All cyanoacrylates are a family of strong fast-acting adhesives. Cyanoacrylate adhesives have a short shelf life if not used, about one year from manufacture if unopened, one month once opened. Every month after the first month of use your cyanoacrylate adhesive will lose its bonding effectiveness.
Cyanoacrylate adhesives polymerize, respectively cure by the catalytic activity between the humidity in the air and the humidity of the adherents. The higher the relative humidity is (e.g. in a room) the faster the product dries. Best atmospheric conditions for good, reliable bonds are between 40 to 70 % relative humidity. If humidity is too low (< 30%) setting time can become very slow; if humidity is too high (>80%) a so-called shock polymerization takes place. The latter provokes a certain shrinking process of the adhesive layer, which leads to less bond strength.
Temperature influences the time of the chemical reaction very much. Generally it can be said that a 50 degree hike in temperature results in twice as fast polymerization time. This is very valid for Cyanoacrylate adhesives. The optimal room temperature for curing of these adhesives is between 68 degrees. The change in viscosity at different temperatures has to be taken into account. The lower the room temperature gets, the higher the viscosity increases and vice versa. This can be of great importance when there are difficult applications.
*VISCOSITY "RESISTANCE TO FLOW" IN TERMS OF ADHESIVES
- High = Very thick
- Medium = Thicker than water
- Low = Water like