Sikaflex®-554 + SikaBooster® S-50
Accelerated STP adhesive for assembly bonding
Sikaflex®-554 + SikaBooster® S-50 is an accelerated Silane Terminated Polymer (STP) adhesive system especially designed for bonding large components in industrial assembly. It bonds well to a wide range of substrates with minimal pretreatment.
- Good adhesion to a wide variety of substrates without primer
- Very good weathering resistance
- Passes DIN EN 45545-2 R1/R7 HL3
- Fast curing by Booster Technology
- Solvent-, isocyanate-, phthalate- and PVC-free
- Capable of withstanding dynamic stresses
PRODUCT BENEFITS
- Good adhesion to a wide variety of substrates without primer
- Very good weathering resistance
- Passes DIN EN 45545-2 R1/R7 HL3
- Fast curing by Booster Technology
- Solvent-, isocyanate-, phthalate- and PVC-free
- Capable of withstanding dynamic stresses
Areas of Application
Sikaflex®-554 + SikaBooster® S-50 is suitable for joints that will be subjected to dynamic stresses. Suitable substrate materials are metals, particularly aluminum, metal primers, paint coatings, sheet steel, ceramic materials and certain plastics. It bonds well to a wide range of substrates with minimal pre-treatment. Seek manufacturer’s advice and perform tests on original substrates before using Sikaflex®-554 + SikaBooster® S-50 on materials prone to stress cracking. 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
| Chemical base | Silane Terminated Polymer | |
| Color (CQP001-1) | White, black | |
| Cure mechanism | Moisture-curing A | |
| Density (uncured) | adhesive (depending on color) SikaBooster® S-50 | 1.44 kg/l 1.15 kg/l |
| Booster content | by volume by weight | 2.5 % 2.0 % |
| Non-sag properties | Good | |
| Application temperature | ambient | 5 ─ 40 °C |
| Open time (CQP526-1) | 20 minutes B | |
| Early tensile lap-shear strength (CQP046-1 / ISO 4587) | see table 1 | |
| Shrinkage (CQP014-1) | 2 % | |
| Shore A hardness (CQP023-1 / ISO 48-4) | 55 | |
| Tensile strength (CQP036-1 / ISO 527) | 3.5 MPa | |
| Elongation at break (CQP036-1 / ISO 527) | 500 % | |
| Tear propagation resistance (CQP045-1 / ISO 34) | 20 N/mm | |
| Tensile lap-shear strength (CQP046-1 / ISO 4587) | 2.5 MPa | |
| Service temperature (CQP513-1) | -50 ─ 90 °C | |
| Shelf life | Sikaflex®-554 (pail / drum) SikaBooster® S-50 unipack SikaBooster® S-50 pail | 9 months C 12 months C 9 months C |
| Mixer | Statomix MS 13/18 G |
| CQP = Corporate Quality Procedure | A) provided by SikaBooster® S-50 | B) 23 °C / 50 % r. h. | C) stored below 25 °C |
CURE MECHANISM
Sikaflex®-554 + SikaBooster® S-50 cures by reaction with the accelerator and largely independent from atmospheric moisture. For typical strength build up data at 23 °C see table below.
| Time [h] | Lap-Shear Strength [MPa] |
| 2 | 0.25 |
| 4 | 0.7 |
| 8 | 1.2 |
| 24 | 2 |
Table 1: Strength build-up Sikaflex®-554 + SikaBooster® S-50
CHEMICAL RESISTANCE
Sikaflex®-554 + SikaBooster® S-50 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.
All pre-treatment steps must be confirmed by preliminary tests on original substrates considering specific conditions in the assembly process.
Application
Sikaflex®-554 + SikaBooster® S-50 need to be processed with an adequate dispensing system. The mixer type needs to be respected (see table Typical Product Data).
Sikaflex®-554 + SikaBooster® S-50 can be applied between 5 °C and 40 °C 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.
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
The open time is significantly shorter in hot and humid climate. The parts must always be joint within the open time. As a rule of thumb, a change of + 10 °C reduces the open time by half.
For advice on selecting and setting up a suitable pump system, contact the System Engineering Department of Sika Industry.
Tooling and finishing
Tooling and finishing must be carried out within the open time of the adhesive. We recommend the use of Sika® Tooling Agent N. Other finishing agents must be tested for suitability and compatibility.
Removal
Uncured Sikaflex®-554 + SikaBooster® S-50 may 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.