Blow Molding: ‘Collaborative’ Bottle Palletizer

Collaborative robot arm makes new bottle palletizer safe to operate without guarding.

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A new half-cube palletizer with “collaborative” robot capabilities comes from Proco Machinery Inc., Mississauga, Ont. The system automatically palletizes blow molded containers with minimal operator involvement. It is said to cost half as much as conventional automation solutions. The key to the system is a collaborative robot arm, which enables operation without safety guards, though Proco offers guard packages as an option. The collaborative robot (model UR-10 from Universal Robots USA, Inc., Ann Arbor, Mich.; universal-robots.com) is programmed to a maximum speed of 5 m/sec. When a safety sensor detects a person entering the robot’s work space, the robot switches automatically to a low-torque mode, whereby it stops when it experiences 32 N (7.2 lbf) of resistive force. “This is typically not enough force to inflict harm or injury when dealing with blunt force,” says Siva Krish, v.p. of sales for Proco. “If any sharp objects are utilized in the robot tooling, Proco does not use the reduced-operation (low-torque) mode and the machine is wired to emergency stop when a safety sensor detects a human presence.”

This automation system does not require highly skilled workers or engineers to teach it new tasks. It is designed so that maintenance staff with minimum initial training can operate it and do changeovers easily. Alternatively, Proco also offers onsite and offsite programming and training services at “minimal cost.”

The half-cube palletizer has already been sold to leading U.S. custom blow molders of PET containers. It is a fully integrated packaging module, including the six-axis robot arm, infeed conveyor, pallet-lift magazine, and slip-sheet/tray pick-and-place mechanism on a common sub-frame that is fitted with leveling pads and caster wheels. The system has a maximum height of 55 in., said to be the half-cube configuration that is common to most U.S. blow molding operations. The only manual operations are when the operator places the empty trays in the magazine and, when palletizing is complete, an alarm sounds for the operator to pull out the pallet and place another pallet in the magazine. The system handles both slip sheets and trays in 44 × 56 in. and 40 × 48 in. sizes.