Palletizing technologies and their importance in increasing productivity and facilitating the supply chain
Mina Theodorou, Theodorou Group Marketing Director
In the field of industrial production and distribution of products, the pallet is the product transfer unit from production to the warehouse or the final customer. Proper management is critical in order not to add additional costs to existing packaging processes but also to ensure a smooth flow of products within the supply chain. What is required is the right pallet with the right product to arrive at the right destination in time, safely and at the lowest possible cost.
The purpose of this article is to present new methods and technologies at the various stages of pallet formation (building, wrapping and marking) that contribute to (a) reducing production costs; (b) safeguarding productivity; and (c) and product safety and quality. The investment on the above offers a competitive advantage to the enterprises and creates the conditions for strengthening their position in the domestic and international supply chain.
As palletizing (tertiary packaging), we define the part of the packaging process in which the secondary or group packaging of the products (crates, multipacks, sacks, etc.) are placed on pallets, ready either for transport to the warehouse or for immediate dispatch to the next stage of the supply chain (distribution centers, customers, etc.).
Palletizing can be divided into three distinct phases:
A. Form or build a pallet
B. Wrapping the formed pallet with stretch film
C. Pallet marking, coding and traceability
In its most basic form, palletizing is done manually, resulting in high labor and raw material costs, productivity decrease, high probability of errors, unacceptable stabilization of the pallet, and so on. For the above reasons, the manufacturing industry has begun using methods and technologies for automating palletizing processes. Below we will try to present these technologies so that each industry can choose the technologies that are most suited to its own production requirements.
A. Technologies for the automatic creation of pallets
Once an industry decides that manual pallet building is unacceptable, it must choose either an automatic robotic system, or an automatic system with sequential layers or Cartesian. Given that layering or cartesian systems only cover specialized applications, the overwhelming majority (over 90%) of applications are made using robotic arms specially designed for palletizing.
The arm takes hold of the secondary packages and places them in a specific arrangement on the base (usually wooden) of the pallet. Successful building requires maximum coverage of the available base surface and optimal exploitation of its maximum permissible weight and height.
The robotic arms used in palletizing applications are usually four axes, rarely six, with a lifting capacity of 40 to 700kg and a working radius of about 3 meters. Their use offers the following advantages:
- Reliability of operation
- Minimum requirements in terms of maintenance
- High speeds that ensure high productivity
- Ability to move anywhere within their range of action, which gives them exceptional flexibility to handle different products
- Accuracy and repeatability of movements, which guarantees a consistent result in the formation of the pallet
One factor to be considered for the proper choice of both the palletizing system and the integrator to design, construct and install is the quality of the equipment used. The use of equipment made by specialized firms with recognized manufacturing quality ensures the reliability of the system and its durability over time.
Of particular importance is the correct design of the grapple. The grapple, one of the vital points of the robotic arm, holds and manages the products, empty pallets and cartons that can be placed between the layers of the pallet. It has to be designed based on the company's specifications and product specifics. In particular, it must operate reliably and accurately so that the products are not destroyed, but they are also installed in a way that guarantees the stability and safety of the pallet during its later transport. Also the grapple can be designed to "catch" one or more boxes at the same time.
Thus, a robotic arm can be designed to cover up to five production lines simultaneously building corresponding pallets. In this way, flexibility is offered and the rate of production increases. This is impossible for a classic layer palletiser, so the robotic solution saves both initial investment costs and space.
For safety and reliability of the robotic system is also critical careful electrical and mechanical design, adapted to the needs of each application. A properly designed system, both in terms of electrical and mechanical architecture and software, allows for its scalability or gradual implementation. This is particularly important, especially in cases where the operational and financial capabilities of the business require a fractional investment. Equally important is the ability to easily adapt the system to existing factory equipment.
In addition, a palletizing system must guarantee the safety of its operators and workers in general. For this reason, it must be accompanied by a complete safety system (eg fence, locks, optoelectric grids) and comply with safety regulations. Also necessary for safety and optimal efficiency are the detailed operating and maintenance manuals and the thorough training of system operators in real operating conditions to be provided by the system manufacturer. Finally, it is particularly important to thoroughly test the operation of the system at both the manufacturer's and the company's premises and its rapid installation and integration into production. This reduces downtime and production losses.
