By Liz Stevens, writer, Plastics Business
Engineering Industries (EI), Verona, Wisconsin, is a provider of custom injection molding solutions. EI specializes in injection molding, insert molding and gas-assist molding, and offers a full range of engineering, technology, materials and quality services tailored to meet unique customer needs. With value-added capabilities and a focus on solving complex manufacturing challenges, EI delivers high-quality, customer-specific solutions. The company produces injection molded parts for a range of industries, including agriculture, electronics, durable medical, appliance, consumer and power hand tools. The team also assists with engineering and material selection recommendations for customers.
EI’s automation mantra is “think big, start small, prove value and scale fast.” The company had four labor solution projects featured in the MAPP 2024 Benchmarking and Best Practices playbook, all of which implemented robots, cobots and end-of-arm tooling. To learn more about EI’s automation philosophy and its labor solutions, Plastics Business talked with Kyle Barry, engineering supervisor.
“In addition to evaluating, designing, standardizing and integrating automation equipment,” Barry explained, “I also oversee our engineering department to bring new projects to realization. This allows our engineers to work with our outside mold shops and mold designers to plan for automation from the start.”
After using an integrator on its first automation project involving two gantry-style robots and end-of-arm tooling (EOAT), Engineering Industries now executes automation projects with only in-house talent. “Since the initial integration and with the exception of new robot installation, all EOAT, programming and added equipment are handled internally,” said Barry. “Our cobot installations and integration are fully handled internally.”
“Our automation efforts,” Barry explained, “allow us to reduce non-value-added labor and focus our people on critical value-added activities without reducing headcount. When possible, we strive to incorporate value-added processes at the press while a piece is being molded.” This philosophy has extended to some rather complex assemblies, resulting in multiple press-side operations that might require two or three operators to complete. “By automating one or two press-side tasks,” said Barry, “we can free up an operator for another job. In addition to the immediate labor savings, scheduling a two-operator job is easier than a three-operator job, giving us more flexibility in responding to customer needs. We have realized press-hour savings as a result of our automation projects.”
Right image: The entire removable EOAT with two pair of blue four-cup vacuum devices for removing molded parts, and on the reverse side, a single pneumatic gripper that can pivot 90° and a red quick-changer.
Press-Top Robot with EOAT and Handoff Fixture Tends One-Cavity Family Mold
One of EI’s labor solution automation projects centered on a one-cavity family mold job that required two operators, in which one person manually opened the door of the press, removed molded parts and loaded a new handload of threaded brass inserts for the next cycle. Barry and his team installed a circular, rotating handoff fixture and a WEMO press-top robot with a customized EOAT single gripper and a pair of four-cup suction devices.
“Now,” said Barry, “a single operator queues up brass inserts in the handoff fixture to be over-molded, automation takes care of loading the inserts into the mold and removing the finished parts, and the operator assembles and packages the products.” The EOAT also is fitted with a quick-change connector, making it usable for multiple robots, multiple jobs and multiple presses.
The benefits of this automation initiative include gaining more than 150 press hours and labor hours annually that can be used for other jobs.
Evaluating Projects to Automate and Workforce Training in Robotics
Barry explained how potential automation projects at Engineering Industries are evaluated. “We typically look at the process to determine if it is similar to anything we have done in the past,” he said, “and to judge whether we currently have the skills and equipment to automate it. We then will look at the ROI of the project and ensure the cost of the project can be justified.” Once automation has been implemented, EI employees are trained. “Our production supervisors and leads all are trained internally to start and recover the robots/cobots,” said Barry. “At the operator level, workers have the authority and training to restart a cobot after a protective stop.”
Cobot Lends a Hand to Insert Mold Cores and Remove Molded Parts
This EI automation initiative was aimed at the task of picking and inserting two-piece metal cores into a mold and extracting the over-molded parts. The metal cores are required to accommodate a heavy undercut on the interior of the mold. Originally, operators on this job had to manually load metal core inserts into the mold – a painstaking job since a misplaced insert could ruin the molded part and might damage the cores and the mold itself.
The labor solution included the addition of a Universal UR 3 cobot with EOAT that uses pneumatic magnetic grippers to pick and load two two-piece cores into a 3D-printed nest, and which then inserts the cores into the mold. The cobot also has two pneumatic grippers with custom-machined fingers that extract the two molded parts and the cores from the mold. An operator now removes the two-part cores from the finished over-molded parts and repositions the cores for the cobot to pick for the next cycle.
Right image: A pair of metal inserts in gray with the plastic over-molded part shown in translucent pink.
This automation endeavor has paid off handsomely for Engineering Industries. “With this loading automation,” said Barry, “a consistent cycle time now is achieved. Since integration, there has been zero damage to the mold or the metal cores.”
