Cyanoacrylates dispense quantity

The adhesive is put under pressure and the dispense valve is opened for a certain time to provide the correct quantity of adhesive (see Figure 10.15). Since the cyanoacrylate contacts the pressurised air, the dryness of the air is important and an air filter on the mains air line is recommended. A pressure/time system is best suited for cyanoacrylates up to a viscosity of 5,000 mPa-s, i.e., self levelling products. 

When excess adhesive has been applied, the surface to volume-of-adhesive ratio is too low and the moisture on the surface will be insufficient to neutralise the stabiliser in the adhesive. The cyanoacrylate vapour will escape and fuming will occur. Reduce the quantity of the adhesive by using fine bore application nozzles and/or dispensing equipment. 

Anaerobic reactive adhesives and cyanoacrylate adhesives are applied by means of special metering units that dispense small predetermined quantities at the required time intervals. 

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