Packaging system integration advice from NCC Automated Systems

Automation and controls can help packaging implementations, and NCC Automated Systems Inc. offers advice by answering questions from Control Engineering about an automated vegetable processing and packaging line with robotics, palletizing and conveyors that runs multiple products up to 320 bags per minute.

Question: Can you please describe the packaging-related project?

Answer: NCC provided a turnkey, fully integrated packaging system for a vegetable processor. The system included a full range of packaging equipment including multi-head combination weighers, VFFS baggers, robotic case loaders, case formers and closers, robotic palletizing cell and approximately 1,000 feet of conveyor. NCC project value was $7.5 million, not including customer purchased combination weighers and VFFS baggers.

Q: What was the scope of the project and goals?

A: Originally stated definition of success: When this project is completed, NCC will have supplied and commissioned a food packaging line that provides customer with an efficient and effective system producing all packages and cases at desired rates. The system will provide a safe operating environment for all employees involved on the line.

Reason for project/business value: The plant was interested in installing a new packaging line for a frozen vegetable product line. The new packaging line will consisted of new processing equipment and new packaging equipment (including palletizing equipment). The line packages a variety of vegetable blends, meals and other items. Multiple products are produced and changeovers happen regularly.

Previous state: Since this was a new packaging line, the current state did not exist. Similar lines next to where the new line was to be installed already were running the products, bags and cases.

New state: A new product distribution system, four baggers and four scales were installed. In addition, a new packaging line was be installed simultaneously to handle the bags produced by the bagger. The cases produced from the packaging line were conveyed via new overhead case conveyor that will be palletized by a new palletizing system. The existing stretch wrapper was used to wrap completed pallets. 

Q: What types of automation, controls, or instrumentation were involved?

A: The controls architecture diagram explains.

Bagger transfer conveyors to auto case packing: Frozen product is discharged from the customer supplied freezer and onto the product distribution system. Each bagger can discharge up to 80 bags per minute (320 bags per minute, total). The bagger discharge conveyors include a bag flipper to properly orient the bag (seal side down).

Each bagger discharge conveyor has a polycord discharge conveyor that allows product to fall through should a bag not be properly sealed. The bag flippers and bag discharge conveyors are controlled via bagger control panel. Bags then travel across the checkweigher and X-ray machines. NCC will supply air blast rejects for each device on each bagging line. “Good” bags then travel towards the auto case loading conveyors.

The bags discharged from Bagger #1 travels at a higher elevation than Bagger #2. The bags from Bagger #1 reach a speed-up conveyor that will discharge the bags onto the bag infeed conveyors for prior to the case packer bag loader conveyor (right angle transfer). The same design bag conveying philosophy is used on each bagger.

Once the bags reach case packer case loader infeed the robot picks-and-places the bags accordingly.

Case forming and case transfer to auto case loading: Two case formers form carton blanks and discharge them onto NCC empty case accumulation conveyors to supply four auto case loader stations. One former feeds empty cases to two case loaders. A divert arm on the empty case conveyors diverts cases to either case loader as needed. A lift gate is provided between the case former and case loader to allow maintenance/operator access to the case loaders. Empty cases are accumulated on NCC conveyor. A manual operator switch located near the divert arms allows operators to manually divert cases to case loader #2 and #4.

Auto case loading stations: Four auto case loaders will be supplied to pick and place bags into empty cases. Empty cases will travel into the case loader from the opposite side the bags enter the case loader. The case loader uses two Fanuc M10 vision-guided robots in a single-pick configuration, thus allowing for correction of 360 degrees of bag miss-orientation.

This eliminates the need to pick multiples for simple, reliable picking of individual packages. The combination of single-picking and long-reach robotic arms allows for perfect bag placement at full depth into the bottom of cases. Should the robots miss picking a bag, it travels to the end of the case loader bag conveyor and drop onto a chute to be discharged into a bin/tub.

Full case discharge to case closing: Full cases discharge from each case loader and travel onto full case accumulation conveyors. A case clamp located on each full case accumulation conveyor holds cases back, releasing them one at-a-time onto a case speed-up conveyor. The case speed-up conveyor starts and stops based on an encoder signal received from the programmable logic controller (PLC).

The encoder creates virtual pockets that each case can be discharged into on the ARB merge conveyor. The encoder ties in all four case speed-up conveyors to ensure that the merging of cases is seamless. All cases that discharge from the case loader will transfer at a right angle from the speed-up conveyor to the merge conveyor due to the ARB conveyor design.