Choosing Tasks for Automation
Much of Engineering Industries’ automation revolves around picking inserts or cores, placing inserts or cores in molds, removing parts from molds and using de-gating fixtures to remove runners. Barry explained the decision-making that pointed to these types of tasks. “The main reason these tasks have been focused on,” he said, “is because typically these are multi-operator jobs, which usually have an operator on the press door.” This scenario often causes inconsistent cycle times and typically higher scrap. “By removing an operator from the door,” said Barry, “we can reduce our labor requirements, improve the cycle time and reduce scrap.”
Focusing on picking, placing and extracting also allows EI to iterate this kind of automation for other jobs, building upon designs and installations that already have been proven.
“Our automation mantra is ‘think big, start small, prove value and scale fast,’” Barry said. “We are a high-mix molder, using numerous resins and value-add operations to serve various industries. We standardize solutions to the extent it is possible, and we look for opportunities to apply a solution to a similar mold or process. This allows us to reduce the investment and time required to integrate automation into new processes.”
Press-Top Robot Fetches Molded Parts and De-Gates Runners
In this labor-saving solution, part de-gating had been handled by an operator at the press – a full-time manual job with no value added. Engineering Industries added a WEMO press-top robot with EOAT and modified a manual de-gating fixture that had been custom-built for the parts produced at this press.
Now an overhead gantry robot lowers into the open injection mold machine, extracts the molded items (four parts connected to an “H” runner) and moves into position – inside the guarding area – at the de-gater to clip off two of the four parts which drop onto a conveyor. The robot then pivoted 180° to present the other two parts to be separated from the runner. The robot drops the runner into a discard chute and returns to its overhead position to await the next cycle.
This EOAT, like others at Engineering Industries, has a “quick-change” connector with one electrical connection and one air connection, making it portable and compatible with other robots at the company. The de-gater on this job also is portable; it is secured with two bolts. Set-up and tear-down at this press takes about one hour.
With automation, the operator on this job has been freed up entirely, saving the company 1,000 operator hours annually.
Getting a Grip
To automate movement for the range of parts produced at Engineering Industries, a variety of gripping elements have been designed and built. “When evaluating a project,” Barry explained, “we try to keep the gripping as simple as possible.” EI uses vacuum cups for parts that have simple geometry and will, therefore, fall freely. “With complex parts,” said Barry, “grippers and slides are required to ensure parts consistently are removed from the mold.”
The job described earlier – which calls for inserting two-part metal cores into the mold – uses the most complex gripping that EI has integrated. “We are using two magnetic grippers with a nesting block to pick and load four steel handload cores into the mold,” he said. “Finding a compact, reliable, repeatable solution to pick and place the four steel handloads was a challenge that required a significant review and off-line validation before putting it all together. A dropped core or a core misplaced in the mold could result in significant damage to the mold.”
Cobot Performs Precision Placement of Inserts
On a job in which four threaded brass inserts must be placed into a four-cavity mold, performing the task manually held little value-added work for an operator but required sustained speed and continual precision.
Engineering Industries automated the job by using a bowl feeder and a channel to orient and present inserts, and a Universal UR 3 cobot with two types of EOAT. The cobot uses a gripper to place each of the four inserts into a nest fixture. The cobot then uses another gripper attachment, which matches the nest fixture’s layout and allows the cobot to grasp and precisely place the four inserts in the mold simultaneously.
This EOAT has two types of gripping elements: a single gripper and a pneumatic four-slot gripper. The EOAT first picks four brass inserts, one at a time, and drops them into a four-slot nest fixture. After the four inserts are dropped into the fixture, the EOAT rotates to position its four-slot gripper beneath the nest fixture. The nest fixture opens slightly, and the inserts drop into the matching four-slot gripper, after which the EOAT moves to the open mold and an air blast shoots the inserts onto pins in the mold.
A Stable Full of Technologies
Engineering Industries currently has five gantry-style robots, four Universal UR 3 cobots and two Universal UR 5 cobots. “Each cobot is mounted on a mobile cart that was designed and fabricated in-house,” Barry explained. “Because these are mobile and not dedicated to a specific job or mold, they can be scheduled and deployed as needed.”
One lesson that Barry learned from these automation projects is that it pays to standardize. “Standardize components,” he suggested, “to find components that work well and set the standard. It drastically reduces the design process when standard items can be utilized.”
Barry described the company’s future automation plans. “Our automation roadmap for 2025 is focused on applications with electric actuations and on increasing the utilization of our cobots,” he said. “In-mold labeling also is an area we are interested in exploring. These areas of focus will require us to research new products, find new vendors and develop best practices.”
More information: www.engind.com
