A palletizing system takes finished packages from a conveyor, arranges them into a stable pattern, builds them layer by layer onto a pallet, and delivers the load for wrapping or storage. Plants use one when cases, bags, trays, or bundles move at a rate or weight that makes manual stacking slow, inconsistent, or hard on operators.
What a palletizing system includes
The palletizer itself, whether a robot or a layer-forming machine, is only one part of the system. A complete installation also has infeed conveyors, devices that turn or orient packages, an empty pallet dispenser, sometimes a slip sheet or tier sheet dispenser, a discharge conveyor for finished loads, safeguarding around the load-building area, and a control system that ties it together. Most plants add a stretch wrapper downstream.
That breadth is why palletizing solutions are hard to compare by machine type alone. Two suppliers can quote different scopes under the same heading: one may include the pallet dispenser and wrapper interface, and another may list them as options. The guide on how to choose a palletizer shows how to put rate, pattern, and scope figures on the same basis before comparing offers, and the commissioning and acceptance checklist covers the wider buying process.
This page is the starting point for the palletizing section. The two detailed guides cover robotic palletizers and conventional palletizers, and the equipment overview shows where palletizing sits in the rest of the packaging line.
Main palletizer types
Palletizers are usually grouped by how they move product from the infeed to the pallet. The boundaries blur, because many modern machines borrow ideas from more than one group, but the groups are still the most useful way to start a selection.
Robotic palletizers
A robotic palletizer uses an articulated arm, most often with a tool that grips by vacuum, clamping, forks, or a combination. The arm places individual cases, small groups, or whole layers on the pallet according to a stored pattern. Because patterns live in software, one cell can build many different loads, and one robot can serve more than one infeed or pallet position. Throughput depends heavily on how many packages are picked per cycle. The robotic palletizers guide covers tools, cell layouts, specifications, and safeguarding in detail.
Conventional high-level palletizers
A conventional palletizer forms an entire layer on a flat plate or table, then deposits that layer on the pallet in one motion. In a high-level design, products arrive on an elevated infeed conveyor, the layer forms above the pallet, and the pallet lowers as layers are added. One manufacturer guide puts high-level infeeds at roughly 100 to 144 inches above the floor. The layer only has a short distance to travel, which is why this architecture suits the highest sustained rates. It usually needs vertical conveying, such as a spiral or lift, to bring product up to the infeed. See conventional palletizers for how the two architectures work.
Conventional low-level palletizers
A low-level machine receives product near floor or waist height. The same manufacturer guide gives a typical infeed height of 30 to 36 inches. Product is gathered into rows and a layer, and either the layer-forming head or the pallet platform moves vertically so each layer reaches the top of the load. The machine travels farther for each layer, so rates are generally lower than high-level designs. In return, installation is simpler, most parts can be reached from the floor, and the machine connects directly to existing floor-level conveyors without a lift.
Layer and hybrid palletizers
Hybrid designs combine conventional layer forming with robotic or mechanical placement. One manufacturer article describes a robotic arm mounted inside a conventional frame, meant to keep the controlled-entry safeguarding and compact footprint of a conventional machine while handling bags and delicate packages. Other layer-handling cells use a robot to pick a prepared layer from a forming table. Forming the layer first raises the effective rate, because the robot moves a full layer per cycle instead of one case.
Gantry palletizers
A gantry, or Cartesian, palletizer moves a gripper along straight axes above a stationary pallet. Gantries suit plants that need precise placement over a clear area, and they can be built with a compact floor footprint and overhead structure. Travel across the pallet area can limit speed, and the load hangs from a long structure, so engineers check structure stiffness, vibration, and maintenance access with the supplier.
Bag palletizing
Bags are flexible and shift as they are lifted, and a bag load gets its stability from how the bags settle against one another. Systems built for bags typically use grippers that support the bag from beneath or from the sides, and some include a compaction step to square the stack. A supplier article describes designs ranging from a turning-arm robot to a gantry-style arm with a vertical sliding gripper, built for sacks of paper, raffia, or plastic film. Conventional machines can also handle bags when layers are compressed and squared before placement.
Quick selection table
The table describes tendencies, not guarantees, and any specific machine can differ. Confirm figures with a supplier using your own package, pattern, and pallet.
| Type | Package types | Relative rate | SKU and pattern flexibility | Floor space | Typical fit |
|---|---|---|---|---|---|
| Robotic | Cases, trays, bundles, bags, pails, mixed | Moderate; rises with multi-case or layer picks | High; patterns stored in software | Moderate; the arm needs a swept envelope plus guarding | Many SKUs, frequent changeovers, mixed packages |
| Conventional high-level | Uniform cases, cartons, bundles | Highest sustained | Lower; mechanical adjustments for new formats | Smaller at floor level, taller overall | Single or few SKUs, high sustained output |
| Conventional low-level | Uniform cases, cartons, bags | Moderate | Lower; mechanical adjustments for new formats | Compact in height, floor-level access | Moderate rates, limited ceiling height |
| Layer or hybrid | Cases, bags, delicate packs | Moderate to high | Moderate to high | Varies by design | Mixed flow with some delicate or bagged product |
| Gantry | Cases, bags, sacks | Lower to moderate | Moderate to high | Compact floor, tall structure | Tight floor plans, precise placement |
| Bag-specific | Valve, open-mouth, and film bags | Varies | Moderate | Varies | Powders, feed, seed, fertilizer, aggregates |
System architecture
Most palletizing cells follow the same sequence, even when the machines look very different.
