Space-Age Joining of Different Materials is Accelerating


Structural adhesives used in joining auto body

To join dissimilar materials, improve structural integrity and reduce weight, the aircraft and automotive industries are turning to the use of structural adhesives.  To achieve optimum adhesion, adhesives must thoroughly “wet out” the part surface to be bonded, which means enough adhesive must be applied in the right location. However, there is a challenge in determining the volume and the location of the dispensed beads.  Detection of skips, gaps, bubbles, neck downs, and miss-locations are also required. The dispensing equipment can be moving at 200 to 300 millimeters per second, and even faster in some cases.

To solve the problems facing manufacturers, Coherix developed an in-line bead inspection solution called Predator3D™.  The sensor head fits right around the dispensing nozzle and provides continuous 360 degree three-dimensional viewing of the bead. Bead volume, location, and other critical information are presented real-time to users. With the 3D bead math models, any skips, neck downs or bubbles can also be reported to a Human-Computer Interface (HMI) simultaneously.

Two configurations are commonly used in dispensing.  The first is to have the dispensing nozzle mounted directly on the robot while the part is stationary; the second is to mount the nozzle on a pedestal with the robot picking up the part and moving it under the nozzle.  Predator3D works in both configurations, and takes measurements on all four 3D sensors at 400 times per second.

Today, with the rapid and reliable inspection results provided by Predator3D, manufactures may no longer need to tear apart subassemblies or entire bodies to inspect whether the structural adhesives have the right “wet out.”


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