Moba egg graders are packed with technology. Some designs are worth further investigation as they represent crucial customer value. In this series of articles, we will be zooming in on these “hidden gems”. This time, we take a closer look at the packing lanes of the Omnia and Forta egg grading machines.
Egg packaging comes in many shapes and sizes. However, from an egg grading point of view, three different packaging types can be distinguished:
– Trays, which are usually made from pulp or plastic.
– Consumer packs, which are closed after filling, with either an attached or a separate lid. These packs are made from all kinds of materials — the most commonly used materials are pulp or (recycled) PET.
– Special packs that generally require a specific packing lane to be processed.
For a pack to be processed automatically, it needs to be 4–6 eggs wide. Packs that have less than four eggs in a row are usually linked together, for example a 3×4 or a 2×6 pack. In this case, the linked pack is again six eggs wide and can be processed accordingly. However, the length of a pack can vary — a consumer pack can have two to four rows that can be handled by a standard packing lane.For egg packaging that has more than four rows, Omnia graders with special packing lanes are available.
When packing eggs, two things are very important:
· Grading efficiency; getting the right eggs to the right lane in the right amount
· Egg handling; getting the eggs into the pack without breaking them
Of course, when a pack needs to be closed, it should be properly closed, but an important factor here is also the quality of the pack that is processed.The Moba denester used on the packing lanes of the Omnia and Forta can process more than 1,500 different packs — no easy feat. Every pack that is processed needs a specific setup, which is used for one thing and one thing only: getting the eggs in the right position in the pack as quickly and as gently as possible. To make this possible, the lane is equipped with two servo-motors that have an encoder. One servo-motor controls the pusher chains for transporting the packs, while the other controls the dropset. Together these motors enable the packing lane to position packs and deposit eggs with an accuracy of 1 mm while being able to run at a packing speed of up to fifty packs per minute!
This very high processing speed requires a carefully planned speed trajectory. If you look more closely at the movement of the pack while it is being processed, you will see that the speed of the pack can be divided into three actions:
1. Acceleration (ramp-up)
2. Constant movement
3. Deceleration (ramp-down)
Even so, a filled pack especially will have some momentum when moving. To make sure that this momentum doesn’t affect its position on the packing lane, the cup of the pack is held by a special ledge, which is mounted in front of the pusher, on the chain holding the pack in place.
Grading efficiency
The supply of eggs to a specific packing lane varies all the time. The maximum speed of the dropset is 100 cases (36,000 eggs) per hour on a packing lane six eggs wide. In case the number of eggs arriving at the packing lane exceeds this capacity, the extra eggs will be diverted or can remain in the buffer section (the buffer section is part of the Omnia grader) for one more revolution to be deposited a few moments later, when the dropset is empty. This means that a sudden flood of eggs can still be handled by one packing lane.The opposite can also occur. In some cases, the quantity of eggs processed is lower than the maximum number of eggs the packing lane can handle. In this case, the packing lane’s processing speed will be reduced. There are essentially three different packing speeds that can be chosen automatically by the lane’s control system. This feature avoids unnecessary wear and tear on the packing lane’s moving parts.
Finally, sometimes egg packaging can only be handled at a reduced speed, because of the pack’s specific properties. In this case, the maximum processing speed of the pack can be lowered so that the packing lane can still process the pack in question in the best way possible.
Egg handling
Due to the various shapes and sizes of egg packaging, the dropset needs to be flexible in multiple ways. The first important setting is the height at which the eggs are deposited. The height of a pack can vary between approximately 30 to 65 mm. If the dropset is set to drop eggs at a height of 30 mm, but the pack’s height is more than that, the dropset won’t be able to open properly and the eggs will have no room to be deposited.
Secondly, the dropset needs to be able to match the pitch of the cups in the pack. This pitch between cups can vary from 45 to 55 mm. If the dropset cannot match the distance between these cups, eggs will break. To overcome this problem, the dropset has six different settings to enable the eggs to fall straight down into whichever pack is being processed.
