Palletizers are materials handling machines used for the loading and unloading of pallets before and after shipping as well as during storage. Pallet loads are frequently used for mass shipping and distribution as a convenient means of consolidating many smaller units into one larger, more easily handled unit.
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.
Palletizer - Chantland MHS
Palletizer Equiptment - Möllers North America, Inc.
Palletizer machines - Möllers North America, Inc.
Palletizer machines - Columbia Machine, Inc.
Palletizer - Frain Industries
Palletizer machines - Frain Industries
Like many other processes, stacking in manufacturing is also automated with the use of palletizers, machines that count the feed, orient the incoming load, and put loads in rows and in layers. The machine mimics the assembly line where multiple conveyors of different types are designed together accomplish stacking, effectively.
There are a number of operations included in standard palletizers. The first step is counting or metering a product when it was on the in-feed conveyor, and as it moves forward, the product is rotated or oriented in a desired position; then the product is moved into a predetermined place to form a row or layer. Once the layer is formed, the layer is compressed for tight packing with the help of a layer compression device. When the layer is made, it is moved to a load hoist by a layer stripper. Once the pallet is made, forklifts take it away, and pallet dispensers replace an empty pallet automatically.
In general, two types of palletizers are available on the market, one that does not employ robotic arms and the other that does.
Robotic pelletizers have robotic hands that pick and stack products. They are further divided into two types based on design: gantry and articulated.
In gantry palletizers, a robotic arm, which can move linearly in three dimensions, is fitted on a platform. Gantry palletizers are automated palletizing systems and work without any assistance. This type of palletizers is used when a centralized station receives different types of products to be put into pallet. The robotic arm movement is pre programmed and does not have rotary points. The products are delivered to the unit and whole operation occurs within the platform.
In articulated robot palletizers, a robotic arm with three rotary joints is installed on floor, pedestal, or roof, based on the need. For operation, additional palletizing equipment, like a conveyor belt is needed, which brings the finished products to the robot. Articulated robot palletizers, based on the requirement, pick single or multiple finished products from the conveyor and put them on the pallet. In some designs, pallets are fed in to the palletizer; however, in most designs, the robotic arm itself lifts a pallet when needed. In more sophisticated systems, a slip sheet, a delivery system, is also added to cut down the movement of the arm for additional purpose and increase efficiency.
Palletizers that do not use robotic arms stack products using a combination of conveyor belts and are further divided based on the design whether they are near the ground and above: floor level infeed palletizers and high level infeed.
Floor level infeed palletizers
Floor level in-feed palletizers are automatic palletizers that are installed in the production area and work on the level of production equipment.
High level infeed palletizers
High level infeed palletizers are used when production areas need to be cleared and elevated up to nine feet in height. An operator needs an elevated platform to operate the machine, which makes them costlier than floor level machines.
With the increasing need of cutting cost and processing time in manufacturing, automation has been incorporated in almost every stage of manufacturing. Whether it is feeding, washing, assembling or packing, there are myriad of machines that have automated and work with minimal assistance from operators.
In the packing field that involves selecting, transporting, orienting, counting and stack, machines called palletizers can automate the process, making it faster and more efficient. Palletizers are also called load transfer stations and pallet stackers.
In the primary efforts to make palletizing easy, the palletizing equipment was designed with lifts and platen. Lifts make it easy for loaders to elevate the station up to conveyor belt height, whereas platen helps to rotate the palletizing station manually to work on different angles. The table helps to cut bending motion and work laterally, which reduce injuries cause by repeated motion.
However, palletizers are far more complex than palletizing equipment, doing a number of functions ranging from metering the incoming load, orientation of load, dispending pallet, forming layers and many more.
Based on the level at which feeding is done, palletizers are divided as floor level in-feed and high level in-feed.
Floor level in-feed palletizers
This type of palletizer is used when the conveyor that feeds the unit is low to the ground. To be adjacent to the conveyor, the palletizers are designed to be low to the ground and are fitted near the feeding point. This type of installation helps to reduce traffic snag of incoming items, which limits accessibility if not checked. This also makes monitoring easy as the production person and fork operator can monitor the functioning of palletizers. Moreover, if something goes wrong, floor level in-feed components are easily accessible. However, the design has some disadvantages. As the unit is low to the ground, the space below the conveyor cannot be used. However, the most limiting demerit is that it is installed around the production line, and needs passages for movement of forks and other heavy machinery, making the area a bit unsafe for workers.
