Palletizers

Many manufacturing and distribution plants use automated palletizers, palletizing systems and robotic palletizers for pallet loading and unloading. Automated conveyor palletizers may be low-level palletizers, which load packaged units from a floor level, or they may be high level palletizers, which move packaged units on an elevated platform. Palletizing machines may be designed to handle a single type of product, such as bag palletizers, case palletizers, drum palletizers and bottle palletizers, or they may handle several different types of packages. Large-scale distribution centers and manufacturing facilities that handle incoming shipments often use depalletizers to unload packaged units, and palletizing equipment accessories such as pallet dispensers and load transfer stations are used to assist in managing both pallets and loads. Palletizers can also be referred to as case pickers; the terms "case picking" and "palletizing" are used interchangeably by some professionals, though case picking often refers strictly to the picking of individual products by warehouse staff in distribution operations.

There are three main types of palletizers: robotic palletizers, low level palletizers and high level palletizers. Robotic palletizers are typically stationed between a conveyor line of incoming product units and a pallet dispenser. A hydraulic robotic arm lifts cases, bottles, bags or drums using flat pincer arms or suction cup arms in organized rows onto a pallet, stacking units with extreme precision. Robotic palletizers may be altered to work with different types of product units and are excellent for handling fragile or heavy product units. Even though they can only move one object at a time, they are still dramatically faster than human loaders and can load without becoming fatigued or injured. Low level and high level palletizers are conveyorized palletizers with a feed area that receives the goods that are to be palletized. In low level palletizers, which are also sometimes called floor-entry palletizers, products are loaded from the ground level, while high level palletizers are loaded from above. The packaged units are received by roller conveyors and are continuously transferred and sorted to the pallets by automated conveyor rollers, allowing greater packaging speed than robotic palletizers. Low and high level conveyors may be fully automatic, requiring no manual involvement, or they may be semi automatic, requiring loads to be manually connected and disconnected from the palletizer lifting arm.

Automatic and robotic palletizers have many advantages over manual pallet loading, including precision, load stability and a contribution to a reduction in worker injury frequency. Palletizing units can work faster and have better consistency than a human operator. The repeated lifting, rotating, wrenching and other strenuous movements that palletizers can sustain with ease can cause injury to human workers. Reduced employee injury risk contributes to a more pleasant work environment, which in turn contributes to higher productivity and efficiency. Also, a lower number of employee injuries reduces workplace health coverage costs. The United States Occupational Safety and Health Administration has proposed stiff fines for companies that do not make adequate provisions for employee well being, and many companies look for creative ways to minimize hazards beyond the standard put forth by agencies like OSHA. Palletizers are an investment in productivity and employee safety. Many varieties are equipped with QuickSTOP collision sensors and Smartscan work cell perimeter guards. QuickSTOP sensors are installed on palletizers to detect equipment damage. Upon detection of such damage, the machine would shut itself down, preventing additional damage or product loss. Smartscan systems are used to detect the proximity of humans to palletizer equipment. If a human worker gets to close to a palletizer, Smartscan-equipped machines will automatically turn themselves off in order to prevent employee injury.

Palletizers' automation is the key factor in their contribution to operational efficiency and safety. A properly chosen, installed and maintained palletizer can spark a dramatic increase in productivity. Also, the kinds of product losses that are caused by human materials handling accidents are eliminated when palletizer systems are employed instead. A palletizer can move more quickly and more regularly than can a human with a manual pallet jack or forklift. Palletizers do not become distracted, and the precise repeatability of their motion guarantees consistent, careful loading and unloading of palletized materials. While the initial investment in a palletizing machine can be expensive, many operations recoup that investment many times over during the course of a palletizer's lifespan. Workplace injuries can be extremely expensive, depending on the nature of the injury; palletizers, by precluding the possibility for such injuries, contribute to healthier and therefore more productive workplaces.

Images Provided by Columbia Machine, Inc.

Images Provided by Möllers North America, Inc.

Palletizer Types

• Articulated arm palletizers are a type of robotic palletizer that have a jointed arm that gives them a greater range of motion and flexibility while positioning products.
  
• Automatic palletizers assemble products on pallets by themselves or with little assistance. They can often be part of a larger shipping system.
  
