Safety in system: Protection for man and machine - under this motto, the Schmersal Group develops and produces safety switching appliances and systems for the entire machinery and plant construction for decennia already. In some industries, special and additional requirements are applicable.
As customer-focussed company, who intensively deals with the wishes of the manufacturer and users of machines, Schmersal has taken up these challenges from the start. As a result, specific products and solutions were developped for many industries and for some of them, an own portfolio has been developped as well.

Harvesting, drying, filleting, heating, shredding and crushing, mixing, filling, packing: The food-processing industry includes many, usually mechanically performed process steps. During these process steps, the standards and directives with regard to machinery safety must be observed. Moreover, the food-processing industry in particular has other fields of activity as well, where the selection of switchgear or command devices at the manmachine interface is highly important.

Hygiene is a key issue in the food-processing industry. Four hygienic zones can be distinguished, for which strictly defined constructive details of the "hygienic design" are applicable:

• Dry zone (non-contact area; protection against soiling required)
• Splashing zone (foodstuff can splash;the operators touch the foodstuff and the machines; risk of contamination or crosscontamination)
• Wet zone (high risk of bacterial contaminations; low-pressure cleaning with chemicals or hot cleaning)
• Aggressive zone (even higher risk of contamination; frequent hot steam cleaning or high-pressure cleaning with aggressive detergents)

The Hygienic Design also influences the choice of safety switchgear. An example: the food-processing industry was the first branch, which used safety sensors instead of the conventional electromechanical safety switches. These non-contact operating safety switchgear can be smoothly cleaned due to the smooth surfaces of the sensor and the actuator and moreover provide for concealed mounting.

Stringent hygienic standards are applicable to those components or periphery of foodprocessing machinery, which are in contact with the product; as a result, the safety switchgear and actuating elements must meet the highest requirements as their protection class is regarded. Many series therefore are IP69K. These switchgear must be able withstanding a water jet of at least 80 bar with a temperature of 80°C.

In food production, machinery and plants often operate with short cycles and in a three-shift operation in interlinked plants. The expected availability is accordingly high. Schmersal switchgear meet these requirements. They stand the test in various applications, even under unfavorable ambient conditions.

When mixed to air in a particular proportion, all organic dusts are inflammable. Therefore, the regulations of the dust explosion directive must be observed e.g. when filling/bottling and storing powdered food products and their primary products (flour, baking mixtures, pudding powder, coffee and cacao powder). The Schmersal Group offers a comprehensive range of switchgear for automation and machine safety, which is approved and certified to the ATEX and IECEx Directives.

The Schmersal Group furthermore aims at establishing good contacts and exchanging experiences with food-processing machinery builders, so that new switchgear is developped and the individual consultancy is provided with the highest level of practice-orientation. T o that effect, Schmersal is, amongst others, member of the "Packaging Excellence Center" (PEC). This Centre of Competence for packaging and automation technology reunites many companies manufacturing machinery and plants for the food packaging industry.