Augat Automotive, now part of Tyco Electronics Corp. (Wilmington, DE), manufactures precision terminals, fasteners and connectors for use in electronics applications. To protect one of its under-the-hood automotive connectors, the company needed to encapsulate some 80 wires that allow the plug-in device to tie together an onboard computer network.
Because of the harsh environment in which the connectors operate, the encapsulating process had to be extremely precise and robust. It also needed to be fast to enable a target throughput of 720 connectors per hour.
To dispense the two-part polyurethane encapsulating material, the company installed a SEE-FLO 690 meter, mix and dispense system from Sealant Equipment Inc. (Plymouth, MI). The system employs positive-displacement metering pumps to dispense a precision 2:1 mix ratio by volume. As the rods are forced into the metering cylinders, outlet valves allow the resin and hardener to flow through four Snuf-Bak mix-at-the-nozzle dispense valves equipped with a SEE-FLO disposable, static-mixer nozzle. If production is stopped for five minutes or more, the nozzles purge themselves so that they will always be loaded with fresh material.
The A and B components making up the resin are fed to the system via transfer pumps that are gravity fed from four 55-gallon drums. The system incorporates special “breathers” and hoses to prevent moisture in the atmosphere from contacting the material.
The dispensers are part of an automated system that employs aluminum pallets to transfer work in progress. Each pallet accommodates four connector assemblies. PLC-based controllers integrate the dispensing equipment with the rest of the production line. After potting, the four connectors are carried by conveyor to an infrared oven for curing. The pallets then enter a cooling section where the assemblies are brought down to a temperature of 125 F, so that workers can remove them from the line and pack them for shipment.
For more on dispensing, visit www.sealantequipment.com or call 734-459-8600.