Many shapes populate the savory snack world. Most of them, such as shell, rounds,or square tubes, wheels, 2 or 3-root spirals and many others, are very similar to dry pasta shapes.
These shapes are somehow easy to obtain, as they are usually die cut products. In other words a die with desired shape inserts is mounted on the extruder just after the end of extrusion screw on what is usually defined as the head of the extruder itself. A cutting device is placed against the die; once the extrusion screw is switched on it conveys the dough through the barrel and then through the die. The inserts mounted on the die shape the dough, then a knife cuts the shaped product according to the desired length. In order to have a portfolio of different products, it is enough to have a number of dies, each with different insert shapes. There are lots of die makers and because of the relative simplicity of the above-mentioned process there are a lot of die cut savoury snacks out there.
Some producers offer, beside die cut shapes, more complex products usually developed for young consumers. These shapes reproduce famous cartoons or just fantasy characters, sometimes targeting a special time of the year such as Halloween.They might be presented with a full body or just part of it, the head or the face for example. All of them are produced in such a way they maintain an impressive definition even after being fried or hot air toasted. Some of these shapes are more defined than others, and normally definition depends from the type of process applied to extruded dough. Two types of processes are generally applied: stamped and punched.
The first one is derived from biscuit productions. In other words, a sheet is extruded then laminated using one or more couple of rolls, then stamped (cut) using a properly designed, and built stamping roller unit pretty similar to those used for biscuits production.
The advantages of this procedure are higher output and some how easier process compared to punched products. However there are a few disadvantages such as inferior shape definition after expansion, difficulty to use high fiber and cereal ingredients. The alternative process consists on a properly built punching unit, which is normally derived from dry pasta production experience. In other words, a shaft with a proper cutting device mounted on a piston rod, which drives the cutting device through a mold. The overall unit is somehow more complex than the previous machine adopted from biscuit production, and normally its output is lower. However, the snack pellet shape definition is really amazing even after the expansion. Most of all the sharp cutting systems adopted allow to produce from a wide range of product including high fibres, multi cereals, inclusions etc. There are two types of “punching units”. The first one requires two “strokes” to form and cut the final shape being eyes and mouth stamped first, and the outer shape stamped after using, as said, a two strokes action. The second machine stamp eyes, mouth and overall shape all in one stroke. The difference between the two solutions is the cost of stamping unit, which is quite higher for the machine that stamps all the shape in a single stroke.however out put with one strock machine is higher.
Here some samples from both tecnics.