Stack’em Up

Pick and Place Robot Arm
Pick and Place Robot Arm

A customer was having a problem with stacking plastic parts after an injection molding process.  The robotic arm removes the part from the mold, trims the part by a die cutter, and then stacks the part into a tote.  The problem occurred when stacking the plastic part into multiple columns inside a tote for shipping.  Static was generated and became strong enough to “slide” the part out of position.  They needed a solution to reduce the downtime required to realign the stacks.

Knowing that non-conductive materials can generate static from rubbing, sliding, and trimming, we focused on the best area for elimination.  With this application, we went after the trimming process.

When it comes to static elimination, EXAIR has multiple products for multiple applications.  Due to the process, we were dealing with varying distances between the static eliminator and the stacked parts.  Two Super Ion Air Knives (SIAK) were chosen to both cover the area properly and to provide a static eliminating air stream over the necessary distance. Being that the ions will not pass through the product, we had to use one SIAK for the top of the target and another SIAK for the bottom of the target.  The idea was to hit both sides of the target to completely neutralize the parts.

We were able to locate one SIAK about 12” (30 cm) from the bottom surface of the part.  The robot arm was able to carry the part across the ion air stream from the die cutter to the tote.  We located the second SIAK near the tote to neutralize the top of the parts.  The tote was 36” (91.5 cm) deep and we had to accommodate for the variation in distance caused by the stacking height, we used a longer SIAK to “shoot” the entire area inside the tote with ionized air.  As the parts were placed in each column, the top surfaces of the parts were now neutralized.  The parts were able to be stacked onto each other as originally designed.

With a variety of static elimination products, EXAIR is able to accomplish many more solutions for difficult applications.  If you feel that static is an issue, you can always contact one of our application engineers to help you.

John Ball
Application Engineer
Twitter: @exair_jb


Image courtesy of Nick O’Neill Creative Commons License