Hamburg-based company Dr.Weigert is a producer of cleaning and disinfecting agents. The manufacture of such products involves potentially dangerous and manufacturing processes and, as such, employee protection is high on the list of the company’s priorities.
“Protecting man and machine from dangerous processes in manufacturing and logistics is a top priority at Dr. Weigert, as well as being responsible for hygiene and protecting the environment,” said Dirk Böttger, who has been working at Dr. Weigert for 16 years.
As a qualified process technology engineer and current Deputy Operations Manager, Böttger knows about the safety risks involved in quick, automated processes such as those in the film wrapper and rolling gate areas. Choosing reliable partners is essential.
Leuze electronic manufacture safety-related protective devices for the safeguarding of material flows in the film wrapper and rolling gate areas, which operate fault-free and enable a high degree of system availability.
Modern systems have new safety requirements
Dr. Weigert mixes cleaning and disinfecting agents in accordance with the company's own recipes for professional cleaning and disinfecting in laboratory techniques and medical technology, the large scale kitchen sector and the pharmaceutical, cosmetics and food industry.
After mixing, the chemical products are poured into plastic canisters with different volumes and designs, and then stacked on pallets by robots. Driverless transportation systems take the products stacked on europallets to the area in which the goods receive an outer packaging in the new TOSA 126 E film wrapper.
The entire material flow process, from the film wrapper’s in and outflow, to passing through the rolling gate on the way to the warehouse, has been realised by Leuze electronic using a holistic, safe system solution concept.
“As well as the reliable quality of its safety technology, we particularly appreciate the company’s competent advice, quick support and efficiency - we are therefore delighted to incorporate Leuze electronic safety components into our safety concepts,” said Dirk Hähner, Managing Director of a Dr.Weigert partner, Industrieautomation.
Particularly when a tricky task has to be carried out in a special application, Leuze electronic often has solutions at the ready. “We promise our customers Smart Sensor Business 4.0 - which is not a marketing term or advertising slogan but a real promise to the customer by us, the sensor people,” said Frank Bröcker, who has been the Hamburg area Sales Manager for ten years.
“What we mean by this is providing customers with simple usability of the products that they use, and based on in-depth expert knowledge from many years of experience in the industry, develop new, creative solutions together with customers that are specially adapted to their requirements.”
When the new TOSA film wrapper was commissioned, the rolling gate at the exit of the material flow in the direction of the warehouse was also replaced with a new one. The previous door was not safeguarded by any safety technology whatsoever. However, new additions to the machinery directive now stipulate that safety related monitoring is mandatory. “Rolling gate protection is not that simple, since muting with sensors was hardly feasible due to lack of space - and without a consistent, holistic safety concept we would not have been given the order,” said Hähner. A specific safety related requirement was that transportation of material into and out of this danger area, which is safeguarded from unauthorised access, would take place safely in the future.
Due to the lack of space in the rolling gate area, a space saving safety solution was sought which detected the approach of the wrapped europallet on the conveyor belt, temporarily bypassed the protective field and therefore, ensured that the transported material could pass through without problems. However, it was important that the protective field is only bypassed when the transported material is approaching, and that access by persons is still prevented. Until now, additional sensors were required for detecting the transport material - and therefore also for distinguishing between transport material and persons.
Hähner put his faith in Smart Process Gating, the new sensorless muting process from Leuze electronic, and succeeded in winning over the customer. This is a new muting process developed by Leuze electronic, which does not require additional muting sensors to protect danger zones which have to be safeguarded against unauthorised entry.
The process is based on type 4 safety light curtains of the MLC series and integrated in the MLC 530 SPG model. The integration of an SPG application into a system is considered to be a system solution as far as safety technology is concerned. This results from the interaction of the safety light curtain, the system control and, if necessary, mechanical elements.
“In order to do this, the system manufacturer requires competence and experience in safety design as well as knowledge of the relevant safety related, international standards,” added Hähner. “For example, the gating sequence must be programmed in the PLC and the safety system solution itself has to be created.”
Böttger is extremely satisfied with the decision to use the Smart Process Gating application: “The pallets are transported without problems - even partial pallets with a gap between the load. The safety device operates in an extremely reliable way. The installation and service costs are kept within limits, since the omission of additional muting sensors also means that they do not need to be installed and adjusted.”
Overall, the system can be designed to be very compact and space saving, because no room has to be provided in front of or behind the light curtain for muting sensors. The operators are protected, and the risk of tampering is also reduced. And something that is extremely important compared to the past. The specification of the MLC 530 SPG safety light curtains is designed in accordance with the safety related, international standards.