Pretzels are an undisputed staple in many European markets. They are instantly associated with craftsmanship, for a reliable snacking choice. For production consistency, automation that replicates the craft is the challenge. The MULTITWIST system by FRITSCH earned awards for the technology solution used to produce perfectly twisted pretzels.
Forming twisted products is one of the most demanding and, at the same time, labor-intensive and time-consuming manufacturing processes in the production of any baked goods. FRITSCH researched how to automate this process and developed the twisting unit for a rich collection of products requiring manual shaping, for high-
volume production and product diversity.
Trendy pretzels and the extended family of creations
The unit is at the heart of the MULTITWIST system: using two grippers, the machine not only twists pretzels in various shapes and sizes, but also sticks, rings and labor-intensive products, such as single-strand braids and knots. One twisting unit can reach an output of up to 2,000 pieces per hour, when producing pretzels and ring-shaped specialties. Up to 1,500 pieces of twisted knots and single-strand braids can be processed per hour.
The pretzels can vary in size, shape, weight and the placement of the twisted ‘arms’. A pretzel is never ‘just a pretzel’, the specialist points out: “There are also regional differences to consider; for example, whether a pretzel has a thicker section, a ‘belly’, or not. We also see a higher demand for pretzels made of sweeter doughs, such as brioche.” The FRITSCH system can even customize the positioning of the pretzel’s ‘arms’.
With a growing trend for greater variety in terms of shapes and sizes, in addition to the classic pretzels, customized twisting tools are designed, depending on the intended product ranges. Solutions for rings, single-strand braids, knots, and pretzel buns – these are only some of the
frequently-asked custom solutions for the FRITSCH twisting machine.
“Especially when it comes to sizes, trends can vary considerably, from large 10 oz to small snack products such as small knots with a weight of 40 g,” the specialists from FRITSCH explain. Pretzel buns are also a popular variety – a very tightly twisted pretzel, often topped as a kind of roll. “The FRITSCH MULTITWIST can reliably produce these tightly twisted pretzel buns with a capacity of up to 2,000 pieces per hour,” they highlight.
The latest product added to the capabilities of the MULTITWIST is the so-called ‘10 oz pretzel’, with a dough weight of approx. 330 g. Such large pretzels are popular varieties, usually seen at folk festivals or sports events. They could only be produced manually before FRITSCH adapted the process to the MULTITWIST, the company says. The challenge with developing the right process for this product came from handling the 800 mm-long dough strand as it was transferred to a 650 mm-wide infeed table leading to the twisting unit. To achieve this, the strand is first formed into a U shape before, and then it can be twisted into a pretzel. The capacity of a twisting unit for 10 oz pretzels is 1,200 pieces per hour.
The list of specialties the MULTITWIST can process continues to grow: “New end products are constantly being developed, for which we develop matching, connected components,” the specialists note. Depending on the design of an existing line, bakeries also have the option to expand them in product variety.
Energy savings were also pursued, among regular developments to the MULTITWIST: “The efficiency class of the three-phase AC drives has been adapted to IE3 over time,” FRITSCH highlights.
Different, but consistent
Several features ensure the results will be in the desired parameters, for consistency in all shapes and sizes. Some variations may occur before the dough arrives at this processing stage; for consistent forming results, upstream processes must be calibrated to provide pieces of dough of consistent characteristics, at the right time.
When that doesn’t happen, there are options for sorting out sub-standard dough strands: “The MULTITWIST system is equipped with a centering and ejection system (center device) to ensure that dough strands that do not match in length or are not centered on the conveyor belt can be sorted out or aligned. Here, the dough strands are visually scanned by a camera and the shape and length of the strand are checked. If the parameters do not match the set values, the dough strand is rejected by criteria of length, centered placement on the conveyor belt, or strand symmetry,” FRITSCH specialists explain. Guide plates are installed at the transfer points, to ensure that the dough strand always runs straight into the molding plates. All these steps ensure the twisting process is carried out efficiently.
The common denominator
Consistent pretzel quality starts with consistent dough forming. Dough strands are the basis for all MULTITWIST products. The system uses cylindrical or conical dough strands, which are molded from a coiled piece of dough using a strand machine.
One more step upstream, the dough arriving at the pretzel strand machine is first round-molded and pressed flat with a special device. The flat piece of dough is then coiled, for the stranding machine, where a two-stage molding process is set up, with a molding board. A strand of dough is now created – the common denominator of all pretzel-like products. They can have different shapes, from cylindrical to conical or bulbous, for different styles of end products.
Tool changeovers
To swap between products, the current twisting table and its respective tool have to be replaced with the one corresponding to the next specialty. Changeovers are designed to be made without the need for special tools, in a straightforward process that only takes a few minutes.
”The latest product added to the capabilities of the MULTITWIST is the so-called ‘10 oz pretzel’, with a dough weight of approx. 330 g. Such large pretzels are popular varieties, usually seen at folk festivals or sports events. They could only be produced manually before FRITSCH adapted the process to the MULTITWIST.”
FRITSCH specialists
Safety features are in place to ensure the tool used and the associated program are a match, with all twisting tools monitored via RFID modules. “The MULTITWIST is able to recognize whether the tool being used matches the program that has been set. If it does not, the line displays an error to avoid damaging the toolset,” FRITSCH highlights.
Twist and bake!
For industrial production, FRITSCH can design a layout with several twisting modules running in parallel, making the MULTITWIST system very flexible in terms of output: “A single twisting module is capable of producing up to 2,000 pretzels per hour.
Depending on the customer’s requirements, a MULTITWIST can be combined with up to 10 twisting modules, representing a piece-per-hour performance of up to 20,000,” the specialists from FRITSCH illustrate.
The production is replicated at the desired scale, consistently. The process steps on maximum-capacity industrial lines could be set up as follows: 10 rows of dough pieces are transferred from a pre-proofing cabinet with an upstream dough divider. A distribution system with individual conveyor belts is then used to feed the twisting sections, the same process used for single lines. After flattening and coiling the dough piece, the strand is molded with the pretzel strand machine and then twisted to the requested product. Afterward, the products are deposited onto a common conveyor belt, which transfers the products to the downstream process via a discharge unit. Pretzels are ready to be baked and enjoyed.
