And nowhere is this more important than in the contract-packaging environment, where greater flexibility can mean greater opportunities for new business.
At Market Resource Packaging, LLC (www.mrppackaging.com), a contract packaging business in Cranbury, NJ, flexibility was such an essential factor in its choice of a robotic solution that it developed a portable, mobile work cell that can “basically straddle any two pieces of equipment in the plant,” relates plant manager Scott Conklin.
Supplied by Faber Associates (www.faberinc.com) and integrated in-house, the system consists of a Denso (www.densorobotics.com) VS-6556G six-axis robotic arm, suspended upside-down from a portable metal frame. The robot is controlled via Denso’s RC7M controller and is equipped with a Dalsa (www.dalsa.com) IPD two-camera vision system.
The original application for the robot was a temporary promotional mailing piece, where a packet or sachet of laundry detergent was affixed with glue to a folded card. The challenge was to place the sachet within a very tight tolerance. Applying the sachets manually was a slow process, Conklin relates. “And we still had a high rate of reject,” he adds.
In designing the automated work cell, the requirement was to pick a sachet in a random location from a moving conveyor and place it onto the card, located on another moving conveyor in a specific location, with ±1⁄8-in. accuracy, at 50 pieces/min.
Says Conklin, “I felt that by choosing one of the more difficult tasks for the robot—using a two-camera vision system to pick pieces from random locations and orient them before placing them on a moving target—everything else we attempted to use the robot for would be that much easier.”
The accurate picking and placing of sachets is made possible through the Dalsa cameras, running the company’s proprietary Sherlock 7 advanced machine vision software. The camera locates the packets and cards on the conveyors and sends the offset information to the robot controller. The controller then combines this data with the conveyor speed information to track each packet. It then picks the packet with a vacuum cup when it comes within range of the robot arm and places it on the outfeed conveyor.
“The Sherlock vision software gives us a tremendous amount of power and flexibility in many ways,” says Conklin. “We can simply use the system to detect a piece, or we can program it to verify that the piece being picked is the right lot code or UPC code. We can also program the vision system to detect imperfections so as not to pack a damaged piece.”
Programming of the robot can be done in one of two ways: through an optional pendant controller, or through the Dalsa system, “which is actually a very powerful computer,” explains Conklin. “When we integrated the system here, we built a control panel that includes a touchscreen interface and ties the robot and vision and all of the I/O together. Through the use of a cordless keyboard, most if not all programming can be completed.”
Since employing the system for the promotional packaging project, Conklin says that Market Resource Packaging increased its efficiency and decreased its reject rate by 18%. The use of the robotic work cell also eliminated the need for up to three operators during a 24-hour shift.
And, while the robot is currently set up to run similar jobs, it offers “tremendous flexibility” for future applications, says Conklin. “We tried to take many types of equipment and processes into consideration prior to integrating the robot. By doing so, we can deploy our robotic work cell to do numerous simple tasks that would normally require multiple people.”
