Sometimes we talk to clients who are ready to get rid of their legacy machinery and replace the whole shebang. Typically, the cost to do this often makes the whole shebang look a lot better than it did before they heard that price.
The thing is, updating machinery isn’t an all-or-nothing proposition. Take the case of Medifast. They package pricey powders for weight-loss patients, so they need a high level of accuracy to avoid expensive waste.
They had legacy machines pouching the powder and packing the pouches into cartons. In both cases, they were running fine. But there were some issues.
Not only does the powder have to be portioned very precisely, but the pouches also have to be stacked just right. Stacking seven pouches of powder with the top of the pouches right above one another won’t work. The powder settles into the bottom of the pouch, so pouches stacked on top of one another actually end up making a taller stack on the bottom side of the pouches than on the top side. What happens next? That tidy stack that needs to be placed neatly in a cardboard box becomes unstable and all those plump pouches slide off.
The solution, of course, is to stack them head to foot, as it were, so that the tops and bottoms alternate.
That means the robotic arm has to make a twist as it stacks the pouches. That’s easy enough for Rexroth controllers, whether the servo motors are old or new. So Medifast connected the poucher and the cartoner and the robot itself to an IndraMotion MLC motion logic control platform.
Here’s what else is great: the Rexroth controller includes a library of ready-to-use kinematics that let the controller provide the precise movements needed, and the connections allow the robot to make those movements in exactly the right places, even though the pouches are moving on a conveyor belt at the time. No special programming is required.