High level in-feed palletizers
To make production area free from the packaging stage, high level in-feed palletizers are used, which receive loads significantly above the ground, around nine feet. As it is above the ground level, an operator has to work on elevated platform. However, in some designs, the controlling area remains on the ground. A separate controlling area makes it costly. They have some advantages as well. First, they keep the production area clear. Second, the movement of forks is easier, and the distance between the storage area and packaging area can be shortened.
To choose between the two types, it is necessary that buyers do a thorough research before investing, as a number of factors determine which type of palletizer will serve your purpose. Among them, the most important is the area; for small units, floor level in-feed palletizers work better, as maintenance and monitoring is easier than high level in-feed palletizers.
Numbers of palletizers have filled the market, ranging from conventional conveyor-based to sophisticated robotic palletizers. However, all have some disadvantages associated with them. Therefore, to overcome the shortcomings, hybrid palletizers are designed, which combine the high rate of stacking of conventional designs with the flexibility of robotic designs. The design effectively takes the best from both designs and provides an option that can palletize multiple loads at once.
Hybrid designs can easily handle the finished products from numbers of production lines and still take less space than the alternatives. They are designed in such a way that it can be fitted with additional palletizing equipment if needed, and they give buyers option to upgrade even after installation.
In general, three types of hybrid palletizers are available: shuttle cars, rotary tables, and robotic arms.
In shuttle car design, shuttle cars, which move with the help of a track or chain-type conveyor, carry the pallets and are employed at a layer forming section. Instead of letting a product flow into the system and be oriented individually, hybrid palletizers aggregate the products, and when enough products are accumulated, it is fed into the layer forming section, where a layer is formed. Once the layer is formed, it is moved to the pallet, just like the conventional machines. As one pallet is filled, another takes its space as they move along the tracks. Pallet dispensers repeatedly feed shuttles with empty pallets as they move into the layer forming section; the automation makes the job faster and more efficient. Similarly, a loaded pallet is transported to the unload area on a conveyor. For monitoring and metering purposes, a bar code reader is utilized.
This type of hybrid palletizer works almost similar to the shuttle car design. The only difference is the presence of rotating tables instead of shuttles that move on chains or tracks. This design does not have any apparent advantage over shuttle car design; however, some buyers choose rotary tables based on the type of case to be handled.
This type of palletizer hybridizes the shuttle design and single robotic arm operation. A robotic arm with three jointed points picks and stacks in tandem with shuttle cars. Just like the shuttle system, the cases accumulate on the in feeding conveyor, and the robotic arm picks and stacks the cases based on the programming. A bar code helps the arm to read different cases and stack them on the empty pallet affixed on shuttles. Tie and slip sheets are also accessed by the robotic arm when needed. The design has flexibility of robotic operation and the speed of shuttle design, and can manage multiple feeding conveyors. The shuttle car then delivers the finished pallet to the transporting point. When the load is transported, the empty pallets are again fed into the system by a pallet positioning system.
Hybrid palletizers can be costly and are usually used in facilities with multiple product manufacturing.
- A pallet that stays within a
facility and is not exchanged, traded or delivered off site.
- The top or bottom surface of the pallet.
- The amount of bending in a pallet or one of its components when under a load.
- The place for forks to enter and move the pallet, usually between decks or under the top deck.
- The weight of a unit load concentrated across the entire length or width of the pallet or along a narrow area.
- The area of material that is in contact with and is supporting a unit load.
- Vehicles that move unit loads and storing or retrieving pallets and unit loads.
- Platforms used to stack goods on for shipping, storing or moving. They can have two-way or four-way entry by fork trucks.
- A computer-aided design program that helps determine safe load carrying capacities, performance, life and economy of wooden pallets.
- A manual wheeled platform used for lifting palletized unit loads.
- The maximum load carrying capacity and deflection of a pallet where, at the ends of the deckboards, the rack frame sustains the pallet.
- The maximum carrying capacity of a pallet where, only at the ends of the stringers or stringer boards, the rack frame sustains the pallet.
- A panel used to support the base of a palletized load in rack-storage facilities.
- Bands that secure the goods or load to the pallet.
- The amount of output or production in a given period of time.
- Panel placed on top of goods on a pallet that protects them from damage when strapping occurs.
- The collecting of goods to be moved or shipped onto a pallet.