Packaging
Wrap Around Case Packer with Dual Robots for food products lying down or upright
Friday 25. April 2008 - In continuation of its range of "Ready to Pack" modules and machines, Cermex has just developed a new version of wrap around case packer for one of its customers, a French SME in the food industry.
It is able to load cartons or flowpacked aluminium trays of frozen food either horizontally (products referred to as “lying down”) or on edge (products referred to as “upright”)
for optimal industrial flexibility and merchandising!
Over and above the integration of two robots in a same wrap around case packer, this new application demonstrates the importance of Cermexs policy of designing by functional and industrial sub-assemblies adopted more than 3 years ago. All new Cermex machines are developed or redeveloped based on this pragmatic approach which consists in optimising the expertise of each team of technicians in the Design Offices (120 employees out of a total staff of 500), before combining the elements into a unique machine for the customer.
Unlike other approaches, this approach combines the best of empirical and human knowledge (such as expertise in cardboard handling) with the best of current technology (such as the development of robotics).
This application presented at Interpack is a perfect illustration.
An original product collating principle by associating robots!
After being spaced out at the case packer infeed, the frozen products in cartons or flowpacked aluminium trays are stacked directly in the tooling of one of the two robots. The tooling is in fact a mechanical gripper which descends step by step on each product in order to build up the programmed number of cartons or trays.
In order to meet the speed, two identical robots are installed on each side of the product infeed conveyor, so that the second robot can take over from the first one when the latter is loading its stack of products into the case.
For this application, Cermex chose the Fanuc 6-axis M16 iB/20 robot which moves in any direction and, by rotation of the lower arm, loads the product batches into the case, i.e.:
Via the top in one cycle for cartons (products upright)
Sideways for the flowpacked trays, in one or more cycles depending on the number of stacks (products lying down)
The principal advantage of the Cermex solution: optimised robotics
The principal advantage of this solution, with two robots integrating the product collating system, consists in making the most of the mechanical potential of the robot. Instead of reaching up to 50 cycles/min with each robot loading single products in order to keep up with the nominal product infeed speed, Cermex divides this speed by 5 or even 10 by handling a complete batch for each cycle.
The payload is increased in this configuration but by multi-referencing products/suppliers, Cermex can choose THE robot reference suited to each application.
The effects of inertia related to speed and acceleration are much easier to control at low speed than at high speed. Accuracy in gripping and loading the products is also more reliable at this level of speed, a significant point for applications with this type of primary packaging (flowpacks in particular).
Controlled product manipulation is also guaranteed during loading by keeping the batch of cartons on edge using the suction cups on the gripping head (grippers retracted) until the case flaps are folded, thus preventing products from falling.
Case handling on the WB45 Wrap Around Case Packer
At the same time as products are collated and loaded, the Cermex WB case packer extracts and erects the cardboard blank (trays with upper ledges in this instance) which encases the products as per Cermex standards in terms of automation of corrugated cardboard packaging. Operations are as follows:
Case extraction/forming
Blanks are stocked on an ergonomically designed horizontal magazine which limits the pressure exerted on the blank to be extracted. The blank is pre-extracted by a suction cup system and then extracted in-line by a motorised device with frequency inverter so as to accurately position the packaging on a transfer conveyor.
Case transfer
Perfectly positioned between the front and rear brackets, the blanks are transferred to the various machine stations by servo-motor.
Product collation and loading
Operation carried out by the two 6-axis robots as described above.
Case folding, gluing and pressing
After loading, the inner flaps are folded in order to hold the products firmly in the case during transfer.
A gun fitted on a mechanically-driven mobile support applies glue to the joining lug in a continuous even line.
N.B.: This wrap around case packer with dual robots can handle, from the start, up to 11 different product/case formats within its size range!