried out within the snap time of the adhesive. No tooling agents must be used.
Removal
Uncured Sikasil® AS-785 can be removed from tools and equipment with Sika® Remover-208 or another suitable solvent. Once cured, the material can only be removed mechanically.
Hands and exposed skin have to be washed immediately using hand wipes such as Sika® Cleaner-350H or a suitable industrial hand cleaner and water.
Do not use solvents on skin.
Application limits
To exclude materials influencing Sikasil® AS-785, all materials such as gaskets, setting blocks, sealants etc., in direct and indirect contact have to be approved by Sika in advance.
Where two or more different reactive sealants are used, allow the first to cure completely before applying the next.
Sikasil® AS-785 may only be used for serial application after a detailed examination and written approval of the corresponding project details by Sika Industry.