To
accurately mix and dispense two-part adhesives, assemblers should choose their
equipment wisely.
All MMD equipment requires some type of feed package, ranging from simple,
low-cost gravity tanks to pumps that feed adhesive from a drum or pail. The
appropriate feed package depends on the individual process and adhesive
requirements. For example, nitrogen can be pumped into a feed tank to protect
moisture-reactive adhesives, or the feed tank can be pressurized with air or
other gases to boost material flow.
MMD systems can be built with a range of control options. Operator-controlled
dispense systems are used when large volumes of material are needed and precise
shot size does not matter. Flow is initiated and stopped by the operator.
Semiautomatic systems deliver precise, repeatable shots of adhesive. An
operator controls the system, but only to start the dispensing cycle. Volume is
controlled either mechanically or electronically.