What is a palletizing robot? Explanation of its mechanism and selection of arm

The shipping and receiving tasks in factories and logistics sites often involve heavy manual labor, leading to significant physical strain on workers. The alleviation of workload through palletizing robots for loading and unloading tasks has drawn attention. This column explains the mechanism of palletizing robots, which are anticipated for automation of loading and unloading, and provides considerations for selecting them.

What is a Palletizing Robot?

A palletizing robot is a robot tasked with unloading incoming goods and stacking picked items onto pallets in predetermined arrangements. It may also be referred to as a palletizer or palletizing robot. Traditionally, automation of palletizing and depalletizing operations has garnered attention due to issues such as labor shortages and accident prevention.

High-performance robot arms are gaining attention across various industries for handling heavy lifting and stacking tasks. This technology enables the possibility of producing multiple varieties in small quantities, improving food freshness, and reducing shipping times, among other advantages.

Furthermore, in logistics warehouses and factory warehouses, large quantities of goods are received daily. These incoming goods are unpacked, sorted by type and purpose, and transported to storage locations.

What is the difference between palletizing and depalletizing robots?

The difference between palletizing and depalletizing robots lies in the operational process. Palletizing involves stacking items, whereas depalletizing refers to unloading items from a pallet. Additionally, a depalletizing robot automatically unloads incoming goods according to the arrangement of items on the pallet. While depalletizing robots can be implemented using similar equipment as palletizing robots, attention must be paid to the differing requirements of the facility due to the differences in operational processes.

Reasons for the Need for Palletizing Robots

In recent years, a chronic shortage of labor due to the increasing volume of logistics has been identified as a challenge for companies involved in logistics. The graph below illustrates the trend in the number of parcels handled for delivery from 2017 to 2022, as reported by the Ministry of Land, Infrastructure, Transport and Tourism. As indicated by this graph, the volume of parcels handled has increased by approximately 20% over the span of six years.



Therefore, in order to cope with the increasing volume of goods, companies are advancing automation through the introduction of equipment such as robots. Furthermore, efforts are being made to improve working conditions by aiming for employee satisfaction (ES) and securing personnel through consideration for employees and ES (Employee Satisfaction) factories.

Mechanism of Palletizing Robots

Palletizing robots are equipped with gripping mechanisms and arms designed to securely grasp product packaging boxes, allowing them to maintain consistent positioning of boxes and pallet arrangements. The robot repeats pre-programmed movements (teaching) to accurately stack boxes in their designated positions. Particularly, gripping mechanisms capable of close stacking support efficient placement of adjacent boxes. To ensure the safety of workers, measures such as barriers and interlocked doors are implemented to prevent access within the robot's range of motion, ensuring the safety of both the robot and the workers.

Important Considerations for Selecting the Arm of a Palletizing Robot

When introducing a palletizing robot, a crucial aspect is the selection of the robot hand. The choice of hand must align with the transported workpieces or processes. Incorrect selection can lead to inefficient operations and unexpected issues. When selecting the arm, it's essential to comprehensively consider various requirements such as the weight and characteristics of the loaded items, processing speed, among others, in addition to the workpieces. Below, we will introduce the criteria required for the hand and the types of hands.

Requirements for the Hand of a Palletizing Robot

An absolute requirement is to 'avoid damaging or breaking the target object.' Similarly, it is crucial to prevent dropping the target object. If these issues occur, it could lead to significant losses such as halting the entire logistics process or delivering defective products to customers. To mitigate such risks, the design of the hand must incorporate elements such as appropriate gripping force, friction, shear force, and pressure, suitable for the transported items.

Types of Hands for Palletizing Robots

The types of hands for palletizing robots can be broadly categorized into gripping hands and suction hands.

Gripping Hand

This type of hand firmly grasps the target object using its fingers. Depending on the size and hardness of the target object, the number and type of fingers can be adjusted. Therefore, it can securely grip a wide range of objects regardless of their shape or material. Additionally, gripping hands exert powerful holding force by applying pressure, making them effective for firmly securing the target object during operations such as welding or cutting.

Suction Hand

A suction hand is a type of hand that uses vacuum pads or magnetic pads to adhere to the target object. Its primary feature is the operability to fix or release the target object with just the ON/OFF of electricity. Therefore, it is used in environments where rapid processing is required.

However, when using vacuum pads for suction, it's important to be cautious of air leaks from porous target objects. Additionally, magnetic pads cannot be used with non-ferrous metals such as aluminum, wood, or processed products. Furthermore, it's necessary to note that vacuum pad types require regular replacement due to clogged filters, and magnetic pads may degrade over time, requiring periodic replacement.

As mentioned above, selecting the hand for palletizing robots is crucial and challenging. Therefore, it is recommended to seek advice from experts based on past cases.

Benefits of Introducing Palletizing Robots

One of the initiatives undertaken by companies involved in logistics, as mentioned above, is the automation of tasks using robots. In the depalletizing process, tasks previously performed manually, such as conveying, extracting items from outer packaging boxes, depositing them into small sorting containers, and even handling empty outer boxes, are now handled by robots. Automation with robots enables reduction in manual labor and liberation from the risk of carrying heavy objects by humans. Moreover, with robot-operated tasks, consistent quality standards can be maintained even during long hours of operation, leading to improvements in both work quality and efficiency.

Case Study of Palletizing Robot Implementation

In one customer's factory, there are transactions with over 100 suppliers, and more than 400 types of parts are delivered in reusable boxes. These parts are dispensed to the production line, and the emptied reusable boxes are returned to the suppliers. Sorting these reusable boxes requires considerable effort, with 10 workers handling the task daily, processing over 30,000 empty boxes per day during peak times. Additionally, storage space is required due to the irregular arrival of reusable boxes.

As a solution, the distribution data of reusable boxes was analyzed, and the introduction of a shuttle-type automatic warehouse was proposed. AGVs, palletizing robots, and image processing devices were also introduced, reducing the workforce from 10 to 3 people, eliminating the primary sorting process, and reducing the workspace by 20%. This automation achieved personnel reduction and space efficiency.

LOGITO proposes the most suitable palletizing robot manufacturer for our customers.

LOGITO is a solution service aimed at automating logistics provided by Daiichi Jitsugyo. We have provided extensive support to manufacturing plants in Japan, including the introduction of automated warehouses, AGVs, as well as palletizing and depalletizing robots as introduced in this article, to fully support the automation of our customers' logistics. If you have any concerns about logistics, including palletizing and depalletizing, please feel free to contact us via the inquiry link below.