Structural Adhesives with Customized Fast Curing
- PDF / 1,175,558 Bytes
- 6 Pages / 595.276 x 790.866 pts Page_size
- 85 Downloads / 180 Views
Structural Adhesives with Customized Fast Curing Commercial transportation industry is constantly challenged by increasing production efficiency and reducing costs, while introducing new design solutions based on lightweight materials. Two innovative adhesive technologies, 'Powerflex' and 'Curing by Design', have been developed to maximize the potential offered by modern lightweight design as well as to improve productivity by immediate curing at precisely defined time.
Claudio Di Fratta, Antonio Corsaro, David Hofstetter, Michael Schlumpf, Bernhard Bosshard, Marko Zivaljic, Fabien Choffat
For instance, a lighter bus can accommodate more passenger seats; a caravan with thinner walls has more internal space that can be organized for a more livable environment for travelers. Although lightweight solutions bring various advantages in engineering and design phase, their implementation may be not successful if it disregards the needs of production departments, which often struggle with efficien-
© Sika AG
The development of commercial and special vehicles (e.g., buses, caravans, trucks, trailers, etc.) is progressively more characterized by lightweight design and production efficiency. The reduction of vehicles’ weight by introducing lighter materials or multi-material design concepts leads not only to the achievement of less CO2 emissions, but also to the increment of goods capacity and passenger comfort.
Figure 1 > Comparison of DMA between “Powerflex” technology and standard structural adhesive in commercial transportation
18
adhesion 3 I 20
cy problems. While production managers aim at speeding up fabrication and assembly of vehicle components, they must reduce manufacturing costs. Moreover, they have often to cope with order backlogs, which make harder to increase output at lower costs. Among the diverse methods available for assembling and joining vehicle components, adhesive bonding keeps up with manufacturers’ challenging demands, as well as can open new possibilities for lightweight and multi-material design. In order to achieve the full potential offered by assembly bonding, however, structural adhesives are required to show higher performance and an enhanced curing behavior, compared to standard bonding products used in commercial transportation industry. As an example, combining aluminum with steel alloys or with modern composite materials poses the issue of the accommodating differences in thermal expansion [1]. This is particularly problematic when external temperatures are low, because standard structural adhesives employed by commercial vehicle manufacturers typically undergo a significant embrittlement in cold conditions. Consequently, they are not able to compensate for thermal stresses and expose the joints to failure, even if they appear flexible and compliant at room tem-
Material property Tensile strength
Typical value range 10 – 20 MPa
Elongation at break
100 – 400 %
Elastic modulus
20 – 800 MPa
Lap-shear strength (1 mm thick)
10 – 20 MPa
Impact peel strength
> 50 N/mm
Shore
Data Loading...
