Adhesive Inspection Using 3D Smart Sensors

Gluing and bonding is a common method used in the assembly of automotive and electronics components, as well as in product packaging. This technique, however, presents a challenge—namely, how to inspect hundreds of meters of glue lines using a non-destructive solution to ensure uniform application.

Increasing Prevalence of Industrial Adhesives

Adhesive technology has reached the point where industrial glues can often adhere a part better and faster than welding or using fasteners. In addition, glue can be applied to the whole track rather than at select locations along the mating surface, resulting in a tighter, potentially watertight bond.

As a result of the increased application of industrial glues and sealants in component assembly, factories are being asked to provide robust inspection for these materials within their inline production systems.

Why Factories Need 3D for Adhesive Inspection

While 2D technology can identify the path of the glue, it is unable to generate the type of volumetric measurement that is critical to achieve robust quality control. In addition, 2D performs very poorly in feature identification when the scan target has low contrast (e.g., the adhesive is transparent).

Volumetric measurements are critical in this application because excess volume can result in leakage and rejection of the final part. Alternatively, insufficient or broken glue beads can lead to poor adhesion or seal and premature failure.

3D scanning and inspection is able to quickly and accurately determine the width, position, height and volume of the applied adhesive. 3D is contrast-invariant, allowing detection of transparent or translucent glues to generate accurate measurements.

3D Scanning is Able to Take Volumetric Measurements

Correct Adhesive Volume VerifiedDefective Adhesive Identified


How 3D Smart Sensors Solve the Problem

A smart 3D line profiler can be used to solve this application in two ways. The first is at the application-specific level, when the sensor is mounted onto a robot, or nozzle, and inspects the adhesive bead to ensure it is properly applied and within the right volume tolerance. This can be a closed loop design where sensor measurements are communicated to the dispensing system to adjust adhesive output for uniform results, which in turn are measured by the sensor.

Adhesive Inspection Using 3D Smart Sensors

The second approach is to mount the sensor to a fixed location and take advantage of the sensor’s measurement field of view to scan the part as a whole, which is then inspected for bead volume and location in addition to other quality checks.

3D smart sensors can run adhesive measurement algorithms in the sensor and communicate directly with dispensing logic to eliminate the need for PLCs or additional computers. Users can even develop custom algorithms for deployment in a smart sensor to handle more complex scenarios.

For details on how Gocator 3D smart sensors are used for this application in the electronics industry, we invite you to download our Adhesive and Sealant Inspection Industry Application.