In conclusion, choosing the right robotic palletizing solution integrator guarantees finding a solution suited to the needs of the business with significant benefits in reducing operating costs, ensuring productivity and smooth flow of products in the supply chain. At the same time it ensures the rapid and successful adaptation of the system to production and its quick payment back.
B. Pallet stretch film wrapping
Wrapping the pallet with stretch film is a major cost, especially when wrapping is done manually. However, the pallet wrapping is necessary to ensure its stability and safe movement in the supply chain.
When a business decides to abandon the manual wrap, it basically has two options:
- Semi-automatic wrapping
The pallet is transported manually (usually with a pallet truck) to a specific position and an automatic mechanism takes over the wrap. Technology in semiautomatic stretch wrapping machines has advanced a lot and offers three reliable types of machines:
a) with a rotating disk rotating the pallet while the mechanism places the stretch film
b) with a rotating carrier (arm or ring) that rotates around the stationary pallet and places the stretch film
c) with a "robot" that rotates around the stationary pallet and places the stretch film
- Fully automated wrapping
In this case, the wrapping mechanism is integrated into the packaging line and there is no longer any need to manually move the pallet. And here we have three types of machines, either by palletizing the pallet or by stacking a pallet and rotating the stretch film (arm/ring or robot).
The choice between the above types is directly related to the required productivity. In the first case we can have up to 35 pallets per hour, while in rotating cases we can get up to 150 pallets per hour.
Stretch film technology
Apart from the particular system that will be chosen (semi-automatic or automatic) the most important factor in the wrapping technology is the stretch film itself. Modern packaging materials technology offers a huge variety of stretch film that can stretch up to 400% while their thickness can be up to 7 μm.
The choice of the appropriate stretch film should result from a careful investigation of the specific palletizing needs. Many businesses are still buying stretch film by kg, ignoring the fact that what really counts is the cost per pallet wrap. There are a few cases where we have helped businesses reduce the cost of pallet wrapping with stretch film up to 80% by suggesting the appropriate type of stretch film and of course without reducing product safety along the supply chain.
C. Pallet marking, coding and traceability
No pallet can leave the production process if it is not properly marked, usually by using two labels on two successive sides. Palletizing is the focal point of gathering information in every production process and the correct marking of each pallet allows:
- Traceability by providing useful information for updating management systems (EPR, MRP, etc.) for actual production
- Measuring factory productivity
- Proper storage of the pallet and its proper transport in the supply chain
- The possibility of direct shipping, when the pallet does not pass through the warehouse, but is required to be transported directly from production to the loading point for the next supply chain stage. This is achieved when ONLINE communication with ERP integrates information about the destination of the pallet on the label. It goes without saying that this coding must be done within the framework of the production process.
It is obvious that industrial information technology starts from palletizing and its implementation requires a specialized company in the field of industrial marking, coding and traceability.
As far as the labeling of pallets is concerned, it can be done either offline or online. In the offline case, a thermal label printer is used and labels are pasted manually. In the online case, an automatic PRINT AND APPLY system is used in which the thermal label printer is incorporated into an automatic label tagging mechanism.
And here the choice of the appropriate method is related to the particular requirements of the factory. Due to the importance of coding pallets and the need to use standardized information on labels - either machine-readable or man-readable - which should be understandable at all stages of the supply chain, GS1 has issued a specific directive (GS1- 128) for printing the encoded information on the labels, as well as the pallet points where to be applied.
About Zenon Automation SAICT
It is obvious that palletizing should act as a single system to achieve all the desired benefits described above. Zenon Automation SAICT functions as a central systems integrator in palletizing, having even considerable expertise and know-how in robotics. Due to the fact that the palletizing requires additional specialized know-how, Zenon Automation SAICT cooperates with each of the palletizing projects with Theodorou Automation SAICT, which specializes in the marking, coding and traceability systems, as well as with Nefton Technologies SA specialized in the technology of wrapping systems and materials of stretch film pallets. All three companies belong to Theodorou Group.
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