Flexible system meets or exceeds all system goals and objectives. Robot builds pallet load in prescribed stacking pattern with each layer rotated 180-degrees and fill seams facing the center of the pallet. Robot system easily meets required 6 bpm production rate. Robot system provides tight, consistent loads with less bag damage and particulate release, which significantly reduces washdown and maintenance frequency.
Project Challenges
- Provide a flexible system to palletize individual 6-mil poly bags of silicate product onto pallets at two shrink-wrap stations. To minimize damage and release of particulate that turns gummy when exposed to humidity or moisture, bags must be “placed,” not “dropped.” Goal is to lower maintenance costs by reducing washdown frequency.
- Pattern is a 3 x 2 matrix with fill seams facing the center of the pallet. Loads consist of 8-10 layers, with each layer rotated 180º.
- Bag size is approximately 21" x 16" x 6" (±2.0") and weight is 22.7-24.9 kg. (50-55 lbs). Pallets are 1,219.2 mm L x 1,016 mm W x 152.4 H (48" x 40" x 6") or 1219.2 mm L x 914.4 mm W x 152.4 mm H (48" x 36" x 6").
- System must be capable of reliable operation in a sodium/ potassium silicate environment. All equipment, except robot, is subjected to periodic low-pressure wash down with hot water spray. Aluminum, copper, brass and bronze are not compatible with plant environment. Metal components (other than stainless steel) must be protected with polyurethane or special paint.
- System must achieve cycle time of 6 bags/minute.
Motoman Robotics Solution
Motoman Robotics provided a custom HP165 palletizing solution that meets customer’s production and wash-down requirements, including:
- Motoman HP165 robot with NX100 controller.
- Custom jacket for robot protection.
- Riser bases for robot and controller.
- Custom end-of-arm tool (stainless steel fork-style gripper).
- NEMA 4X electrical enclosures, including: – Allen-Bradley PowerFlex4® VFDs for conveyor control. – Allen-Bradley CompactLogix PLC package. – Allen-Bradley PanelView Plus 600 Human-Machine Interface.
- Conveyors (wash-down rated): – Bag infeed conveyor – 609.6 mm (24") OAW x 1.22-m (4') L box channel slider bed belt. – 90-degree slider bed powered belt curve conveyor – 609.6 mm (24") OAW, 914.4 mm (36") inside radius. – High-speed check weigher – continuous belt conveyor weighing system with controller and touch-screen control. – Bag roller pick-up conveyor – 1.52-m (5') L chain-driven live roller (CDLR) type.
- (2) Stretch wrappers with pallet turntables.
- Cell guarding package that complies with ANSI/RIA 15.06-1999 safety standard, including: 2.44-m (8') high woven wire perimeter safety fence; (2) access gates with captive key gate interlocks; and an infeed bag conveyor pass-through opening.
Fixtures/Tooling Details
Custom end-of-arm tooling consists of a fork-style gripper that fits between conveyor rollers to lift individual bags. Gripper has pneumatic crowder device that provides sufficient top compression to maintain bag position during robot motion. Includes gripper sensors.
Ref: ACS-105