Posted by Jill Worth | 03 / 31 / 17 0 Comments

Speed and efficiency in plastic injection molding equate to cost savings. So, it is no surprise that robots play a significant role in improving the manufacturing process. From simple sprue pickers to complex automated End-of-Arm Tooling (EOAT), the industry is taking advantage of this automation trend. 

The design and development of EOAT at The Rodon Group begins with our engineering department. They work with the manufacturing team to develop CAD drawings of the parts needed to build the EOAT. Once complete, the design is sent to the tool room where dedicated toolmakers create the parts. The EOAT is assembled along with the electronics, pneumatics, and sensors needed to meet the specific processing requirements of the job.  It’s a very collaborative process. 

At The Rodon Group, the majority of the 117 injection molding machines are equipped with robotic EOATs. The basic operations of the robotic arms are controlled by an NC (numerical control) box that receives instructions from a controller that is programmed by a Rodon employee. The NC code tells the robot how to perform the required tasks, such as complicated packing. Our custom engineered solutions speed production, improve quality and meet some of the most demanding technical requirements.

Injection molding is a perfect process for parts with complex geometries, resin requirements, and surface finishes. However, many projects present unique manufacturing challenges.

At Rodon, we specialize in high-volume molding and often use a hot-runner system in our machines.  This hot-runner approach not only improves cycle times but also improves overall quality. 

Sometimes, in cold-runner applications, softer resin materials can present a regrind challenge. In most operations, the runner is added to the regrind as the parts are being packed by the main arm. With softer materials, the runners need additional time to cure. Rodon developed an innovative “clothes line” approach where several runners can be cured on a sub-arm while the parts continue to be manufactured.

Rodon has also improved efficiency through the innovative use of sub-arm robots. “We use two-Rodon Employee in front of Nissei machinearmed robots a bit differently than the rest of the industry,” says Facilities Manager, Tony Hofmann. “Working with STAR Automation, a major manufacturer of servo robots, we developed a way to utilize a sub-arm to handle the runner and pack product. This method frees up an operator and creates better value for the customer.”  

There are a variety of part handling configurations used throughout the industry including grippers and suction cups.  At Rodon, silicon suction cups are the preferred choice. “We produce a lot of parts for the food industry, so our EOAT must be food compliant. Also, grippers can leave small marks.  We always think about the downstream impacts of our processing. Our QC team is a lot happier when they don’t have to worry about unwanted part blemishes.”, says Hofmann.

Another important consideration in the design and build of an EOAT are the sensors. Rodon uses sensors to detect parts, check for any short shots and pack boxes. When a sensor finds a problem, it alerts the operator. In the case of an overcap, the sensors are programmed to grab the array of parts, compact the array on the end-of-arm tool and pack them without touching the sides of the box.  “For some of our K’NEX parts, we came up with a creative way to encapsulate the toy components without grippers by using a specially made EOAT that receives the parts and then closes a door to “capture” the part for packing.

Customers may not be aware of the extra effort required to build these EOATs in-house, but the benefits are numerous.  Well-designed robotics can help speed processing and packing times. And, they improve overall part quality and reduce costs. If you would like more information on how The Rodon Group can provide an innovative solution to your next high-volume, injection molding project, contact us at

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Topics: Plastic Injection Molding, Manufacturing, Automation and Robotics