- Packages arrive from the case sealer, case packer, or bundler. The infeed conveyor must deliver them in a controlled, predictable stream. A palletizer sized for an average rate can still miss its target during surges, so gaps and surges matter.
- Cases may need to be turned, grouped, or aligned to match the pattern. On conventional machines, rotation and row forming happen in the layer-building stage. On robots, the tool or a simple turning station adjusts orientation.
- A conventional machine collects rows into a full layer. A robotic cell picks packages directly, or picks a layer prepared on a forming surface.
- A dispenser delivers an empty pallet to the build position, and a slip sheet or tier sheet unit adds sheets when the load requires them. Finished loads leave on a discharge conveyor.
- Most loads go to a stretch wrapper, a labeling station, or both. Some machines wrap while the next pallet builds, and one manufacturer article describes concurrent wrapping inside the palletizer frame as a way to save the floor space of a separate wrapper.
Any of these stages can limit the rate. A fast robot will not help if the infeed delivers cases unevenly, and a fast layer former will wait if empty pallets arrive late. This is why vertical conveyors and accumulation sections often appear in the same scope as the palletizer.
Decision factors
Six factors do most of the work in separating one system from another.
Speed
Set the required rate from the highest sustained output of the lines feeding the cell, not from the average. One manufacturer comparison says conventional layer machines generally hold an advantage at sustained high rates on uniform packages, while robots are described as stronger at variable work. Define the unit carefully: cases per minute, layers per minute, and pallets per hour describe different things and cannot be compared without conversion.
Pattern complexity
Count the patterns, pallet sizes, and layer counts the line must build. A cell that builds a single pattern all week makes different demands from one that builds dozens. Ask how new patterns are created, whether operators can do it from the screen, and whether the supplier must reprogram. Load stability checks, including how corners and layers interlock, belong with the pattern review.
Changeover
Mechanical changeover on a conventional machine can involve adjusting guides and stops. Robotic changeover is often a recipe selection, plus a tool change if the package differs. What matters is how long it takes your operators on your hardest product change, and how often that change happens.
Sanitation
Food, beverage, and pharmaceutical environments may require washdown-rated components, smooth surfaces, and few exposed crevices. Palletizing usually sits after secondary packaging, so contact with product is rare, but dust, moisture, and cleaning chemicals still reach the equipment. Specify the cleaning method up front.
Maintenance
Conventional machines have more mechanical parts that wear, such as chains, gearboxes, and layer-forming mechanisms. Robots have fewer moving parts in the arm, but tools, vacuum components, and cables need regular attention. Ask for the recommended spare parts list, access to wear parts, and the training maintenance staff will need.
Safety
Machine type changes the safeguarding approach. Robot cells fall under ISO 10218, adopted in the United States as ANSI/A3 R15.06, and an A3 article explains that the standard’s second part addresses the integrated application, including the end-effector, workpiece, and peripheral equipment. Conventional machines typically use interlocked guards and controlled-entry access. The safety-related control parts are commonly designed to ISO 13849-1, which defines performance levels. A qualified risk assessment of the whole installation, including pallet exit points and maintenance access, should set the final safeguards.
How palletizing connects to the rest of the line
A palletizer is the last mechanical step of the production line and the first step of the warehouse. Upstream, it depends on consistent case sealing, accurate case dimensions, and a conveyor system that presents packages in the right order. The conveyors section covers the transport equipment feeding the cell, including the vertical conveyors that raise product to a high-level infeed.
Downstream, the loaded pallet moves to a wrapper, labeler, or accumulation conveyor and then to storage or shipping. The relationship also runs the other way. Plants that receive packaging or ingredients on pallets use depalletizing equipment at the head of the line, and plants that handle bulk containers can look at bulk depalletizers. A site that both palletizes and depalletizes can share pallet handling, empty pallet storage, and conveyor routes between the two.
When planning a new installation, treat the palletizer, its infeed, and its downstream wrapper as one project with one set of rate assumptions, so a limit in one place does not surprise the team after installation.
Choosing a starting point
Before involving suppliers, work through these questions:
- What are the packages, weights, and pallet sizes, and which SKU is the hardest?
- What sustained rate does upstream output require, with room for growth?
- How many patterns and how many changeovers per week does the line expect?
- How much floor area and ceiling height are available, and how high are the existing conveyors?
- What sanitation and safeguarding does the plant and the insurer expect?
- Are the wrapper, labeler, and pallet dispensers in scope?
With those answers, the choice often narrows to two types. Robot cells tend to appear when variety and floor space dominate, and conventional machines appear when uniform packages and sustained rate dominate. Hybrid and gantry options come into play when floor space, package fragility, or bags change the answer.
For the individual machines, see case palletizers, high level palletizers, and low level palletizers. The palletizer cost guide and the robotic versus conventional palletizer comparison help with budgeting and design choice. To see palletizing in use, read beverage packaging automation and pallet handling.
