Sikaflex®-271
Glazing adhesive with acceleration option
Sikaflex®-271 is an elastic polyurethane adhesive system for glazing applications. Suited for bonding materials relevant for direct glazing such as paints, glass, ceramic frits, painted and e-coated surfaces in commercial-vehicle production and repair. Sikaflex®-271 is compatible with Sika’s black-primerless bonding process and can be accelerated with Sika’s Booster and PowerCure systems.
- Excellent application properties
- Curing can be accelerated with Sika Booster and Sika PowerCure
- High mechanical strength
- Solvent-free
PRODUCT BENEFITS
- Excellent application properties
- Curing can be accelerated with Sika Booster and Sika PowerCure
- High mechanical strength
- Solvent-free
Areas of Application
The Sikaflex®-271 system is designed especially for manual and automated direct-glazing application out of bulk packaging in the Transportation OEM market. Seek manufacturer’s advice and perform tests on original substrates before using Sikaflex®-271 on materials prone to stress cracking.Sikaflex®-271 is suitable for experienced professional users only. Test with actual substrates and conditions have to be performed to ensure adhesion and material compatibility.
Product Details
| Chemical base | 1-component polyurethane | |
| Color (CQP001-1) | Black | |
| Cure mechanism | Moisture-curing | |
| Density (uncured) | Adhesive | 1.2 kg/l |
| Non-sag properties | Very good | |
| Application temperature | ambient | 10 ─ 45 °C |
| Skin time (CQP019-1) | 20 minutes A | |
| Open time (CQP526-1) | 15 minutes A | |
| Shrinkage (CQP014-1) | 1 % | |
| Shore A hardness (CQP023-1 / ISO 48-4) | 65 | |
| Tensile strength (CQP036-1 / ISO 527) | 7 MPa | |
| Elongation at break (CQP036-1 / ISO 527) | 300 % | |
| Tear propagation resistance (CQP045-1 / ISO 34) | 10 N/mm | |
| Tensile lap-shear strength (CQP046-1 / ISO 4587) | 5 MPa | |
| Service temperature (CQP509-1 / CQP513-1) |
4 hours 1 hour | -40 ─ 90 °C 120 °C 140 °C |
| Shelf life | unipack pail / drum | 9 months B 6 months B |
| CQP = Corporate Quality Procedure | A) 23 °C / 50 % r. h. | B) Storage below 25 °C |
CURE MECHANISM
Sikaflex®-271 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.
Diagram 1: Curing speed Sikaflex®-271
CHEMICAL RESISTANCE
Sikaflex®-271 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®-271 can be processed between 10 °C and 45°C (climate and product) 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.
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 recommended to apply the adhesive in form of a triangular bead (see figure 1).
Figure 1: Recommended bead configuration
Sikaflex®-271 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 parts must always be installed within the open time. The glass must always be installed within the open time. Never join bonding parts if 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®-271 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!