Vision integration speeds production, cuts waste for plastics manufacturer

Automation Integrator Guide: New vision system simplifies product inspection for a more efficient manufacturing process.

By Ben Dawson November 7, 2012

A U.S.-based plastics manufacturer that also operates facilities abroad worked with an Intek Systems, a distributor and system integrator, looking beyond an existing automation supplier with products that were too costly and couldn’t meet specific requirements.

Many everyday consumer products that are simple in appearance, form, and function are often produced through a highly complex manufacturing process. Yet even the most complicated processes can be simplified and improved—often very cost effectively—when disparate technology is replaced with a fully integrated, best-of-breed solution. And, for many manufacturers, these solutions can be found by partnering with a system integrator or automation distributor.

Intek has experience in servo, motion control, machine vision, safety solutions, and pneumatics, said John Bridgen, senior applications engineer at Intek Systems, to integrate automation “using open architecture components to address each specific customer problem.”

Light and dark challenges

“The customer was in the process of buying a servo-driven control from one vendor, a Web-control solution from a second vendor, and a vision system from Intek,” Bridgen said. The products needed to be interoperable to improve production capabilities, and the proposed solution would have been difficult for the maintenance team to support, he said. The manufacturer wanted to speed the accurate sealing and separating of each product and incorporate special product features.

At a production rate of six parts per second, with a web that encompassed 15 processes and spanned hundreds of feet in length, ensuring the accuracy and coordination of all components was critical, Bridgen said. Further, based on continuous control variations, key elements of the manufacturing process occurred at distinct points on the machine that were not relative to each other. Frequent adjustments were required because the materials used were very pliable and susceptible to changes in temperature.

In the customer’s initial configuration, which limited control, a missed manufacturing-process element would result in increased scrap due to the rejection of hundreds of pieces in one shift. The customer’s challenges were compounded because, depending on pending orders, the line could produce products of different colors, dark and light. This made monitoring the manufacturing process even more difficult, and it was something the customer’s existing vision system couldn’t accommodate.

“Once we understood the customer’s challenges, we knew that we needed to incorporate a more robust vision system,” Bridgen said. Specifications and samples were sent to another vision supplier, where they were quickly imaged. The customer “could see instantly how using the right tools would provide the most effective solution to their challenges.”

Top lights, bottom lights

Project requirements were met using a vision system, 640 x 480 pixel monochrome camera, and strobe control. The installation included a set of top lights, which allowed for accurate imaging of the darker products, and a set of bottom lights, which ensured accuracy with lighter products.

Along with the vision system, which provided process feedback and quality checks, the solution incorporated a high-speed servo system to complete the manufacturing process.  The Kollmorgen servo system, which is also connected to the Ethernet network, uses information from the vision system to provide on-the-fly corrections to the process control.

As the installation was nearing completion, hourly quality control checks were taken on the products produced on the new production line, Bridgen said. “Production managers remarked that it was amazing to see how consistent the finished products were.”

The solution also included an all-in-one HMI-PLC for the operator interface, data collection, and reject system that are integrated into one control panel and connected over the Ethernet network via Modbus TCP Ethernet protocol.

The solution allows capabilities beyond what was available previously, said Bridgen, “for less than half of what they would have paid for the systems they originally considered, which would have worked only with light colored materials, and with inferior results.”

In the two years since development and implementation of the first system, the installation provided the manufacturer with greater control, particularly over the number of products that are rejected. When the vision system identifies a “bad” product, the operator can tell immediately where it is in the web and set the reject mechanism to discard that specific product, as well as the ones immediately before or after, or based on whatever reject criteria are appropriate. This dramatically reduced the number of finished products that don’t meet specifications.

The plastics manufacturer has deployed and duplicated this line in the U.S. where they have multiple production lines; the project has since been relocated to another of the company’s facilities as a turnkey solution.

Intek worked with the machine vision vendor to support the line after relocation.

– Ben Dawson is director of strategic development at Teledyne Dalsa. Edited by Mark T. Hoske, content manager, CFE Media, Control Engineering and Plant Engineering, mhoske@cfemedia.com.

Key concepts

  • At six parts per second, integration, accuracy, and coordination of components were critical.
  • Technologies: machine vision, HMI-PLC, data collection, and reject system integrated into one control panel, connected via Ethernet
  • Lighting above and below helped with light and dark products.

Consider this

How would vision-enabled automated quality control help any of your processes?

ONLINE

www.controleng.com/machinevision

Select an automation system integrator with machine vision experience:

www.controleng.com/integrators

www.inteksystems.com/services

www.teledynedalsa.com

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Technologies inside: Vision integration speeds production, cuts waste for plastics manufacturer