End of line automation White paper
Absolutely user friendly
Integrated stretch palletizer for nonwoven products
Nonwoven products are lightweight, compressible and – consequently – sensitive. In addition, their dimensions vary within certain tolerances. The unfavorable results of traditional palletizing methods are unstable stacks. In sum, we already have four good reasons to switch to a palletizer specifically designed for nonwovens.
Published in o-com consumer/nonwovens 02/2011
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First stop on the way to distribution centers and supermarkets: OPTIMA RTP series receives the packaged products from an infeed conveyor. Incoming packages are automatically aligned and placed into the correct position. In this step, the robot arm picks up several products and puts them into the storage frame according to a defined pattern.
For positioning the products precision concerning the storage position is not needed as much as high operating speed. Nevertheless, the stacks are of good quality – once a complete layer has been arranged within the frame, a defined amount of force aligns the products. In a further step, the layer is placed into final position: The roller frame base is retracted open and the layer is placed onto the pallet. This approach guarantees that the stacked products remain in place.
Wrapping is done by standard stretch film. The wrapping is carried out alongside the loading operations of the storage frame, so that after stacking the last product layer it can be stabilized by film. The user has many options: Wrapping intervals, the specific number of turns per layer, at the bottom and the top are optional. The operative tension of the film can be adjusted to the products to be transported and settings are saved in the machine control. A driven roller conveyor discharges the finished pallets from the stretch palletizer OPTIMA RTP series.
Additional modules such as inserters for tier sheets, top sheets, an empty pallet magazine for automatic feeding and a link to subsequent storage logistics are available.
OPTIMA RTP series – Advantages
The robot has a motor-driven gripper equipped with angled edges at the bottom. This increases gripping security and operating speed. The angled edges allow significant reduction of the gripping force, so that the sensitive nonwoven products can retain its shape. Simultaneously, the device allows the use of a aster robot type.
Controls and HMI
All movements are defined in the machine control or human machine interface. Assisted by copy and paste functions, the menu-guided input allows operators to set up their own processes. All product sizes, product types and positioning patterns per layer, wrapping methods and other specific procedures are defined and stored in the HMI, and any input can be performed during operation.
Complex programming is not necessary, which is particularly important for new formats. Experience has shown that this type of format definition involves lower training costs. However, there are no limits to layer and stacking patterns. And finally, the simple operation greatly reduces the risk of downtime and product damage as a result of incorrect programming.
Storage frame The frame used for centering the products on each layer allows the use of a smaller, faster robot. All movements of the robot are carried out at high speed. When using the frame, precision is not the primary factor.
Vertical movement of storage frame
When the robot has formed a layer, the frame is lowered, retaining the entire layer in place. For lightweight disposable hygiene products, Optima Group Nonwovens’ RTP25 model’s vertically moving frame is particularly suitable, as it firmly holds the compact and stable stack formations in place.
The pre-stretched film used for securing the stack is wrapped by a system that continuously measures applied forces and controlling them according to the relevant setting. This is a highly protective approach for the lightweight nonwoven products, because the stack is wrapped without being moved on the pallet and it is kept firmly in place. Optima Group Nonwoven’s method of simultaneously stacking and wrapping is unique in the market.
There are numerous wrapping variants: For example, partially wrapped stacks, two individually wrapped stacks on top of each other, with and without connection or special reinforcements on top and bottom ... - all these formations are possible. Moreover, formations can be modified in detail with regard to number of turns, film tension and other ariables to suit product properties.
Yet another advantage of the OPTIMA RTP series: Wrapping can be started and film can be cut anywhere as needed. This reduces film consumption, and allows finished pallets to leave the palletizer earlier.
Technical Data Overview
Length: 150 – 800 mm, Width: 150 – 650 mm, Height: 150 – 400 mm, Max. weight: 10 kg
Material: PE stretch foil
Stretch: Max. 250 %, to be preselected
Roll width: 500 mm
Roll diameter: 300 mm
Pallet type: Euro 800 x 1.200 mm
Industrial (Chep) 1,000 x 1,200 mm
Stack height: Max. 2.200 mm incl. pallet
Stack weight: Max. 500 kg without pallet
Layers per pallet: Max. 12
Products per layer: 4 – 32
Product input: Max. 25 products/min.
Pallet magazine: 10 empty pallets
Discharge: for one filled pallet