Bake, pretzel, bake

Article of 22 February 2019 

Brezel Produktion

In the south of Germany, a freshly baked pretzel with butter and aromatic coffee is a must on any breakfast table. The perfect shape, ‘symmetrically twisted, with a fat belly and thin arms’, requires a lot of manual work – or clever automation technology with Festo components. The Schill bakery in Denkendorf has opted for the latter - with the aim of using its specialised staff for other tasks – for example for adding the final touches to bakery products.

Before the pretzel enters the oven, it passes along a short production line. The dough is first kneaded and portioned automatically. Then it is transported on a conveyor belt to the next work step: rolling out. Here, the dough strand is formed into the typical pretzel shape: a fat ‘belly’ that thins out into the ‘arms’ at either end.

From compressed air preparation to actuator and gripping technology: this pretzel-twisting machine contains a great deal of Festo know-how.
From compressed air preparation to actuator and gripping technology: this pretzel-twisting machine contains a great deal of Festo know-how.

This dough strand is now aligned on the conveyor belt with a positioning unit from Festo, so that the grippers can later grip in exactly the right places and form a symmetrical pretzel. This is followed by the actual twisting process, in which gripping technology with actuators from Festo is used. Thanks to the sensitive end-of-arm tooling, the dough strand is gently picked up at the ends. Then it all happens very fast: in less than a second, the strand of dough becomes a precisely twisted pretzel.

The system positions the dough strand on the conveyor belt with millimetre precision so that it can later be processed into a uniform pretzel.
The system positions the dough strand on the conveyor belt with millimetre precision so that it can later be processed into a uniform pretzel.

Suitable for use in dusty environments

Anyone working in a bakery should not be allergic to flour – the same applies to the components of a pretzel-twisting machine. Master baker and owner Martin Schill appreciates that Festo pneumatic components still function perfectly even with high levels of flour dust. This requires special seals, for example.

After a short setting-up time the twisting machine can do more than just pretzels

The twisting machine is a real jack-of-all-trades: whilst one moment it is producing pretzels non-stop, after a short setting-up time it can already braid complexly twisted single-strand braids. For this purpose, new gripper units are mounted which are adapted to the end product.

  • Hier ist präzises Arbeiten gefragt: Der Teigstrang wird in Sekundenschnelle in sich verschlungen.

    Precise work is required here: the dough strand is twisted rapidly

  • Mit ein paar Handgriffen hat Bäckermeister Martin Schill die Komponenten getauscht und die Maschine schlingt statt Brezeln kleine Einstrangzöpfe.

    With a few simple steps, master baker Martin Schill has exchanged the components and the machine twists small single-strand braids instead of pretzels

If an error should occur during retooling, this is no problem thanks to sensor technology: the machine detects the incoming dough and stops automatically if, for example, pretzel dough runs over the belt in single-strand mode.

The machine produces around 2,300 pretzels per hour – almost four times as fast as Martin Schill twisting pretzel dough for an hour non-stop. ‘The advantage is that the employee can use the time gained to use their expertise for other tasks in the bakery – we have lots of delicate and individual tasks for which we can use any free pair of hands,’ says Martin Schill.