• Bag palletizers include gripping modifications specifically designed to allow for the placement of bags on pallets; they can also be used to unload bags from pallets.
  
• Can palletizers arrange filled or empty cans onto pallets for shipping or moving.
  
• Case palletizers lift cases from tables and place them onto a pallet or previous layer of product.
• Case picking is the movement of products in a warehouse in preparation for shipment or during organization. Case picking can refer to such product movement as it relates to the movement of palletized bulk quantities, and it can refer to the movement of individual products.
• Depalletizers remove products by layer from pallets for leveling or stocking purposes.
  
• Drum palletizers move filled or empty drums onto pallets for shipping or moving.
  
• Gantry palletizers are a type of robotic palletizer that consists of a combination of a robotic arm and an overhead crane or I-beam.
• High level palletizers are palletizing systems that load or unload pallets at raised elevations.
• In-line palletizer systems can stack complete layers of cartons or bags at one time.
• Load transfer stations are pallet transfer systems that transfer loads from one pallet to another pallet without disassembling. 
• Low level palletizers, or floor level palletizers, are a type of automated conveyor palletizer that can load packaged units from a floor level.
• Manual palletizers are manually-operated machines used to move products on and off of pallets.
  
• Pail palletizers include modifications specifically to arrange pails on pallets for shipping and/or movement.
• Pallet dispensers, also known as pallet feeders, are devices that are used to feed or dispense empty pallets to conveyors in larger palletizing systems or automatic palletizers.
• Palletizing refers to the packaging process of arranging products on a pallet for transportation purposes.
• Palletizing equipment refers to the various machines used to pack and transport pallets.
• Palletizing machines are automated machines or conveyor systems that arrange a maximum load of packaged product units onto a pallet for distribution. 
• Palletizing systems are material handling systems that arrange a maximum load of packaged product units onto a pallet for distribution.
• Robotic palletizers lift and move goods to pallets automatically or semi-automatically, relieving workers from the potential hazards of heavy, repetitive lifting.
  
• Row stripper palletizers are a type of in-line palletizer that organizes a row and pushes it aside until another row is formed and put on top of the previous row, which is done until a full pallet is completed.
  
• Selective compliant articulated robot arm (SCARA) palletizers are a type of robotic palletizer that use a mast and cross arm to place products.
  
• Semi-automatic palletizers allow an operator to stack layers of heavy products with no lifting.
  
• Vacuum-head unit is a type of in-line palletizer that clutches products with air powered suction cups and places the items on the pallets. 

Palletizer Terms

Captive Pallet - A pallet that stays within a facility and is not exchanged, traded or delivered off site.
 
Deck - The top or bottom surface of the pallet.
 
Deflection - The amount of bending in a pallet or one of its components when under a load.
 
Fork Entry - The place for forks to enter and move the pallet, usually between decks or under the top deck.  
 
Line Load - The weight of a unit load concentrated across the entire length or width of the pallet or along a narrow area.
 
Load Bearing Surface - The area of material that is in contact with and is supporting a unit load.
 
Mast-Equipped Automatic Guided Vehicles (AGVs) - Vehicles that move unit loads and storing or retrieving pallets and unit loads.
 
Pallets - Platforms used to stack goods on for shipping, storing or moving. They can have two-way or four-way entry by fork trucks.
 
Pallet Design System (PDS) - A computer-aided design program that helps determine safe load carrying capacities, performance, life and economy of wooden pallets.
 
Pallet Jack - A manual wheeled platform used for lifting palletized unit loads.
 
Racked Across Deckboards - The maximum load carrying capacity and deflection of a pallet where, at the ends of the deckboards, the rack frame sustains the pallet.
 
Racked Across Stringers - The maximum carrying capacity of a pallet where, only at the ends of the stringers or stringer boards, the rack frame sustains the pallet.
 
Slave Pallet - A panel used to support the base of a palletized load in rack-storage facilities.
 
Strapping - Bands that secure the goods or load to the pallet.
 
Throughput - The amount of output or production in a given period of time.
 
Top Cap - Panel placed on top of goods on a pallet that protects them from damage when strapping occurs.
 
Unit Load - The collecting of goods to be moved or shipped onto a pallet.