Construction adhesive with durability and color indicator

With the so-called traffic light adhesive, it has been possible for the first time to use a color indicator to signal the curing process of an adhesive process using the traffic light colors red, yellow and green. If the use-by date of the new 2-component construction adhesive Scotch-Weld 7270 B / A from 3M is exceeded, the viscoplastic hybrid construction adhesive turns blue.

This visualization makes the chemical process during the joining of materials clear and thus prevents a premature loading of bonded components. This is a great advantage in the timely clocked processes of the manufacturing industry.

The principle of the color indicator in the new adhesive works according to the "traffic light language" and is easy to translate: red and white indicate that the components are fresh and ready to use. In the mixing nozzle, both components combine, the chemical reaction begins and leads to a color change to yellow. Green gives the starting signal for reaching the hand strength and a first loading of the materials after the joining.

This direct color-selective coupling technology is the basis for a secure process of structural bonding of metals and fiber composites in the manufacturing industry. With gap-filling properties, the adhesive also offers very good tensile shear and peel strengths with high temperature and good aging resistance.

While the color indicator clearly signals the optimum mixing of the components and the build up of the strength, the integrated durability indicator additionally indicates the usability of the product.