There is a vast difference between a rolled or laminated pasta and an extruded pasta. First it is important to understand the different processes utilized to make an extruded versus a rolled or laminated pasta.
Extruded pasta is formed by virtue of force. A worm or screw housed within a barrel turns at a continuous rate forcing mixed pasta dough down this barrel. Once the product reaches the end of this barrel, it encounters a die. An "extruder" die is usually a flat object of substantial thickness with various openings on its surface. The shape of these openings determines the shape of the final product. Extruded pasta is the type of pasta commonly seen on the grocery store shelves (Barilla, DeCecco, Ronzoni, etc.).
Rolled pasta is formed by passing mixed dough through a set of adjustable opening rollers several times to form a continuous sheet of pasta dough. Each time this sheet is passed through the rollers, the space between the rollers is decreased making the sheet thinner. The force applied by a set of rollers strongly integrates the sheet giving it resiliency and strength. Once the sheet reaches the desired thickness, it is passed through a set of cutting rollers. These rollers are not adjustable and determine the final width of the product.
Rolled pasta is superior to extruded pasta in many ways. Some of these ways are as follows:
*Rolled pasta is up to 50% less dense than extruded pasta. This makes the final cooked product lighter or more delicate.
*The thickness of the final product is completely adjustable with a rolled product. One could make pasta that is almost transparent. With an extruder, you are limited by the die. The final product is always the same thickness and shape as the openings in the die.
*Rolled pasta cooks in 1/2 to 1/3 of the time that it takes to cook extruded pasta.
*Rolled pasta is known to be more porous and therefore holds sauce better.
*During formation, extruded pasta experiences a great deal of pressure, heat (from friction) and twisting (from the motion of the worm). In many cases, water is used to cool both the product and the machine. These factors cause internal stress on the pasta which leads to a compromised product quality. This compromised quality explains why extruded pasta does not hold sauce as well as rolled pasta and also why expensive drying units are necessary to dry extruded pasta.
*Vast fluctuation in recipe formulations are possible when you are producing a rolled pasta. Such gourmet ingredients as cracked pepper, basil, grilled radicchio, etc. can be laminated into the dough. Ingredients such as these would clog up die openings and render an extruder useless.