5.4.2.1 Manual Dispensing

Manual dosification is currently the most common method for dispensing adhesives. This method relies on the operator to control the total volume of adhesive dispensed, the flow rate, the bead profile and bead location. This method generally involves some form of manual dispense gun, such as a cartridge gun. Many adhesives may be dispensed directly from the manufacturer’s package, with or without additional consumables, such as dispense tips.

This method is usually selected when assembly or manufacturing throughput is low and quality/consistency concerns are not significant. Manual dispensing is the highest cost method of the three, as labour costs are higher, part scrap rates are higher and adhesive tends to be overapplied, making it likely that total adhesive cost will be higher. This is particularly important when a high-cost adhesive is used and less of a concern when low-cost adhesives are used.

The final consideration in manual dispensing is the human factor (covered in detail in Section 4). As the human factor relates to adhesive selection, one must account for the size of the application, the viscosity of the adhesive and the number of parts to be assembled. For example, a high viscosity adhesive dispensed in an application with a large surface area may lead to work fatigue. If incorporating dispense equipment is not feasible, a lower viscosity adhesive may need to be selected to accommodate applicator comfort.