Hartmann revamps warehouse automation
15 January 2019
With storage capacities for Paul Hartmann AG hitting their limits, the manufacturer of medical and care products was searching for new solutions for its storage logistics, and turned to Gebhardt to develop a new, highly dynamic shuttle warehouse in Herbrechtingen, Germany.
Paul Hartmann AG has 200 years of success as a leading international provider of medical, care and hygiene products to draw on. What began in 1818 as a mechanical spinning mill is now a globally active group, with about 10,400 employees represented in nearly forty countries. The traditional company supplies hospitals, care facilities and specialist stores with high-tech products, e.g. for wound management, incontinence hygiene, compression therapies, immobilisation and first aid, in addition to products for diagnosis and risk prevention in the operating room.
The company’s logistical hub for medical products has 65,000 pallet spaces and around 130 employees, making it the Hartmann group’s largest fully automated high-bay warehouse. The hub is part of the plant premises where highly automated production facilities and storage for materials and raw materials are located. A new automatic small parts warehouse (ASPW) was needed due to the company’s continuous growth and is built on the logistical centre’s premises.
39 one-level shuttles
Gebhardt Fördertechnik planned, delivered, installed and put into operation a three-aisle ASPW operated by 39 one-level shuttles (OLS) and with four picker work stations, separate conveyor lines for dispatch boxes and source trays, a central order start with automatic box erection and labelling, and the conveyors are linked to manual picking areas and seven dispatch working stations.
In addition to the warehouse hardware, Gebhardt also supplied the corresponding software such as the Gebhardt Storeware MFS, the Gebhardt Storeware WMS and the control system for the plant. The project also included updating the old two-aisle inventory warehouse (ASPW). In the course of retrofitting, the warehouse was connected to the new conveyor systems (CS) and order picking.
Designing the new warehouse as an OLS warehouse was project leader Thomas Engelhard of Gebhardt’s optimum solution for the customer’s needs: “The shuttle system offers much higher storage and retrieval capacity compared with classic ASPW solutions, with efficient and dynamic access to the goods to be stored and retrieved according to the "goods-to-man principle.”
The modular design of the individual channel routes also allows the storage system to be flexibly expanded as needed. The good use of space, low maintenance and repair expenditures, fast assembly and low investment and operating costs were also points in favour of this solution.
Highly dynamic material flow
In the incoming goods area, the goods are delivered in boxes from production or pallet storage and repacked by a worker from the pallet onto source trays, which are then sent on conveyors to the OLS warehouse. All three aisles of the shuttle warehouse are equipped with a lifter for storage and retrieval in the front zone, which can store and retrieve two containers at once. This allows each individual lifter to store or retrieve 528 trays per hour. Therefore together, they have a capacity of about 1,500 double cycles per hour, which allows the trays to be retrieved quickly at the picker work stations. The warehouse has approximately 4,500 spaces for trays and also provides room as a buffer for dispatch boxes.
Thirteen Gebhardt StoreBiter 300 OLS per aisle are used in the shuttle warehouse, which store the trays initially. With a maximum load capacity of 2 x 50 kg, the shuttles draw energy through a rail system in this process. In the event of failure, they can be removed downwards from each warehouse level at the end of the aisle using special extraction devices. The warehouse is enclosed on all sides and is always filled with air so that items can be stored in a low-dust environment according to the standards for quality management of medical products.
Automatic box erection
Then the actual picking process begins with a central order start: After the automatic box erection, the finished dispatch boxes are given barcode labels and shipped. They then go to the separate conveyor loop for dispatch boxes to be ejected, which manages around 800 boxes per hour. It is decided in the WMS which of the four picking work stations a box should move to. Four of these dispatch boxes are processed simultaneously at each work station.
Parallel to this, the source trays start with the items needed from the shuttle warehouse to the picking work stations. They are organised by the one-to-final-distribution principle: The picker can pick the goods from one source tray at their work station into the four dispatch boxes. The source trays are assigned so that they can pack the material into the boxes as efficiently as possible. To supply the work stations with the right items in the right sequence for the orders, a storage tower with 22 spaces is located at each station, which can achieve a double cycle of 200 per hour. If a source tray is not needed at a picker work station at the moment, it will be temporarily buffered in this sequencer and retrieved and sequenced again when called.
The Gebhardt WMS picking dialogue guides the worker through the picking process: When they remove goods from the source tray, a put-to-light system marks the corresponding destination box with a blue light. The picker then knows which dispatch box they should put the items in. If they picked the correct number of items, they confirm this in their dialogue. In this way, an average of 250 source trays and a proportionate number of dispatch boxes are processed per work station.
To make grabbing ergonomic, automatically adjustable lifting platforms are installed so that the picker is at the conveyor at a level as ideal as possible for their height. Also for ergonomic reasons, the source trays and destination boxes are tilted towards the pickers at an angle of 15°. The tilted position also signals to the worker that the dispatch box has not yet been fully picked. Once the tilting device turns downward, the picker knows that the box is ready for dispatch and they need to move it onto the conveyor.
The dispatch boxes are then sent along a NERAD-S conveyor to the individual dispatch lanes, and to one of the seven dispatch work stations. The boxes receive a label here, are strapped and regrouped and dispatched on the respective shipping pallets. However, if they are not intended for dispatch yet, the boxes are first sent to the shuttle warehouse and temporarily buffered in separately designated storage spaces. During this process, the source trays also move from picking back into the shuttle warehouse via the tray conveyor loop. If a source tray is needed at another picker work station within a short time frame, however, it can also be sent directly there.
The old ASPW inventory warehouse - with two aisles and stacker cranes - was updated by Gebhardt and connected to the new conveyor systems and the new warehouse’s picking process. Because larger trays are used in this warehouse that are not compatible with the new plant, a completely separate conveyor system must be installed for it.