Alternate Packaging Solutions supplies nonaerosol spray packages to the consumer products industry. Several years ago, APS acquired the patents for a pumping system it calls Twist-N-Mist(TM) that sprays a mist like an aerosol can without requiring propellant gas and without pressurizing the container. To operate the sprayer, a user grasps the bottle to which the sprayer is attached and twists the cap.

This activates an internal piston that forces product in the container up into a rubber bladder, which will develop an internal pressure of up to 90 lb/sq in. The user then presses the sprayer on the top to dispense a fine mist. The sprayer can be equipped with different spray tips for different products and/or spray patterns. Initially, the sprayer will be manufactured with a 51-mm finish.

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"The patents for the sprayer were originally issued in the early 1990s, and we picked them up a few years ago and decided to develop them into a commercial package," says APS president Richard Harris. "Following several years of development, new patents have been issued for a significantly improved version of the original sprayer. The big advantage of the Twist-N-Mist is that it gives the consumer the advantage of a continuous spray without the environmental concerns of an aerosol. It will spray in any position and can be used with a variety of bottle designs. The sprayer will initially be available only with a fifty-one-millimeter finish, but there's no reason it can't be produced in other finishes in the future."

APS contracted contract manufacturer Davlyn Industries, Monroe Twp., NJ, to produce the cap, and Davlyn ultimately hired TurboFil Packaging Machines, LLC (www.turbofil.com) to design and build the machine to assemble the cap.

"We contacted a number of companies, but none of them except TurboFil came up with an acceptable proposal," says Davlyn corporate manager Scott Pangborn. "This is an extremely complex cap with eleven components, and the other companies proposed an operation where the caps would be assembled semi-automatically. This would have been very slow and expensive and was not acceptable. Taking my initial concept, TurboFil came up with a design for a completely automated assembly process that looked very promising, so we contracted with them."

This decision was not based on faith alone. "We've worked with TurboFil before, and they've always done an exceptional job for us, so I knew they would produce a good system," says Pangborn. As it turns out, his faith was totally justified. "TurboFil built an impressive operating system," he says enthusiastically.

As shown on the drawing, right, the system incorporates three discrete, but interconnecting and synchronized, indexing, rotary, cap-assembly monoblocs, which are connected by a conveyor, 10 vibratory bowls and a web feeder to automatically unscramble and/or feed parts to the monoblocs. Pucks transport the caps through the monoblocs and from monobloc-to-monobloc on the conveyor.

Some components are attached to the top of the cap, while others must be inserted on the bottom, so the monoblocs are required to pick up a partially assembled cap, invert it so a component can be placed into the bottom, and then turn it back right-side up for transportation to the next assembly step.

Controlling and integrating the multitude of components is a challenge, and TurboFil contracted with Festo Corp. (www.festo-usa.com) to develop the controls and automation for this complex series of operations. At each station, the machine must inspect the assembly of each part before the next part is put in place. This is accomplished by strategic placement of a variety of sensors at each station to make sure that each part is properly seated and/or inserted.

Complicating the assembly is the fact that each component requires a specific action. Some of the parts are small and difficult to handle. Some must be accurately assembled with minimum tolerance. Some must be twisted to engage, which requires a special pneumatic linear rotary actuator. It was also necessary to be able to turn assembled parts in order to place subsequent parts both from the top and the bottom. These operations were facilitated by the use of Festo's special high-speed, high-accuracy pick-and-place units. It was also necessary to control the three monoblocs to act like one machine. For this, Festo used its own PLC, which is based on Allen-Bradley protocols to synchronize the speed of the three machines.

The system integrator was essentially a partner with us in this project. Their programmer was excellent, and they delivered quality parts on time. They really helped us out, and I'm very satisfied with them.

Festo manufactures many of its own automation components in addition to PLCs, and these were included in the control package. As part of the package, Festo wrote the control logic for this system utilizing DeviceNet communication protocol, which, in this case, allows communication with 200 I/O points. Other major components of the control include a touchscreen operator interface and an emergency-stop safety module.

Each indexer consists of five to seven assembly stations designed to add parts to the traveling puck. Each of the three indexing stations is equipped with Festo manifolds, input modules (16 inputs each), output modules (eight outputs each) and a communication module, as well as linear and rotary actuators, high-speed pickers, grippers, air jets, vacuum generators and sensors. Each indexer incorporates an Allen-Bradley Powerflex 40 variable-speed controller from Rockwell Automation (www.rockwell.com), a safety contactor, a safety-gate monitor and a DC motor controller.

When the system is turned on, the controller verifies that air pressure is present and all actuators are in home position, and it then progresses sequentially through the initialization process. Each indexer initializes individually, but all three must be initialized for the machine to run. As part of the startup, the operator can select all indexers to run simultaneously or run them individually, select which parts will be assembled and turn the bowl feeders on or off. This is done through the Festo-supplied operator panel.

Operation of all assembly stations is dependent only on CAM signals, which indicate the beginning and the end of the working cycle, and sensors that verify that parts are present. An assembly station will not add a new part if the previous part has not been assembled. To prevent possible damage to the machine, all actuators will return to their home position if a signal is received indicating that the table is about to turn, regardless of whether the cycle has been completed or not.

Each bowl feeder is programmed to stay on as long as parts are not detected in the vibratory track for that feeder. When parts are detected, the feeder will turn off. The feeder turns back on again when parts are not detected, and the cycle repeats. Backup sensors are installed on the conveyor between indexers, and if a backup is detected, the system will finish the current working cycle, and then stop the machine operation and power off the machine.

Several emergency-stop conditions will stop the machine. A manual E-stop button will disconnect power to the machine, which will stop all the operations and also shut off the air supply. Mechanical clutches on each indexer will disable the indexer having the problem and will stop that indexer and power off the other indexers after the cycle in process is finished. Similar actions occur when the air supply is not present on one of the indexers, a puck is missing on one of the indexers or one of the indexers has been overloaded. All E-stop conditions are displayed on the operator interface, where the operator can determine the cause of that condition.

"Festo was essentially a partner with us in this project," says TurboFil general manager Eli Uriel. "Their programmer was excellent, and they delivered quality parts on time. They designed and built the main electrical cabinet and supplied all the components in it. They really helped us out, and I'm very satisfied with them."

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