The filled cases travel down the ARB merge conveyor and onto a case settling conveyor (on a slight incline) to help the bags settle within the case. Once around the powered curve the cases continue to travel to the case spacing/turning conveyor. This conveyor is a dual belt case turning conveyor that will turn the cases so that they are traveling the correct orientation (narrow edge leading) into the case closer. All of the other cases are not turned and travel straight on this conveyor (long edge leading). The case turning conveyor also will act as a case speed-up conveyor to provide the proper gap required for the checkweigher. Conveyor speed adjustment buttons (up/down) is located near the case turning conveyor. This allows the operator to manually adjust the conveyor speed up or down, based on how well the cases are turning.

Full cases then travel across an Ishida checkweigher. Any underweight cases will be rejected from the line. “Good” cases will travel onto a case closer infeed conveyor (on a slight incline) and then enter the case closer back-to-back.

Case closer discharge to incline spiral conveyor: Sealed cases then discharge onto a case transfer conveyor prior to reaching the case lay down conveyor. The case is required to be rejected from the line due to open flaps prior to being laid down. The reject of the open flap case occurs after the case closer.

All cases will then travel onto a transfer conveyor. The transfer conveyor also includes an overhead case lay down mechanism. The case lay down conveyor is used for laying down the single case only. The lay down conveyor will grip and rotate the case while in motion. The area is large enough that if the customer decides to change to gluing two single facing cases together, a combiner can be retrofitted into the line. All of the other cases will continue to travel straight through without manipulation.

After passing through the lay down conveyor, the cases will reach another dual belt case turning conveyor that will turn the cases so they are traveling in the correct orientation (narrow edge leading) onto the printer belt conveyor. The dual belt case turning conveyor also will pull a gap between the cases prior to reaching the print heads. The cases will not be turned and travel straight on this conveyor (narrow edge leading). Conveyor speed adjustment buttons (Up/Down) are located near the case turning conveyor. This allows the operator to manually adjust the conveyor speed up or down, based on how well the cases are turning.

After the case information is printed onto the cases, they discharge onto another conveyor that inspects the cases for open flaps and correct bar codes. If an inspected case has an open flap, no bar code or incorrect bar code, the case will be rejected from the line. “Good” cases travel to an incline spiral conveyor towards palletizing.

Overhead case conveyor to decline spiral conveyor: The cases will discharge from the incline spiral conveyor onto overhead case conveyors. The case conveyors will allow for “contact” accumulation of full cases should the palletizer go down. When the overhead case conveyor reaches the palletizing room the cases will make a left turn. The cases then incline over the existing spiral conveyor on Poly 11 and reach a decline spiral conveyor. The decline spiral conveyor will discharge the cases onto the palletizing system infeed conveyor.

Palletizing: Once the cases discharge from the spiral conveyor, they will enter the palletizing. The palletizing system consists of case conveyor to present the cases to the system (Intralox DARB style), fork-style pallet dispenser, 3-strand empty pallet conveyor, two Fanuc robots to build the pallet pattern correctly, 3-strand full pallet conveyors, powered roller conveyors to match up with existing stretch wrapper roller conveyors, all safety fencing/guarding required and control panel. The completed pallets discharge the palletizing system and connect to the existing pallet conveyor.

The pallets then travel down to the existing stretch wrapper will the cases will be wrapped and an operator manually places a label onto the completed pallet. The new discharged power roller conveyors are controlled from existing control panel.

Q: What were particular project challenges?

A: There were four challenges that came up during the project:

• How well the stand-up bags will be run (new item)
• Project delivery timelines
• Very small case conveying and palletizing
• Rework of existing control system.

Q: How were those issues resolved?

A: By recognizing these as known risks up front, we put plans in place to mitigate as well as contingency plans.

Q: Can you share some positive metrics associated with the project?

A: We don’t have great access to the production performance after install, but we were on time, on schedule and on budget.

Kevin Mauger is president, NCC Automated Systems Inc. Edited by Mark T. Hoske, content manager, Control Engineering, CFE Media, mhoske@cfemedia.com.

KEYWORDS

Packaging automation, case study 

System integration of a multiple-machine packaging system for a vegetable processor included robots and conveyors and palletizers.

Multiple products run and packages and cases move safely.

The line packages a variety of vegetable blends; changeovers happen regularly.

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