Palletizing technology for a variety of products

Alcan Packaging has a Cayey plant in Puerto Rico. Some of the plant's molding equipment is dedicated to the production of bottles and lids, which are sold to Procter & Gamble for packaging of products from famous cosmetic companies such as Noxzema and Olay.

Alcan recently purchased a system designed and manufactured by Schneider that smoothly transports the bottles from the molding machine to the automatic control area, and stacks pallets with an automatic device. The pallets for the pallets were then transferred to a reciprocating car supplied by Schneider, which was transported by a skip to the new stretch film packaging machine manufactured by ITW Muller.

The Schneider Integrated System, which has been in operation since early last year, has reduced the number of employees for the factory by 8 employees. This also partially proves its cost-saving features. Both Alcan Packaging and Procter & Gamble want the Cayey plant's palletizing process to go one step further. Noó Gonzálz, the plant's technical support manager, said that the process required two large palletizers before. Although the automatic stacking was performed, it was estimated that there were too many workers. Gonzálz said: “The previous two palletizers pushed the bottles one layer at a time to a pallet. Each layer of the bottle was placed on the pallet and the position was reduced. A worker put a skateboard on it and then Put the next layer of the bottle on the slide and continue until the pallet is full, so that there is always a need for an operator to operate, the skateboard must be manually placed on each floor, when there are too many bottles In particular, when the weight is light, the bottle can easily fall down if the system moves incorrectly."

Alcan's palletizing system operates in two shifts of 12 hours per shift and 7 days per week. The system receives the output from the four molding machines of the previous process. The two injection blow molding machines produced blue and white polyethylene bottles from Noxzema with capacities of 2.5 ounces, 6 ounces, 10.75 ounces, and 14 ounces, respectively. The other two injection molding machines produced polypropylene bottles for Olay products with capacities of 50ml, 60ml and 100ml respectively, and the colors were natural or gray.
            　　
Bottle conveying

Prior to purchasing the automatic operating system, Alcan had invited three well-known suppliers to bid for the project. Gonzálz said: “Most suppliers tell us that they can only provide a specific product type, and others cannot. After interviewing Schneider, they only get a satisfactory answer.” Rafael Benitez, General Manager of Gonzálz and Cayey Plant, and Engineers Glenn Estad and Dan Lock jointly decided to purchase the system. Gonzálz stated that he discovered the Schneider integrated system through Motoman. He said: "In my previous work, I was exposed to Motoman's automation equipment for 7 years and its work was incredible."

Although there are some differences in the way the four molding machines convey the bottles, the overall process of palletizing the bottles is similar.

After the Olay bottle was exported from the two machines, it directly went into the lifting conveyor. After the two molding machines are discharged, they go directly to a flat-face chained transport area. When a group of bottles (16 for each mold production) is delivered to this area, the conveyor stops temporarily. Then, a servo drive system with a bearing lifts the conveying area to a certain height, opens the conveying device, and conveys the bottles along the conveying device installed on the wall and the ground. After the conveyance is completed, the conveyor device is lowered to the original position. According to Schneider, this work cycle repeats every 30 seconds. Due to the limited space in the factory, it is necessary to use a lifting conveyor.

The bottles are transported to a cooling channel for 30 seconds of cold treatment, which is especially important for thick-walled bottles because they can only be touched after processing. After coming out of the cooling channel, the bottles are transported to the automatic palletizing area. The Noxzema bottles are treated slightly differently, and when the bottles come out of the molding machine they enter the conveyor belt 3 m above the ground. They rise slightly below the height of the Magnolia oil bottle and are fed into the automatic palletizing zone through the S-shaped conveyor belt, instead of going through the lifting device into the automatic palletizing zone like Olay.

Stacking

The four bottle production lines are output in a single row from the cooling channels and then enter a warehouse through a wall. The warehouse includes a fully enclosed automatic palletizing area. For the sake of operational safety, the area is also enclosed and is approximately 30m x 70m in size. The stacking system has been programmed, and Alcan's operators can switch between various sizes of bottles and tray covers. This process is operated by an Allen-Bradley Control Logix PLC control system with an operator interface. This system is provided by Rockwell Automation.

During palletizing, the bottles are parked in four lanes until the correct stacking number is removed. The number varies depending on the type and size of the bottle. Each bottle is staggered, with 16 bottles in the first row, 15 in the next row, 16 in the next row, and so on. This arrangement helps to stabilize the bottles in each layer.

In order to lift the bottle, the robot from Motoman uses a 6-end tool head, each end for bottles of different diameters. The control system will remind the robot to rotate to the appropriate tool head, then the vacuum cup on the tool head will contain 16 bottles from the conveyor belt. The automatic arm moves along the arc, picks up the bottle on the No. 1 conveyor belt, places the No. 1 pick machine, puts the bottle on the No. 2 conveyor belt into the No. 2 pick machine, and so on. The Olay bottle cap placed in a 360-degree plastic tray was conveyed from the fifth line to the automatic palletizing zone, and the fifth line was located in the center of the four bottle production lines. If necessary, the automatic arm can be used to lift wooden pallets and skateboards. The skateboarding station is next to two Olay bottle production lines. The palletizing station is located next to the two Noxzema bottle production lines.

When a pallet has been filled, it is output to the tractor chain pallet conveyor. The shuttle train of the Schneider system travels along a path perpendicular to the four pallet trucks. The skips on the polyurethane wheels move back and forth along the tracks, the rails are bolted to the ground, and the skip slides to a suitable pallet position to receive a full pallet. The pallets were placed on a skip and transported to ITW Muller's Octopus film stretch wrapper. The wrapper rotates along a fixed load, the machine works very well, and the price is moderate compared to other wrappers that the company considers. The packaged goods are transported by forklift into the designated area of ​​the warehouse.

Gonzálz stated: "Since the operation of this system, we have not required additional repairs and maintenance so far. This automated system not only saves labor costs and avoids the loss caused by falling bottles in the previous palletizing process, but also for us. The factory saves valuable space. This automatic palletizing device does not take up much space compared to the space occupied by the two large palletizing machines that we used before. Although this automation device is specially designed for the bottle/cover. , but it is flexible enough to be used for a variety of tasks. Gonzálz expects that the return on investment for the system will take only a little more than two years."

Source: Packaging Machinery