Increased efficiency of palletising and depalletising of fruit and vegetables for Amplus

Processes inside the line are fully automatic. The depalletising and palletising procedure begins when the pallets appear on the appropriate conveyors. Newly stacked pallets are directed to an automatic pallet wrapper, from where they are transported for collection.

Pallet entry zones

The depalletising process takes place in two zones, designed in a modular way. In the product pallet entry section, the operator unpacks the pallet to the required height, marked with an LED marker located next to the line entrance. The operator then scans the product’s label. Thanks to this, information about the introduced product is transferred to the robot and the labeling machine, which results in the adjustment of the appropriate robot work program and label printing. After placing the pallets on the input conveyors, the operator confirms that the line is ready for operation using a button on the control pendant. The pallet entry zone is a place where pallets are checked for quality and prepared for unpacking.

Depalletising and palletising zones

Entry to the zone is automatic, on roller conveyors and turntables. One depalletising zone allows for buffering from one to five pallets on the conveyors.

The line has been designed in such a way that the depalletised product is automatically placed on a new pallet (palletized).

New pallets are dispensed automatically by the machine, which is able to store up to 12 pieces and then dispense them individually to the line in response to the demand reported by the control system.

Pallet wrapping and receiving area

Stacks of finished pallets with the product, after the palletising process, are transported via a system of conveyors and turntables to the wrapping machine, and a label is automatically applied along the way. Thanks to automatic wrapping, pallets are quickly and reproducibly secured for distribution to customers.

The working area of the entire line is secured with a protective fence. The entrance zones to the line are protected by a system of light curtains with a muting option. Thanks to this, the highest safety standards of this type of solutions are maintained.

The most important stage of our team’s work was the design and implementation of production of a gripper that is able to pick up the entire layer of cardboard boxes and put them aside, creating even stacks. The cartons are open at the top, which is unusual packaging for this type of automation and was quite a challenge. This type of packaging is less stable than closed cartons, and the fruit and vegetables it contains make it moist, further complicating the process. In addition, such packaging contains positioning teeth, improving the stability of the entire pallet with the product, but forcing the robot to work with extreme precision.

The robot’s gripper consists of a set of movable side bands that allow for repeated gripping of a package of cartons and proper positioning on a new layer. The positions of the side bands are adjusted using a servo drive, which allows for smooth changeover of the gripper depending on the reference and adjustment of the pressing force of the cartons. An additional function is to move the empty pallet to the palletising zone.

The set of conveyors and turntables was designed specifically to meet the partner’s requirements. They allow pallets to be transported at a height of 100 mm from the floor, making it possible to use low pallet trucks.

Then, the process of wrapping the pallet with stretch foil required the design of a special lift that allows integration with the low conveyor system without the need to interfere with the floor. The lift is able to lift a pallet weighing up to one tonne by a height of 80 mm.

We have design and installation teams in the fields of automation, robotics, mechanics, and electric engineering (including prefabrication of control cabinets). Such comprehensive and well-coordinated teams enable the implementation of production and technological line projects from beginning to end. It was no different in this case. All work was carried out by Proster teams, supervised by leaders and project managers.

Even before implementation, thanks to our experience with this type of solutions, we advised the partner on process improvements that would help optimize the operation of the line.

The construction stage included, among other things, designing the robot’s gripper, dedicated conveyors and roller turntables. In the meantime, automation and robotics engineers were working on programming the line controls and industrial robots to work with the product.

After carrying out construction works and mechanical and electrical assembly of individual devices, we carried out tests of the line and key automation elements. We built our gripper and tested it for durability and performance. This allowed us to improve it to take full advantage of its functionality.

Tests in the presence of a partner

A shortened version of the station was created in our assembly hall, thanks to which we were able to configure and test the control programs at an early stage. It also allowed us to carry out functionality and performance tests of the lines, where our partner’s representatives were present.

After the tests were approved, mechanical and electrical assembly took place at the Amplus plant. After launching the entire line, our programmers focused on optimizing and achieving full operating efficiency.

The last stage of the project was to provide line operation training for Amplus staff, hand over the line to the partner (together with instructions for operation and maintenance of machines and devices) and support with production assistance.