Sikaflex®-255 FC
Fast curing direct glazing adhesive for commercial vehicles
Sikaflex®-255 FC is a 1-component, high-strength adhesive for commercial-vehicle glazing and glass replacement applications. It provides a long open time and ensures safe application even in warm conditions. Sikaflex®-255 FC is compatible with Sika’s black-primerless bonding process.
- Fast-curing
- Very good processing properties
- Wide adhesion range on most relevant substrates
PRODUCT BENEFITS
- Fast-curing
- Very good processing properties
- Wide adhesion range on most relevant substrates
Usage
Sikaflex®-255 FC is designed for direct glazing applications with mineral glass-based windows in the Transportation OEM and vehicle glass replacement markets. This product is suitable for experienced professional users only. Tests with actual substrates and conditions have to be performed ensuring adhesion and material compatibility.Packaging
| Cartridge | 300 ml |
| Unipack | 600 ml |
| Drum | 200 l |
Product Details
| Chemical base | 1-component polyurethane | |
| Color (CQP001-1) | Black | |
| Cure mechanism | Moisture-curing | |
| Density (uncured) | 1.2 kg/I (10.0 lb/gal) | |
| Non-sag properties | Very good | |
| Application temperature | 10 ─ 35 °C (50 ─ 95 °F) | |
| Skin time (CQP019-1) | 40 minutes A | |
| Open time (CQP526-1) | 20 minutes A | |
| Curing speed (CQP049-1) | (see diagram) | |
| Shrinkage (CQP014-1) | 3 % | |
| Shore A hardness (CQP023-1 / ISO 48-4) | 60 | |
| Tensile strength (CQP036-1 / ISO 527) | 6 MPa (870 psi) | |
| Elongation at break (CQP036-1 / ISO 527) | 450 % | |
| Tear propagation resistance (CQP045-1 / ISO 34) | 12 N/mm (70 pli) | |
| Tensile lap-shear strength (CQP046-1 / ISO 4587) | 4 MPa (580 psi) | |
| Service temperature (CQP509-1 / CQP513-1) | -40 ─ 90 °C (-40 ─ 194 °F) | |
| Shelf life | cartridge / unipack drums | 9 months B 6 months B |
| CQP = Corporate Quality Procedure | A) 23 °C (73 °F) / 50 % r.h. | B) storage below 25 °C (77 °F) |
CURE MECHANISM
Sikaflex®-255 FC cures by reaction with atmospheric moisture. At low temperatures the water content of the air is generally lower and the curing reaction proceeds somewhat slower (see diagram 1).
Diagram 1: Curing speed Sikaflex®-255 FC
CHEMICAL RESISTANCE
Sikaflex®-255 FC is generally resistant to fresh water, seawater, diluted acids and diluted caustic solutions; temporarily resistant to fuels, mineral oils, vegetable and animal fats and oils; not resistant to organic acids, glycolic alcohol, concentrated mineral acids and caustic solutions or solvents.
Application
Surface Preparation
Surfaces must be clean, dry and free from grease, oil, dust and contaminants.
Surface treatment depends on the specific nature of the substrates and is crucial for a long lasting bond. Suggestions for surface preparation may be found on the current edition of the appropriate Sika® Pre-treatment Chart. Consider that these suggestions are based on experience and have in any case to be verified by tests on original substrates.
Application
Sikaflex®-255 FC can be processed at temperatures (climate and product) between 10 °C and 35 °C (50 °F and 95 °F) but changes in reactivity and application properties have to be considered. The optimum temperature for substrate and sealant is between 15 °C and 25 °C (59 °F and 77 °F).
Consider the viscosity increase at low temperature. For easy application, condition the adhesive at ambient temperature prior to use. To ensure a uniform thickness of the bondline it is recommend to apply the adhesive in form of a triangular bead (see figure 1).
Figure 1: Recommended bead configuration
Sikaflex®-255 FC can be processed with manual, pneumatic or electric driven piston guns as well as pump equipment. The open time is significantly shorter in hot and humid climate. The glass must always be installed within the open time. Never install a glass after the adhesive has built a skin.
For advice on selecting and setting up a suitable pump system, contact the System Engineering Department of Sika Industry.
Removal
Uncured Sikaflex®-255 FC 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 a suitable industrial hand cleaner and water.
Do not use solvents on skin.